Casting, Forming, Welding-II Pune University MCQs
Casting, Forming, Welding-II Pune University MCQs
This set of Casting online test focuses on “Processing of Thermosetting Plastics”.
1. What is the minimum pressure required in a compression molding process?
a) 0.5 MPa
b) 1 MPa
c) 1.5 MPa
d) 2 MPa
Answer: a
Explanation: Processing of thermosetting plastics is classified as, compression molding and transfer molding. The minimum pressure that is required for the complete operation of compression molding is 0.5 MPa.
2. What is the minimum temperature required in a compression molding process?
a) 120°C
b) 125°C
c) 130°C
d) 135°C
Answer: b
Explanation: None.
3. What is the maximum pressure required in a compression molding process?
a) 35 MPa
b) 40 MPa
c) 45 MPa
d) 50 MPa
Answer: d
Explanation: The maximum pressure that is required for the complete operation of compression molding is 50 MPa.
4. What is the maximum temperature required in a compression molding process?
a) 240°C
b) 245°C
c) 250°C
d) 255°C
Answer: c
Explanation: Processing of thermosetting plastics is classified as, compression molding and transfer molding. The maximum temperature that is required for the complete operation of compression molding is 250°C.
5. In compression molding, the curing time does not depend on which of the following factors?
a) Material
b) Curing temperature
c) Geometry
d) Thickness
Answer: b
Explanation: When there has to be molding done for thermosetting materials, mainly compression molding is preferred. While doing this, curing has to be done. The time needed for curing depends on the material used, geometry and thickness of the material.
6. What is the maximum curing time required in a compression molding process?
a) 2 minutes
b) 3 minutes
c) 4 minutes
d) 5 minutes
Answer: d
Explanation: The maximum curing time that is required for the complete operation of compression molding is 5 minutes.
7. What is the minimum curing time required in a compression molding process?
a) 0.4 minutes
b) 0.5 minutes
c) 0.6 minutes
d) 0.7 minutes
Answer: b
Explanation: The minimum curing time that is required for the complete operation of compression molding is 0.5 minutes.
8. What is the maximum pressure required in a transfer molding process?
a) 80 MPa
b) 90 MPa
c) 100 MPa
d) 120 MPa
Answer: c
Explanation: Processing of thermosetting plastics is classified as, compression molding and transfer molding. The maximum pressure that is required for the complete operation of transfer molding is 100 MPa.
9. What is the minimum pressure required in a transfer molding process?
a) 20 MPa
b) 40 MPa
c) 50 MPa
d) 70 MPa
Answer: a
Explanation: The maximum pressure that is required for the complete operation of transfer molding is 20 MPa.
10. Speed of production in transfer molding is higher than that of compression molding?
a) True
b) False
Answer: a
Explanation: It is counted among one of the advantages of transfer molding over compression molding that the speed of production is quite higher. Not just that, but the maintenance in transfer molding too is lower than compression molding.
This set of Casting Puzzles focuses on “Processing of Thermosetting Plastics – 2”.
1. Thermosetting materials are the polymeric materials which get soften on heating with or without pressure.
a) True
b) False
Answer: b
Explanation: Thermosetting materials are the polymeric materials that get permanent hardness once the heat is given to the material. These are the polymers which require heat and pressure to mould them into shape. These polymers cannot be re-softened once they are set and hardened by heat.
2. Thermosetting plastics are generally used for making products of high strength and rigidness.
a) True
b) False
Answer: a
Explanation: Thermosetting polymers basically involve cross-linked molecular structure and thus it is ideal for making products which demand rigidity and strength. Due to cross linking in thermosetting polymers, these are made hard, tough, and cannot be re-moulded as thermoplastic polymers.
3. Which of the following types of molecular structure present in thermosetting polymers?
a) Linear polymers
b) Branched polymers
c) Cross-linked polymers
d) Network polymers
Answer: c
Explanation: Cross-linked polymers are described by adjacent linear chains that are brought one to another at several locations by covalent bonds. Cross linking is completed by a non-reversible chemical reaction. Often, cross-linking is finished by additive atoms which are covalently bonded to the chains in the thermosetting polymers.
4. Polyurethanes plastics can be made in flexible foams even after belonging to thermosetting polymers.
a) True
b) False
Answer: a
Explanation: Polyurethane plastics are belonged to the thermosetting plastics or polymers. Polyurethane is the only polymer that can be formed in both rigid and flexible foams. The flexible polyurethane foam is generally used in the manufacturing of mattresses, carpets and furniture. And the rigid polyurethane foam is used in making of chairs and mirror frames.
5. Polyethylene, polypropylene and polyvinyl chloride are the main example of thermosetting polymers.
a) True
b) False
Answer: b
Explanation: Polyethylene, polypropylene and polyvinyl chloride are basically examples of thermoplastics material. And thermosetting material’s example includes polyurethanes, polyesters, epoxy resins and phenol resins which are used for manufacturing of aircraft parts, tires and auto parts.
6. Thermosetting plastics like epoxies can be used for filament wound rocket motor casings in missiles by combining with glass fibers.
a) True
b) False
Answer: a
Explanation: Epoxies can be used in various ways. In adding with glass fibers, it is capable of making composites that are of high strength and heat resistant. These composites are basically used for making motor casings in missiles, aircraft parts, fixtures etc. Epoxies are also found in industrial equipment and in protective coatings of appliances.
7. Polyurethane plastics are highly reactive to chemical compounds due to lack of elasticity in these plastics.
a) True
b) False
Answer: b
Explanation: Polyurethane plastics come in the category of thermosetting plastics. In this type of plastics, elasticity is generally very high. Due to this property of high elasticity, it can be used in decorative and protective coatings. The high elasticity also makes these polyurethane polymers highly resistant to any chemical attack.
8. Phenolic plastics can also be used as binder for holding plies of wood in making of plywood.
a) True
b) False
Answer: a
Explanation: Phenolic plastics or polymers are belongs to thermosetting plastics. These are the special type of resins which can be used in potting compounds, casting resins, and laminating resins. They can also be used in making of electrical equipment. Phenolic plastics are very popular binders for holding plies of wood in manufacturing of plywood.
9. Thermosetting plastics can be used for manufacturing of windshield for airplane.
a) True
b) False
Answer: b
Explanation: For the manufacturing of windshield for airplane, poly-acrylics plastics are used which basically belongs to the group of thermoplastics. Poly-acrylics are transparent, high tough in nature and can be easily shaped in any form. Due to such properties of this material, it is widely used for making of windshields for airplane.
10. Mechanical properties of any plastics are mainly dependent on the temperature, force and time of load applied.
a) True
b) False
Answer: a
Explanation: Mechanical properties relate to movement or breakage of the polymer due to some mechanical variation such as application of load. Mechanical properties are mainly dependent on the temperature, force or load applied, and the duration of time the force is applied. It can also be affected by ultra-violet radiation when used outside.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Injection Moulding Process”.
1. How is the die used in injection molding cooled?
a) Oil
b) Air
c) Water
d) Contact with cold surface
Answer: c
Explanation: When it comes to molding of polymers in thermoplastics, injection molding process is the most common of the methods. In this method, whenever the die has to be cooled, there is water used to cool it.
2. How does the piston in the clamping unit move?
a) Hydraulic energy
b) Pneumatic energy
c) Heat energy
d) Suction
Answer: a
Explanation: There is a clamping unit employed for holding the two halves together and for the opening and closing of the mold. A moving piston is provided which operates the power press. This piston works on hydraulic energy.
3. Where does the granular molding material get loaded into?
a) Barrel
b) Hopper
c) Pellets
d) Split
Answer: b
Explanation: In a ram or plunger type injection molding system, the granular molding material has to be first loaded into a hopper, after which, with the help of a feeding device it gets metered out inside a cylinder.
4. Which of the following material is not made by injection molding?
a) Nuts
b) Tubes
c) Car handles
d) Electrical fittings
Answer: b
Explanation: Injection molding is one of the most widely used method of molding among molding with polymers. There are various applications of this method such as nuts, bolts, cups, car handles, electrical fitting parts, but not tubes and rods.
5. What is the minimum temperature allowed to be given to the injection molding process?
a) 120°C
b) 130°C
c) 140°C
d) 150°C
Answer: d
Explanation: In the molding process of polymers in thermoplastics, injection molding process is the most common of the methods. The minimum allowable temperature that can be given to the system is 150°C.
6. Which of the following factors is not considered in a ram type injection molding?
a) Inner pressure of material
b) Outer pressure of material
c) Volume of material
d) Temperature of material
Answer: c
Explanation: Among the following, the inner pressure of the material, the outer pressure of the material as well as the mold and the temperature of the material and mold are important factors to be considered. The volume of material is not counted among important factors.
7. What is the minimum pressure allowed to be given to the injection molding process?
a) 90 MPa
b) 100 MPa
c) 140 MPa
d) 170 MPa
Answer: b
Explanation: None.
8. What is the maximum temperature allowed to be given to the injection molding process?
a) 300°C
b) 320°C
c) 350°C
d) 400°C
Answer: a
Explanation: The maximum allowable temperature that can be given to the system is 300°C, in this particular method of molding.
9. The barrel is used for the opening and closing of the mold.
a) True
b) False
Answer: b
Explanation: A barrel is an instrument that is placed near the nozzle, and it plays no role in the opening and closing of the mold. There is a clamping unit employed for holding the two halves together and for the opening and closing of the mold.
10. There is a varied pressure provided in the solidification unit of injection molding process.
a) True
b) False
Answer: b
Explanation: Injection molding is considered to be one of the most widely used methods. In this method, there are dies that eject the solidified component, before which it is kept under constant pressure.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Injection Moulding Process – 2”.
1. Which of the following processes of moulding is widely used for the manufacturing of bottle caps and automotive dashboards?
a) Compression moulding
b) Transfer moulding
c) Injection moulding
d) Jet moulding
Answer: c
Explanation: Injection moulding is a manufacturing process which uses thermoplastic and thermosetting plastic materials to make products like bottle caps, automotive dashboard, combs etc. In this process, material is fed into a barrel of high temperature, then by mixing it is forced into a mould cavity where it solidifies and gets hardened.
2. Complex shape of parts or components cannot be formed by the injection moulding process.
a) True
b) False
Answer: b
Explanation: Injection moulding is a most common and dominant of all the other plastic processing methods. The process of injection moulding is very versatile and can produce very complex shaped components with the application of multisided moulds. In this process, even components with metal inserts can also be produced.
3. Components from injection moulding process are made very expensive due to the application of very costly equipment.
a) True
b) False
Answer: b
Explanation: In injection molding process, dies are costly to produce parts; the dies can be used to form thousands of parts at very faster rate, so that cost of components reduces that implies this method is very economical for large scale production which can produce any simple or complex products in abundant amount.
4. The three mould technique is generally preferred than the two mould technique in injection moulding process.
a) True
b) False
Answer: a
Explanation: The design in three mould technique has some advantages that it allows more even distribution of melt into the sides of mould cavity. And also provides more automation to the moulding process in comparison with two mould technique. So, the three mould technique is always preferred than the two mould technique in injection moulding process.
5. Which of the following cooling systems is used in injection moulding process to increase solidification rate of components made?
a) Air jet cooling system
b) Water cooling system
c) Cooling with free convection
d) Cooling with fins
Answer: b
Explanation: The cooling system is made by including some passages in the mould walls that are usually connected to an external pump. Cool water is circulated through the passages to extract heat from the hot polymers or plastics components made in the injection moulding process. This cooling system increases the solidification rate which basically reduces the production time.
6. The moulding directions in injection moulding can affect the cost of equipments used in the process.
a) True
b) False
Answer: a
Explanation: The moulding directions involved in injection moulding process basically determines number of cams or inserts which to be used in the process. And if the number of inserts used is more, then the cost involvement will also be more. The moulding is always made in such a way to optimize number of cams as well as the cost.
7. The flow of plastic in the mould cavity is more proper and smooth if the thickness of the component made is very small.
a) True
b) False
Answer: b
Explanation: In injection moulding process, if the component thickness is very small, then the plastic flow is prevented due to high friction. The flow can also be restricted if the gate is very far away from the features of the geometry, or a obstruction in path of flow may also result in prevention of flow.
8. Shrinkage of the plastic parts in mould cavity can results in generation of sink holes in the plastic.
a) True
b) False
Answer: a
Explanation: Shrinking of plastic in mould cavity can result sink holes which are a type of defect that can ruin the product. To avoid such defects, cross-sectional thickness should be maintained uniformly throughout the component. And ribs and gussets must be used which provides mechanical strength to the parts made in the mould.
9. A heavy surface finishing is always required for components made in injection moulding machine.
a) True
b) False
Answer: b
Explanation: Injection moulding is very advantageous when it needs to manufacture intricate parts in abundant quantity. In injection moulding machine, components are often moulded directly in the machine with surface finish and other features like color thereby excluding the secondary finish, which also excludes the cost of further machining.
10. In injection moulding process, ribs are generally provided for the reinforcement to avoid sink marks from the component.
a) True
b) False
Answer: a
Explanation: In order to have reinforcement, ribs can be used which mainly avoid the problem of marks formed on the parts. Reinforcing ribs are generally provided perpendicular to the parting line and made thinner than the mould walls. It is always recommended that the thickness of the ribs should lie between 40% and 60% of wall thickness.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Blow Moulding and Thermoforming “.
1. In blow molding, to inflate soft plastic, which medium is used?
a) Air
b) Water
c) Oil
d) Alcohol
Answer: a
Explanation: Blow molding process is typically used for the blowing process of hollow plastics. While blow molding, the plastic has to be inflated, in order to do so, air has to be blown inside with a high amount of pressure.
2. Which of the following plastics is not used in blow molding?
a) Terephthalate
b) Polypropylene
c) Polythene
d) PVC
Answer: a
Explanation: For blowing processes, there are certain plastics only which are properly suited for the operation, while any other material might fail. Hence, for operating through blow molding process, polypropylene, polythene and PVC are used.
3. What is the minimum air pressure required in the blow molding process?
a) 350 kPa
b) 400 kPa
c) 450 kPa
d) 500 kPa
Answer: b
Explanation: In the blow molding process, there is some amount of pressure that has to be given to the air for blowing the bottles. The amount of pressure to be given depends on the material. The minimum pressure that can be given in this process is 400 kPa.
4. What can be the maximum pressure to be given to plastic for blow molding process?
a) 700 kPa
b) 750 kPa
c) 800 kPa
d) 850 kPa
Answer: c
Explanation: Air with an extreme amount of pressure, when is needed, it might mean the material is thicker and denser. The amount of pressure that can be provided depends totally on the material. The maximum pressure that can be provided in blow molding process is 800 kPa.
5. Which of the following is not a type of blow molding process?
a) Injection blow molding
b) Extrusion blow molding
c) Multi-smaller blow molding
d) Multi-larger blow molding
Answer: c
Explanation: Blow molding basically is a process of inflation of air under pressure into the plastics inside the mold cavity. There are only three known types of blow molding, namely, injection blow molding, extrusion blow molding and multi larger blow molding.
6. What is the minimum thickness required by the plastic for vacuum forming?
a) 0.125 mm
b) 0.25 mm
c) 0.375 mm
d) 0.5 mm
Answer: a
Explanation: Vacuum forming is one of the classifications of thermoforming processes. Around its circumference, a clamp is attached or we need to know the minimum thickness. The minimum thickness that can be allowed for this operation is 0.125 mm.
7. Which of the following is not an application of blow molding process?
a) Toy bodies
b) Door liners
c) Bottles
d) Pipes
Answer: b
Explanation: Among the following, only door liners is not an application of blow molding process. Internal door liners are made using thermoforming process, while toy bodies, bottles and pipes are made using blow molding process.
8. What is the maximum thickness that can be allowed for a plastics sheet in a vacuum forming process?
a) 3 mm
b) 3.1 mm
c) 3.2 mm
d) 3.3 mm
Answer: c
Explanation: Vacuum forming process is one of the important processes that are employed in thermoforming processes. The maximum thickness of the plastic sheet has to be noted, as a clamp is to be fitted around the plastic sheet. The maximum allowable thickness of this plastic sheet is 3.2mm.
9. The heater in the vacuum forming process is heated up to 90°C.
a) True
b) False
Answer: a
Explanation: In vacuum forming process, there is a clamp that has to be used for holding the plastic sheets. There is a heater employed for heating the mold cavity. The heater brings the polymer in a temperature range of 55°C to 90°C.
10. The initial cost in blow molding is low.
a) True
b) False
Answer: a
Explanation: In blow molding, there is a mold cavity present inside the soft plastic, into which, the air with high amount of pressure has to be blown. The capital required for mold initially is quite less, making it a little inexpensive process.
This set of Casting Objective Questions & Answers focuses on “Blow Moulding and Thermoforming – 2”.
1. Which of the following moulding processes is widely used for the manufacturing of plastic bottles?
a) Compression moulding
b) Injection moulding
c) Jet moulding
d) Blow moulding
Answer: d
Explanation: In blow moulding process, a heated tube of plastic material is situated between the two halves of mould, then the mould is closed and air or inert gas is usually blown at a pressure of 200 – 400 bars, which helps in expanding of tube outward to occupy the mould cavity. After that the part cools down to get hardened and then the part is ejected from the mould.
2. Blow moulding is a very slow process, however economical for producing products with better quality.
a) True
b) False
Answer: b
Explanation: The blow moulding process is very fast and can produce components mainly plastic parts very fast and economically. The process can be completed by manual means or by semi-automatic or automatic machines. Blow moulding process is especially used for the production of plastic bottles.
3. In extrusion blow moulding process, it is very difficult to trim away excess of plastics.
a) True
b) False
Answer: a
Explanation: Extrusion blow moulding process is a type of blow moulding in which air is injected into the neck of container to blow up the plastic material that then occupies the mould cavity. In this method, tooling cost is low but it includes some difficulties in trimming away of excess plastic, it also possess high scrap rate of the plastic material.
4. Single stage stretch blow moulding is always preferred than two stage stretch blow moulding for increase in production rate.
a) True
b) False
Answer: b
Explanation: Two stage stretch blow moulding is same as single stage stretch blow moulding, except preforms which are already made in the two stage process. The single stage process is generally accomplished by using single machine, where the two stage process uses preforms that already present in the process. This results in saving of time which directly increases production rate.
5. Single stage stretch blow moulding process is mostly used for small level production.
a) True
b) False
Answer: a
Explanation: Single stage process includes an extruder to inject liquid plastic into the mould where the plastic is cooled to form a preform . This preform is reheated and placed in the bottle mould. Then it is stretched by using compressed air in the mould cavity. This all processes require too much time to accomplish themselves, so it is only suitable for small level production.
6. Thermoforming process involves injecting of molten plastic into a mould cavity by application of compressed air.
a) True
b) False
Answer: b
Explanation: In thermoforming process, a sheet of plastic is used which covers the shape of any die by heating it to the desired temperature and then it is stretched over the die using vacuum, thus it is also called as vacuum forming. Then the pressure is applied to the plastic sheet by using pressurized air.
7. In thermoforming process, it is very difficult to control thickness of moulded parts or sheets.
a) True
b) False
Answer: a
Explanation: In thermoforming process, the tooling is mainly cheap to produce, but the process leaves small marks on the moulded sheets that can be controlled. But the main quality control issue possesses non-uniform thickness of parts or sheets which are difficult to handle, this may also result in warping or tearing of the moulded sheet.
8. In thermoforming, it is very easy to mould the plastic materials which are of crystalline nature.
a) True
b) False
Answer: b
Explanation: The most widely used plastic materials in thermoforming process are amorphous or non-crystalline nature. This mainly includes moulding of plastic materials such as polyvinyl chloride , polyethylene, polystyrene, acrylic, polycarbonate etc. Crystalline nature of materials cannot be moulded through this process.
9. Thermoforming is basically a cheap process as compared to injection and blow moulding process.
a) True
b) False
Answer: a
Explanation: Thermoforming can be used in both high and low volume production processes. The main advantage of this process includes low initial tooling and equipment costs. Due to this, this process is cheaper when compared with injection and blow moulding processes. Thermoforming is widely used for production of parts for industries including medicals, appliances etc.
10. Which of the following materials is mostly used for making of thermoforming moulds?
a) Steel
b) Grey cast iron
c) Aluminium
d) White cast iron
Answer: c
Explanation: Thermoforming moulds are always made of aluminum because of its light weight, machine ability, and good thermal conductivity. Aluminum moulds may also contain passages through which water can be pumped for cooling of components, which may greatly affect the shrinkage and other features of the components made.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Extrusion in Polymers”.
1. Which of the following material is not used in extrusion?
a) Wax
b) Granules
c) Powder
d) Pellets
Answer: a
Explanation: Extrusion is a process of forcing plastic which is at a very high temperature, through the dies, and gets opened at a required shape. The raw materials used for extrusion with polymers contain granules, powder and thermoplastic pellets.
2. In extrusion process, extra shearing occurs in which part of the system?
a) Feed section
b) Pumping section
c) Collapse section
d) Transition section
Answer: b
Explanation: The section where an additional amount of melting and shearing occurs is called a pumping section.
3. Melting section is another name for which section?
a) Feed section
b) Transition section
c) Pumping section
d) Collapse section
Answer: b
Explanation: Melting section is one of the types of extrusion in polymers. Extrusion is a process of forcing plastic which is at a very high temperature, through the dies, and gets opened at a required shape. Melting section is another name for transition section.
4. How are extruded materials cooled?
a) Water
b) Contact with chilled surface
c) Air
d) Oil
Answer: d
Explanation: On completion of extrusion, the material is very hot and has to be cooled down. There are various agents which are used cooling these materials down, such as, air or water or its direct contact with a very cold surface.
5. Which of the following is not an important factor of cooling in extrusion?
a) Reduction in shrinkage
b) Reduction in distortion
c) Ease of adding colours
d) Rate of cooling
Answer: c
Explanation: There are various factors of cooling, a few of them are, reduction in shrinkage, reduction in distortion and the rate of cooling too has to be considered.
6. Which of the following is not an application of polymer extrusion?
a) Door insulation seals
b) Chewing gums
c) Cables
d) Circuit boards
Answer: d
Explanation: Circuit boards is not an application of polymer extrusion. Door insulation seals, chewing gums and cables are the applications of polymer extrusion.
7. Film extrusion process, best involves film having a thickness below what length?
a) 0.2 mm
b) 0.3 mm
c) 0.4 mm
d) 0.5 mm
Answer: d
Explanation: Extrusion of films is one of the most important processes in extrusion. For the films having a thickness below 0.5 mm, these films are best suited for extrusion and can be further applied for making various bags.
8. In the cable extrusion process, what is the speed of product winding?
a) 40 m/sec
b) 50 m/sec
c) 60 m/sec
d) 70 m/sec
Answer: b
Explanation: For the insulation purpose, the coating of any wire or cable is one of the most vital polymer extrusion process. The wire is cooled and then it is wound to large spools at a speed of 50 meters per second.
9. Calendering is mostly suited for making PVC.
a) True
b) False
Answer: a
Explanation: Calendering process is considered to be one of the most important sheet forming process. Calendering has many products like phenyl, cellulose or vinyl floor tiles. It is most suited for making PVCs.
10. Tubes having U shape cannot be manufactured by polymer extrusion process.
a) True
b) False
Answer: b
Explanation: Polymer extrusion has a variety of applications such as candy canes, chewing gums, window frames, solid rods, pipes or tubes having U or J sections.
This set of Casting Question Paper focuses on “Extrusion in polymers – 2”.
1. Extrusion is a process that uses an electric system for processing various polymers.
a) True
b) False
Answer: b
Explanation: Extrusion is a process used for the processing of various types of thermoplastics and rubbers. The extrusion process is a simple process in which liquid or molten polymer is forced through a shaped die by applying high pressure. The pressure is basically generated by the action of screw rotation against the barrel wall in the extrusion process.
2. Which of the following equipment is used for controlling the temperature of polymer material in the extrusion process?
a) Thermo resister
b) Thermometer
c) Thermocouple
d) Glass tube
Answer: c
Explanation: In extrusion process, polymer material pellets are fed into an extruder by a hopper. Then the material is conveyed by a feeding screw and forced through a shaped die that converts polymer materials into continuous polymer products. Heating elements are placed on the barrel which soften and melt the polymer. The temperature of the polymer material is mainly controlled by thermocouples.
3. Thermosetting polymers can be processed by extrusion process by forming cross-linking in the extruder.
a) True
b) False
Answer: a
Explanation: Extrusion process is mostly used for thermoplastics polymer materials; it can also be used for processing the elastomers and thermosetting polymers, which basically causes cross-linking in the extruder during the heating process of polymer material. The plastic or polymer products can be further formed by the thermoforming process.
4. In processing polymers, injection moulding process is almost similar to extrusion process except for the screw operation.
a) True
b) False
Answer: a
Explanation: Injection moulding process is similar to extrusion process. The only difference between the two processes is in the screw operation. In extrusion, screw rotates continuously which provides output of continuous products like pipe, rod and sheet. A reciprocating screw is used in injection moulding which rotates while moving in forward and backward directions.
5. Extruder is a device used for the finishing of processed polymer products in the extrusion process.
a) True
b) False
Answer: b
Explanation: In the extrusion process, extruder is a machine tool or device that forces ductile and soft heated solids through die openings of the desired shape to produce a continuous film, strip, or tubes of polymer materials. In this process, many kinds of polymers like thermoplastics, thermosetting, elastomers etc. are processed with the help of extruder.
6. Continuous type of extruder is generally equipped with rotating parts in the extrusion process.
a) True
b) False
Answer: a
Explanation: There are mainly two types of extruder in the extrusion process of polymers, which are continuous and discontinuous extruder. Continuous extruders are generally fitted with rotating components. And in discontinuous extruders, plastic or polymer is extruded in a recurrent manner, which is only suitable for batch type production processes like injection moulding.
7. Multiple screw extruders are mostly preferred than the single screw extruders in the extrusion process.
a) True
b) False
Answer: b
Explanation: In the extrusion process, extruders are equipped with a screw as their main mixing part. Screw extruders are mainly of two types which are single and multiple screw extruders. In most of the cases, single screw extruders are used for the processing of polymer materials in the industries, because of its simple design, low cost and high reliability.
8. In the extrusion process, a cast type barrel is mainly used for the heating of polymer material.
a) True
b) False
Answer: b
Explanation: There are mainly two types of barrel heaters used in the extrusion process, which are band and cast barrel. The band type barrel is used for heating the polymer material while the cast type includes some channels to contain a flow of cooling medium which is usually water, but the oil is more preferred because it can prevent thermal shock to the barrel.
9. Extruder die is a machine part that gives final shape to the polymer material used in the extrusion process.
a) True
b) False
Answer: a
Explanation: Extruder die is a machine part that gives final shape to the polymer material in the extrusion process. It produces a channel through which liquid polymer exit the extruder by applying pressure that increases in the barrel during the process. The liquid polymer comes out from the die with a constant speed, that’s why the design of die is very important for specification and accuracy.
10. In the extrusion process, a water cooling system is used which automatically controlled by a sensor.
a) True
b) False
Answer: a
Explanation: In the extrusion process, the extruder includes a water cooling system that circulates around the barrel mechanism. The water cooling system is generally controlled by a sensor that automatically controls the system. The sensor also selects the temperature at a predefined point in the processing section of polymer materials.
This set of Casting online quiz focuses on “Introduction of Foundry industry”.
1. Which of the following is not a type of a foundry?
a) Captive foundry
b) Jobbing foundry
c) Semi Production foundry
d) Auto production foundry
Answer: d
Explanation: Foundries are classified according to their type of work and the form of constitution and structure of their organization. The foundries are hence classified into four types namely, captive foundry, jobbing foundry, semi production foundry and production foundry.
2. What is the total capacity possessed by ferrous Indian foundries?
a) 1,00,000 tons
b) 1,50,000 tons
c) 2,00,000 tons
d) 2,50,000 tons
Answer: d
Explanation: There are many foundries in India. A few big foundries are located in Durgapur, Asansol, Rourkela, Bhopal and Bangalore. The total capacity possessed by Indian ferrous foundries is more than 2,50,000 tons.
3. Which of the following is a ferrous foundry?
a) Brass foundry
b) Bronze foundry
c) High alloy steel foundry
d) Zinc-base foundry
Answer: c
Explanation: Among the following, a high alloy steel foundry is a type of steel foundry and steel foundries come under ferrous foundries, while the remaining ones are non-ferrous foundries.
4. Which of the following is not a metal joining process?
a) Riveting
b) Bending
c) Pressing
d) Brazing
Answer: b
Explanation: Riveting, brazing, pressing, soldering, adhesive bonding and bolt-screw fastening are few of the techniques of metal joining process. But, bending is not one of them, it is a shaping process.
5. In an automobile engine, up to what percent of parts are manufactured by casting?
a) 65%
b) 75%
c) 80%
d) 90%
Answer: d
Explanation: Casting is one of the most all round process used in manufacturing. Up to 90% of the automobile engine parts are manufactured using casting, and around 50% of the total weight of the tractor is manufactured using casting.
6. Which of the following is not a metal removing process?
a) Grinding
b) Milling
c) Swaging
d) Hobbing
Answer: c
Explanation: Grinding, milling, hobbing, planning, reaming, shaping, boring, turning and broaching are a few of the techniques of metal removing process. But, swaging is not a part of them, it is a type of metal shaping process.
7. Which of the following is a metal shaping process?
a) Press forging
b) Broaching
c) Riveting
d) Lapping
Answer: a
Explanation: Among the following, broaching is a metal machining process or a metal removal process, riveting is a metal joining process, lapping is a surface finishing process and press forging is a shaping process.
8. Casting provides uniform directional properties.
a) True
b) False
Answer: a
Explanation: Casting provides a great amount of freedom in terms of design. It helps in providing uniform directional properties and good vibrational properties.
9. Which of the following is not a surface finishing process?
a) Honing
b) Grinding
c) Boring
d) Lapping
Answer: c
Explanation: Honing, grinding, anodizing, lapping, polishing and metal spraying are a few of the surface finishing techniques. But, boring is not one of them, it is a technique that is used for metal removal process.
10. Products made through casting can avoid joining process.
a) True
b) False
Answer: a
Explanation: Products which are made from casting processes, possess an advantage of being formed into one single piece. When the production is done in one piece, it eliminates the requirement of any joining process.
This set of Casting Question Bank focuses on “Classification of Foundry Metals and Alloys”.
1. Which of the following is not a cast steel?
a) Low alloy steel
b) Magnesium alloy steel
c) Carbon steel
d) High alloy steel
Answer: b
Explanation: Cast steel are a further classification of foundry metals and alloys under ferrous metals and alloys, that is, having iron base. Low alloy steel, high alloy steel and carbon steel are cast steels, but not magnesium alloy.
2. Which of the following forms of iron is least malleable?
a) Austenitic
b) Pearlitic
c) Ferritic
d) Martensitic
Answer: a
Explanation: Malleable irons are cast irons which are classified under iron base materials, under foundry metals and alloys. Among these phases of iron, the austenite phase of iron is measured to be showing the least amount of malleability.
3. Which among the following is not a cast iron?
a) White iron
b) Compacted graphite iron
c) Gray cast iron
d) Pig iron
Answer: d
Explanation: Among the following, white iron, compacted cast iron and gray cast iron are different types of cast irons, but pig iron is not. It is from pig iron, that cast irons are made, by re-melting them.
4. What is the amount of carbon present in low carbon steel?
a) Less than 0.5%
b) Less than 0.7%
c) Less than 0.4%
d) Less than 0.2%
Answer: d
Explanation: Low carbon steel has the lowest amount of carbon mixed with iron in the alloy. The amount of carbon present in low carbon steel is less than 0.2% and that of medium carbon steel has carbon composition of about 0.2% to 0.5%.
5. What is the amount of carbon present in high carbon steel?
a) More than 0.5%
b) More than 0.7%
c) More than 0.4%
d) More than 0.2%
Answer: a
Explanation: More than 0.5% amount of carbon present in high carbon steel.
6. Which among the following is a heavy metal?
a) Titanium base
b) Aluminium base
c) Zinc base
d) Magnesium base
Answer: c
Explanation: The given metal bases are all non-ferrous metal bases, which are classified under foundry metals and alloys. Among these, the only heavy metal is the zinc base, while all others are light metals.
7. Which of the following is a light metal?
a) Copper base
b) Lead base
c) Nickel base
d) Magnesium base
Answer: d
Explanation: Magnesium base is a light metal.
8. What is the amount of silicon present in cast carbon steels?
a) 0.25% – 0.6%
b) 0.25% – 0.8%
c) 0.45% – 0.9%
d) 0.45% – 0.1%
Answer: b
Explanation: The amount of silicon that is present in terms of percentage composition is found to be 0.25% to 0.8%. Elements like silicon and manganese are added in the steel alloys for the purpose of deoxidation.
9. What is the amount of manganese present in cast carbon steels?
a) 0.5% – 1.0%
b) 0.25% – 0.5%
c) 0.45% – 0.8%
d) 1% – 2%
Answer: a
Explanation: 0.5% – 1.0% amount of manganese present in cast carbon steels.
10. Chromium is added to stainless steel.
a) True
b) False
Answer: a
Explanation: Stainless steels are of three types, martensitic, ferritic and austenitic. Stainless steels are resistive to corrosion. These stainless steels contain chromium or nickel apart from its regular additives.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Cast Irons”.
1. Presence of which material in a gray cast iron causes reduced ductility?
a) Graphite
b) Aluminium
c) Coke
d) Zinc
Answer: a
Explanation: Among all the types of cast irons that are manufactured, gray cast irons are most widely used. The colour of this alloy is dull gray. Gray cast iron contains graphite flakes, which are responsible for the reduced ductility and strength.
2. What would be the tensile strength of gray cast iron of class 20?
a) 120 MPa
b) 163 MPa
c) 138 MPa
d) 152 MPa
Answer: c
Explanation: Tensile strength of gray cast iron of class 20 is 163 MPa.
3. What is the tensile strength of thick gray cast iron?
a) 71 MPa
b) 83 MPa
c) 95 MPa
d) 107 MPa
Answer: b
Explanation: Tensile strength of thick gray cast iron is 83 MPa.
4. What is the tensile strength of thick gray cast iron?
a) 276 MPa
b) 283 MPa
c) 295 MPa
d) 207 MPa
Answer: a
Explanation: Tensile strength of thick gray cast iron is 276 MPa.
5. Up to what mass of gray cast irons can shell molds take?
a) 300 kg
b) 400 kg
c) 500 kg
d) 600 kg
Answer: c
Explanation: Shell molding is one of the most important processes which has also been employed for the production of gray cast irons. Gray cast irons weighing up to around 500 kg are usually processed by this method.
6. Green sand molding provides the best surface finish.
a) True
b) False
Answer: b
Explanation: Green sand moldings are found to provide good amount of surface finish, but an even better quality of surface finish and accuracy of dimensions is offered by shell molding process.
7. Shell molding process is a costly process for gray iron castings.
a) True
b) False
Answer: b
Explanation: When gray cast irons have to be processed, there is some amount of machining required to it, which demand high costs. But, if gray cast irons have to be shell molded, the overall cost of the product goes down, making it an economical process.
8. Up to what thickness can hot box process can be used for production?
a) 10 mm- 40 mm
b) 30 mm- 50 mm
c) 40 mm- 80 mm
d) 70 mm- 100 mm
Answer: d
Explanation: In hot box process, there is a core box employed, wherein the sand mixtures are poured along with the liquid resins, which act as binders. The thickness up to which hot box process can be used is 70 mm to 100 mm.
9. Which of the following materials cannot be used for making a core box?
a) Aluminium
b) Steel
c) Zinc
d) Cast iron
Answer: c
Explanation: None.
10. What is the temperature in a core box typically?
a) 120°C – 160°C
b) 180°C – 260°C
c) 200°C – 270°C
d) 290°C – 350°C
Answer: b
Explanation: None.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Cast Irons – 2”.
1. What should be the range of percentage of carbon in iron to be called as cast iron?
a) 0.1-0.5
b) 0.5-1.0
c) 1.0-2.0
d) 2.0-5.0
Answer: d
Explanation: Cast iron is the oldest ferrous material that is used for commercial purposes. It is mainly a mixture of iron and carbon . It can also include materials like sulfur , silicon , and manganese . Generally, for the cast iron, the percentage of carbon in iron is 2 to 5 percent.
2. The shaking out of cast iron casting from mould cavity is known as fettling process.
a) True
b) False
Answer: b
Explanation: The cast iron is first melted in furnace and then poured into the mould cavity. After cooling of cast iron in the mould it is broken out. All the excess of metal from the process, gates, runners etc are removed in a process called as fettling, which also have operations like grinding and shot blasting to produce the good surface finish of the castings.
3. Cast iron generally has low tensile strength but excellent compressive strength.
a) True
b) False
Answer: a
Explanation: Cast iron is normally of nonmalleable and brittle nature which defines that, it is not easy to bend or stretched the casting into any shape due to low tensile strength. Cast iron parts tend to fracture by little of deformation, but cast iron has excellent compressive strength which highly required in making of structures of buildings and bridges.
4. Which of the following types of iron represents purest form of iron in the manufacturing process?
a) Pig iron
b) White cast iron
c) Wrought iron
d) Grey cast iron
Answer: c
Explanation: The purest form of iron is wrought iron which has negligible amount of carbon in it. It is highly malleable and tough material which can be used for making products by rolling or forging operation instead of casting process. It is basically obtained by melting pig iron which is also called crude iron.
5. Which of the following types of cast iron includes black flakes of graphite in it?
a) White cast iron
b) Grey cast iron
c) Ductile cast iron
d) Malleable cast iron
Answer: b
Explanation: Grey cast iron generally includes thin and little black flakes of graphite. These black flakes cause cast iron to appear in grey color, so it is called as grey cast iron. Presence of graphite can make it use as a lubricant in some manufacturing processes. But it has less tensile strength and toughness than the other cast irons.
6. The cast irons are highly corrosive resistant material due to presence of high silicon content in it.
a) True
b) False
Answer: a
Explanation: The composition of cast iron generally varies depending on the grade of pig iron used in its manufacturing process. High silicon content in cast iron makes it resistance to oxidation and corrosion by creating a tight adhering oxide layer to minimize other further attacks. Iron castings are used in applications where this type of resistance gives relatively good service.
7. High manganese content in cast iron provides excellent weld-ability of the material.
a) True
b) False
Answer: b
Explanation: Cast iron mostly contains 2 to 5% carbon, 1 to 3% silicon and approx 1% manganese. The presence of such contents makes their weld-ability poor. Cast irons are relatively cheap and can be easily casted into any complex shapes and machined, but most of the grades of cast iron are not weld-able.
8. Cast iron is widely used in industries because of its high ratio of performance to cost involved in manufacturing.
a) True
b) False
Answer: a
Explanation: Cast iron is widely used because of its high ratio of performance to the cost that they offer. This high value of ratio is also achieved by easy controlling of microstructure and properties in the casting condition, this enables its various applications without giving any heat treatment to the casted parts or components.
9. Grey cast iron generally has poor machinability due to the presence of graphite flakes in it.
a) True
b) False
Answer: b
Explanation: When the fracture of grey cast iron occurs, the crack path follows the graphite flakes and the fracture surface appears grey in color due to the presence of graphite. The graphite flakes have good damping features and high machinability because the graphite flakes work as a chip breaker and also lubricates the tools or machines.
10. Which of the following parts are mostly manufactured by using grey cast iron?
a) Pistons
b) Surgical equipment’s
c) Thin sheets
d) Engine blocks
Answer: d
Explanation: The fluidity and expandability of molten grey cast iron at the time of solidification, due to the formation of graphite flakes, this iron becomes ideal for the manufacturing of shrinkage free and intricate castings components like engine blocks. The graphite presence greatly enhances mechanical properties in grey cast iron.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Aluminium and Its Alloys”.
1. Presence of which material in aluminium alloy provides ductility to the alloy?
a) Silicon
b) Iron
c) Copper
d) Zinc
Answer: c
Explanation: With the presence of about 2% to 5% of copper metal in aluminium alloy aids in the increase in ductility of the alloy, that is, it becomes easy for the alloy to be stretched into wires.
2. Which furnace is not used for heating aluminium alloys?
a) Electric arc furnace
b) Pot furnace
c) Induction heating furnace
d) Crucible furnace
Answer: a
Explanation: Aluminium alloys can be melted or heated directly or indirectly by fuel firing furnace. The heating can take place in a pot furnace, induction heating furnace, a crucible furnace or a reverberatory furnace.
3. Which of the following is not a purpose of fluxing and flushing the aluminium alloys?
a) Removal of dissolved hydrogen
b) Removal of dissolved oxygen
c) Separation of dross from melt
d) Entrapment of dross
Answer: b
Explanation: Fluxing and flushing are an important task in aluminium alloy foundries. It is done for removing the dissolved hydrogen from the melt, for separating the dross from molten metal and to entrap the dross.
4. What is the silicon composition present in an LM-17 cast aluminium alloy?
a) 3%
b) 12%
c) 5.5%
d) 11.5%
Answer: d
Explanation: In an LM-1 cast aluminium alloy, silicon content is 3%. In an LM-13 cast aluminium alloy, silicon content is 12%. In an LM-8 cast aluminium alloy, silicon content is 5.5% and in an LM-17 cast aluminium alloy, the silicon content is 11.5%.
5. Which gas is not used for fluxing and flushing in aluminium alloys?
a) Argon
b) Chlorine
c) Nitrogen
d) Oxygen
Answer: d
Explanation: Fluxing and flushing is an operation which is done for the removal of hydrogen from the molten metal. In this process, argon gas, chlorine gas, nitrogen gas and helium gas are used as fluxes and not oxygen.
6. Up to what length can the surface finish be achieved by green sand in aluminium alloys?
a) 600 micro inch
b) 650 micro inch
c) 700 micro inch
d) 750 micro inch
Answer: b
Explanation: When green sand is used for molding in aluminium alloys, the surface finish can be achieved from about 300 micro inch to 650 micro inch, which is about 7500 micro mm to 16,250 micro mm.
7. Which of the given metals is not counted among late additions in aluminium alloys?
a) Boron
b) Titanium
c) Manganese
d) Sodium
Answer: c
Explanation: There are certain metals which are added very late in the molten cast. By doing this, aluminium alloys get refined. A few of those metals are, boron, titanium, sodium, chromium and columbium. Manganese is added in aluminium during the operation, not late.
8. Aluminium alloys are not susceptible to which of the following?
a) Macro shrinkage
b) Drossing
c) Micro shrinkage
d) Solidification shrinkage
Answer: a
Explanation: Aluminium alloys are susceptible to drossing, micro shrinkages and solidification shrinkages, but not to macro shrinkages. For the prevention of entering of dross in mold cavity, gating system is installed.
9. A runner is located away from the drag.
a) True
b) False
Answer: b
Explanation: A runner has to be located in the drag. The area of the runner should be small and ideally equal to the ingate area. It should be streamlined to avoid turbulence.
10. Pouring basins are used for reducing vortex formation.
a) True
b) False
Answer: a
Explanation: The design made for pouring basins in the working of aluminium alloys, is purposed for the reduction of turbulence and vortex formation. It also aids in the reduction of mechanical washing of dross.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Copper Alloys”.
1. What is the general density of steel?
a) 6.67 g/cc
b) 7.87 g/cc
c) 8.77 g/cc
d) 5.77 g/cc
Answer: b
Explanation: A steel is basically a mixture of iron and carbon. The composition of iron varies according to the alloy, high alloy steels contain more amounts of carbon and low alloy steels contain less amount of carbon. The density of steels in general is found to be 7.87 g/cc.
2. What is the density of copper alloys?
a) 6.67 g/cc
b) 7.87 g/cc
c) 8.93 g/cc
d) 5.77 g/cc
Answer: c
Explanation: A steel is a mixture of iron and carbon and copper alloys are mixtures of mainly copper and a few other materials like zinc and nickel with it. The main copper alloys can be brass and bronze. The density of copper alloys in general is found to be 8.93 g/cc.
3. Which colour is obtained by copper alloys, when zinc is added to it?
a) Red
b) Blue
c) Silver
d) Yellow
Answer: d
Explanation: It is one of the most unusual properties of copper alloys, that on addition of different materials in them, there is a change observed in its appearance, that is, the colour of the mixture starts changing. On addition of zinc metal in copper, the colour of the mixture changes to yellow.
4. Which colour is obtained by copper alloys, when nickel is added to it?
a) Red
b) Blue
c) Silver
d) Yellow
Answer: c
Explanation: None.
5. What amount of impurity is allowed for copper to be used in electric applications?
a) 0.1%
b) 0.2%
c) 0.3%
d) 0.4%
Answer: a
Explanation: Copper and its alloys find themselves a variety of applications in the field of electrical and micro electrical works. For copper to be able to get used in electric appliances, the maximum impurity that can be allowed is 0.1%.
6. Which of the following materials, on adding with copper, doesn’t increase its strength?
a) Cadmium
b) Silver
c) Sodium
d) Aluminium Oxide
Answer: c
Explanation: Copper originally does not possess a very high amount of strength. For properties of copper to be used, but with more strength, this copper needs to be mixed with certain material, which will provide it the required strength. Cadmium, silver and aluminium oxide are few of those materials which will aid in increasing its strength.
7. What is the tensile strength of cast manganese bronze?
a) 490 MPa
b) 759 MPa
c) 676 MPa
d) 324 MPa
Answer: a
Explanation: 759 mega pascals is the tensile strength of quenched and tempered copper-aluminium alloy. 676 MPa is the tensile strength of cold worked zinc. 324 MPa is the tensile strength of annealed zinc and 490 MPa is the tensile strength of cast manganese bronze.
8. What is the tensile strength of pure annealed copper?
a) 324 MPa
b) 676 MPa
c) 759 MPa
d) 209 MPa
Answer: d
Explanation: None.
9. Copper alloys are mostly hot treated?
a) True
b) False
Answer: b
Explanation: For properties of copper to be used, but with more strength, this copper needs to be mixed with certain material, which will provide it the required strength. Cadmium, silver and aluminium oxide are few of those materials which will aid in increasing its strength. This process of increasing strength is done by treating the alloy through cold working.
10. Iron needs higher temperature ranges for its extraction.
a) True
b) False
Answer: a
Explanation: The metal copper has its occurrence in large quantities. This material can be successfully extracted from the mines before the iron is extracted, the reason being, copper extraction happens at lower temperatures.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Copper Alloys – 2”.
1. For protection of copper alloys from corrosion, a special type of coating is applied on it.
a) True
b) False
Answer: b
Explanation: No any special protective treatments are required for copper alloys against corrosion, as they have capability to protect themselves from corrosion. For the sea water applications, copper alloys are used which have high resistance to corrosion and chloride which is present in sea water in an abundant amount.
2. Which of the following parts are mostly manufactured by using copper alloys?
a) Pistons
b) Engine blocks
c) Journal bearings
d) Aircrafts
Answer: c
Explanation: In the manufacturing of journal and other types of solid bearings, copper alloys are mostly preferred. Many other components like worm wheels, gear selector forks and electricity wires are also made by using copper alloys; it is mostly preferred where low friction and high wear resistance is required.
3. Copper alloys generally have sparking nature due to its high ductility.
a) True
b) False
Answer: b
Explanation: Copper alloys components are generally of non-sparking nature, that’s why they are preferred in manufacturing of electrical equipment and components where there is a chance of fire hazard. And the ductile nature of copper alloys is totally independent to its non-sparking nature.
4. Copper alloys have low thermal conductivity but high electrical conductivity.
a) True
b) False
Answer: b
Explanation: Copper alloys have high thermal conductivity as well as high electrical conductivity. Due to high electrical conductivity, they are used in making of electric wires, in motor winding etc. And high thermal conductivity of copper alloys useful in making of heat exchangers, in piping of power-plants, air conditioning, refrigerators etc.
5. Copper alloys possess good mechanical properties even at high temperatures.
a) True
b) False
Answer: a
Explanation: Copper and its alloys have an optimized combination of tensile and compressive strength, hardness, ductility and resistance to shock load to use for various applications. And the mechanical properties of copper alloys at high temperatures are even better than the other non-ferrous materials.
6. At zero level temperature of copper alloys, they become very hard and brittle in nature.
a) True
b) False
Answer: b
Explanation: At zero level temperature of copper alloy castings, no any kind of embrittlement occurs; in fact, the tensile strength of copper castings enhances at low temperature. Therefore, the copper castings can be used at very low temperatures without any significant changes to the properties of the castings.
7. Castings or components of copper alloys have high machinability and recyclability.
a) True
b) False
Answer: a
Explanation: Many alloys consist of lead to increase machinability with easy chip formation. But, copper components itself have excellent machinability. And copper alloy castings are recyclable too, the scrapes of copper alloys castings can be melted and can be used again in the manufacturing of other copper parts.
8. In general, copper is highly reactive with sulphur and its chemical compounds.
a) True
b) False
Answer: a
Explanation: Copper may resists the oxidation, but it is highly reactive with sulphur and its chemical compounds, it produces copper sulphide during the reaction which can be unpleasant for the casting components. The main copper contaminants significantly are phosphorous and iron besides oxygen.
9. Copper is generally a polymorphous material with body centered cubic lattice structure.
a) True
b) False
Answer: b
Explanation: Copper is a non-polymorphous material with face centered cubic structure. The FCC structure is the only reason for ductility in the copper material. Pure copper is generally reddish in color, and addition of zinc produces the yellow color of the copper and nickel produces the silver color of the same.
10. It is very difficult to cast pure copper metal in mould cavity because of shrinkage problems.
a) True
b) False
Answer: a
Explanation: It is very difficult to cast pure copper in mould cavity because very large shrinkages occur during the solidification of castings, and a large amount of gasses are trapped in the casting at high temperatures which results in the melted material gassing and the porosity in casting components.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Magnesium Alloys”.
1. Pure magnesium melts at what temperature?
a) 600°C
b) 650°C
c) 700°C
d) 750°C
Answer: b
Explanation: The temperature at which the pure form of magnesium gets ignited by itself is 473°C, and the temperature at which magnesium in its purest form is found to melt is 650°C.
2. Which of the following metals is least used in making magnesium alloys?
a) Aluminium
b) Zinc
c) Copper
d) Manganese
Answer: c
Explanation: Magnesium metal in itself is not one of the strongest metals and is hence adulterated with other materials to form strong alloys. Among the following, aluminium, zinc and manganese are highly used in making magnesium alloys.
3. Which of the following can be the casting temperature for magnesium alloys?
a) 630°C
b) 760°C
c) 850°C
d) 970°C
Answer: b
Explanation: When it comes to casting of magnesium alloys, the casting temperatures have to be kept in real control, that is, if the temperatures go too high, the metal might catch fire. The temperature range for casting magnesium alloys is 720°C to 800°C.
4. Which of the following is not a property of a magnesium alloy?
a) High damping capacity
b) High electrical conductivity
c) Good fatigue strength
d) High thermal resistivity
Answer: d
Explanation: Magnesium on getting mixed with other elements starts possessing many different properties. It contains good damping capacity, good electrical conductivity and good fatigue strength, but not, thermal resistivity.
5. What is the color of pure magnesium metal?
a) Red
b) White
c) Black
d) Yellow
Answer: b
Explanation: The purest form of magnesium is considered to be in its weakest form, and hence other elements are added in it to enhance its quality. The physical qualities too change on addition of other elements. Originally, the color of pure magnesium metal is silvery white.
6. What should be the temperature of the mixture while alloying takes place?
a) 550°C
b) 600°C
c) 650°C
d) 700°C
Answer: d
Explanation: During the mixture getting processed, first the magnesium is melted, and then zinc metal is added. Aluminum is mixed in it through stirring. While this is happening, it has to be ensured, that the complete alloying process takes place at 700°C.
7. In magnesium alloys, what is the maximum amount of allowed aluminum?
a) 11%
b) 13%
c) 19%
d) 24%
Answer: a
Explanation: Magnesium alloys are basically a composition of various metals mixed with magnesium to improve its physical, chemical, mechanical and thermal properties. In this, the maximum allowable aluminum that can be added is only 11%.
8. What should the temperature ideally be to remove the casting after making of magnesium alloys?
a) Below 450°C
b) Below 300°C
c) Below 350°C
d) Below 300°C
Answer: d
Explanation: It is always advisable that the castings should never be removed too quickly, as it might lead to distortion of the cast because it is still hot. Therefore, when the temperature of the cast is below 300°C, the magnesium alloy cast can be removed.
9. In grain refinement process, only hexachlorobenzene is used.
a) True
b) False
Answer: b
Explanation: In grain refinement process, there is another process called carbon inoculation, in which, tablets of organic compounds are used, namely hexachlorobenzene and hexachloroethane.
10. Magnesium alloys have a low strength to weight ratio.
a) True
b) False
Answer: b
Explanation: Magnesium alloys possess many desirable mechanical, physical and thermal properties, which may help in better casting processes. One of these properties is a high strength to weight ratio.
11. In sand casting of magnesium alloys, what is the amount of silica sand used in an American mix?
a) 80 lb
b) 90 lb
c) 100 lb
d) 110 lb
Answer: c
Explanation: It is mainly observed that magnesium alloys are manufactured with the help of sand molds only. The amount of silica sand used in magnesium alloys is 100 lbs in both the British mix and the American mix.
12. In sand casting of magnesium alloys, what is the amount of bentonite sand used in a British mix?
a) 3 lb
b) 4 lb
c) 5 lb
d) 6 lb
Answer: b
Explanation: In the production of magnesium alloys, there are a variety of sands employed. For this, bentonite sand has to be used for the sand casting of the alloys. The amount of bentonite sand used is 4 lbs in both British as well as American mix.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Magnesium Alloys – 2”.
1. In general, magnesium alloy components tends to have fine grain structure in it.
a) True
b) False
Answer: b
Explanation: In general, magnesium alloy component tends to have coarse grain structure unless some suitable procedures are taken to insure the formation of fine grains. The procedure involves superheating of molten metal to 2500 or 3000 ⁰C. And then after holding it there for a certain period of time, it cools down to the desired temperature and pouring operation takes place without any delay.
2. Magnesium is a very light material that can be suitable in aircraft applications.
a) True
b) False
Answer: a
Explanation: Magnesium is very light metal in comparison with other structural metals. Magnesium is commonly used in a wide range of markets and applications, from automobiles to aircraft applications. In most of the cases of manufacturing, weight reducing is the primary objective for magnesium alloys.
3. Magnesium metal is very light material, but not lighter than aluminium metal.
a) True
b) False
Answer: b
Explanation: Magnesium is mainly distinguished by its low density, which is nearly about 25% of steel and about 60% of the aluminium metal. This property makes magnesium to use for very lightweight construction. In expensive cars, it is highly used in the construction of crankcase and in other parts to increase power to weight ratio.
4. Magnesium cannot be used extensively for precision casting applications.
a) True
b) False
Answer: a
Explanation: Magnesium cannot be used extensively for precision casting applications because it is highly reactive with silica containing constituents like plaster or other mould materials. Silica is mostly present in slurry in which it acts like binding material. Reaction of magnesium with silica produces magnesium oxide and magnesium silicide which may imparts defects in the casting components.
5. Adding of zirconium in magnesium metal results in the formation of magnesium-zirconium alloy of enhanced ductility.
a) True
b) False
Answer: b
Explanation: The grain size is highly affected by adding zirconium in magnesium metal. Addition of less than 0.6% zirconium in magnesium is sufficient to obtain grain size less than 80 microns in casted components. This further increases hardness in the material due to formation of fine grains and ductility also decreases simultaneously.
6. Inhibitors are generally used in mould to avoid reaction of magnesium with moulding materials.
a) True
b) False
Answer: a
Explanation: When moulding materials like silica, moisture and binders make contact with magnesium, the reaction takes place which arise problems in the castings of magnesium alloys. To avoid reaction, the mould is modified by using some techniques like drying and by including inhibitors in the moulding materials.
7. Which of the following compounds can be used as an inhibitor in moulding materials for avoiding chemical reaction with magnesium alloys?
a) Sodium silicate
b) Water
c) Hydrogen silicate
d) Potassium borofluoride
Answer: d
Explanation: Moulding materials are effectively inhibited by adding 1 to 2 percent of potassium borofluoride. And controlling of inhibitor content in moulding materials is very important because they can affect setting times. Sometimes elimination of silica content from moulding materials also takes place to avoid chemical reactions.
8. Magnesium metal possesses better noise and vibration damping characteristics than aluminum.
a) True
b) False
Answer: a
Explanation: Magnesium is the lightest material in all the engineering materials. It has good ductility, better noise and vibration damping features than aluminium and also has excellent cast-ability. Alloying of magnesium metal with aluminium, manganese increases the strength of the components and also reduces the weight of the casted parts, so magnesium alloys are very important materials for applications where weight saving is a dominant objective.
9. Magnesium alloys do not require any special coating as they are self protective from corrosion.
a) True
b) False
Answer: b
Explanation: Different types of coatings are applied to magnesium alloys to increase corrosion resistance. Coatings for magnesium alloys are applied by using hexavalent chromium material which provides excellent protection, but do not considered as eco-friendly. To avoid environmental problems, Teflon resin is basically applied instead of any other coatings.
10. Teflon resin coating can be used to increase the lubricity of magnesium alloys.
a) True
b) False
Answer: a
Explanation: Teflon resin is a low cost coating which is primarily used for magnesium alloys to improve corrosion resistant properties. It is a chromium free corrosion resistant coating that can be also used for improving lubricity and frictional resistance. It also includes non-wetting features which keeps the casting moisture free.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Foundry Fluxes and Refractories”.
1. The mixing of flux in the casting material produces endothermic reaction.
a) True
b) False
Answer: b
Explanation: The flux is mixed with casting while solidification that basically reacts with a network of oxides and converts them into a powder that floats on the casting so it becomes easier to separate out that part. The whole reaction takes place is exothermic. The flux is normally used after the cleaning process which prevents progressive oxidation.
2. Which of the following materials are commonly used as flux in the casting process to prevent oxidation?
a) Sodium silicate
b) Lead
c) Sodium chloride
d) Sodium carbonate
Answer: c
Explanation: Sodium chloride is commonly used as flux in the casting process to prevent oxidation. Sometimes potassium fluoride is also preferred as a flux due to its excellent volatility. It not only prevents the oxidation, the other inclusions are also reduced by using flux. This process avoids metal wastage and avoids several defects formation.
3. Degassing process during the formation of castings can prevent inclusion of hydrogen absolutely.
a) True
b) False
Answer: b
Explanation: After degassing process, the hydrogen does not stop coming in the casting material. This can only be controlled by using fluxes in the casting material but it is always recommended to determine the gas quantity before casting process, a device called reduced pressure gas determination equipment is then used for determining the gas content.
4. What should be the melting point ⁰ of flux used for mixing with aluminium casting?
a) 440⁰C
b) 555⁰C
c) 606⁰C
d) 660⁰C
Answer: d
Explanation: The melting point for flux to be used for aluminium casting should be approximately 660⁰C. However, the oxidation in aluminum is inevitable but flux is essential to avoid contact of aluminium melt to atmosphere and to get dry dross after skimming process which generally maintains the quality of casting material.
5. The fluxes used in the casting process must have low vapour pressure.
a) True
b) False
Answer: a
Explanation: If the flux has high vapour pressure then it will not be easy to control it as vapourization will takes place which will have no any affect on the casting material. So it is always suggested to have low vapour pressure of fluxes that will easily mix with the material and will give excellent results in order to prevent oxidation.
6. Which of the following devices is mainly used for thermal analysis of flux?
a) Thermocouple
b) Thermometer
c) Thermo resister
d) Spiral optical tube
Answer: a
Explanation: The flux is first melted inside a crucible and then a thermocouple is inserted into the molten flux. After the cooling process of molten flux, the temperature variations are recorded with respect to time. The melting nature, the variation in viscosity and the melting range of the molten flux with temperature is recorded.
7. Refractory materials are basically used for strengthening the casting materials used in the casting process.
a) True
b) False
Answer: b
Explanation: Refractory materials are materials that have high melting points and they basically act as a heat resisting barrier between high and low temperature zones. Refractory materials are useful in constructing structures like boilers, furnaces etc. as they minimize heat losses through the structure during working conditions.
8. Refractories are generally inorganic non-metallic materials which can resist very high temperature.
a) True
b) False
Answer: a
Explanation: Refractories are inorganic nonmetallic materials which can resist very high temperature without any physical or chemical variations. It is essential to generate a certain range of refractory materials with different features to be resistant to thermal shock, be chemically inert and to possess good thermal conductivity.
9. Silicon carbide is widely used as refractory material in the mould making for casting processes.
a) True
b) False
Answer: b
Explanation: Silicon carbide is a good refractory material, but cannot be used in mould making process because it is highly reactive with oxygen and gets burns itself during oxidation. To avoid such oxidation problems, zirconia is preferred which can also bear very high temperatures and perfectly acts as a refractory material.
10. Refractoriness of a material should always be greater than its application temperatures.
a) True
b) False
Answer: a
Explanation: Refractoriness is a property at which a refractory material deforms under its own load. The refractoriness is generally indicated by Pyrometric cone equivalent . It should always be greater than the application temperatures. Refractoriness is decreased when the refractory material is continuously under loading conditions.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Melting of Titanium Alloys”.
1. In general, titanium is denser than steel due to compactness in grain structure of titanium.
a) True
b) False
Answer: b
Explanation: Titanium is a low density material which is approximately 60% of the density of steel. It is mainly strengthened by alloying and deformation methods. It is a nonmagnetic metal which has low thermal conductivity. Its coefficient of thermal expansion is generally less than that of steel and less than half that of aluminium.
2. Titanium alloys have melting point greater than that of steels.
a) True
b) False
Answer: a
Explanation: Titanium alloys have melting point greater than that of steels, but maximum temperatures for various applications normally range from 428 °C to approximately 540 °C. It mainly depends upon the composition and its characteristics. Titanium aluminide alloy can achieve temperature up to 760 °C for some applications.
3. Titanium is a toxic material which can also be affected by the attack of chlorides or mineral acids.
a) True
b) False
Answer: b
Explanation: Titanium has the ability to un-react with any coating or material, so thereby it shows a high degree of resistance against the attacks of chlorides and mineral acids. Pure titanium is a nontoxic material, so its alloys and it can be compatible with human tissues and bones biologically without any significant effects to the human body.
4. The properties of titanium can remain constant with abrupt variations in the temperature of a material.
a) True
b) False
Answer: a
Explanation: Titanium has good properties like strength, low-thermal expansion with low modulus with respect to its low-high cycle of fatigue strength, corrosion resistance, and weld-ability. Titanium is the only material that includes this combination of properties over a temperature range starting from the surrounding temperature to approx 550 ⁰C.
5. Which of the following materials is the most dominant in aero engine applications?
a) Iron
b) Brass
c) Titanium
d) Copper
Answer: c
Explanation: Titanium is the single material which is very dominant in compressor stages of aero engine applications. Aluminium and steel can also be used, but the use of titanium is very effective. Its alloys greatly improve the aerodynamic cycle and propulsive efficiency also with improvements in thrust to weight ratio.
6. Melting and casting of titanium are very difficult due to its high chemical reactivity with mould materials.
a) True
b) False
Answer: a
Explanation: Many problems arise in process of melting and casting of titanium due to its great chemical reactivity with mould material and its great affinity for surrounding gases. To avoid such problems, graphite or investment moulding is preferred which are also difficult but possible to produce equipment in aero engine and biomedical applications.
7. In general, titanium castings exhibits excellent fatigue strength due to its high rigidity.
a) True
b) False
Answer: b
Explanation: Titanium castings generally have beta structure which is combined with excellent creep resistance, fatigue crack resistance and tensile properties. But the titanium castings exhibits very low fatigue strength due to the presence of porosities in the castings. These porosities can be treated by isostatic pressing to improve properties of the titanium castings.
8. Refractory oxides do not have any effect on molten titanium metal at the time of casting process.
a) True
b) False
Answer: b
Explanation: Most of the refractory oxides like zirconia and alumina react with molten titanium to generate a layer which is enriched in oxygen or inter-metallic compounds of titanium. The oxide mixes in molten titanium which gives rise to a contaminated layer that can be considered as precipitate as a separate phase on cooling.
9. Which of the following methods of melting is not used for melting titanium metal?
a) Induction method
b) Vacuum arc method
c) Electron beam melting
d) Cupola furnace melting
Answer: d
Explanation: Various melting methods are used for melting of titanium metal. For example, induction, vacuum arc and electron beam melting, in which vacuum arc and electron beam melting methods are widely used, though efforts are made continuously for producing other different methods to gain better control on melting and to have better utilization of scrap materials. And cupola furnace is basically used for melting iron alloys.
10. Titanium metal generally has a high melting point and low thermal conductivity.
a) True
b) False
Answer: a
Explanation: Titanium metal has a high melting point and low thermal conductivity which is responsible for producing a steep thermal gradient in the casting during solidification. The reaction with mould materials forms surface layers which include oxygen and other elements taken from the mould. This affects the mechanical properties of the castings. So to avoid such problems, graphite or investments moulds are used instead of simple moulds.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Melting of Steel and Stainless Steel”.
1. How is much amount of chromium normally added in steel to be called as stainless steel?
a) 1-2 %
b) 2-5 %
c) 5-10%
d) 10-30 %
Answer: d
Explanation: Stainless steels mainly contain 10-30 % of chromium besides other elements such as carbon, manganese, silicon, sulphur etc. Chromium produces corrosion resistance property in steel, that’s why the material is known as stainless steel as no any kind of stains are occur on the surface of the steel.
2. Which of the following types of stainless steels contain maximum amount of chromium in it?
a) Duplex stainless steels
b) Martensitic stainless steels
c) Austenitic stainless steels
d) Precipitation hardenable stainless steels
Answer: a
Explanation: Duplex stainless steels contain approximately 25 % of chromium while rest of the stainless steels contain less than that of duplex stainless steels. All the stainless steel materials contain chromium and carbon besides other elements. In production of stainless steels, controlling of carbon and chromium content should be proper.
3. In the manufacturing of stainless steel, oxidation of carbon and chromium cannot be possible.
a) True
b) False
Answer: b
Explanation: In the manufacturing of stainless steel, both chromium and carbon can be oxidized due to decarburization of molten casting. Carbon oxidation in comparing with chromium oxidation may occur at temperature above 1220 ⁰C in the pure state conditions. But experimentally, carbon oxidation can occur at temperature above 1800 ⁰C than that of chromium.
4. Which of the following materials is required in a technique of decarburizing the molten steel?
a) Calcium carbonate
b) Sodium chloride
c) Carbon ferrochrome
d) Sodium ferrochrome
Answer: c
Explanation: Decarburization technology uses high carbon ferrochrome to decarburize the molten steel at lower temperatures. If carbon oxidizes first with respect to chromium at low temperatures, then the reduction in pressure from atmosphere to a lower value will be required. Reduction in pressure is mostly done by vacuum oxygen decarburization method.
5. In argon oxygen decarburization method, whole process is carried out in a converter type of vessel.
a) True
b) False
Answer: a
Explanation: The argon oxygen decarburization process is mainly carried out in a converter type of vessel which is generally lined up with magnesite bricks. Then a combination of argon and oxygen is filled by the application of tuyeres located on the side of the converter vessel. Then the melt of steel is charged into the vessel for further processing.
6. Preheating of scrap material in steel making process can increase the overall productivity.
a) True
b) False
Answer: a
Explanation: The energy required for steel making in the electric vessel is mainly for the melting down of scrap material. Preheating of scrap material can reduce the energy requirement which further reduces the time in making of steel that can directly increase the overall productivity. Other advantages include decrease in electrode consumption and the refractory wear.
7. The dust produced from electric furnaces in steel making procedure is directly thrown out to the atmosphere via chimney.
a) True
b) False
Answer: b
Explanation: In steel making, dust is produced in the electric furnace during melting of steel. The produced dust is carried away in the off-gases which basically contains iron and some non-ferrous materials like zinc and lead. So not only environmental considerations but also for the economic considerations, the dusts are collected and recovery of valuable materials is done.
8. Obsolete scrap is the scrap which is relatively pure and its chemical composition is known.
a) True
b) False
Answer: b
Explanation: Obsolete scrap generally contains iron and steel parts which are rejected due to end of their service life. It is often mixed with other metals like copper, zinc and tin to form other steel alloys. And home scrap is known as the scrap which is relatively pure and chemical composition is known.
9. Steel yield is highest in continuous casting method which significantly reduces scraps.
a) True
b) False
Answer: a
Explanation: It is always aimed to have higher steel yield in steel industries through attributes of equipment and technologies used in steel making. The steepest decrease in the amount of scraps is mainly achieved by the application of continuous casting method which has highest casting or steel yield.
10. Copper cannot be removed from steel scraps by the method of conventional refining.
a) True
b) False
Answer: a
Explanation: It is not possible to remove copper from steel scraps by the method of conventional refining. It can be removed by treating steel scraps with sulphide fluxes and also by treating it at reduced pressure of the gas phase which basically includes vapourization of copper from the steel scraps.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Methods and Materials for Degassing”.
1. The term degassing is basically employed for optimizing the use of materials used in production of casting components.
a) True
b) False
Answer: b
Explanation: During production of casting products, gases such as oxygen, hydrogen and nitrogen get dissolved in the casting. The term degassing is employed for the removal of these gases from the casting melt. Dissolved oxygen from molten casting cannot be extract as molecular oxygen, removing of oxygen from melt is called as de-oxidation.
2. Excess of nitrogen in molten casting can cause embrittlement of casting components.
a) True
b) False
Answer: a
Explanation: During solidification of molten casting in mould cavity, excess of nitrogen is extracted from the melt which can cause blow holes and embrittlement of heat affected zone of casting component. So, it is very necessary to remove nitrogen from the melt to produce castings of desired quality and defects free.
3. The presence of hydrogen in molten casting strengthens the casting components.
a) True
b) False
Answer: b
Explanation: Solubility of hydrogen in the melt is generally low at ambient temperature. Hydrogen in molten casting damages or weakens the mechanical properties which also results in occurrence of porosity and losing of tensile ductility in the casting parts. Thus, removal of excess hydrogen is very necessary during solidification of the molten casting.
4. Degassing can be carried out by placing ladle containing liquid metal under vacuum.
a) True
b) False
Answer: a
Explanation: In ladle degassing method, the effectiveness is reduced from top to bottom of the molten metal. Bottom layers of metal are not much affected by the vacuum as these layers influenced by the pressure due to column of liquid metal. So the entire molten metal content is exposed to the vacuum for the complete degassing operation.
5. Which of the following gases is used in the method of recirculation degassing?
a) Hydrogen
b) Nitrogen
c) Argon
d) Oxygen
Answer: c
Explanation: In the method of recirculation degassing, argon gas is used which is bubbled through the porous holes located at the bottom side of ladle. The speed of degassing will increases with the increase in rate of circulating the liquid metal through the vacuum region. And the circulating speed is increased by the increase in flow rate of argon gas.
6. Which of the following formulas is used for determining the circulation rate in recirculation degassing?
a) R = 1.42*10 3 *Q 1/3 *d 1/3 *{ln}
b) R = 2.42*10 3 *Q 1/3 *d 1/3 *{ln}
c) R = 5.14*10 3 *Q 1/3 *d 1/3 *{ln}
d) R = 7.42*10 3 *Q 1/3 *d 1/3 *{ln}
Answer: d
Explanation: The circulation rate in recirculation degassing is given by-
R = 7.42*10 3 *Q 1/3 *d 1/3 *{ln} , where R is the circulation rate in Kg/sec, Q is the injection rate of argon gas, P1 is the pressure at the base, P2 is the pressure in the vacuum chamber and D is the internal diameter.
7. The effectiveness of vacuum treatment is reduced by the increase in surface area of the molten metal exposed to vacuum.
a) True
b) False
Answer: b
Explanation: The effectiveness of vacuum treatment is always increased by the increase in surface area of the molten metal exposed to vacuum. The increased surface area of the molten metal exposed to the vacuum; for example, in the form of a thin gas induced stirs which can accelerate the degassing operation. And the degassing time should be kept minimum as much as possible.
8. In vacuum treatment of molten metal, temperature of the melt can be decreased.
a) True
b) False
Answer: a
Explanation: Temperature of melt decreases during the vacuum treatment of molten metal. This is basically caused by exposing of more surface area to the vacuum chamber. To maintain the heat from the molten metal additional heating of the metal is usually done to compensate for the loss of heat.
9. In vacuum degassing method, low viscosity is considered to have negative influence on the reaction rate.
a) True
b) False
Answer: b
Explanation: The viscosity influences the efficiency of vacuum degassing; a high viscosity is considered to have negative influence on the reaction rate. The viscosity is generally not considered in the kinetics; instead, a constraint is used that limits the viscosity to be below 0.5 Pas. The melt should have low viscosity which also reduces the time involved in the procedure.
10. The effect of temperature change is generally neglected during the vacuum degassing process.
a) True
b) False
Answer: a
Explanation: The reduction in temperature changes the composition of equilibrium steel and hence mass transfer coefficient changes dynamically. The effect of temperature change is generally neglected during the vacuum degassing process, but the temperature change is analyzed so that the operation does not finish at the low temperatures.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Cold Set Resin Binders”.
1. What is the pH level of leachate?
a) 1-3
b) 3-6
c) 6-9
d) 9-12
Answer: c
Explanation: The pH level of the leachate has the requirement to be somewhere in between 6 to 9 on the pH scale. This would indicate that, the substance leachate is a basic substance.
2. From what is furfural alcohol derived?
a) Carbon dioxide
b) Waste water
c) Waste vegetables
d) Sulphur dioxide
Answer: c
Explanation: Furfural alcohol gets derived from vegetable matter which is wasted, by processing it under pressure.
3. What is the source of fuel of the boiler in process energy?
a) Waste from FA processing
b) Waste from CO 2 production
c) Waste from SO 2 production
d) Waste from NO 2 production
Answer: a
Explanation: The waste that is achieved after processing of furfural alcohol is used to fuel the boiler in the process energy.
4. For casting, in phenolic esters, formaldehyde levels are low.
a) True
b) False
Answer: a
Explanation: On mixing and even on casting, in the phenolic esters, the formaldehyde levels are found to be exceedingly low.
5. What is the formaldehyde level in phenolic ester in mixing?
a) Less than 0.2 parts per million
b) Less than 0.3 parts per million
c) Less than 0.4 parts per million
d) Less than 0.5 parts per million
Answer: d
Explanation: None.
6. What is the formaldehyde level in phenolic ester in casting?
a) Less than 0.2ppm
b) Less than 0.3ppm
c) Less than 0.4ppm
d) Less than 0.5ppm
Answer: d
Explanation: None.
7. What is the phenol level in phenolic ester in casting?
a) Less than 2ppm
b) Less than 3ppm
c) Less than 4ppm
d) Less than 5ppm
Answer: a
Explanation: None.
8. What should the total percentage of re-use of sand in reclamation be?
a) 80%
b) 85%
c) 90%
d) 95%
Answer: d
Explanation: There is some amount of threat which is faced by the phenolic-ester compounds. This threat causes a kind of limitation to the reclamation. Ideally, the total percentage should be 95%.
9. Potassium hydroxide melts at what temperature?
a) 260°C
b) 360°C
c) 460°C
d) 560°C
Answer: b
Explanation: Potassium hydroxide is known to have its melting point at a temperature of 360°C, but it is known to have a very high boiling point of 1320°C.
10. Potassium hydroxide boils at what temperature?
a) 1260°C
b) 1320°C
c) 1840°C
d) 2560°C
Answer: b
Explanation: None.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on ” Gas-Vapour Cured Resin Binders”.
1. Which of the following is an advantage of high volume core production?
a) Durability
b) High strength
c) Low cost
d) Cures low volume production
Answer: c
Explanation: The very basic requirements of high volume core production is, low cost and fast manufacturing.
2. High volume mould production is done using which sand?
a) Green sand
b) Dry sand
c) Loam sand
d) Sharp sand
Answer: a
Explanation: When it comes to the production of high volume core productions, the cost essentially should be low. High volume mould production is done using green sand only.
3. Which of the following is not an advantage in low volume core production?
a) High production
b) Consistency
c) Mould rigidity
d) Hardenability
Answer: d
Explanation: In low volume core production, it offers high rate of production, better consistency and mould rigidity, but not hardenability.
4. Which of the following is not an advantage of moderate to high volume aluminium castings?
a) Growth in low pressure
b) Flexibility
c) Low cost
d) Low brittleness
Answer: d
Explanation: In moderate to high volume aluminium castings, low pressure growth, flexibility and lower costs is an advantage, but not low brittleness.
5. What does LPS stand for?
a) Limited Production Sand casting
b) Low Pressure System
c) Limited Production System
d) Low Pressure Sand casting
Answer: d
Explanation: LPS stands for Low Pressure Sand Casting. The growth in LPS in mainly found to be used only in for the cylindrical blocks and heads.
6. What is mixed with calcium hydroxide on sand for CO 2 cured polyacrylate?
a) Sodium polyacrylate
b) Calcium polyacrylate
c) Aluminium polyacrylate
d) Iron polyacrylate
Answer: a
Explanation: According to the reaction, sodium polyacrylate is mixed with calcium hydroxide (CaOH 2 ) on sand and is later cured with carbon dioxide gas.
7. In Amine cured phenolic urethane, what is used as the catalyzing reagent?
a) Primary amine
b) Secondary amine
c) Tertiary amine
d) Nitrogen dioxide
Answer: c
Explanation: In amine cured phenolic urethane, a tertiary vaporized amine is used as a catalyst and is therefore, used for the catalyzation of the reaction.
8. What reacts with polyether phenolic resin to give polyurethane structure?
a) Diphenyl methane diisocynate
b) Triphenyl ethane diisocynate
c) Diphenyl ethane diisocynate
d) Triphenyl methane diisocynate
Answer: a
Explanation: In amine cured phenolic urethane, a tertiary vaporized amine is used to catalyze the reaction between polyether phenolic resin and Diphenyl methane diisocynate to give out polyurethane structure.
9. In Ester cured alkaline phenolic, what is used as a coreactant?
a) A phenol
b) A ketone
c) An ester
d) An aldehyde
Answer: c
Explanation: In Ester cured alkaline phenolic, there is an ester called methyl formate, which is usually used as a coreactant.
10. Green sand has high volume production rate than gas-vapour cured system.
a) True
b) False
Answer: b
Explanation: The production rate in gas and vapour cured system, is comparatively lower than that of green sand.
This set of Casting Questions and Answers for Aptitude test focuses on “Comparative Properties Of Gas-Vapour Cured Resin Binders”.
1. Which of the following is produced by Novalak – acid system?
a) Ketone
b) Carboxylic acid
c) Ester
d) Aldehyde
Answer: d
Explanation: The novalak – acid system produces formaldehyde, which by the name suggests is an aldehyde and methanol while production of cores.
2. The novalak – acid system needs what temperature conditions?
a) 15°C – 25°C
b) 25°C – 35°C
c) 35°C – 45°C
d) 45°C – 55°C
Answer: c
Explanation: The novalak – acid system needs to be operated in between the temperature range of 35°C – 45°C. When this system gets operated in these temperature ranges, it is observed to yield best results.
3. Which of the following is not a casting performance of phenolic – urethane cores?
a) Moderate hot strength
b) Good hardenability
c) Surface finish
d) Low nitrogen level
Answer: b
Explanation: Under casting performance of phenolic – urethane cores, having good hardenability does not come under it.
4. In the given figure, phenolic urethane has what kind of a performance in transverse strength?
casting-questions-answers-aptitude-test-q4
a) Good performance
b) Moderate performance
c) Poor performance
d) Did not perform
Answer: a
Explanation: In the given figure, phenolic urethane has shown a good performance in transverse strength. The first column is indicating the answer here.
5. In the given figure, Epoxy-acrylate has what kind of a performance in transverse strength?
casting-questions-answers-aptitude-test-q4
a) Good performance
b) Moderate performance
c) Poor performance
d) Did not perform
Answer: a
Explanation: In the given figure, epoxy-acrylate has shown a decently good performance in transverse strength. For epoxy acrylate, one may look at the second column.
6. In the given figure, novalak-acid has what kind of a performance in transverse strength?
casting-questions-answers-aptitude-test-q4
a) Good performance
b) Moderate performance
c) Poor performance
d) Did not perform
Answer: a
Explanation: Novalak-acid, in the given figure has shown a good performance in transverse strength. For novalak-acid system, the column 4 can be considered.
7. In the given figure, alkaline-phenolic has what kind of a performance in transverse strength?
casting-questions-answers-aptitude-test-q4
a) Good performance
b) Moderate performance
c) Poor performance
d) Did not perform
Answer: b
Explanation: None.
8. In the given figure, alkaline phenolic – CO 2 cured has what kind of a performance in transverse strength?
casting-questions-answers-aptitude-test-q4
a) Good performance
b) Moderate performance
c) Poor performance
d) Did not perform
Answer: c
Explanation: In the given figure, alkaline phenolic-CO 2 cured, has shown a poor performance in transverse strength.
9. In the given figure, polyacrylate – CO 2 cured, has what kind of a performance in transverse strength?
casting-questions-answers-aptitude-test-q4
a) Good performance
b) Moderate performance
c) Poor performance
d) Did not perform
Answer: c
Explanation: None.
10. Epoxy – acrylate requires SO 2 for curing.
a) True
b) False
Answer: a
Explanation: Sulphur dioxide is by nature an acidic compound. Epoxy-acrylate largely needs sulphur dioxide for its curing, needing good control of it.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Sand Reclamation Techniques”.
1. Thermal systems can be sufficient for reclamation of chemically bonded sands.
a) True
b) False
Answer: a
Explanation: Chemically bonded sand uses binders to form rigid moulds by the application of heat. Reclamation of sand can be done by thermal, mechanical or wet scrubbing processes. But, thermal systems alone are sufficient for the reclamation of sands. Most of the thermal systems used are gas fired, however electrically fired thermal systems are also used widely.
2. High degree of cleanliness can be achieved by the dry reclamation systems in reclaiming the sand.
a) True
b) False
Answer: b
Explanation: Dry reclamation system uses the mechanical scrubbing principle to separate the clay and the organic coatings. They can be utilized with all general types of sand. However, it is not possible to achieve the degree of cleanliness by the dry reclamation systems as compared to the other types of reclamation systems.
3. The wet reclamation systems are eco-friendly and widely used for reclaiming the sand particles.
a) True
b) False
Answer: b
Explanation: The wet reclamation system uses wet scrubbing action to reclaim the sand. This method is quite effective in cleaning, but the cost of maintenance is very high and water discharge creates many problems which are unpleasant to the environment. These considerations have restricted their use in reclaiming the sands.
4. Burning of organic binders can be possible in thermal reclamation systems for reclaiming the sand.
a) True
b) False
Answer: a
Explanation: Thermal reclamation system provides heat to the sand and high temperature is achieved which is enough to burn the organic binders. These systems can be gas fired or electrically operated for the reclaiming of sand. Thermal systems are specifically suitable for organically bonded sands, but the higher temperature gas fired systems can also be utilized for the clay bonded sands.
5. Sand reclamation is defined for repeatedly using new sand for the making of moulds in production of castings.
a) True
b) False
Answer: b
Explanation: Sand reclamation is a physical and chemical treatment of used foundry sands so that they can be reused in making of cores and moulds for the production of casting components. The true reclamation cleans each and every single grain within the sand, whereas reconditioning is defined for the partial cleaning and treating of sand mass.
6. After reclamation of sand, reclaimed sand should be dry at an acceptable temperature.
a) True
b) False
Answer: a
Explanation: Proper reclamation includes many objectives like the reclaimed sand should be dry at an acceptable temperature. It should be bonded and must have moulding and core making sand properties same as that of the new sand. And the reclaimed sand should produce casting parts of good quality same to those produced by the new sand.
7. Reclamation may improve the casting quality, but does not affect the economic expenditure.
a) True
b) False
Answer: b
Explanation: For the increasing cost of new sand and limited availability of high quality sand sources, reclamation is very important and necessary from the economic point of view. It reduces the cost involved in making of moulds and cores by keeping the quality equal to that produced by the new sand. Reclamation makes the processes economical and environmental friendly.
8. Thermal reclamation system removes the organic as well as the inorganic binders associated with the sand.
a) True
b) False
Answer: b
Explanation: Thermal reclamation systems burn away and remove all the organic binders from the sand, but it does not remove the inorganic binders associated with the sand mass, which are generally fused with the sand grains. Thermal reclamation units can be either electrically operated or gas fired, depending on the degree of reclamation and convenience.
9. In the dry reclamation system, a strong metal plate is used on which used sand is blasted to get converted into fine powder.
a) True
b) False
Answer: a
Explanation: Dry reclamation process crushes the sand lumps into grain size, and then the binders are removed from the sand grains by the use of mechanical abrasion. Released fines particles are separated and then dry sand is prepared by crushing the sand to the metal plate by blasting which removes all the metal particles and the resulting fines are taken to a dust collector.
10. A vigorous scrubbing action takes place in the method of wet reclamation of sand.
a) True
b) False
Answer: a
Explanation: In wet reclamation, a scrubbing action takes place in water to dissolve binders from the sand mass. Loose clay gets suspended in the water and scrubbing action removes the clay coatings from the sand grains. Wet reclamation treats clay bonded sands very efficiently and the reclaimed sand mass is almost equal in quality and purity to new sand.
This set of Casting Assessment Questions and Answers focuses on “Tem Tech Thermal Sand Reclamation”.
1. In the tem tech thermal sand reclamation system, how many fluidized beds are used?
a) One
b) Two
c) Three
d) Four
Answer: b
Explanation: In the tem tech thermal reclamation system, a fluidized bed plays an important role in the sand reclamation system. There are in total two fluidized beds that are used.
2. In the tem tech thermal sand reclamation system, the recirculating air ensures what?
a) Even pressure drop
b) Even temperature drop
c) Even volume drop
d) Even loss of mass
Answer: a
Explanation: In tem tech thermal sand reclamation system, the recirculating air ensures an even pressure drop at all its orifices.
3. What is the heat source of fluidized bed in tem tech thermal sand reclamation system?
a) Flame heating
b) Ultraviolet heating
c) Infrared heating
d) Conduction heating
Answer: c
Explanation: In tem tech thermal sand reclamation system, overall there are two beds involved in it and in them, shortwave infrared emitters are used in the beds.
4. In tem tech thermal sand reclamation system, in the infrared heating system, which material is used in the beds?
a) Copper
b) Iron
c) Silver
d) Tungsten
Answer: d
Explanation: In tem tech thermal sand reclamation system, in the heating process by shortwave infrared emitters, tungsten elements are used.
5. What is the maximum working temperature in a fluidized bed in tem tech thermal sand reclamation system?
a) 1000°C
b) 2000°C
c) 3000°C
d) 4000°C
Answer: b
Explanation: In tem tech working system, there are two fluidized beds involved. The maximum working temperature in a fluidized bed in a tem tech thermal sand reclamation system is 2000°C.
6. The infrared radiation passes through what before entering into the fluidized bed?
a) Prism
b) Concave lens
c) Quartz
d) Convex lens
Answer: c
Explanation: In the tem tech thermal sand reclamation system, the infrared radiation passes through a quartz sleeve before entering the fluidized bed.
7. Up to what accuracy can the temperature of the bed be controlled in tem tech thermal sand reclamation system?
a) ± 1%
b) ± 2%
c) ± 3%
d) ± 4%
Answer: b
Explanation: The temperature of the bed can be controlled to an accuracy of ± 2%, in tem tech thermal sand reclamation system. These fluidized beds essentially need a very accurate temperature control.
8. In tem tech thermal sand reclamation system, what is the maximum current temperature?
a) 600°C
b) 700°C
c) 800°C
d) 900°C
Answer: c
Explanation: In tem tech thermal sand reclamation system, a high amount of temperature has to be maintained. The maximum current temperature is 800°C.
9. In tem tech thermal sand reclamation system, how much is the energy conversion efficiency?
a) 75%
b) 80%
c) 85%
d) 90%
Answer: c
Explanation: In tem tech thermal sand reclamation system, it is observed that the energy that is used gets reused and by other methods, the efficiency is taken up to great heights. There is a high energy conversion efficiency of 85%.
10. One of the goal of tem tech thermal sand reclamation system, is to lower fluidization.
a) True
b) False
Answer: a
Explanation: One of the very important goals of tem tech thermal sand reclamation system, is to lower the fluidization, to lower emissions to atmosphere.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Testing Of Core Sands”.
1. With an increase in volume of air passed, what change is seen in the permeable number?
a) Increases
b) Decreases
c) No change occurs
d) No relation among the two
Answer: a
Explanation: With an increase in the volume of air passed, there is an increase in the permeable number, since the two have a direct relation.
2. With an increase in height of the specimen, what change is seen in the permeable number?
a) Increases
b) Decreases
c) No change occurs
d) No relation among the two
Answer: a
Explanation: With an increase in the height of the specimen, there is an increase in the permeable number, since the two have a direct relation.
3. With an increase in volume of air passed, what change is seen in the air pressure measurement?
a) Increases
b) Decreases
c) No change occurs
d) No relation among the two
Answer: a
Explanation: None.
4. With an increase in the height of the specimen, what change is seen in the air pressure measurement?
a) Increases
b) Decreases
c) No change occurs
d) No relation among the two
Answer: a
Explanation: None.
5. With an increase in area of the specimen, what change is seen in the permeability number?
a) Increases
b) Decreases
c) No change occurs
d) No relation among the two
Answer: b
Explanation: With an increase in the area of the specimen, there is a decrease in the permeability number, since the two have an inverse relation.
6. With an increase in air pressure measurement of the specimen, what change is seen in the permeability number?
a) Increases
b) Decreases
c) No change occurs
d) No relation between the two
Answer: b
Explanation: With an increase in the air pressure measurement of the specimen, there is a decrease in the permeability number, since the two have an inverse relation.
7. With an increase in air pressure measurement of the specimen, what change is seen in the air pressure measurement?
a) Increases
b) Decreases
c) No change occurs
d) No relation between the two
Answer: b
Explanation: None.
8. For baking standard core sand, the specimen needs to be heated at what temperature?
a) 800°F
b) 900°F
c) 1000°F
d) 1100°F
Answer: c
Explanation: The core sand has to be baked first and brought to a comparatively high temperature. For baking standard core sand, the specimen needs to be heated at about 1000°F and above it.
9. For how long is a specimen heated in a standard core above 1000°F?
a) 8-10 minutes
b) 10-12 minutes
c) 12-14 minutes
d) 14-16 minutes
Answer: b
Explanation: The core sand has to be baked first and brought to a comparatively high temperature. A standard core sand bake has to be heated above 1000°F for about 10 to 12 minutes.
10. Core hardness test includes testing of only baked cores.
a) True
b) False
Answer: b
Explanation: In the core hardness test, the hardness of both green cores as well as the baked cores are taken into consideration.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Selection of Remelting Furnace”.
1. Which of the following furnaces is the primary method for melting the cast iron metal?
a) Electric arc furnace
b) Rotary furnace
c) Cupola furnace
d) Induction furnace
Answer: c
Explanation: Cupola furnace is a furnace which is a primary method for melting the cast iron metal in the iron foundries. The cupola furnace has many unique features which are responsible for its widespread use as a melting unit. Cupola furnace is basically used for melting the scrap material or pig iron for production of several cast irons. It is also used for producing nodular and malleable cast irons.
2. In cupola melting furnace, an air-cooled vertical cylinder is used for cooling the cast iron materials.
a) True
b) False
Answer: b
Explanation: In cupola melting furnace, a typical water cooled vertical cylinder is used which is generally lined with refractory material. The charge is introduced into the furnace through an opening half way up the vertical shaft. The charge mainly includes alternate layers of the material to be melted, flux and coke fuel.
3. The combustion section of the cupola furnace is also called as oxidizing zone.
a) True
b) False
Answer: a
Explanation: The combustion section of the cupola furnace is also known as oxidizing zone. It is generally located between the upper part of the tuyeres and a theoretical level above it. The maximum height of this section can be up to 30 cm. The combustion takes place in this section by taking the free oxygen completely from the air and generating abundant heat.
4. Which of the following furnaces is mainly used for re-melting the steel metal?
a) Blast furnace
b) Electric arc furnace
c) Rotary furnace
d) Cupola furnace
Answer: b
Explanation: A furnace is a tool used for melting the ferrous and nonferrous materials for the production of castings; different furnaces are used for melting and re-melting the ferrous and nonferrous materials. A blast furnace basically used for melting the iron ore to get pig iron, cupola furnace is used to produce cast iron metal and an electric arc furnace is used for re-melting the steel metal.
5. It is always advisable to have negligible amount of sulphur in the solid fuels used in the furnace.
a) True
b) False
Answer: a
Explanation: The flue gases from the fuel makes direct contact with the metals used in the furnace, the type of fuel selected is very important. For example, many metals cannot tolerate sulphur in the fuel. Solid fuels basically create particulate matter which can interrupt the metal placed inside the furnace. To avoid this problem, gaseous or liquid fuel is used in the place of solid fuels.
6. Heat transfer in furnaces takes place only through the convection mode of heat transfer.
a) True
b) False
Answer: b
Explanation: In furnaces, heat is transferred to the metal or stock by both the radiation and convection mode of heat transfer. Radiation mainly occurs from the flame, the furnace walls, roof and hot combustion products. And convection occurs due to the movement of hot gases over the metal surface. But at the high temperatures, the radiation mode of heat transfer is dominant in the furnaces.
7. Induction melting is very sensitive to the quality of materials as compared to the cupola or electric arc melting furnaces.
a) True
b) False
Answer: a
Explanation: Induction melting produces very less fumes than that produced by the melting in an electric arc furnace or cupola melting furnaces. It is very easy to achieve melt composition in induction melting. And induction melting is very sensitive to the quality of materials used as compared to the cupola or electric arc melting furnaces.
8. Resistance furnace is a furnace that uses fuel gases like propane, acetylene or natural gas.
a) True
b) False
Answer: b
Explanation: In resistance furnace, a current is passed through the charged material which results in high resistance that further causes heating of the charged material. The heating is mainly due to the radiation from the heating material. And fuel gases like propane, acetylene or natural gas are mainly used in oxy-fuel furnaces in which oxygen is combined with these gases to generate heat.
9. Gas reverberatory furnaces are mostly used for melting the ferrous materials for the production of castings.
a) True
b) False
Answer: b
Explanation: Gas reverberatory furnaces are generally used for melting the non-ferrous metal in the casting foundries, as they gives large reservoir of liquid metal and ensures steady and reliable supply of metal to the foundry shop. So that, many large and medium sized foundry shops use them as central melting system.
10. Rotary furnaces are not suitable for large sized foundries in the production of castings.
a) True
b) False
Answer: a
Explanation: Rotary furnaces are mostly used for small and medium sized foundries which uses cupola or induction furnaces. They are highly efficient than the other type of furnaces like reverb furnaces for small production. In these furnaces, heat transfer has occurred through both the radiation and direct contact between the molten metal and the refractory material.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Cupola”.
1. Which of the following cannot be operated through cupola furnace?
a) Cast irons
b) Copper alloys
c) Bronze
d) Zinc
Answer: d
Explanation: Among the following, zinc cannot be operated through cupola furnace, whereas the irons, copper base alloys and some kinds of bronzes are operated using a cupola furnace.
2. Which instrument is attached at the top of cupola?
a) Air blast
b) Coke bed
c) Wind box
d) Spark arrester
Answer: d
Explanation: A spark arrester is positioned at the top of the cupola furnace, below which starts the stack zone, or the cupola furnace is open at the top.
3. What should the height of a cupola furnace?
a) 5m
b) 6m
c) 7m
d) 8m
Answer: b
Explanation: The height of a cupola furnace commonly about 6m, whereas the cupolettes have a height of approximately 2.5m to 4m. There is a spark arrester attached to the top of the cupola.
4. The bottom of the cupola is made up of which material?
a) Pig iron
b) Cast iron
c) White iron
d) Grey iron
Answer: b
Explanation: The bottom being the legs of the cupola are made up of cast irons, also the doors for bottom opening of cupola are made of cast iron only.
5. The volume of air passing in cupola is calculated using which device?
a) Area meter
b) Surface meter
c) Volume meter
d) Pressure meter
Answer: c
Explanation: The air flows in the cupola, passing through the combustion zone. This volume of air can be calculated using a device called as Volume meter.
6. What is the maximum capacity of a cupolette?
a) 0.25 ton
b) 0.5 ton
c) 0.75 ton
d) 1 ton
Answer: d
Explanation: Small cupolas are called as cupolettes. The capacity of a cupolette ranges from 0.5 ton to 1 ton. These cupoletes have a height of about 4.5 meters to 6 meters.
7. Cupola produces metal of uniform quality.
a) True
b) False
Answer: b
Explanation: Cupola does not have a specific time duration of the operation. Hence, there is no uniform quality in the production of metal.
8. What is the purpose of auxiliary tuyeres?
a) Raise solidification efficiency
b) Drop solidification efficiency
c) Raise melting efficiency
d) Drop melting efficiency
Answer: c
Explanation: Auxiliary tuyeres are basically used for providing to increase melting efficiency. They are fitted in one or more number of rows.
9. For how much time is the cupola fired before pouring?
a) 2 hours
b) 3 hours
c) 4 hours
d) 5 hours
Answer: b
Explanation: The process of lighting is starting the cupola and firing it for about 3 hours, a little before the metal is needed for pouring.
10. A cupola is cylindrical in shape.
a) True
b) False
Answer: a
Explanation: A cupola is basically a cylindrical metal shell which is either welded or riveted to the boiler plate. It is mainly open at the top.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Zones and Efficiency of Cupola”.
1. Where is the cupola situated above tuyeres for superheating, combustion or oxidizing zone?
a) 15cm to 30cm
b) 25cm to 40cm
c) 35cm to 50cm
d) 45cm to 60cm
Answer: a
Explanation: For superheating, combustion or oxidizing zone, the cupola is generally situated at the top, approximately 15cm to 30cm above the tuyeres.
2. What is contained inside the well of cupola?
a) Molten iron
b) Solid iron
c) Molten steel
d) Solid steel
Answer: a
Explanation: Inside the well of a cupola, there is molten iron collected. The well is positioned in between of bottom of tuyeres and tapered ram sand bottom.
3. Which of the following is not considered under metal charge?
a) Steel scrap
b) Zinc scrap
c) Cast iron scrap
d) Pig iron
Answer: b
Explanation: Among the following, metal charge is found to consist of steel scrap, cast iron scrap and pig iron, but not zinc scrap.
4. What is the amount of silica used in a slag?
a) 20% to 30%
b) 30% to 40%
c) 40% to 50%
d) 50% to 60%
Answer: c
Explanation: Slag is known to be acidic in nature and it is found to have some amount of silica content in terms of percentage composition of about 40% to 50%.
5. In the formation of carbon dioxide, what should the temperature of coke be?
a) 55°F
b) 60°F
c) 65°F
d) 70°F
Answer: b
Explanation: Among exothermic reactions, the production of carbon dioxide is one of the reactions. In this reaction, coke is used as a source of carbon. The temperature of coke should be 60°F.
6. What is the range of efficiency of cupola?
a) 20% to 40%
b) 30% to 50%
c) 40% to 60%
d) 50% to 70%
Answer: b
Explanation: The efficiency of cupola is decided by factors like heat used in preheating, heat used in coke, heat used in oxidation and heat in the air blast. The efficiency of a cupola varies from 30% to 50%.
7. The efficiency of cupola does not depend on heat in the air blast.
a) True
b) False
Answer: b
Explanation: The efficiency of cupola depends on the heat used in preheating, heat used in coke, oxidation heat and also, heat in the air blast.
8. How much heat is produced in the formation of Carbon dioxide?
a) 13269 BTU
b) 2910 BTU
c) 14452 BTU
d) 6723 BTU
Answer: c
Explanation: In the production of carbon dioxide, which is an exothermic reaction, a total of 14452 BTU of heat is released at every round of carbon. The temperature of coke for this should be 60°F.
9. In the reducing zone, during the endo-thermic reaction, what is the amount of heat absorbed?
a) 13269 BTU
b) 2910 BTU
c) 14452 BTU
d) 6723 BTU
Answer: b
Explanation: In the reducing zone or the protective zone, when carbon dioxide reacts with coke, an endo-thermic reaction takes place, in which heat of the order 2910 BTU is gets absorbed.
10. Oxidation of manganese liberates more heat than oxides of carbon.
a) True
b) False
Answer: a
Explanation: Oxidation of carbon and oxidation of manganese are both exothermic reactions, that is, these reactions liberate heat. But, oxidation of manganese or silicon liberates more heat than oxidation of carbon.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Coke Bed Charge Calculations”.
1. Given: cupola diameter = 65cm, Height of groove = 135cm, coke density = 490kg/m 3 . Find mass of bed charge.
a) 234.7 kg
b) 219.5 kg
c) 209.5 kg
d) 216.5 kg
Answer: b
Explanation: According to the question, d = 65cm = 0.65m, h = 135cm = 1.35m, w = 490 kg/m 3 . Therefore, according to the formula, W = π/4 x d 2 x h x w => W = π/4 x 0.65 2 x 1.35 x 490 => W = 219.5 kg.
2. Given: cupola diameter = 35cm, mass of bed charge = 300kg, coke density = 505kg/m 3 . Find height of groove.
a) 6.1 m
b) 5.8 m
c) 3.6 m
d) 7.2 m
Answer: a
Explanation: In this question, d = 35cm = 0.35m, w = 505 kg/m 3 , W = 300kg. Therefore, according to the formula, W = π/4 x d 2 x h x w, => h= 300 / (π/4 x 0.35 2 x 505) => h = 6.1m.
3. Given: cupola diameter = 45cm, mass of bed charge = 325kg, height of groove = 6.5m. Find coke density.
a) 314.38 kg/m 3
b) 309.54 kg/m 3
c) 193.92 kg/m 3
d) 340.57 kg/m 3
Answer: a
Explanation: Here, d = 45cm = 0.45m, W = 325kg, height of groove, h = 6.5m. Therefore, according to the formula, W = π/4 x d 2 x h x w, => w= 325 / (π/4 x 0.45 2 x 325 x 6.5) => w = 314.38 kg/m 3 .
4. What is the minimum efficiency, in general of a cupola?
a) 15%
b) 30%
c) 25%
d) 35%
Answer: b
Explanation: The minimum efficiency of a cupola is 30%, and that, the maximum efficiency is 50%. Hence, the efficiency ranges from 30 to 50% only.
5. Given: cupola diameter = 50cm, Height of groove = 155cm, coke density = 480kg/m 3 . Find mass of bed charge.
a) 146 kg
b) 148 kg
c) 156 kg
d) 164 kg
Answer: a
Explanation: Here, d = 50cm = 0.5m, h = 155cm = 1.55m, w = 480 kg/m 3 . Therefore, according to the formula, W = π/4 x d 2 x h x w, => W = π/4 x 0.5 2 x 1.55 x 480 => W = 146.08 kg.
6. Given: cupola diameter = 30cm, mass of bed charge = 270kg, coke density = 545kg/m 3 . Find height of groove.
a) 6 m
b) 5 m
c) 3 m
d) 7 m
Answer: d
Explanation: Here, d = 30cm = 0.3m, w = 545 kg/m 3 , W = 270kg. Therefore, according to the formula, W = π/4 x d 2 x h x w, => h= 270 / (π/4 x 0.3 2 x 545) => h = 7.008m.
7. Height of the groove is inversely related to the diameter of the cupola.
a) True
b) False
Answer: a
Explanation: According to the formula, W = π/4 x d 2 x h x w, the height of the groove is inversely proportional to the diameter of the cupola, that is, with an increase in the height there is a decrease in the diameter of the cupola.
8. The weight of the bed charge does not depend on which of the following factor?
a) Diameter of cupola
b) Height of groove
c) Type of metal used
d) Coke weight density
Answer: c
Explanation: The weight of the bed charge depends only on the diameter of the cupola, height of the groove and the coke weight density. It does not depend on the type of metal used.
9. Given: cupola diameter = 53cm, mass of bed charge = 465kg, height of groove = 7.2m. Find coke density.
a) 372.72 kg/m 3
b) 292.73 kg/m 3
c) 223.62 kg/m 3
d) 390.57 kg/m 3
Answer: b
Explanation: Here, d = 53cm = 0.53m, W = 465kg, height of groove, h = 7.2m. Therefore, according to the formula, W = π/4 x d 2 x h x w => w= 465 / (π/4 x 0.53 2 x 7.2) => w = 292.73 kg/m 3 .
10. The melting rate is directly proportional to the diameter of the cupola.
a) True
b) False
Answer: b
Explanation: The melting rate is inversely proportional to the square of the diameter of the cupola, that is, with an increase in the diameter there would be a decrease in the melting ratio and vice versa.
This set of Casting Problems focuses on “Air Requirements And Metallurgical Control For Cupola”.
1. What mass of oxygen is required for burning 1 kg of iron?
a) 1.12 kg
b) 2.67 kg
c) 2.35 kg
d) 1.92 kg
Answer: b
Explanation: Oxygen is the primary requirement for the process of burning to take place. For the burning of a metal such as iron, a high amount of oxygen will be needed. The mass of oxygen required for burning iron is 2.67 kg.
2. What volume of oxygen is required for burning 1 kg of carbon?
a) 7.67 m 3
b) 9.89 m 3
c) 8.98 m 3
d) 6.67 m 3
Answer: c
Explanation: None.
3. Carbon pickup does not depend on which of the following factors?
a) Size of coke
b) Height of coke bed
c) Cupola temperature
d) Cupola diameter
Answer: d
Explanation: Magnitude of carbon pickup depends on various factors such as the presence of original carbon content, size of the coke, height of the coke bed, temperature of cupola and a few more, but it does not depend on the diameter of the cupola.
4. In the iron-iron carbide diagram, what is the carbon percentage by weight at eutectic point?
a) 0.8%
b) 3%
c) 4.3%
d) 6.67%
Answer: c
Explanation: In the iron iron-carbide equilibrium diagram, the eutectic point is achieved at a temperature of 1147°C. At this point, the percentage amount of carbon is 4.3% by weight.
5. In the iron-iron carbide diagram, what is the carbon percentage by weight at eutectoid point?
a) 0.8%
b) 0.18%
c) 4.3%
d) 6.67%
Answer: a
Explanation: None.
6. At what temperature, in the Fe-Fe 3 C diagram, does the peritectic region occur?
a) 1400°C
b) 1423°C
c) 1492°C
d) 1539°C
Answer: c
Explanation: In the iron – iron carbide diagram, or the Fe-Fe 3 C equilibrium diagram, the peritectic transformation occurs at a very high temperature. The temperature point of peritectic reaction takes place is 1492°C.
7. In the iron-iron carbide diagram, what is the carbon percentage by weight in the peritectic region?
a) 0.8%
b) 0.18%
c) 4.3%
d) 6.67%
Answer: b
Explanation: None.
8. Carbon picks up can be of what order?
a) 10%
b) 15%
c) 20%
d) 25%
Answer: b
Explanation: In carbon pick up, there is an increase in the carbon content because of absorption from coke, but there is a reduction also, because of oxidation. The order of carbon pick up can be of 15%.
9. During metallurgical control, what is the amount of manganese that is lost?
a) 5%
b) 10%
c) 15%
d) 20%
Answer: c
Explanation: During metallurgical control, the amount of manganese lost is about 15%. This loss takes place because of the presence of oxygen, that is, an oxidation reaction takes place.
10. Sulphur is present in coke.
a) True
b) False
Answer: a
Explanation: Sulphur is present in coke, but in a very small composition, approximately 0.5% to 1%, which is picked up by cast iron.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Cupola Charge Calculations”.
1. What is the amount of pig iron in a cupola charge?
a) 10% – 20%
b) 10% – 30%
c) 30% – 40%
d) 20% – 45%
Answer: b
Explanation: The amount of pig iron present inside a cupola charge varies from 10% to 30%, where the exact amount depends upon the type of iron that is used.
2. How much steel scrap is present in refined irons?
a) More than 25%
b) More than 60%
c) More than 50%
d) More than 95%
Answer: c
Explanation: Refined irons are considered to be the second best source of high carbon material. The steel scrap which is present in refined irons is a little more than 50%.
3. What is the main source of high carbon steel material?
a) Pig iron
b) Cast iron
c) White iron
d) Steel scrap
Answer: a
Explanation: Steel scrap is a big source for high carbon steel materials, but is considered as the second biggest source. The main source for high carbon steel materials is pig iron.
4. According to the UK standards, in general, what is the diameter of the iron bar which is used in iron castings?
a) 18mm
b) 12mm
c) 30mm
d) 43mm
Answer: c
Explanation: None.
5. What is the tensile strength of grade 220 iron?
a) 220 Dyne/mm 2
b) 220 N/m 2
c) 220 N/mm 2
d) 220 Dyne/cm 2
Answer: c
Explanation: According to the standards of UK, the castings are made in a specified grade of iron. Hence, iron having a grade of 220, is equivalent to iron having a tensile strength of 220 N/mm 2 .
6. The sulphur content in acid-cupola operation does not depend on which of the following factors?
a) Quantity of coke
b) Slag basicity
c) Tensile strength of the steel
d) Quantity of steel
Answer: c
Explanation: In the acid-cupola reaction, the sulphur content is always increased. This increase in the sulphur content depends on quantity of coke, quantity of steel, the slag basicity, but not the tensile strength of steel.
7. What should be the lowest sulphur pick-up in the acid-cupola reaction?
a) 10%
b) 13%
c) 18%
d) 21%
Answer: a
Explanation: There is no such method in existence which will be able to tell us the amount of sulphur pick-up. But, the lowest amount of sulphur pick-up in acid-cupola reaction should not be more than 10%.
8. What should be the highest sulphur pick-up in the acid-cupola reaction?
a) 90%
b) 63%
c) 68%
d) 51%
Answer: a
Explanation: There is no such way by which one may be able to identify the amount of sulphur pick-up. But, the highest amount of sulphur pick-up in acid-cupola reaction should not be more than 80% to 90%.
9. Close temperature control is easy to maintain in the cupola.
a) True
b) False
Answer: b
Explanation: It is considered among one of the limitations of cupola, that the close temperature control is a little difficult to maintain in the operation of a cupola.
10. Cupola operation is inexpensive.
a) True
b) False
Answer: a
Explanation: Cupola operations are considered to be having a simple design and its construction is also simple. The initial cost is low when compared to other furnaces, hence the operation is considered to be an inexpensive one.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Reverberatory Furnace”.
1. Using what is the lining of the reverberatory furnace done?
a) Acid
b) Base
c) Water
d) Salt
Answer: a
Explanation: The air furnace or the reverberatory furnace, is an acid-lined reverberatory furnace. This furnace can be used for the manufacture of malleable iron and gray iron castings.
2. Which coal is used as a fuel in an air furnace?
a) Lignite
b) Bituminous
c) Anthracite
d) Peat
Answer: b
Explanation: In the air furnace or the reverberatory furnace, a pulverized bituminous lump coal is used as a fuel. If not a bituminous coal, oils are used for the same purpose.
3. What is the minimum capacity of an air furnace?
a) 5 tons
b) 7 tons
c) 9 tons
d) 11 tons
Answer: a
Explanation: Reverberatory furnace is used for the production of malleable iron and gray iron castings. The minimum capacity of an air furnace or a reverberatory furnace is around 5 tons.
4. What is the maximum capacity of an air furnace?
a) 35 tons
b) 70 tons
c) 19 tons
d) 50 tons
Answer: a
Explanation: None.
5. In the following figure of the air furnace, what does the question mark represent?
casting-questions-answers-reverberatory-furnace-q5
a) Fire bridge
b) Skimming door
c) Hearth
d) Bungs
Answer: b
Explanation: The given figure is that of an air furnace or a reverberatory furnace. The question mark in the picture is depicting a skimming door.
6. In the following figure of the air furnace, what does the question mark represent?
casting-questions-answers-reverberatory-furnace-q6
a) Bungs
b) Hearth
c) Fire bridge
d) Fire bars
Answer: c
Explanation: The question mark in the picture is depicting a fire bridge. This bridge is used for holding the molten metal. The given figure is that of an air furnace or a reverberatory furnace.
7. In the following figure of the air furnace, what does the question mark represent?
casting-questions-answers-reverberatory-furnace-q7
a) Bungs
b) Fire place
c) Fire bars
d) Hearth
Answer: d
Explanation: The question mark in the picture is depicting a hearth. The given figure is that of an air furnace or a reverberatory furnace. This hearth finds its place above the fire bridge in the apparatus.
8. In the following figure of the air furnace, what does the question mark represent?
casting-questions-answers-reverberatory-furnace-q8
a) Firing door
b) Firing place
c) Firing bridge
d) Firing bars
Answer: a
Explanation: The given figure is that of an air furnace or a reverberatory furnace. The question mark in the picture is depicting a firing door. Air and fuel are flown through this door only.
9. In the following figure of the air furnace, what does the question mark represent?
casting-questions-answers-reverberatory-furnace-q9
a) Hearth
b) Sight holes
c) Bungs
d) Fire bars
Answer: c
Explanation: The question mark in the picture is depicting a few bungs. These bungs insure the proper charging of the metal. The given figure is that of an air furnace or a reverberatory furnace.
10. Malleable iron can be produced using a reverberatory furnace.
a) True
b) False
Answer: a
Explanation: Malleable iron and high test gray iron castings are few such examples which can be produced using the reverberatory furnace or the air furnace.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Rotory Melting Furnace”.
1. Where was the rotary melting furnace originated?
a) Germany
b) Italy
c) U.S.A
d) England
Answer: a
Explanation: The concept of the rotary melting furnace was first developed in Germany, and later because of its success, was adopted by the U.S.A and other countries of Europe.
2. What is the shape of a rotary melting furnace?
a) Spherical
b) Cylindrical
c) Cuboidal
d) Hemi-spherical
Answer: b
Explanation: The rotary melting furnace is a cylindrical shell made up of steel shell. The rotary melting furnace is used for rotating or rocking purposes.
3. What is the speed of rotation of a rotary melting furnace?
a) 0.5 rpm
b) 1 rpm
c) 2 rpm
d) 3 rpm
Answer: b
Explanation: The rotary melting furnace is used for rotating and rocking purposes. This furnace makes a complete rotation about itself every minute, hence the speed of rotation of a rotary melting furnace is 1 rpm.
4. After how many heats, should the refractory lining be renewed?
a) 50-100
b) 100-200
c) 200-300
d) 300-400
Answer: c
Explanation: The refractory lining must be renewed, as the constant heating processes may cause it to damage. After approximately, 200 to 300 heats, the refractory lining should be renewed for a smooth operation.
5. In the given figure of a rotary melting furnace, what does the question mark depict?
casting-questions-answers-rotory-melting-furnace-q5
a) Burner
b) Exhaust box
c) Refractory lining
d) Molten metal
Answer: c
Explanation: In this given figure of a rotary melting furnace, the question mark is depicting the refractory lining, which is just below the steel shell. This lining has to be renewed after a certain usage.
6. In the given figure of a rotary melting furnace, what does the question mark depict?
casting-questions-answers-rotory-melting-furnace-q6
a) Steel shell
b) Exhaust box
c) Refractory lining
d) Molten metal
Answer: a
Explanation: The question mark is depicting the steel shell, which is the outer body of the furnace. The shape of this furnace is typically cylindrical.
7. In the given figure of a rotary melting furnace, what does the question mark depict?
casting-questions-answers-rotory-melting-furnace-q7
a) Steel shell
b) Exhaust box
c) Refractory lining
d) Molten metal
Answer: b
Explanation: None.
8. In the given figure of a rotary melting furnace, what does the question mark depict?
casting-questions-answers-rotory-melting-furnace-q8
a) Steel shell
b) Exhaust box
c) Refractory lining
d) Molten metal
Answer: d
Explanation: In this given figure of a rotary melting furnace, the question mark is depicting the molten metal, which is then being heated and further treated for the production of malleable cast iron.
9. In the given figure of a rotary melting furnace, what does the question mark depict?
casting-questions-answers-rotory-melting-furnace-q9
a) Exhaust box
b) Burner
c) Refractory lining
d) Molten metal
Answer: b
Explanation: Here the question mark is depicting the burner. This burner is situated at the opening of the furnace at its mouth. The burner simply burns the fuel and air mixture for heating operations.
10. The rotary furnace can have a capacity of 80 tons.
a) True
b) False
Answer: b
Explanation: A typical rotary melting furnace cannot have a capacity of 80 tons, the reason being, its minimum capacity to be 1 ton, and maximum capacity to be up to only 50 tons.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Open Hearth Surface”.
1. The impurities are burnt from which material in an open hearth furnace to produce steel?
a) Cast iron
b) Gray iron
c) Pig iron
d) Copper
Answer: c
Explanation: The materials such as high carbon content or other impurities which are present inside the pig iron are burnt in order to obtain steel.
2. Open hearth process did not allow the steel to be in contact with which gas?
a) Nitrogen
b) Helium
c) Carbon dioxide
d) Neon
Answer: a
Explanation: The contact of steel with the nitrogen gas causes the steel to become brittle. This was one of the difficulties which was later overcome by open hearth furnace.
3. What is the minimum capacity of an open hearth furnace in steel foundries?
a) 5 tons
b) 4 tons
c) 6 tons
d) 3 tons
Answer: a
Explanation: Open hearth process was primarily used only for steel making, it was later brought to use in steel foundries. The minimum capacity of open hearth furnace in steel foundries is 5 tons.
4. Which of the following is not charged in the open hearth furnace?
a) Scrap metal
b) Flux
c) Pig iron
d) White iron
Answer: d
Explanation: In an open hearth furnace, the scrap metal, flux and the pig iron are charged through the charging doors. But, white iron is not charged into the open hearth furnace.
5. What is the maximum capacity of an open hearth furnace in steel foundries?
a) 250 tons
b) 100 tons
c) 160 tons
d) 130 tons
Answer: b
Explanation: None.
6. Which material is applied to the hearth if the process is acidic?
a) Silica
b) Dolomite
c) Silicon monoxide
d) Xenon di fluoride
Answer: a
Explanation: In an open hearth furnace, there is a large basin which is called as hearth furnace. If the operation is going to be acidic, there is a lining of silica provided to the hearth.
7. Which of the following is not used as a fuel in an open hearth furnace?
a) Atomised oil
b) Natural gas
c) Peat
d) Producer gas
Answer: c
Explanation: Only gaseous fuels are used for the burning process in an open hearth furnace. Peat is a very basic form of coal and cannot be used as a fuel here.
8. Open hearth furnace is a faster operation process than oxygen furnace.
a) True
b) False
Answer: b
Explanation: The open hearth furnace had this as one of its limitations, that the process was time consuming. It took more time than basic oxygen furnace and electric arc furnace.
9. Which material is applied to the hearth if the process is basic?
a) Silica
b) Dolomite
c) Silicon monoxide
d) Xenon di fluoride
Answer: b
Explanation: None.
10. Only acid lined furnace depend on type of steel to be produced?
a) True
b) False
Answer: b
Explanation: Acid lined furnace and basic lined furnace in the hearth depend upon the type of steel to be manufactured and the type of metal charge.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Converter”.
1. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q1
a) Shell
b) Tuyeres
c) Wind box
d) Refractory lining
Answer: a
Explanation: Here, the question mark is representing the outer shell of the converter. Inside the shell, then lies the refractory lining.
2. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q2
a) Shell
b) Tuyeres
c) Wind box
d) Refractory lining
Answer: d
Explanation: None.
3. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q3
a) Shell
b) Tuyeres
c) Wind box
d) Refractory lining
Answer: b
Explanation: In the following figure, the question mark is representing the part called tuyeres. Tuyeres are situated at the left of the side blown converters, and air is blown through the charge from left to right.
4. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q4
a) Shell
b) Tuyeres
c) Wind box
d) Refractory lining
Answer: c
Explanation: In the shown figure, the question mark is representing a wind box. This box is located a little outside the side blown converter towards the left. From this box, air blasts are passed.
5. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q5
a) Tuyeres
b) Liquid metal
c) Trunnion for tilting
d) Wind box
Answer: c
Explanation: The question mark is representing a trunnion. This trunnion is used for tilting the entire apparatus, which is giving the required angle to the side blown converter.
6. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q6
a) Tuyeres
b) Liquid metal
c) Trunnion for tilting
d) Wind box
Answer: b
Explanation: In the given figure of a side blown converter, the question mark is representing liquid metal, which is being operated upon in order to make steel.
7. In the given figure of a side blown converter, what does the question mark represent?
casting-questions-answers-converter-q7
a) Shell
b) Tuyeres
c) Air blast in
d) Liquid metal
Answer: c
Explanation: None.
8. Up to what temperature can molten steels be produced in a side blown converter?
a) 2300°F
b) 980°F
c) 1350°F
d) 3300°F
Answer: d
Explanation: For the production of thin sectioned steel castings, side blown converters can be treated up to a temperature of 3300°F for molten steels.
9. Which of the following material is used in converters for making steel?
a) White iron
b) Gray iron
c) Cast iron
d) Copper
Answer: c
Explanation: Among the following, cast irons are treated in converters where the cold air blast gets blown and steels are made. Apart from cast irons, pig irons are also used in converters for making steel.
10. The converter method is not widely employed.
a) True
b) False
Answer: a
Explanation: The converter method of converting cast irons or pig irons into molten steels is not widely employed when it is looked upon through the production point of view.
This set of Basic Casting Questions and Answers focuses on “Crucibles – Advantages and Production”.
1. Among the following, production through which material is not possible in a crucible?
a) Glass
b) Metal
c) Pigment
d) Oils
Answer: d
Explanation: Crucibles are known for operating under high temperature conditions. These crucibles can be employed for the production of glass, metal and pigment, but not oils.
2. Which of the following metals or alloys cannot be used for making crucibles?
a) Nickel
b) Zirconium
c) Mercury
d) Platinum
Answer: c
Explanation: For the making of crucibles, nickel and zirconium have been employed in the recent times. Platinum had been used for this purpose in the earlier times, owing to its inertness, but mercury cannot be used for making it.
3. The crucible process is used for production of which material?
a) Pig iron
b) Cast iron
c) Tool steel
d) Gray iron
Answer: c
Explanation: The crucible process is used for the production of tool steel. Hammered iron which had rich carbon content in it was first used for producing tool steel.
4. Which of the following is not a property of a crucible?
a) Retention of thermal conductivity
b) Resistance to chemical attack
c) Retention of electrical conductivity
d) Resistance to erosion
Answer: c
Explanation: It is very necessary for the crucible to have retention of thermal conductivity, to possess resistance to chemical attacks and to erosion. But, there is no need for retention of electrical conductivity.
5. What is the maximum pressure which the isostatic presses can take for making crucibles?
a) 890 atm
b) 1270 atm
c) 1000 atm
d) 1100 atm
Answer: c
Explanation: Isostatic presses are one of the most advanced methods of making a crucible. For forming, these presses can work up to a pressure of 1000 atmospheres.
6. Which of the following does not hold valid for an isostatic press?
a) Consistent mixture
b) High pressure operation
c) High density of product
d) Wet mix used
Answer: d
Explanation: An isostatic press is considered to be one of the most advanced methods of making a crucible. The entire operation is at high pressure conditions. The mixture used is consistent, because of which the product formed has high density. But the mixture that is taken, is completely dry.
7. Which of the following cannot be counted among the advantages of a crucible?
a) Uniform heating
b) Low flexibility
c) Low installation cost
d) No contamination of charge
Answer: b
Explanation: Melting various materials through crucibles is an old process. This process has the advantage of uniform heating and no contamination of charge by the product obtained from combustion. The operation is inexpensive, and the flexibility is high.
8. Production of crucibles is inexpensive.
a) True
b) False
Answer: a
Explanation: Production of crucibles is a very inexpensive process. It does not include much capital and the installation costs are also not very high.
9. Which of the following is not a raw material for making a crucible?
a) Clay
b) Wax
c) Graphite
d) Silicon carbide
Answer: b
Explanation: For making a crucible, various types of clays are used, carbon in the form of graphite is used, since, graphite has a higher melting point and also silicon carbide is used, but not wax.
10. Crucibles do not possess refractoriness.
a) True
b) False
Answer: b
Explanation: Crucibles work at conditions of very high temperature, hence it is extremely important for the crucible to possess the ability to withstand high temperature, that is, refractoriness.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Crucible Furnaces”.
1. Which of the following furnaces is not the type of crucible furnace?
a) Pit furnace
b) Pot furnace
c) Oil fired tilting furnace
d) Stack furnace
Answer: d
Explanation: Pit furnace, pot furnace and oil fired tilting furnace are the types of crucible furnace, but stack furnace is different furnace which is a modified reverberatory furnace where its efficiency is improved by better sealing of the furnace and flue gases are mainly used for preheating the charge materials.
2. A crucible is basically a metal plate used for directional solidification in the casting process.
a) True
b) False
Answer: b
Explanation: A crucible is basically a type of container which carries molten metal to transport it to the mould cavity. It is capable of withstanding very high temperatures necessary for melting the materials like glass, metal, pigments etc. Crucibles are mainly made of graphite or silicon, which are inexpensive and economical to use in the casting process.
3. Square crucible furnaces are more efficient than the round crucible furnaces.
a) True
b) False
Answer: b
Explanation: Round crucible furnaces are generally more efficient than the square crucible furnaces because there is uniformity of thermal load in the round furnaces. These furnaces are sized according to the number of crucible used in the furnace. And the burner port is normally placed below the bottom of the crucible which basically depends on the type of metal melting.
4. Silicon carbide can be used as a liner for the crucible furnaces.
a) True
b) False
Answer: a
Explanation: The liners used in the crucible furnaces mainly are casted bricks which are mostly made by using the silicon carbide. Alumina ceramic can also be used as a liner, or sometimes high temperature refractory materials like clay or cement are used as liners which are rammed on the crucible furnaces.
5. Cracks may be generated due to the firing of liners used in the crucible furnaces.
a) True
b) False
Answer: a
Explanation: When the ramming of liners is done, they usually wrapped in plastic tightly and then after some time, they are fired gradually. It is very important to maintain the dryness of the refractory material used for liners because it may trap moisture inside it. When this liner is fired, there are chances of generating cracks in the liners.
6. Crucible furnace is a very expensive method of melting the metal for small scale production.
a) True
b) False
Answer: b
Explanation: Crucible furnace is not an expensive melting method, it is a very cheap method of melting the metal and it is mainly preferred for melting small volumes of non-ferrous materials. It is very popular in jobbing and die casting foundry shops because tapping and charging process is very easy with another type of alloy.
7. Crucible furnaces are economical for melting metal, but heat loss is the major problem in the crucible furnaces.
a) True
b) False
Answer: b
Explanation: In crucible furnaces, there is no direct collision of flame on the material. And the heat loss to the outside surrounding is restricted by the refractory walls. However, the energy efficiency of the crucible furnace is low with approximately 60% of the heat loss affected by the radiation and the temperature control is also very difficult in the crucible furnaces.
8. Radiant energy transmission can be minimized by implementing a radiant panel lining in the crucible furnaces.
a) True
b) False
Answer: a
Explanation: Radiant energy transmission is generally minimized by having a radiant panel lining in the crucible furnaces, which basically merges high-alumina radiant panel with the low thermal mass insulating material. This produces a surface area that raises radiant energy transfer to the outer surface area of the crucible.
9. Heat loss through the sides of the crucible furnace does not affect the efficiency of the furnace.
a) True
b) False
Answer: b
Explanation: Reduction in heat loss through the sides of the crucible furnace can increase the efficiency of the furnace. It is generally estimated that the technology used like pre-fired radiant panels can improve the efficiency of crucible furnace by 30 % and also improves the melting rates of material used in the furnace.
10. Crucible furnace is a type of stationary furnace used for melting and holding the molten metal.
a) True
b) False
Answer: a
Explanation: Crucible furnace is a compact furnace which is widely used for melting and holding molten metal with the help of crucible. It is a type of stationary furnace which cannot move and remains fixed to a position. It has major advantages like energy saving, higher melt yield and better quality of molten metal.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Electric Furnace”.
1. Which of the following is the maximum temperature limit of the electric arc furnaces?
a) 1200 ⁰C
b) 1400 ⁰C
c) 1600 ⁰C
d) 1800 ⁰C
Answer: d
Explanation: The electric arc furnaces can be defined as the furnaces in which charged materials are heated by the application of an electric arc. In general, these furnaces exist in all the sizes, from the smallest to the largest one having capacity of nearly about 400 tons. The electric arc furnaces can achieve temperatures up to 1800 ⁰C.
2. An air-cooled roof is used in the electric arc furnaces for making the steel metal.
a) True
b) False
Answer: b
Explanation: The electric arc furnaces are widely used for making steel metal, it basically consists of a water cooled roof which shapes like a section of a sphere. These furnaces also include graphite electrodes which normally enter into the furnace through the roof which can be refractory lined or water cooled.
3. Thread couplings are widely used for the addition of new segments of electrodes in the electric furnaces.
a) True
b) False
Answer: a
Explanation: An electric furnace mainly has three electrodes which are made round in section, and typically in segments with threaded couplings, so that new segments can be added during wearing of electrodes. Then the charged material is heated by the passing of current through the charge and the radiant energy which is developed by the arc.
4. In electric arc furnaces, the handling and maintaining of electrodes are done by manual means.
a) True
b) False
Answer: b
Explanation: In electric arc furnaces, almost all the processes are performed with automation. For example, a positioning system is used that automatically raised and lowered the electrodes in the furnaces. A regulating system is also used which basically maintains uniformity in electric current and power input during the melting of the charge materials.
5. Which of the following processes is known for pouring of molten metal by tilting the furnace?
a) Necking
b) Drawing
c) Tapping
d) Finning
Answer: c
Explanation: The electric furnace is generally built on a tilting plane so that the molten metal can be poured into another container for transportation. The process of tilting the furnace to pour the molten metal is known as tapping. Electric arc furnaces are widely used only where there is plentiful electricity.
6. Slag formation does not take place in the molten metal by using the electric arc furnaces.
a) True
b) False
Answer: b
Explanation: Slag formation does not depend on the type of furnaces; it basically depends upon the type of metal used and the surrounding gases. Slag usually floats on the surface of molten metal which consists of metal oxides. It acts as a source of oxidized impurities and can help for reducing the erosion of the refractory lining material.
7. Which of the following is the primary benefit of using the electric furnaces for melting the metals?
a) High productivity
b) Better quality of materials
c) High strength of metals
d) Less maintenance
Answer: a
Explanation: The primary benefit of using the electric furnaces is the large reduction in the specific energy required to produce the metal. The ratio, energy per weight of the metal is reduced by using the electric furnaces for melting the metals, which directly hikes the productivity. So this method has high productivity.
8. In electric arc furnaces, the metal loss is very less due to electrical heating.
a) True
b) False
Answer: a
Explanation: In electric arc furnaces, the arc produces a heating effect by the radiation and current resistance to melt the scrap materials. An essential advantage of using electrical heating is the minimum metal loss, which basically results in high productivity and better optimization of the melting system.
9. Energy losses are minimum and optimized in the electric arc furnaces during melting metals.
a) True
b) False
Answer: b
Explanation: Energy losses from the surfaces are large due to the large surface area to volume ratio of the electric furnaces that results in abundant energy losses during the operation of melting metals. These losses also arise through the refractory walls and roof due to the large surface area of the furnace.
10. The process of de-slagging is mainly carried out to remove the slag impurities from the furnace.
a) True
b) False
Answer: a
Explanation: In electric furnaces, the process of de-slagging is mainly carried out to remove the slag impurities from the furnace. During the refining process, some of the undesirable metals are oxidized and enters into the slag phase. So the furnace is tilted to pour out the slag from the furnace through the slag door.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Direct Arc Furnace”.
1. Which material is used for making the roof of an acid lined furnace?
a) Silica
b) Dolomite
c) Magnesite
d) Carbon tetrachloride
Answer: a
Explanation: A very heavy steel shell is equipped in making the roof, with the help of refractory bricks. To this, silica is added when the furnace is acid lined.
2. Which material is used for making the roof of an acid lined furnace?
a) Silica
b) Hydrogen peroxide
c) Carbon tetrachloride
d) Magnesite
Answer: d
Explanation: None.
3. What is the minimum transformer power supply needed by the direct arc furnace?
a) 600 kVA
b) 700 kVA
c) 800 kVA
d) 900 kVA
Answer: c
Explanation: For the remelting of steel, a high amount of power supply is needed by the direct arc furnace. The minimum transformer power supply needed by the furnace is 800 kVA.
4. What is the capacity of a largest direct arc furnace?
a) 110 tons
b) 115 tons
c) 125 tons
d) 140 tons
Answer: c
Explanation: The direct arc furnace is widely used in the steel foundries for the remelting unit. The largest direct arc furnace is found to have a capacity of 125 tons for remelting steel.
5. What is the maximum transformer power supply needed by the direct arc furnace?
a) 35,000 kVA
b) 40,000 kVA
c) 45,000 kVA
d) 50,000 kVA
Answer: b
Explanation: None.
6. What is typically the diameter of a direct arc furnace?
a) Up to 5m
b) Up to 6m
c) Up to 7m
d) Up to 8m
Answer: b
Explanation: The direct arc furnace is widely used in the steel foundries for remelting steels of various compositions. In general, the diameter of a direct arc furnace is found to be only up to 6 meters.
7. What would be the amount of current carried by the electrode for a direct arc furnace having capacity 50 tons?
a) 25 kilo amperes
b) 25 mega amperes
c) 25 micro amperes
d) 25 nano amperes
Answer: a
Explanation: For a direct arc furnace having a capacity of around 50 tons, the electrode would carry a current of approximately 25,000 amperes, which is 25 kA. These electrodes can be moved upwards and downwards.
8. Roofs of the furnace have a small life.
a) True
b) False
Answer: a
Explanation: The roofs of the furnace bear with many damages during the operations. A few spare roofs should always be available since the roof does not have a very long life.
9. Basic refractories are costlier than acid refractories.
a) True
b) False
Answer: a
Explanation: To be operating in a basic refractory, it is advantageous as the inferior scrap can be used for the production of good quality steel. Hence, basic refractories are costlier than acid refractories.
10. How much is the thermal efficiency of a direct arc furnace?
a) 50%
b) 60%
c) 70%
d) 80%
Answer: c
Explanation: In a direct arc furnace, the analysis of the melt can be accurately calculated and its efficiency can go as high as up to 70%.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Rocking Furnace”.
1. Which of the following material is not melted by an indirect electric arc furnace?
a) Steel
b) Copper
c) Cast iron
d) Zinc
Answer: b
Explanation: An indirect electric arc furnace cannot be used for melting zinc, but for melting steel, cast iron or copper and its alloys, this method can be used.
2. What is the maximum capacity of a rocking furnace?
a) 0.5 ton
b) 1 ton
c) 2 tons
d) 3 tons
Answer: c
Explanation: An indirect arc furnace or a rocking furnace has its capacity ranging from a few kilograms to up to 2 tons. It is generally used for smaller melts.
3. Which of the following factors keeps the liquid metal level below the pouring sprout?
a) Angle of rocking furnace
b) Velocity of rocking furnace
c) Mounting distance
d) Temperature of the metal
Answer: a
Explanation: In the operation of indirect electric arc furnace, the liquid metal level has to be kept below the pouring sprout level. To accomplish this, the angle of rocking adjusts itself in different manners and maintains the liquid level.
4. How does the heat transfer take place in the rocking furnace?
a) Radiation-conduction
b) Conduction-convection
c) Convection-radiation
d) Only radiation
Answer: a
Explanation: In a rocking furnace, the heat is first radiated from the hot refractory walls and the arc and conduction when the furnace starts rocking from the wall lining.
5. Which of the following is not valid for rocking furnace operation?
a) Causes overheating
b) Uniform composition of melt
c) Damage to the refractory lining
d) Fast melting
Answer: a
Explanation: In an indirect electric arc furnace, the rocking of furnace causes the melting to speed up, it also causes uniform composition of melt and does some damage to the refractory lining. This process does not cause overheating, instead it avoids it.
6. Which metal is charged before the actual operation in a rocking furnace begins?
a) Gray iron
b) Copper
c) Pig iron
d) Zinc
Answer: c
Explanation: Inside the furnace, before beginning the actual process, the pig iron is charged. Above this charged pig iron, the scrap is then placed.
7. The electrodes used in the rocking furnace are typically made up of which material?
a) Aluminium
b) Zinc
c) Magnesium
d) Graphite
Answer: d
Explanation: In an indirect electric arc furnace, the electrodes are made up of graphite generally. When the scrap is placed, these electrodes are brought near for the current to jump.
8. Where does the diameter of the electrode, in rocking furnace become low?
a) Near cathode
b) Near anode
c) In the middle
d) Between cathode and the mid
Answer: c
Explanation: The graphite electrode is designed in such a way that its diameter gets reduced at the middle of the electrode. This reduction in diameter causes a high amount of resistance in the electrode, hence generating large amount of heat.
9. Low cost scrap metal can be used for rocking furnace.
a) True
b) False
Answer: a
Explanation: It is one of the advantages of the indirect electric arc furnace, that it does not essentially need a costly metal, but can operate even on low cost scrap metal.
10. The rocking furnace operation is expensive.
a) True
b) False
Answer: a
Explanation: The rocking furnace operation or the indirect electric arc furnace operates without making noise. There are electrodes needed for this operation and some amount of electricity, making it costly.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Induction Furnace – High Frequency”.
1. The oil of which metal is used in high frequency induction furnace?
a) Zinc
b) Copper
c) Aluminium
d) Iron
Answer: b
Explanation: In a high frequency induction furnace, the refractory is placed inside the water cooled copper oil and is packed into its position by ramming it.
2. A high frequency induction furnace can melt metal up to what mass?
a) 10 tons
b) 11 tons
c) 12 tons
d) 13 tons
Answer: c
Explanation: A high frequency induction furnace is used for the melting of comparatively small quantities. Metals up to the mass of 12 tons can be melted using this process.
3. What causes uniformity in the melt composition?
a) Electric stirring
b) Electric shaking
c) Magnetic stirring
d) Magnetic shaking
Answer: c
Explanation: For ensuring uniformity, a magnetic stirrer is employed, in a high frequency induction furnace. This magnetic stirrer distributes the composition of the melt excellently as needed.
4. Which currents are used for inducing heat in the high frequency induction furnace?
a) Alternating primary currents
b) Direct primary currents
c) Alternating secondary currents
d) Direct secondary currents
Answer: c
Explanation: A heavy amount of alternating secondary current, by electromagnetic induction, is induced in the metal charge. This causes the metal to get heated, because of the resistance offered by the metal charge.
5. How much is the thermal efficiency of a coreless high frequency induction furnace?
a) 50%
b) 60%
c) 70%
d) 80%
Answer: b
Explanation: As compared to a core type furnace, a coreless high frequency induction furnace has a lower efficiency. The thermal efficiency of a coreless furnace can be only up to 60%.
6. What is the minimum frequency accepted for the motor, used in current production of high frequency induction furnace?
a) 430 cycles/second
b) 500 cycles/second
c) 550 cycles/second
d) 600 cycles/second
Answer: b
Explanation: In high frequency induction furnace, motors which are equipped for the production of high frequency current can have a minimum frequency of 500 cycles every second.
7. In high frequency induction furnace, time taken by charge to melt is long.
a) True
b) False
Answer: b
Explanation: The process of melting is done very quickly by conduction and radiation, and magnetic stirring makes uniform distribution of the melt composition, which reduces time. Hence time taken by the charge to melt is short.
8. What is the minimum frequency accepted for the spark gap converter, used in current production of high frequency induction furnace?
a) 10,000 cycles/second
b) 15,000 cycles/second
c) 20,000 cycles/second
d) 25,000 cycles/second
Answer: c
Explanation: Spark gap converters which are equipped for the production of high frequency current can have a minimum frequency of 20,000 cycles every second, in high frequency induction furnace.
9. What is the maximum frequency accepted for the motor, used in current production of high frequency induction furnace?
a) 5000 cycles/second
b) 10000 cycles/second
c) 7500 cycles/second
d) 12500 cycles/second
Answer: b
Explanation: Motors which are equipped for the production of high frequency current can have a maximum frequency of 10000 cycles every second, in high frequency induction furnace.
10. What is the maximum frequency accepted for the spark gap converter, used in current production of high frequency induction furnace?
a) 70,000 cycles/second
b) 75,000 cycles/second
c) 80,000 cycles/second
d) 85,000 cycles/second
Answer: c
Explanation: None.
This set of Casting test focuses on “Low Frequency”.
1. A low frequency induction furnace works on what frequency current?
a) 40 cycles/second
b) 50 cycles/second
c) 60 cycles/second
d) 70 cycles/second
Answer: c
Explanation: A low frequency induction furnace works on an alternating current supply. This alternating current possess a frequency of 60 cycles every second.
2. Which of the following can be controlled by a core type furnace for any material?
a) Pressure
b) Volume
c) Temperature
d) Rate of production
Answer: c
Explanation: Any core type furnace can be used as a holding furnace for die casting as well as for permanent mold, as these furnaces are able to control the temperature of the metal.
3. What is the thermal efficiency of a low frequency induction furnace?
a) 60%
b) 70%
c) 80%
d) 90%
Answer: c
Explanation: Any core type induction surface has a high amount of thermal efficiency. A low frequency induction furnace has a thermal efficiency of 80%.
4. What is the maximum capacity of a low frequency induction furnace in general?
a) 4 tons
b) 5 tons
c) 6 tons
d) 7 tons
Answer: b
Explanation: The maximum capacity observed normally in a low frequency induction furnace is about 5 tons, which means, the furnace is able to operating on metals and alloys up to the mass of 5 tons.
5. What is the maximum power which can be provided for a low frequency induction furnace?
a) 350 kW
b) 400 kW
c) 450 kW
d) 500 kW
Answer: d
Explanation: The maximum power which can be provided to a low frequency induction furnace is about 500000 watts, which is 50 kW. The minimum power which can be provided to it is approximately 60W.
6. What is the rate of melting of a low frequency induction furnace per kW rating?
a) 2 – 3 kg/hr
b) 2 – 3.5 kg/hr
c) 3 – 4 kg/hr
d) 3 – 4.5 kg/hr
Answer: b
Explanation: The rate of melting of a low frequency induction furnace is around 2 to 3.5 kg per hour per kilo watt rating of the furnace.
7. A low frequency induction furnace works only on a primary coil.
a) True
b) False
Answer: b
Explanation: A primary coil is employed in the working of a low frequency induction furnace. The coil is wound on laminated steel core and the secondary coil has one turn which is a channel or a loop.
8. What is the amount of loss suffered by an induction heating furnace?
a) 1%
b) 2%
c) 3%
d) 4%
Answer: a
Explanation: In the melting of steel, there are losses suffered in the operation. In an induction heating furnace, the losses suffered are only about 1%.
9. Cast iron castings cannot be produced by melting which of the following materials?
a) Pig iron
b) Steel scrap
c) Iron
d) Copper
Answer: d
Explanation: Cast iron castings can be produced by melting of pig iron, steel scrap, foundry returns such as risers or gates and iron contained alloys, but not copper.
10. Low frequency induction furnace are used for the production of malleable cast irons.
a) True
b) False
Answer: a
Explanation: Any core type furnace is primarily used for remelting of non-ferrous metals and their respective alloys. But a low frequency induction furnace may be used if malleable cast irons are to be produced.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Advantages and Disadvantages of Casting”.
1. Which of the following is the main advantage of using investment casting method?
a) Better quality
b) Low cost
c) Complex shapes
d) Reusable mould
Answer: c
Explanation: In investment casting method, wax is used as pattern material on which slurry is coated and then wax is taken out by melting it. This process of casting is widely used for producing complex shapes of castings. It has many other advantages like good dimensional accuracy and rapid production rate of the casting components.
2. Expensive moulding process is the major disadvantage of using the sand casting process.
a) True
b) False
Answer: b
Explanation: Sand casting is a process which is widely used for the production of simple casting products and it is very economical method of casting as compared to other methods of castings because the mould making process is very cheap process, so low cost is involved in the operations and it can be used for casting almost all the alloys.
3. In slush casting method, negligible metal loss is the main advantage during the casting process.
a) True
b) False
Answer: a
Explanation: The metal does not get wasted by the slush casting method. Even this method saves the molten metal by collecting it, which can be reused for the other casting process. This method makes the casting light in weight by saving the molten metal; hence this method is very economical for the production of castings.
4. Which of the following is the drawback of using the low-pressure die casting technique?
a) Material loss
b) Time consuming
c) Much labour work
d) Uneconomical for small scale production
Answer: d
Explanation: Low-pressure die casting technique is not economical for small-scale production because the machines used in the processes are very expensive, the parts like riser tube and the device used for compressing the gas makes this method very expensive. So this method is only economical when it is used for large scale productions.
5. Which of the following is not the advantage of using the permanent mould casting method?
a) Mould can be used again and again
b) Good thermal conductivity of mould
c) Very complex shapes of casting can be produced
d) Low cost process
Answer: c
Explanation: In permanent mould casting method, a metallic mould is used which can be used again and again, and it has good thermal conductivity too. But this method is not appropriate for producing very complex shapes of castings. For complex shapes casting, the investment casting method is mainly preferred which can produce high extent of complexities in the casting components.
6. Large volume casting with great segregation is the main advantage of using the squeeze casting method.
a) True
b) False
Answer: b
Explanation: In the squeeze casting method, the main purpose is to produce castings of compact size with better strength. In this method, product quality is greatly improved by solidifying the casting under heavy pressure to prevent the dissolving of gases in the solution until the solidification of the casting is completed.
7. Which of the following is the main advantage of using the centrifugal casting method?
a) Defects less casting
b) Maximum casting yield
c) Low cost
d) Fast production of castings
Answer: b
Explanation: In centrifugal casting technique, there is no need for the gates and runners to be used in the process, which can save a lot of molten metal. This makes the increase in casting yield which can reach to the maximum that means negligible metal loss. And no cores are required during the process which makes this method very economical for the large scale production of castings.
8. Which of the following is the main disadvantage of using the hot chamber die casting process?
a) High tooling cost
b) Slow production rate
c) Rough surface finish
d) Not economical for large scale production
Answer: a
Explanation: In the hot chamber dies casting process, many devices like gooseneck, plunger, toggle etc. are used which are generally very costly as compared to the devices used in the other method of castings. Due to this, high tooling cost is the main disadvantage of using this process, and casting of limited size components is another drawback of this method.
9. Which of the following is the drawback of using the sand casting process?
a) Limited alloys
b) Expensive mould
c) Uneconomical for low quantities
d) Labour intensive
Answer: d
Explanation: In sand casting process, the sand is rammed by using the rammer and then the cope and drag box are used as a moulding box to prepare the mould. In this process, much of time is spent and it requires too much labour work. So this method is normally used for small scale production for producing small size castings.
10. Which of the following is the main drawback of using the shell mould casting method?
a) Limited size of casting parts
b) High cost
c) Rough surface finish
d) Slow rate production
Answer: a
Explanation: In shell moulding process, a dump box is used in which a heated metallic pattern is inserted with the sufficient amount of coating sand, then the dump box is rotated by which the pattern has adhered to the coating sand and then the pattern is extracted out by melting. In this process, due to limited size of the dump box, only limited size of casting parts can be produced.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Casting Techniques”.
1. In die casting technique, a single metallic die is used for the production of casting components.
a) True
b) False
Answer: b
Explanation: In die casting technique, the casting process starts when the parts of the die are apart. It generally consists of two parts in which one part is called as stationary half or cover die that fixed to the die casting machine. Another part is called a moving part or ejector die that can slide for extracting out the casted product.
2. The entrapment of gas is negligible in the squeeze casting method that results in lower shrinkage cavities in the castings.
a) True
b) False
Answer: a
Explanation: The squeeze casting technique almost has negligible gas entrapment which results in less shrinkage cavities and good quality of surface with fine details on the casting parts. Aluminum and copper alloys are widely manufactured by this technique. It also produces the fine grain size to enhance the properties of the castings.
3. Investment casting technique cannot produce complex shapes of castings with deep features.
a) True
b) False
Answer: b
Explanation: In investment casting method, complex shapes castings are easily manufactured without any significant defects in the castings. In this method, the pattern is withdrawn by melting it, that’s why it can produce any complex shape casting with deep features. And the thin sections with complexities can also be produced by this method.
4. In continuous casting technique, the high extent of automation is required for the production of castings.
a) True
b) False
Answer: a
Explanation: In continuous casting technique, the operations cannot be performed manually, so higher extent of automation is required in this method to perform the operations easily. For example, cutters, metallic rollers, water sprayers etc. are the automatic equipment which are required to be used for the production of casting components.
5. Slush casting technique cannot be used for the production of high melting temperature metal castings.
a) True
b) False
Answer: a
Explanation: In slush casting technique, high melting temperature metals like brass and aluminium cannot be used for casting because high temperature of molten metal can produce defects in the casting parts and mould. So, only low melting temperature metals can be used in the slush casting system.
6. In permanent mould casting method, metallic cores are mainly used instead of sand cores.
a) True
b) False
Answer: b
Explanation: In permanent mould casting technique, metallic cores are not used generally because the metallic cores cannot be complex with undercuts in the casting process. Also, the metallic core is to be withdrawn immediately after solidification; otherwise, its extraction becomes difficult due to its shrinkage in the mould. So, sand cores are mainly preferred in this method for the casting process.
7. In Co 2 moulding technique, the amount of water is zero percent in the sand mixture used for mould.
a) True
b) False
Answer: a
Explanation: In Co 2 moulding technique, water is not mixed with the sand mixture while preparing the mould. Sodium silicate is generally added in the place of water to act as a binder. So the moisture is completely eliminated from the mould. Due to moisture-less mould, the process can provide high accuracy in the production of casting parts.
8. In vacuum die casting, the melt enters into the mould cavity with less speed than that in the die casting technique.
a) True
b) False
Answer: b
Explanation: In the vacuum die casting method, the removal of all the gases from the cavity makes the vacuum inside the mould cavity, so the force and pressure are negligible in magnitude inside the mould cavity which could be opposite to the injecting pressure of the melt. So, the melt enters into the die with very high speed which also decreases the filling time of melt.
9. Which of the following casting techniques is the best technique for casting tubes and hollow pipes?
a) Die casting
b) Slush casting
c) Centrifugal casting
d) Investment casting
Answer: c
Explanation: Centrifugal casting technique is the best technique and widely used for casting the tubes and hollow pipes which are symmetric in structure with a concentric hole. In this method, molten metal is accumulated at the inward surface of the mould by the fast rotation of mould and then the casting part is extracted from the mould after the complete solidification.
10. In the gravity die casting technique, not every metal can be casted easily.
a) True
b) False
Answer: a
Explanation: In the gravity die casting method, not every metal can be casted easily because of using a metallic mould in the casting process. In this method, the sticking problem arises when metallic mould interacts with the casting metal. Due to this, much of lubricant is used, but still, this method is not suited for every metal.
This set of Casting written test Questions & Answers focuses on “Laser and Electron Beam Melting With Rapid Prototyping”.
1. The electron beam technology is not much efficient as compared to the laser technology used for manufacturing.
a) True
b) False
Answer: b
Explanation: The electron beam technology is several times more efficient as compared to the laser technology. This technology results in less power consumption, less maintenance and low manufacturing costs. In this technology, electron beam melting process combines with vacuum, which can provide high power and excellent material properties.
2. The main purpose of electron beam melting is to build up the metal parts by layer forming.
a) True
b) False
Answer: a
Explanation: In this technology, first the part is designed by the 3D CAD software, and then the file is transferred to the processing software where the geometry is sliced into thin layers. The material is melted by electron beam to fit the geometry defined by the computer model. Then the metal parts are made by layers forming via electron beam melting process in a vacuum chamber.
3. In the electron beam technology, no any cleaning operations are required for the finishing of metal parts.
a) True
b) False
Answer: b
Explanation: In the electron beam technology, when the whole process from CAD software to metal formation is completed, then the net shape metal part can be cleaned and finished by any conventional methods. Finishing and cleaning are very necessary and important for a casting to be used in applications.
4. Which of the following devices is used for generating the electron beam in electron beam melting process?
a) Beam striker
b) Beam laser
c) Electron beam gun
d) Electron runner
Answer: c
Explanation: In electron beam melting process, the electron beam is generated by a device called electron beam gun which is generally located at the top of a vacuum chamber. The Electron Beam Gun is fixed and the beam is deflected to arrive at the desired area, which can melt the metal to form the desired shape of metal parts.
5. In electron beam melting technology, the speed of electron is almost equal to the speed of light.
a) True
b) False
Answer: b
Explanation: In electron beam melting technology, the electrons are emitted from a filament which is generally heated to very high temperature. Then the electrons are accelerated to half the speed of light in the electric field. The beam of electrons is mainly controlled by two magnetic fields in the vacuum chamber. No object can achieve the speed equal to the speed of light in the universe.
6. Which of the following is the advantage of using the electron beam melting technology?
a) Low cost
b) Good surface finish
c) Low maintenance
d) Negligible impurities
Answer: d
Explanation: Electron beam melting is a vital technology in industries. This method has many advantages like high strength properties of metal, high energy level and the most important is the negligible impurities in the metal parts, because this process uses a vacuum chamber that eliminates the all kind of impurities like oxides, nitrides etc.
7. High cost is the only main drawback of using the electron beam technology for the production of metal parts.
a) True
b) False
Answer: a
Explanation: In electron beam melting technology, the vacuum chamber is used which requires maintenance time to time and a shield is also used during the process which covers the x-rays produced by the electron beam in the process. These all expensive equipment are used which makes this technology very costly.
8. The operations of fabrication in electron beam melting are almost similar to that of laser beam melting .
a) True
b) False
Answer: a
Explanation: The operations of fabricating 3D part in the electron beam melting are very similar to that of laser beam melting . However, the major differences between the two systems are the different thickness of powder layer and different building speed which is generally high in the LBM system which gives rise to more rapid cooling in the fabrication of small size specimens.
9. It is not easy to produce hollow metal parts by the electron beam melting technology.
a) True
b) False
Answer: b
Explanation: The electron beam melting process can produce hollow metal parts with internal features, which are not easily produced by any other method. The EBM technology can provide the required mechanical strength and many properties with much less mass of the metal parts. This reduces the cost involved in the raw materials and the weight of the component.
10. In the electron beam melting process, the kinetic energy is instantly converted into thermal energy.
a) True
b) False
Answer: a
Explanation: Electron Beam Melting is a rapid manufacturing process in which when the high-speed electrons emitted from the electron beam gun, strikes the metal particles, the kinetic energy is instantly converted into the thermal energy. This makes a substantial increase in temperature above the melting point of the material.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Dye Penetrant Test”.
1. Which of the following is not a type of developer?
a) Dry powder
b) Water soluble developer
c) Oil soluble developer
d) Water suspendible developer
Answer: c
Explanation: Dye penetrant test is one of the methods of non-destructive testing of the components. The application of developer is one of the steps of inspection of dye penetrant test. Oil soluble developer is not a type of developer.
2. For how long is a penetrant allowed to soak in cracks?
a) 5 to 15 minutes
b) 10 to 30 minutes
c) 15 to 35 minutes
d) 20 to 40 minutes
Answer: b
Explanation: None.
3. Penetrants of which colour are not used?
a) Red
b) Blue
c) Green
d) Yellow
Answer: a
Explanation: The application of penetrant is one of the steps of inspection of dye penetrant test. It is an important feature that one must take care of, that the penetrant used, must not be of red colour, as defects are identified using red colour.
4. Which of the following is not an excess penetrant remover?
a) Solvent removable
b) Water washable
c) Lipophilic pre-emulsifiable
d) Lipophilic post-emulsifiable
Answer: c
Explanation: A penetrant remover material highly depends on the type of material by which the penetrant is made. Among the following, a lipophilic pre-emulsifiable is not a type of excess penetrant remover.
5. Which of the following is not a method of pre-cleaning?
a) Solvent
b) Acid blasting
c) Vapour degreasing
d) Media blasting
Answer: b
Explanation: The application of pre-cleaning is one of the steps of inspection of dye penetrant test. Solvent, alkaline, vapour degreasing and media blasting are a few types of pre-cleaning process, but not acid blasting.
6. Which of the following is not a type of penetrant application?
a) Dipping
b) Spraying
c) Brushing
d) Pouring
Answer: d
Explanation: The application of penetrant is one of the steps of inspection of the dye penetrant test. Among these, dipping, spraying or brushing are different ways by which penetrant can be applied, but not pouring.
7. Which of the following defect is not detected by dye penetrant test?
a) Non-metallic inclusions
b) Leaks
c) Cracks
d) Forging defects
Answer: a
Explanation: Dye penetrant test is one of the methods of non-destructive testing of the components. Leaks, cracks and forging defects are some defects which can be identified by using dye penetrant test. But, for detecting non-metallic inclusions, one will have to do a magnaflux test.
8. What is the amount of time taken for blotting?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes
Answer: b
Explanation: The process of inspection is one of the steps of the important of dye penetrant test. The operation of inspection begins after the article is allowed to blot for around ten minutes.
9. Only fluorescent dye is used in dye penetrant test.
a) True
b) False
Answer: b
Explanation: For the inspection using non-destructive testing, when dye penetrant test is used, there are two types of lights that are used. This type of light which has to be used depends upon the type of die used, fluorescent or non-fluorescent.
10. Only ultraviolet light is used in dye penetrant test.
a) True
b) False
Answer: b
Explanation: None.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Magnaflux Test”.
1. Which of the following defects are not detected by magnetic particle inspection?
a) Surface cracks
b) Quenching cracks
c) Thermal cracks
d) Fatigue cracks
Answer: a
Explanation: Quenching cracks, thermal cracks, grinding cracks or fatigue cracks are a few types of defects which can be detected by magnetic particle test, whereas surface cracks are defects which can be detected by simple visual inspection.
2. When an AC current is used for magnaflux test, what is its frequency?
a) 35 cycles/sec
b) 45 cycles/sec
c) 55 cycles/sec
d) 65 cycles/sec
Answer: c
Explanation: A magnaflux test is the one which is used for testing and detecting for any kind of thermal defect or any kind of quenching crack. For doing this, an alternating current can be used. The frequency of the alternating current is in the range of 50 to 60 cycles every second.
3. Which of the following materials can be tested using magnetic particle testing?
a) Brass
b) Steel
c) Bronze
d) Solder
Answer: b
Explanation: Among the following materials, only ferrous materials can be tested using a magnetic particle test, which is therefore steel. Brass and bronze are copper alloys and solder is an alloy of zinc, lead and tin.
4. Which current is helpful in detecting sub surface discontinuities?
a) High frequency AC
b) Low frequency AC
c) Full wave DC
d) Half wave DC
Answer: c
Explanation: None.
5. Which current is helpful in detecting surface breaking indication?
a) High frequency AC
b) Low frequency AC
c) Full wave DC
d) Half wave DC
Answer: d
Explanation: None.
6. Magnetic particles with fluorescent coating are seen under which light?
a) White light
b) Infrared light
c) Black light
d) Ultraviolet light
Answer: d
Explanation: In magnetic particle testing, only ferrous materials can be tested using a magnetic particle test. The casting which is undergoing magnetic inspection, if it is coated with fluorescence, then it has to be viewed in an ultraviolet light only.
7. What is the skin depth of copper at 60 Hz frequency?
a) 8 mm
b) 8.5 mm
c) 9 mm
d) 9.5 mm
Answer: b
Explanation: The distribution of an alternating electric current inside the conductor, and the flow of current through the skin of the material is called skin effect. The depth of the skin effect is skin depth. For copper, at frequency 60 Hz, the skin depth is 8.5mm.
8. What is the size range of dry particle powder?
a) 5 to 170 micrometers
b) 15 to 185 micrometers
c) 45 to 215 micrometers
d) 65 to 250 micrometers
Answer: a
Explanation: Dry particle powder is basically applied in the form of a spray or a cloud. This powder is designed to be seen in white light. The particle size of dry particle powder is 5 to 170 micrometers.
9. Half wave DC is more penetrative in magnaflux testing than full wave DC.
a) True
b) False
Answer: a
Explanation: For the detection of sub surface defects, a full wave direct current is needed. For the detection of surface breaking indication, a half wave direct current is needed. A half wave direct current is more penetrative than full wave direct current.
10. Magnetic field lines travel from north to south.
a) True
b) False
Answer: a
Explanation: Magnetic field lines are imaginary lines, which travel from north pole of the magnet to the south pole of the magnet. These lines do not travel through the specimen but around it.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Eddy Current Test”.
1. Eddy current testing does not work below what thickness of materials?
a) 0.1 mm
b) 0.2 mm
c) 0.3 mm
d) 0.4 mm
Answer: a
Explanation: It is one of the limitations of eddy current that defects having a thickness larger than required cannot be detected using eddy current method. Conventionally eddy current method cannot detect surface defects below 0.1 mm.
2. Eddy currents are not used for the measure of which of the following properties?
a) Electrical conductivity
b) Magnetic resistivity
c) Hardness
d) Grain size
Answer: b
Explanation: The inspection of structures done by eddy current method is based on the principle of electromagnetic induction. This method of detecting defects can be used for knowing the measure of electrical conductivity, grain size, hardness and magnetic permeability.
3. Eddy current inspection method cannot be detect which of the following defect?
a) Laps
b) Seams
c) Voids
d) Surface crack
Answer: d
Explanation: None.
4. Small drilled hole was a reference calibration in eddy current testing because it was produced in precise sizes.
a) True
b) False
Answer: a
Explanation: For making perfect measurements and calculations, a few artificial defects were tried and a small hole was selected as the standard. The small drilled hole was selected because, it was not just easy to produce, but also, it was produced in precise sizes.
5. What is the heat generated in eddy current operations?
a) VI
b) VIR
c) I 2 RT
d) I 2 R
Answer: d
Explanation: Eddy current method of inspection and heating techniques is used for metal heating. The heat generated by this method can be given by I 2 R, I is current and R is the resistance.
6. The signal display of eddy current system does not take place on which of the following media?
a) Oscilloscope
b) Oscillograph
c) Electric tape
d) Magnetic tape
Answer: c
Explanation: Eddy current method is used as a non-destructive technique. Most of the times, a magnetic tape is used or a oscilloscope or an oscillograph, but not an electric tape.
7. Multi frequency testing allows to overcome problems in eddy current testing.
a) True
b) False
Answer: a
Explanation: It is one of the limitations of eddy current testing that, below a certain thickness of the surface defect, the defect cannot be detected. This particular problem can be overcome by using multifrequency testing.
8. For measuring glue line thickness between aluminium sheets, what should the thickness of the sheet be?
a) 1.2 mm
b) 1.4 mm
c) 1.6 mm
d) 1.8 mm
Answer: c
Explanation: For measuring the glue line thickness of aluminium sheets using eddy current method, initially the surface has to be vitally cleaned. The thickness of the aluminium sheet for calculating glue line thickness is 1.6mm.
9. What is the conductivity of a 7075-T6 aluminium sheet with an average thickness of 1.6 mm?
a) 30 IACS
b) 31 IACS
c) 32 IACS
d) 33 IACS
Answer: b
Explanation: None.
10. With an increase in the density of the material who does it affect the power loss in eddy current?
a) Increases
b) Decreases
c) Does not change
d) Not related
Answer: b
Explanation: According to the power dissipation formula for eddy currents, power loss experienced is inversely related to the density of the material, that is, with an increase in the density of the material, there is a decrease in the power loss.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Ultrasonic Inspection”.
1. What is typically the frequency used in ultrasonic inspection?
a) 0.1 MHz to 15 MHz
b) 0.5 MHz to 13 MHz
c) 1 MHz to 17 MHz
d) 1.8 MHz to 19 MHz
Answer: a
Explanation: Ultrasonic testing is one of the most commonly used method for testing of materials. The general frequency of ultrasonic testing is in the range of 0.1 MHz to 15 MHz.
2. What is the maximum frequency used in the ultrasonic inspection?
a) 35 MHz
b) 40 MHz
c) 45 MHz
d) 50 MHz
Answer: d
Explanation: The maximum frequency that may be needed for an ultrasonic inspection is around 50 MHz. Such frequencies make it easy for the devices to detect the flaws.
3. In which of the following materials, ultrasonic testing cannot be used?
a) Plastics
b) Ceramics
c) Non-ferrous objects
d) Ferrous object
Answer: d
Explanation: Ultrasonic testing is a method for detecting flaws in the article. It can be used on various materials like plastics, ceramics and non-ferrous objects.
4. In pulse-echo method, which defect does the following amplitude-time graph represent?
casting-questions-answers-ultrasonic-inspection-q4
a) No defect
b) Small defect
c) Mediocre defect
d) Large defect
Answer: d
Explanation: Pulse echo method is one of the different types of ultrasonic non-destructive testing. The following graph represents a large defect in pulse echo method.
5. In pulse-echo method, which defect does the following amplitude-time graph represent?
casting-questions-answers-ultrasonic-inspection-q5
a) No defect
b) Small defect
c) Mediocre defect
d) Large defect
Answer: a
Explanation: Ultrasonic inspection method further gets classified under one of the type of called pulse-echo method. It is the most commonly used ultrasonic testing method. The following graph represents a no defect in pulse echo method.
6. In through-transmission method, which defect does the following amplitude-time graph represent?
casting-questions-answers-ultrasonic-inspection-q6
a) No defect
b) Small defect
c) Mediocre defect
d) Large defect
Answer: b
Explanation: The following graph, here represents small defect in through-transmission method. This is a type of through-transmission method. In this method, there are two probes, transmitter and receiver.
7. In through-transmission method, which defect does the following amplitude-time graph represent?
casting-questions-answers-ultrasonic-inspection-q7
a) No defect
b) Small defect
c) Mediocre defect
d) Large defect
Answer: d
Explanation: Ultrasonic inspection method further gets classified under one of the type of called through-transmission method. In this method, there are two probes, transmitter and receiver. The following graph represents large defect in through-transmission method.
8. In through-transmission method, which defect does the following amplitude-time graph represent?
casting-questions-answers-ultrasonic-inspection-q8
a) No defect
b) Small defect
c) Mediocre defect
d) Large defect
Answer: a
Explanation: None.
9. Ultrasonic testing is a portable process.
a) True
b) False
Answer: a
Explanation: None.
10. Ultrasonic testing is a low sensitivity testing method.
a) True
b) False
Answer: b
Explanation: Ultrasonic testing is known to have high penetrating powers, not just high penetrating powers, but they are also known to possess high sensitivity.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Radiography”.
1. On what voltage do the X-rays operate?
a) 350 kV
b) 375 kV
c) 400 kV
d) 475 kV
Answer: c
Explanation: The X-ray are waves are having very short wavelength. The object which has to be tested is exposed to the X-rays, for doing this, high voltage supply is required. The X-rays ideally operate on 400 kV.
2. X-rays are useful in detecting defects in casts up to what thickness?
a) 60 mm
b) 61 mm
c) 62 mm
d) 63 mm
Answer: c
Explanation: The X-rays are waves of high amount of energy in them and are very useful in the detection of defects in the casts. They need a high amount of voltage supply for this and are able to detect defects up to a thickness of 62mm.
3. What is the lower range of wavelength of the X-rays?
a) 0.001 x 10 -5 cm
b) 0.001 x 10 -6 cm
c) 0.001 x 10 -7 cm
d) 0.001 x 10 -8 cm
Answer: d
Explanation: X-rays are known to be waves with very low amount of wavelength. For the production of X-rays, one may usually need an X-ray tube. The shortest X-ray wavelength is calculated to be 0.001 x 10 -8 cm.
4. What is the lower range of wavelength of the X-rays?
a) 40 x 10 -7 cm
b) 40 x 10 -8 cm
c) 40 x 10 -9 cm
d) 40 x 10 -10 cm
Answer: b
Explanation: The X-rays are considered to be rays having a short wavelength. These X-rays can be produced with the help of an X-ray tube or a Cobalt-60 isotope. The longest wavelength of an X-ray is 40 x 10 -8 cm.
5. Which of the following is not a source of production for gamma rays?
a) Cobalt-60
b) Iridium-192
c) Caesium-167
d) Americium-241
Answer: d
Explanation: Among all the above given isotopes, a Cobalt – 60 isotope, Iridium-192 isotope and a Caesium-167 isotope are mainly used for producing gamma rays but not Americium-241 isotope, it is used for making alpha rays.
6. What should the diameter of a Cobalt-60 source used for producing gamma rays?
a) 2 mm
b) 3 mm
c) 4 mm
d) 5 mm
Answer: b
Explanation: For the production of gamma rays, there are some radioactive particles employed. One of them is a Cobalt-60 isotope. The diameter of the source of this isotope is calculated to be around 3 mm in length.
7. For what thickness of a material, do the X-rays give the best results?
a) 50 mm
b) 55 mm
c) 60 mm
d) 65 mm
Answer: a
Explanation: X-rays are considered to be having a larger wavelength as compared to that of gamma rays. Owing to this fact, the penetration power of the X-rays is less. Hence, for a shorter thickness, it would give good detection. The best results are obtained in X-ray detection when the thickness of the material is below 50mm.
8. Which of the following can be a wavelength of gamma ray?
a) 2 x 10 -8 cm
b) 3 x 10 -8 cm
c) 4 x 10 -8 cm
d) 5 x 10 -8 cm
Answer: b
Explanation: Gamma rays are supposedly known to have a shorter wavelength as compared to that of X-rays. The wavelength of gamma rays ranges from 0.005 x 10 -8 cm to 3 x 10 -8 cm.
9. The film produced by an X-ray is called as a radiograph.
a) True
b) False
Answer: b
Explanation: The film produced by an X-ray is called as an exograph. The film that is produced using gamma rays is called as gamma graph and the combination of the two is called as a radiograph.
10. The penetration power of X-rays depends only on the wavelength of the radiation.
a) True
b) False
Answer: b
Explanation: In radiography, there is an X-ray wave used for non-destructive testing. The penetration power of the X-ray depends not just on the wavelength of the radiation but also on the absorbing power of the material.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Metal Forming Processes”.
1. Forming is a process that changes the shape of the metal by changing its phase.
a) True
b) False
Answer: b
Explanation: Forming is basically a term that covers many manufacturing processes. In the metal forming process, the shape of the material or metal is changed by performing an operation like hammering, squeezing, bending, pulling etc. without changing its phase. The raw materials used in the forming process remained in a single solid phase.
2. Which of the following components is mainly manufactured by performing metal forging?
a) Piston
b) Engine block
c) Connecting rod
d) Crankcase
Answer: c
Explanation: Connecting rod is mainly manufactured by forging operation which is specifically known as hot forging process, while parts like piston, crankcase and engine blocks are manufactured by a casting process. In the forging process, a hammer is used which strikes on the heated metallic part to get into the desired shape.
3. The metal forging operation can only be performed by manual means.
a) True
b) False
Answer: b
Explanation: Metal forging is a forming operation which usually performs hammering process to shape the metal part. In the forging process, the metal part is heated sufficiently, and then it is hammered by using a hammer which can be performed by manual means or by automation, depending on the scale of production.
4. Which of the following metal forming processes performs squeezing out of material through a hole?
a) Forging
b) Rolling
c) Drawing
d) Extrusion
Answer: d
Explanation: Extrusion process is a type of metal forming process, in which the material is forced or squeezed out through a hole called die. This process is very similar to squeezing out the toothpaste from the tube. This process is mainly used for metals that are ductile in nature like copper, steel, aluminum and magnesium; this process is also used for polymers.
5. Metal forming is a process in which the metal is deformed plastically to get into the desired shape.
a) True
b) False
Answer: a
Explanation: In general, the metal forming is a large set of manufacturing processes in which the metal is deformed plastically to get into the shape of the die geometry. The tools like dies and punches are mostly used in the processes for the deformation of the material. For the plastic deformation, Stresses beyond the yield strength of the material is required.
6. Which of the following processes is not the type of bulk forming process in the metal forming?
a) Bending
b) Rolling
c) Forging
d) Extrusion
Answer: a
Explanation: Bulk forming is a deformation process which results in a massive shape change of the material. The ratio of surface area to volume of the material is relatively small. It includes processes like forging, extrusion and rolling. But the bending process is a part of sheet metal forming which has surface area to volume ratio relatively high.
7. Which of the following manufacturing processes is mainly considered for producing the components of very high strength?
a) Casting
b) Forging
c) Extrusion
d) Rolling
Answer: b
Explanation: Forging is a deformation process in which the material is compressed between the dies by using the impact load or hydraulic load. This process includes large forces that gradually or instantly deformed the material resulting in production of variety of high strength components like connecting rods, gears, jet engine turbine parts, aircraft parts etc.
8. In metal forging process, the gravity drop hammers are operated by a ram using steam or pressurized air.
a) True
b) False
Answer: b
Explanation: In the metal forming process, drop hammers are mainly of two types which are gravity drop hammer and power drop hammer. Gravity drop hammers are the tools which achieve their energy by the falling weight of a heavy ram. The force mainly depends on the height of the drop and the weight of the ram. And power drop hammers are in which a ram is accelerated by the steam or pressurized air.
9. Rolling is a forming process in which thickness of the metal plate is decreased by increasing its length.
a) True
b) False
Answer: a
Explanation: Rolling is a metal forming process in which the metal plate is squeezed between the two hard rollers. In the operation, the thickness is decreased and the length is increased as the volume of the metal is conserved. This method is mainly used for the production of thin metal plates which can be done by performing hot rolling or cold rolling, depending on the required mechanical properties.
10. Which of the following metal forming processes is best suitable for making the wires?
a) Forging
b) Extrusion
c) Drawing
d) Rolling
Answer: c
Explanation: Drawing is a metal forming process which is widely used for making the wires from round bars of metal. This process is similar to extrusion process, except that instead of pressure on the metal mass, in drawing, the wire is pulled from one side of the metallic round bar which results into the formation of thin wires. This process is only suitable for ductile materials.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Classification of Metal Forming Processes”.
1. Which of the following components are manufactured by the sheet metal forming process?
a) Engine blocks
b) Connecting rods
c) Electric wires
d) Car bodies
Answer: d
Explanation: Sheet metal forming is a process which uses ductile materials like aluminium or low carbon steel to form lightweight products with versatile features. Car bodies are mainly manufactured by sheet metal forming by performing operations like shearing, slitting, cutting, or sawing of thin metal plates. This method is also used for making parts like beverage cans, metal desks, appliances etc.
2. Which of the following processes is not the type of metal forming process?
a) Extrusion
b) Injection moulding
c) Forging
d) Drawing
Answer: b
Explanation: Extrusion, forging and drawing process are the main general types of metal forming process, while the injection moulding is other process which is basically a part of casting process which includes the formation of parts by injecting the melt into a cavity by the help of a plunger. This method is not the part of metal forming because the phase change of metal occurs during the process.
3. Cold forming is a process which works when the temperature of metal is above its re-crystallization temperature.
a) True
b) False
Answer: b
Explanation: On the basis of temperature, metal forming mainly has two types which are cold forming and hot forming. Hot forming is defined as the mechanical working of metal at higher temperature above its re-crystallization temperature. And cold forming is a process which works at temperature below the re-crystallization temperature of metal.
4. Which of the following manufacturing processes operates under the influence of external forces?
a) Metal forming
b) Powder metallurgy
c) Casting
d) Welding
Answer: a
Explanation: In the metal forming process, the raw material is converted into a desired shape by the application of external force. The metal work piece is subjected to plastic deformation which results in changing of shape and size of the work piece or specimen under the influence of external forces or stresses.
5. Which of the following stresses is takes place during performing the wire drawing operation?
a) Tensile stress
b) Bending stress
c) Indirect compressive stress
d) Shear stress
Answer: c
Explanation: Wire drawing is a forming process in which a round metallic bar is pulled by a machine by generating indirect compressive stresses in the bar. This causes thinning of bar and results in the formation of thin wires that further used as a cable or for electricity purposes. Wire drawing is most suitable for ductile materials.
6. Wire drawing process is almost similar to deep drawing process.
a) True
b) False
Answer: b
Explanation: Wire drawing process is quite different from deep drawing process. In wire drawing, metallic bar is pulled to form wires, while in deep drawing process; a flat metal sheet is converted into a concave shape part. This operation is basically performed by stretching the metal for which a blank-holder is used to clamp the blank on the die, and then a punch is used which pushes the metal sheet.
7. Closed die forging process is also called as impression die forging.
a) True
b) False
Answer: a
Explanation: Closed die forging is also called as impression die forging. In this method, die consists of some internal impression that imparted to the work piece or specimen used for the forming. During full closing of die, impression is fully filled with the deformed billet and then further taken out of the impression to form flash.
8. For the minimum metal loss, the flash-less forging is better than the impression die forging.
a) True
b) False
Answer: a
Explanation: In flash-less forging, the material is fully restricted within the die, so no any flash is produced during the process, which completely optimizes the material used. But in impression die forging, flash can be produced which is considered as scrap material that is removed from the formed part. So, the flash-less forging is better than the impression die forging for the minimum metal loss.
9. Formability is a mechanical property which defined as the ability of solid metal to get converted into the liquid phase.
a) True
b) False
Answer: b
Explanation: In the metal forming processes, formability is an essential mechanical property which is defined as the ability of sheet metal or any material to undergo shape change without occurring of any failures like tearing or necking in the metal part. This property is vital and must be present in the material to be used for the metal forming process.
10. Shearing is a cutting operation in which material or work piece is subjected to shear stresses.
a) True
b) False
Answer: a
Explanation: In the shearing process, a proper sized piece of sheet metal is removed from a larger sheet by cutting operation in which the work piece is subjected to shear stresses. Shearing normally starts with small cracks which further grow and failure takes place. This method generates rough surfaces due to rough cutting.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Behaviour in Metal Forming”.
1. Which of the following can help in determining the behaviour of the material in metal forming?
a) Size of material
b) Shape of material
c) Stress-strain curve
d) Color of material
Answer: c
Explanation: The behaviour of materials during metal forming can be determined by the stress-strain curve. The stress-strain curve for most of the materials is divided into an elastic region and a plastic region. In metal forming, the plastic region is the main consideration because the material is plastically deformed during the forming process.
2. A general stress-strain curve of any material represents the plasticity below the yield point.
a) True
b) False
Answer: b
Explanation: In the stress-strain curve of any material exhibits plasticity or strain hardening above the yield point. And below the yield point, the area represents the elasticity of the material. Yield point is only present in the stress-strain curve of ductile materials. In brittle materials, yielding does not take place during the application of load; it directly shows the fracture failure.
3. Flow stress is defined as the instantaneous value of stress required to continue the deformation of metal.
a) True
b) False
Answer: a
Explanation: Flow stress is generally defined as the instantaneous value of stress which is required to continue the deformation of metal, which means to keep the material flowing. It is also defined as the yield strength of the material as a function of strain, or the strength that determines the forces required to complete a specific forming operation.
4. The mechanical strength of the metal decreases due to the strain hardening of the metal.
a) True
b) False
Answer: b
Explanation: At room temperature, the stress-strain curve of most of the materials indicates the deformation of metal. When deformation occurs, the mechanical strength increases due to the strain hardening. The stress needed for continuing the deformation should be increased to match this increase in strength.
5. By keeping the metal at higher temperature, its ductility increases with the decrease in its strength.
a) True
b) False
Answer: a
Explanation: By keeping the metal at higher temperature, both the strength and strain hardening of the metal decreases. And the ductility is increased at the higher temperature. These changes are very important and essential so that any deforming operation can be easily accomplished by lower forces at high temperatures.
6. Better accuracy and surface finish is achieved by performing hot forming process instead of the cold forming process.
a) True
b) False
Answer: b
Explanation: Cold forming is a metal forming process that is performed at room temperature or slightly above. It has many advantages like better surface finish, high accuracy, high strength etc. And by performing hot forming operation, the surface finish of the part is very poor, which requires heavy machining to finish the metal part.
7. In cold forming process, the fuel cost is very less as compared to that in the hot forming process.
a) True
b) False
Answer: a
Explanation: In cold forming process, not much heating is required, which generally saves the fuel costs and permits higher production rate of the metal parts. And in hot forming process, the metal is subjected to very high temperature that requires lot of fuel to generate enough heat, which increases the overall cost of the hot forming operation.
8. The extent of plastic deformation of material is mainly dependent on its grain structure.
a) True
b) False
Answer: a
Explanation: In the metal forming processes, the extent of plastic deformation of the material is mainly dependent on its grain structure. The deformation of metal also depends on the nature of bonding, surrounding temperature and defects like dislocation which might be present in the material during the metal forming process.
9. In general, the coefficient of friction is very low in the metal forming processes.
a) True
b) False
Answer: b
Explanation: In metal forming processes, the coefficient of friction is very high. Due to this, it leads to a condition which is called as sticking friction. In this case, the surface shear stress increases the shear yield strength of the metal and the surfaces adhere to each other. In the forming operation, the metal beneath the surface experiences shear deformation.
10. In metal forming processes, the temperature rise also depends on the rate of deformation of the material.
a) True
b) False
Answer: a
Explanation: In general, the temperature rise of any material is determined by using the stress-strain plot. The temperature rise also depends on the rate of deformation of the material. For slow deformation, the temperature rise of the metal is small as the heat induced gets dissipated through the surrounding air during the process.
This set of Forming Interview Questions and Answers focuses on “Hot Rolling”.
1. Which of the following is not a type of rolling mill?
a) Two-high rolling mill
b) Cluster rolling mill
c) Separation rolling mill
d) Tandem rolling mill
Answer: c
Explanation: Among two-high rolling mill, cluster rolling mill, separation rolling mill and tandem rolling mill. Separation rolling mill is not a type of rolling mills.
2. In two high rolling mill, what is the direction of rolling of the two rollers?
a) Clockwise-anticlockwise
b) Clockwise-clockwise
c) Anticlockwise-Anticlockwise
d) Stationery-clockwise
Answer: a
Explanation: In two high rolling mill, the direction of both the rollers is opposite to one another. Hence, one clockwise while other anti-clockwise.
3. In two high rolling mill, if the direction of the rollers is reversed, what is it called?
a) Two high backward mill
b) Two high beneath mill
c) Two high reversing mill
d) Two high anti mill
Answer: c
Explanation: In two high rolling mill, if the direction of the roller is reversed, then that system is called as, two high reversing mill.
4. In three high rolling mill, what is the direction of rolling of the three rollers?
a) Clockwise-clockwise- clockwise
b) Clockwise-anticlockwise- anticlockwise
c) Clockwise-anticlockwise- clockwise
d) Anticlockwise-anticlockwise-anti clockwise
Answer: c
Explanation: In three high rolling mill, the direction of the rollers in the top and bottom are the same, and the direction of the roller in the middle is opposite to the two.
5. How many rollers are used in four high rolling mill?
a) 3
b) 4
c) 8
d) 14
Answer: b
Explanation: In four high rolling mill, there are four rolls employed for roliing. The direction of two rollers is the same and the remaining two rollers roll in opposite directions.
6. The desired shape and cross section of the billet is achieved in one pass.
a) True
b) False
Answer: b
Explanation: The shape and the cross section shape of the billet, which is desired is not obtained in one single pass. One may have to use multiple pass to achieve desired cross section shape.
7. Which of the following property does not improve in the hot rolling process, of a cast?
a) Ductility
b) Shock resistance
c) Toughness
d) Boiling point
Answer: d
Explanation: When a rolled stack is made, there is an improvement seen in the physical properties of the material, it does not affect the boiling point of the material.
8. Which of the following articles cannot be made from rolling?
a) Rails
b) Helmets
c) Bars
d) Plates
Answer: b
Explanation: Rolling is very useful for making articles like bars, plates and rails, but it cannot be used for making helmets. For making helmets, different methods of casting are used.
9. Before beginning the process, the ingots are heated up to what temperature?
a) 1000°C
b) 1200°C
c) 1400°C
d) 1600°C
Answer: b
Explanation: The material ingot is known for sustaining high temperature and heat conditions. Before the process begins, the ingot is fired using gas and brought up to a temperature of 1200°C.
10. In hot rolling process, velocity of material at exit is lowest.
a) True
b) False
Answer: b
Explanation: In hot rolling process, the velocity of material at entry is lower than the velocity at exit.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Flat Rolling”.
1. During rolling process, the thickness of workpiece squeezed is called what?
a) Shaft
b) Bore
c) Draft
d) Core
Answer: c
Explanation: During rolling process, the workpiece gets squeezed, causing the thickness of the workpiece to reduce. This reduced thickness is called a draft.
2. With an increase in starting thickness, how would it affect the reduction?
a) Increases
b) Decreases
c) Won’t change
d) Not related
Answer: b
Explanation: When the starting thickness of the workpiece gets increased, the reduction of correspondingly gets decreased.
3. How is the draft calculated?
a) Difference between starting and final thickness
b) Sum of starting and final thickness
c) Product of starting and final thickness
d) Ratio of starting and final thickness
Answer: a
Explanation: Draft is calculated as, the difference between the starting thickness of the workpiece and the final thickness of the workpiece.
4. Which of the following has the most magnitude?
a) Slip velocity
b) Surface velocity
c) Entering velocity
d) Exiting velocity
Answer: d
Explanation: Exiting velocity, among the given four velocities, that is slip velocity, surface velocity, entering velocity and exiting velocity, the exiting velocity is considered to be having most magnitude.
5. Which of the following has least magnitude?
a) Slip velocity
b) Surface velocity
c) Entering velocity
d) Exiting velocity
Answer: c
Explanation: None.
6. When a metal is entering, how are the width and the length of the workpiece related to each other?
a) Direct relation
b) Inverse relation
c) Exponential relation
d) No relation
Answer: b
Explanation: When the metal is entering, the width of the metal is inversely proportional to the length of the workpiece, that is, with an increase in the width of the metal, there would be a decrease in the length of the workpiece and vice versa.
7. Roll velocity is lesser than exiting velocity.
a) True
b) False
Answer: a
Explanation: Exiting velocity is has the most magnitude when compared to the other velocities, and is higher than the roll velocity.
8. When a material is being rolled, the perpendicular force on the arc is called what?
a) Thickness force
b) Roll force
c) Angle force
d) Die force
Answer: b
Explanation: There is a force perpendicular to the arc which is in contact when the rolls are pressurizing the material. This force is called a roll force.
9. How would the draft be affected, if the radius of the roller is decreased?
a) Increase
b) Decrease
c) Won’t change
d) Not related
Answer: b
Explanation: Radius of the roller is directly related with the draft. Hence, with a decrease in the roller radius, there is a decrease in the draft value and vice versa.
10. There is no slipping between roller and workpiece.
a) True
b) False
Answer: a
Explanation: There is a certain amount of slipping that is observed, between the roller and the workpiece. The magnitude of slipping is measured by the term called Forward slip.
This set of Forming online test focuses on “Principle Of Roll Pass”.
1. How is the strength of the material, which is to be rolled, reduced?
a) Rolling at low temperatures
b) Rolling at high temperatures
c) Treating with ozone
d) Treating with carbon
Answer: b
Explanation: When the material to be squeezed is rolled at high temperatures, the strength of the material is found to decrease.
2. When the material is entering the roller, what is the tension at the entry zone called?
a) Front tension
b) Above tension
c) Back tension
d) Beneath tension
Answer: c
Explanation: When the material is entering the roller, the tension experienced at the entering zone is called as back tension.
3. When the material is exiting the roller, what is the tension at the exit zone called?
a) Front tension
b) Above tension
c) Back tension
d) Beneath tension
Answer: a
Explanation: None.
4. What increases when the take up reel rotates at a high speed?
a) Front tension
b) Above tension
c) Back tension
d) Beneath tension
Answer: a
Explanation: Among front tension, above tension, back tension and beneath tension, front tension is found to increase when the take up wheel rotates at a high speed.
5. Which of the following is not a thread rolling machine?
a) Cylindrical die machine
b) Reciprocating flat die machine
c) Rotary planetary machines
d) Quick return motion machine
Answer: d
Explanation: Among the following, a quick return motion machine is not any type of thread rolling machine, while the remaining are thread rolling machines.
6. Which of the following is not a type of a pass?
a) Roll down pass
b) Starter pass
c) Leader pass
d) Finishing pass
Answer: b
Explanation: Among the following types of passes, starter pass is not any type of pass, while the remaining three are different types of passes.
7. Thread rolling has a lot of chip formation.
a) True
b) False
Answer: b
Explanation: Thread rolling has it as one of its advantages, that there is no chip formation taking place, avoiding a lot of materials to be wasted.
8. How many dies are used in reciprocating flat die machines?
a) 2
b) 3
c) 4
d) 5
Answer: a
Explanation: In a reciprocating flat die machine, there are only two dies which are used, one of them is stationery, while the other is reciprocating.
9. On what does the reciprocating die stroke depend on?
a) Temperature
b) Pressure
c) Thread diameter
d) Die radius
Answer: c
Explanation: In a reciprocating flat die machine, the reciprocating die stroke depends upon the thread diameter, and there are 2 dies used in this apparatus, out of which, one is stationery.
10. What is the general production rate in thread rolling?
a) 1000 pieces per minute
b) 2000 pieces per minute
c) 3000 pieces per minute
d) 4000 pieces per minute
Answer: b
Explanation: Thread rolling is considered to be one of the fastest methods of manufacturing threads. The rate of production is as high as 2000 pieces per minute.
This set of Forming Questions and Answers for Freshers focuses on “Defects in Rolled Parts”.
1. Which of the following cannot be regarded as a defect in rolled parts?
a) Inhomogeneous deformation
b) Surface defect
c) External cracking defect
d) Internal structure defect
Answer: c
Explanation: Among the following defects in rolled parts, external cracking defect cannot be termed as a defect in rolled parts.
2. Which of the following cannot be regarded as an internal structure defect?
a) Edge crack
b) Zipper cracks
c) Alligatoring
d) Quevering
Answer: d
Explanation: Among the following internal structure defects, quevering is not any kind of a defect which can be regarded as an internal structure defect.
3. Which of the following defect occurs because of the bending of rolls?
a) Zipper cracks
b) Folds
c) Laminations
d) Alligatoring
Answer: a
Explanation: Wavy edges and zipper cracks can occur as defects in the material, if the rolls are bended, but not, folds or laminations or alligatoring. Their causes of occurrence are different.
4. Which defect takes place if the reduction per mass is very low?
a) Zipper cracks
b) Folds
c) Laminations
d) Alligatoring
Answer: b
Explanation: Folds are found to occur during the plate rolling if the reduction per mass is very low. And zipper cracks occur when the given rolls get bended.
5. Incomplete welding may cause which of the following defect?
a) Folds
b) Laminations
c) Wavy edges
d) Zipper cracks
Answer: b
Explanation: Because of incomplete welding in the blow holes and the pipes, small laminations occur, causing the strength of the material to reduce.
6. Which defect is rupturing of sheet and following the roller path?
a) Folds
b) Laminations
c) Alligatoring
d) Wavy edges
Answer: c
Explanation: When the material is compressed against the rolls, the sheet may get ruptured, without laterally, the width getting converted to length. Such a defect is called as alligatoring.
7. In hot rolling, the temperature of working is uniform.
a) True
b) False
Answer: b
Explanation: In hot working processes, the temperature at which the work takes place is not uniform. There is change of temperature that takes place in between the process when it is going on.
8. In which of the following defects is a crown formed?
a) Wavy edges
b) Alligatoring
c) Folds
d) Laminations
Answer: a
Explanation: A crown shape gets formed by the material, due to rolling loads. Crowns get formed in wavy edge defect.
9. The following figure represents which defect?
forming-questions-answers-freshers-q9
a) Alligatoring
b) Zipper cracks
c) Folds
d) Laminations
Answer: b
Explanation: The following figure depicts in itself the defect, this crack is called as zipper cracks. A defect like zipper crack may occur when the rolls which are employed for it, get bended.
10. While rolling, material near the edges experience compression.
a) True
b) False
Answer: b
Explanation: While rolling, due to the metal being continuous, the material present near the edges, experiences tensile force, that is a pulling force, and not pushing or a compression force.
This set of Forming Questions and Answers for Entrance exams focuses on “Open and Closed Die Forging”.
1. What is the open hearth called in which the metal is heated to its plastic state?
a) Roger’s forging
b) Black’s forging
c) Smith’s forging
d) Gold’s forging
Answer: c
Explanation: The open hearth in which the metal is brought to its plastic state by increasing its temperature is called as Smith’s forging.
2. Which of the following process is done above the recrystallization temperature?
a) Hot forging
b) Cold forging
c) Impact forging
d) Gradual pressure forging
Answer: a
Explanation: Among hot forging, cold forging, impact forging and gradual pressure forging, hot forging is done above the recrystallization temperature, but below the melting point.
3. Which of the following method is used for manufacturing screws?
a) Hot forging
b) Cold forging
c) Impact forging
d) Gradual pressure forging
Answer: b
Explanation: For the manufacturing of products like screws, pins or nails, the process of hot forging or impact forging is not recommended. But, for this, cold forging is highly used.
4. Which of the following method is used for manufacturing shafts?
a) Open die forging
b) Closed die forging
c) Impact forging
d) Flashless forging
Answer: a
Explanation: While the manufacture of products like shafts, discs or rings, the method of closed die forging or impact forging or flashless forging is not advised, but open die forging is used.
5. In which of the following process, does the die have a concave surface?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer: b
Explanation: Among the following processes, that are fullering, edging, cogging and cavitising, edging is a process in which, the die has a concave shape.
6. Cold forging causes a reduction in strength of material.
a) True
b) False
Answer: b
Explanation: Strain hardening is caused by cold forging, whereas hot forging results in a reduction of the strength of the material.
7. In which of the following process, does the die have a convex surface?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer: b
Explanation: None.
8. Which of the following operation is called incremental forging?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer: c
Explanation: Among the following process, cogging is the operation in which the surface is contoured a little. This process is also called as incremental forging.
9. Which of the following process is used for making slabs?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer: c
Explanation: Among the following processes, cogging is a process which is used for the manufacturing of processes like blooms and slabs from the cast ingots.
10. The cost of cold dies is high.
a) True
b) False
Answer: a
Explanation: It is observed that the initial cost of dies in case of cold dies forging is comparatively high. Not just that, but this process is also a little complex one.
This set of Forming Question Bank focuses on “Drop And Press Forging”.
1. In which of the following processes most noise is produced?
a) Press forging
b) Drop forging
c) Open die forging
d) Closed die forging
Answer: b
Explanation: Among the following processes, that is press forging, drop forging, open die forging and closed die forging, drop forging is a process where more amount of noise occurs.
2. In which of the following processes most vibration is produced?
a) Press forging
b) Drop forging
c) Open die forging
d) Closed die forging
Answer: b
Explanation: None.
3. Which of the following hammers is also called a gravity hammer?
a) Board hammer
b) Air-lift hammer
c) Power drop hammer
d) Nail hammer
Answer: a
Explanation: Among the following type of drop hammers, that is, board hammer, air-lift hammer, power drop hammer and nail hammer, board hammer is also called a gravity hammer.
4. Which of the following hammers is also called a steam hammer?
a) Board hammer
b) Air-lift hammer
c) Power drop hammer
d) Nail hammer
Answer: c
Explanation: None.
5. Drop forging is the most accurate form of forging.
a) True
b) False
Answer: b
Explanation: It has been observed that press forging is a process which works more smoothly and is lot more accurate than drop forging.
6. In drop forging, the anvil is lighter than the hammer.
a) True
b) False
Answer: b
Explanation: In drop forging, the anvil is a lot heavier than the hammer. To absorb the blow caused by the hammer, the anvil is made 20 times heavier than the hammer.
7. In which of the following processes, life of dies is less?
a) Hot forging
b) Cold forging
c) Drop forging
d) Open die forging
Answer: c
Explanation: In drop forging method, the forging is produced when there is a drop of the hammer on the metal. This causes the life of the hammer and the dies to be less.
8. How much do the presses in press forging weigh?
a) 200-300 tonnes
b) 300-400 tonnes
c) 400-500 tonnes
d) 500-600 tonnes
Answer: d
Explanation: The presses used for such forging processes are manufactured for very heavy use. The presses which are generally used in press forging are of the capacity of 500 to 600 tonnes.
9. Which of the following method is used for making wheel discs?
a) Drop forging
b) Press forging
c) Open die forging
d) Closed die forging
Answer: b
Explanation: Among the following methods, press forging is one method that is the most widely and commonly used method for the manufacture of hollow bodies, wheel discs and panels.
10. Which of the following method is used for making crankshafts?
a) Drop forging
b) Press forging
c) Open die forging
d) Closed die forging
Answer: a
Explanation: For the making of products like car axles, crankshafts, leaf springs and jet turbines, the method of drop forging is used.
This set of Forming Interview Questions and Answers for freshers focuses on “Extrusion and Wire Drawing”.
1. Extrusion process is not suitable for which of the following?
a) Steel alloys
b) Non-ferrous alloys
c) Stainless steel
d) Iron
Answer: d
Explanation: Extrusion process is not suitable for any of the iron alloys, neither is it suitable for iron metal. For extruding stainless steel or other non-ferrous alloys or steel alloys, extrusion process can be used.
2. Which of the following is not made using extrusion?
a) Window frames
b) Doors
c) Helmets
d) Rods
Answer: c
Explanation: Among the following, helmets are not manufactured using extrusion, whereas all other products can be manufactured using extrusion.
3. What is the shape of the billet used in extrusion process?
a) Cubical
b) Spherical
c) Cylindrical
d) Pyramidal
Answer: c
Explanation: The shape of the billet in an extrusion process is designed to be cylindrical only. A cubical or spherical or a pyramidal billet cannot be designed for a good output.
4. Which of the following is also called as forward hot extrusion?
a) Direct extrusion
b) Indirect extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer: a
Explanation: Direct extrusion is also called as forward hot extrusion. This method is most widely used and maximum production is done by this method in extrusion.
5. Backward extrusion is another name for which of the following?
a) Direct extrusion
b) Indirect extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer: b
Explanation: Direct extrusion is also called as backward extrusion. In this method, the metal is extruded back into the plunger.
6. In which of the following operations is a dummy block used?
a) Indirect extrusion
b) Direct extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer: b
Explanation: In direct extrusion or forward extrusion, a dummy block is used during the functioning of the extrusion process.
7. Indirect extrusion needs a large amount of force for functioning.
a) True
b) False
Answer: b
Explanation: Indirect extrusion or backward extrusion does not require a large amount of force for operation, as the billet is stationery.
8. Up to what size can wires can be drawn by wire drawing process?
a) 0.01mm
b) 0.02mm
c) 0.03mm
d) 0.04mm
Answer: c
Explanation: It may be counted among one of the limitations of drawing process, that very thin wires can only be drawn from it. In wire drawing process, wires can be drawn up to the size of 0.03mm.
9. Which of the following metal is used in the wire drawing process in die making?
a) Copper
b) Iron
c) Tungsten
d) Magnesium
Answer: c
Explanation: For making dies in the wire extrusion process, copper or iron or magnesium cannot be used, but the compound tungsten carbide is used.
10. A solid ram is used in direct extrusion.
a) True
b) False
Answer: a
Explanation: A solid ram is used in direct extrusion or forward extrusion, whereas a hollow ram is used in indirect extrusion.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Blanking and Piercing”.
1. Blanking is an operation in which the desired part is the sheet left out after making a punch hole in it.
a) True
b) False
Answer: b
Explanation: Blanking is a kind of shearing operation which is generally carried out along a closed contour. In this operation, the required part is the material inside the sheared contour which is called as blank. For example, circular blanks are taken out from the metal sheet for subsequent deep drawing of cups.
2. Die punch clearance is generally very critical for blanking as well as for punching operation.
a) True
b) False
Answer: a
Explanation: Punching is basically a kind of shearing operation in which the required part is the sheet left out after making a punch hole in the metal sheet. This method is also known as contour shearing. Die punch clearance is generally very critical for blanking as well as for punching operation, as it maintains the kind of finish obtained on the final part.
3. In blanking operation, the clearance is provided on the die for obtaining the blank from metal sheet.
a) True
b) False
Answer: b
Explanation: In the blanking or punching operation, the punch diameter should be smaller than the die hole. The clearance between the die and the punch basically depends on the type of process used. For example, for blanking operation, the clearance is provided on the punch for obtaining the blank from metal sheet.
4. Fine blanking is a finishing operation in which shearing is done with very small clearances.
a) True
b) False
Answer: a
Explanation: Fine blanking is normally a single step finishing operation in which shearing is done with very small clearances nearly about one percent. Close tolerances are provided in order to achieve dimensional accuracy in the operation. In this process, smooth edges are produced by the application of clamping force on the blank which also avoids the distortion of sheet during operation.
5. Which of the following parts is used for holding the metal sheet during blanking operation?
a) Spherical steel ball
b) Roller
c) Pressure pad
d) Magnet
Answer: c
Explanation: A pressure pad or a hold down ring with v-shaped projection is used for holding the metal sheet tightly during the blanking operation. This pressure pad is mainly used at the bottom side of the metal sheet. A triple action press, punch and pressure pad are the main equipment used for the blanking operation.
6. Which of the following represents the approximate percentage of metal loss during the blanking operation?
a) 2%
b) 5%
c) 10%
d) 30%
Answer: d
Explanation: In the blanking operation, the material loss is approximately 30 % of the metal sheet used in the cutting off operations. To reduce the waste or metal loss, the shapes to be cut are arranged on the metal sheet properly, this process of reducing metal loss is called as nesting. Nowadays, CAD software is used for this purpose.
7. A power press machine is used in the blanking operation through which a punch is attached.
a) True
b) False
Answer: a
Explanation: In the blanking operation, the main function of the punch is to strike the metal sheet, which is attached to the hub of the power press machine. The striking power is mainly dependent on the capacity of machine used. The punch is attached through the machine by means of tapering at its top locked by a nut.
8. Forming dies are generally used in the blanking and piercing operations.
a) True
b) False
Answer: b
Explanation: Forming dies are used for changing the shape of the blank without removing any material. For example, drawing dies and bending dies are forming dies. For blanking and piercing operations, cutting dies are used to cut the metal from the metal sheet. They basically use cutting and shearing action for cutting the material.
9. Progressive die is a die which can perform two or more operations in a single stroke.
a) True
b) False
Answer: a
Explanation: Progressive die is also called a follow on die. It can perform two or more operations in a single stroke of a ram. Normally, the first operation is punching which is then followed by the blanking operation. The metal sheet is transferred to the next place in between the stroke to form a complete specimen.
10. Which of the following dies is not the type of cutting dies in the metal cutting operations?
a) Squeezing dies
b) Blanking dies
c) Piercing dies
d) Notching dies
Answer: a
Explanation: Blanking dies, piercing dies and notching dies are widely used in the metal cutting operations. But the squeezing die is a type of forming die which is used for performing metal forming operations. In metal forming, drawing dies and bending dies are also used for the forming of metal sheets.
This set of Forming Assessment Questions and Answers focuses on “Types of Sheet Metal Die”.
1. The raw material for the rolling process is the output of the sheet metal forming process.
a) True
b) False
Answer: b
Explanation: The raw material for the sheet metal forming is basically the output of the rolling process. IN the sheet metal forming process, flat rectangular solid sheets of standard sized are used and then the operations like piercing or blanking is performed on the metal sheets to obtain the desired output.
2. Which of the following methods of manufacturing is used for the production of appliances like the fridge and vacuum cleaner?
a) Forging
b) Deep drawing
c) Sheet metal forming and cutting
d) Rolling
Answer: c
Explanation: Sheet metal forming and cutting processes are widely used for the manufacturing of home appliances like fridge, vacuum cleaner radio, toys, dryers etc. In the sheet metal forming processes, bending operation is takes place which form the metal and sheet cutting is used for shearing out the metal part from the large metal sheet.
3. It is not possible to use cutting dies for the metal drawing operations.
a) True
b) False
Answer: a
Explanation: Cutting dies are mainly used for cutting the metal. They use shearing action for cutting the metal sheet. Various cutting dies are used such as blanking dies, piercing dies, perforating dies, notching dies, shaving dies and nibbling dies. And it is not possible to use cutting dies for the metal drawing operations.
4. What should be the appropriate thickness of the metal sheet when it is used as a raw material for the sheet metal operations?
a) 1 cm to 5 cm
b) 5 cm to 10 cm
c) 7.5 mm to 15 mm
d) 0.4 mm to 6 mm
Answer: d
Explanation: The sheet metal forming and cutting operations are mainly performed on relatively thin sheets of metal. The thickness of metal sheet should be 0.4 mm to 6 mm to operate efficiently. If the thickness is more than 6 mm, then it is normally called as metal plate. The operations are generally performed as cold working.
5. Combination die is a die which combines cutting and non-cutting actions in the blanking process.
a) True
b) False
Answer: a
Explanation: In a combination die, the cutting action like blanking or punching is combined with the non-cutting actions like forming which may further include bending, drawing and extrusion process. More than one operation can be possible in single stroke with the help of combination dies, but the die is more applicable for two operations only.
6. In the metal forming operations, forming dies are also called as progressive dies.
a) True
b) False
Answer: b
Explanation: Forming dies and progressive dies are different from each other. Progressive dies can perform two or more operations in a single stroke in different stages in which mainly cutting operations like blanking and punching are performed. And forming dies are only used for forming operations.
7. Transfer dies are same as progressive dies in which piercing and blanking operations are performed.
a) True
b) False
Answer: a
Explanation: In the metal forming and cutting operations, transfer dies are almost similar to progressive dies, the only difference is that the already cut blanks are fed from the station to station manually or by automation. In the operation, first the blanking is performed which is then followed by the piercing process.
8. Which of the following types of force is predominant in the sheet metal forming processes?
a) Shearing force
b) Compressive force
c) Tensile force
d) Indirect compressive force
Answer: c
Explanation: Tensile force is the predominant force in most of the sheet metal forming operations as compared to the bulk forming which basically involves compressive forces. Due to the tensile stresses in the metal sheets, they may experience localized deformation which is further followed by cracking.
9. Die-punch clearance is mainly provided for inducing strength in the blank obtained by the metal sheet cutting.
a) True
b) False
Answer: b
Explanation: In sheet metal forming or cutting operations, die punch clearance is present which basically used to govern the kind of finish obtained on the final part. Die punch clearance is very critical in operations like blanking and punching because it involves very close tolerances which give accurate and precise details on the finished part.
10. Which of the following materials is used for the manufacturing of dies and punches in the sheet metal forming?
a) Grey cast iron
b) Copper
c) Aluminium
d) Carbide
Answer: d
Explanation: Carbide is mainly used for the manufacturing of dies and punches in the sheet metal forming operations. Sometimes tool steel is also preferred to maintain the lateral rigidity in the tools. Dies and punches must possess mechanical properties such as hardness, strength, rigidity, toughness, machinability etc.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Forging”.
1. Forging is a metal forming operation in which the metal is stretched to form the desired shape of a metal part.
a) True
b) False
Answer: b
Explanation: Forging is a metal forming operation in which heated metal is beaten by a hammer to give it the desired shape. It is basically a deformation process in which the material is compressed between dies by using impact load to deform it. Forging can also be used for making complex shapes of metal parts.
2. Precision forging is a type of forging operation in which the metal stocks and dies are controlled very tightly.
a) True
b) False
Answer: a
Explanation: In precision type forging operation, the volume of the metal stock and the dies are controlled very tightly. Such operations are called as precision forging which is a modern technique of forging. Metal parts of better strength, high quality details, and complex shape can be easily produced by the forging operation.
3. In general, the casted metal part is much stronger and tougher than that produced by the forging operation.
a) True
b) False
Answer: b
Explanation: In general, forged parts are much stronger and tougher than the casted parts made from the same metal. The metal components have high strength because the hammering operation maintains its structure that makes proper alignment of grains along the profile of metal components, which leads to an increase in strength.
4. The open die forging process is also known as upsetting or upset forging process.
a) True
b) False
Answer: a
Explanation: In an open die forging process, the metal billet is heated up to a very high temperature and then compressed between two flat die halves. This method is like a compression test, which is also known as upsetting or upset forging. In the process, billet is basically deformed by a decrease in its height and increase in its diameter.
5. Which of the following processes is mainly used for making the connecting rods?
a) Casting
b) Deep drawing
c) Rolling
d) Forging
Answer: d
Explanation: Connecting rods are generally manufactured by the forging operation. In forging, a hammer is used which strikes on the heated metallic part to get into the desired shape. The properties like strength, toughness, etc are greatly enhanced by performing the forging operation. Forging can be open die forging or closed die forging.
6. In open die forging process, homogenous deformation of billet has occurred with uniform increase in its diameter.
a) True
b) False
Answer: b
Explanation: In open die forging process, the deformation is not homogenous as bulging occurs due to the presence of friction at the interface of die and billet. This friction opposes the motion of billet; this effect is generally called as barreling effect. Homogenous deformation only occurs when the friction is zero, which is an ideal condition for the forging process.
7. In impression die forging process, extra deformed material is produced which is called a flash.
a) True
b) False
Answer: a
Explanation: In impression die forging process, flash can be produced which is considered as scrap material that is removed from the formed part during the finishing of a metal part. But in flash-less forging, the metal is fully prevented within the die, so no flash is produced during the process.
8. Isothermal forging is also known as cold forging operation.
a) True
b) False
Answer: b
Explanation: Isothermal forging is a hot forging operation in which the metal part is maintained at some high temperature. The forging dies are also maintained at the same high temperature. In this method, the metal flows readily that reduces the amount of force required. But this process is expensive than the conventional forging and mainly used for materials like titanium and super-alloys.
9. The metal forging operation can be performed manually or by automation.
a) True
b) False
Answer: a
Explanation: Metal forging is a forming operation that performs hammering to shape the metal component. In forging process, the metal component is heated sufficiently, and then it is hammered by using a hammer which can be performed manually or by automation, depending on the scale of production and properties required in the forged metal component.
10. A cone shaped die is used in the orbital forging for the forging of metal parts.
a) True
b) False
Answer: a
Explanation: In the orbital forging process, forming is done to the meat part by using a cone-shaped die that is simultaneously rolled and pressed into the material. The metal part is supported on a lower die, because of inclined axis of cone. In the process, only a small area of the metal surface is compressed at the stage of forming.
This set of Forming Problems focuses on “Plastic Deformation and Yield Criteria”.
1. In plastic deformation of metal, the deformation is temporary and can regain its original shape.
a) True
b) False
Answer: b
Explanation: Plastic deformation of any material means permanent deformation without the presence of external constraints. The plastic deformation of crystalline materials generally takes place by processes which are very different from that for the amorphous materials. In plastic deformation, material cannot regain its original shape.
2. Elastic deformation can disappear completely when the load is removed from the metal.
a) True
b) False
Answer: a
Explanation: In general, deformation can be of two types, elastic or plastic. Elastic deformation can disappear completely when the load is removed from the metal, whereas plastic deformation is a permanent deformation which occurs when the elastic range of deformation exceeds. The plastic deformation takes place without any failure and does not disappear after removing the load.
3. The fluids reveal its flow behaviour when it is subjected to normal compressive stresses.
a) True
b) False
Answer: b
Explanation: The fluids reveal their flow behaviour only when it is subjected to shearing stress. A little amount of shear stress can deform the flow and it never regains its original shape even after removing the shearing load. The compressive or tensile stress does not make any changes to the fluid behaviour.
4. In crystalline materials, the plastic deformation occurs when the group of atoms or molecules slides past each other.
a) True
b) False
Answer: b
Explanation: Material always shows a non-recoverable deformation when it is subjected to stresses beyond certain minimum stress. Crystalline materials experience permanent deformation when slipping occurs along the definite crystalline planes. But in amorphous materials, permanent deformation occurs when the group of atoms or molecules slides past each other.
5. Metal forming operations can only be performed when the material undergoes plastic deformation.
a) True
b) False
Answer: a
Explanation: In metal forming process, plastic deformation of the material is compulsory. It is a process in which the required shape of metal is achieved by plastic deformation. Stresses are induced in the metal which is greater than its yield strength but less than its fracture strength so that the metal can be deformed into the required shape.
6. The process of forming new grains in the material is known as re-crystallization.
a) True
b) False
Answer: a
Explanation: The process of forming new grains in the material is known as re-crystallization. And the temperature at which the re-crystallization occurs is known as re-crystallization temperature. The plastic or permanent deformation at elevated temperature occurs at less stresses as the growing of new grains are much easier at high temperature.
7. For the plastic deformation, it is not necessary to have higher applied stress than the yield strength of the material.
a) True
b) False
Answer: b
Explanation: In plastic deformation of metal, applied stress is the main parameter which must be higher than the yield strength of the material and less than the fracture strength. The plastic deformation increases with the applied stresses when these stresses present in the middle of yield strength and fracture strength.
8. In plastic deformation of metal, the metal strength decreases as the increase in its temperature.
a) True
b) False
Answer: a
Explanation: In plastic deformation of metal, its strength decreases when the temperature is increased. The plasticity of material is better when the deformation temperature is greater than the re-crystallization temperature but should be below the melting point. Re-crystallization temperature is the temperature at which the metal shows enough plasticity for efficient deformation.
9. The yield point is very important for controlling the various manufacturing processes.
a) True
b) False
Answer: a
Explanation: The yield point of a metal is defined as the point at which a metal starts to deform plastically. Study of yield point is very important for designing of any component as it shows a limit to the load which can be applied to that metal component. The yield point is very important for controlling the various manufacturing processes like forging, rolling, bending etc.
10. In the yield criteria of metal, von-mises criteria are also known as distortion energy theory.
a) True
b) False
Answer: a
Explanation: In the yield criteria of any metal, von-mises criterion is also known as distortion energy theory. This theory shows that the plastic deformation of metal occurs when the value of shear strain energy per unit volume of the body becomes equals to the strain energy per unit volume at the elastic limit of the metal.
This set of Forming Questions and Answers for Aptitude test focuses on “Relationship between Tensile and Shear Yield Stress”.
1. Tensile strength of a material is the ability of a material to resist the lateral load without failure.
a) True
b) False
Answer: b
Explanation: Tensile strength of any material is defined as the ability of a material to resist axial or centric load without failure, it is mainly determined by performing tensile test. When equal and opposite forces are applied to the material simultaneously that axially pulls the material, which further causes elongation of the material by decrease in its diameter.
2. The behaviour of the material is generally determined by its mechanical properties.
a) True
b) False
Answer: a
Explanation: The behaviour of the material is generally determined by its mechanical properties, when a material is subjected to different loading conditions like tensile load, compressive load etc. then properties like young’s modulus, various strengths, toughness, ductility etc. are determined, which are very important in design and manufacturing.
3. The necking phenomenon of material can be observed in tensile test as well as in compression test.
a) True
b) False
Answer: b
Explanation: When an axial load is applied to the material, the material first elongates, then necking occurs and the fracture is produced. The necking phenomenon is only occurring in the tensile test due to the elongation of material, a neck like structure is formed. Its behaviour generally depends on the material used for the test. Necking does not take place in brittle materials.
4. The induced stress in the material and the young’s modulus, both are the properties of the material.
a) True
b) False
Answer: b
Explanation: When a material is subjected to any load then the stress is induced in the material which is not a material property, it basically depends on the load applied and the cross-sectional area of the material. And young’s modulus is a material property which indicates stiffness of the material and it is different for different materials.
5. When material subjected to load then elongation becomes more faster beyond the yield point.
a) True
b) False
Answer: a
Explanation: Beyond the yield point, as the load increases, elongation of material proceeds at a faster rate than before. This part of stress strain curve is called as hardening region. When the load reaches a maximum value, the engineering stress at this point is called as the tensile strength or ultimate tensile strength of the material.
6. Necking is a localized elongation through which the load carrying capacity of material increases beyond its tensile strength.
a) True
b) False
Answer: b
Explanation: In the stress-strain curve, beyond the tensile strength, the load carrying capacity reduces and the test material goes through a localized elongation called necking. There is no any constant strain in this region and the elongation occurs in one small segment of specimen. The stress measured just before the failure is known as the fracture stress.
7. The amount of strain that the material sustains before failure is a property which is called as ductility of the material.
a) True
b) False
Answer: a
Explanation: When a material is subjected to a load, then the amount of strain that the material sustains before failure is an important property which is called as ductility of the material. This property is very useful in manufacturing of machine products which works more dynamically than statically. The ductility is generally measured in terms of its area reduction.
8. In the computation of engineering stress, the actual or instantaneous cross-sectional area is used.
a) True
b) False
Answer: b
Explanation: The original cross sectional area is used in the computation of engineering stresses. But in computation of true stresses, the instantaneous cross-sectional area is used. Because of the length and cross-sectional area both changes at every instant during loading of material. The instantaneous load divided by instantaneous cross-sectional area is called true stress.
9. The relationship between the shear stress-strain is similar to the flow curve for plasticity of material.
a) True
b) False
Answer: a
Explanation: Shear stress basically involves an application of load parallel to the surface of material in the opposite direction. The relationship between the shear stress-strain is similar to the flow curve for the plasticity of material. The applied load always increases as the increase in its strain hardening; then the material becomes much stronger and harder.
10. The brittle material directly fractures without yielding when it reaches the ultimate strength material.
a) True
b) False
Answer: a
Explanation: The behaviour of the material is completely defined by its stiffness. Such material directly fractures without yielding when it reaches ultimate strength material. These materials are called as brittle materials. Examples of brittle material are ceramics, cast iron, etc. These materials are not suitable for forming operation, where permanent plastic deformation is required to get the final product.
This set of Basic Forming Questions and Answers focuses on “Advantage and Disadvantage of Hot and Cold Forming”.
1. Materials like lead and tin can be hot worked at room temperature.
a) True
b) False
Answer: a
Explanation: Hot working or hot forming of materials is normally performed at the temperature above than its re-crystallization temperature, but for materials like lead and tin , the hot working can be done at room temperature because these materials possess very low crystallization temperature.
2. Hot working of brittle materials is not possible as they do not show yielding behaviour.
a) True
b) False
Answer: b
Explanation: At high temperature, the materials generally have great amount of ductility and so there is no limit or restriction on the amount of hot working that can be performed on a metal. Hence, even the brittle materials can be used for the hot working. In hot working, the grain structure of material is refined which enhances the mechanical properties of material.
3. In the hot working of materials, porosity may increase in the material rather than decrease.
a) True
b) False
Answer: b
Explanation: In the hot working of materials, the porosity always decreases and reaches to negligible amount in the material. The high temperature of the material makes dynamic changes in the material and the gases entrapped in the material loses out and vapourized due to the high temperature of material. This minimizes the amount of porosity in the material.
4. Hot working does not affect the properties like tensile strength, hardness etc. when the process is performed properly.
a) True
b) False
Answer: a
Explanation: When the hot working process is properly carried out, then hot work does not affect the mechanical properties like tensile strength, hardness, corrosion resistance, etc. The shear stress is reduced at the higher temperature, so this process does not require much force to obtain the desired deformation, due to this properties remains same.
5. In hot working of material, the continuous reformation of grains can be possible in material.
a) True
b) False
Answer: a
Explanation: In hot working of materials, it is possible to continuously reform the grains in material. It requires proper controlling of temperature and rate of hot working. In hot working, very favourable grain size can be obtained which further enhances the mechanical properties of material. And no any residual stresses are present in the material during hot working which also gives rise to better mechanical properties.
6. In cold working, larger deformation can be obtained more rapidly than that obtained by the hot working.
a) True
b) False
Answer: b
Explanation: The mechanical properties, elongation and izod values are enhanced in the hot working of materials. In hot working, the other properties like directional properties and fibre are also produced in the material which helps in achieving the larger deformation more rapidly than that obtained by the cold working, as the material is present in the plastic state.
7. The surface finish obtained by cold working is better than that achieved by the hot working of material.
a) True
b) False
Answer: a
Explanation: In the hot working of metals, rapid oxidation or scale formation and surface de-carburization processes occur on the surface of metal due to the presence of high temperature. This results in a poor surface finish of the metal and the metal loss too. But in cold working, the temperature is kept moderate which maintains the better surface finish of the metal.
8. In the hot working of steel material, steel metal may lose its strength due to carbon loss.
a) True
b) False
Answer: a
Explanation: In the hot working of steel material, the carbon content can be disturbed; means the carbon loss can occur from the surface of steel metal which leads to losing of its strength. This is a major drawback which can also weaken the surface layer that gives rise to fatigue crack which may further result in complete failure of the metal component.
9. The hot working process is mainly used for achieving the high dimensional accuracy of the metal.
a) True
b) False
Answer: b
Explanation: In the hot working of metal components, the temperature is very high, which is more than the re-crystallization temperature of the metal. This high temperature leads to high thermal expansion of the metal component. This expansion varies the shape and size of the metal, so the dimensional accuracy of the metal component cannot be achieved by hot working.
10. The cold working of material facilitates its cutting operation due to a decrease in its ductility.
a) True
b) False
Answer: a
Explanation: In the cold working of material, the material is deformed plastically which increases the strain hardening. This further increases its strength by losing its ductility; the loss of ductility is useful in machining operation. The breaking of chips becomes much easier due to less ductility, which further facilitates the cutting operation of material.
This set of Forming Questions and Answers for Campus interviews focuses on “Friction and Lubrication in Metal Forming”.
1. The main function of the lubricant is to reduce the tensile or compressive stresses required in metal forming.
a) True
b) False
Answer: b
Explanation: The main function of the lubricant is to control the frictional force that arises due to sliding contact between the sheet metal and cutting tool material during sheet metal forming operation. Lubricants are also used to prevent galling problems by protecting tool material from direct contact with the sheet material.
2. In lubrication, the boundary layer formed consists of long chain hydrocarbons with a polar head.
a) True
b) False
Answer: a
Explanation: In lubrication, the performance of boundary layers and its formation basically depends on its physical and chemical adsorption. The boundary layers formed by a mechanism mainly consist of clusters and long chain hydrocarbons with a polar head. Then this polar group adheres to the surface and forms high viscosity hydrocarbon layers.
3. In the case of un-reactive contacting surfaces, the fatty acids adheres by chemical reaction during lubrication.
a) True
b) False
Answer: b
Explanation: In lubrication, the hydrocarbon layers are meant to reduce the friction and wear under loading conditions. In the case of un-reactive contacting surfaces, the fatty acids only adhere by physical adsorption. For the reactive metal surfaces, the mechanism of chemical adsorption is likely to occur, which combines both the physical and chemical adsorption.
4. Boundary layers formed by chemical adsorption using additives are also called as friction modifiers.
a) True
b) False
Answer: a
Explanation: In the lubrication of metal surfaces, the additives are used to form boundary layers by a mechanism of chemical adsorption. These boundary layers are also known as friction modifiers. In general, the additives used can be fatty acids, ester, or fatty amides. The boundary layer is highly resistant to contact temperature and therefore it can be used for wear and friction reduction.
5. Temperature cannot affect the friction and lubrication present during the metal forming.
a) True
b) False
Answer: b
Explanation: Friction and lubrication in metal forming are greatly influenced by parameters such as temperature, mechanical properties, surface finish, sliding velocity, pressure etc. In general, the viscosity of lubricant decreases with the increase in temperature and vice-versa. And friction becomes more vigorous when the temperature is very high during the metal forming operation.
6. Strip drawing test is a method which is mainly used for evaluating the characteristics of lubricants.
a) True
b) False
Answer: a
Explanation: In strip drawing test method, a strip is used which drawn between two opposite plane dies that are wider than the strip. The amount of stretching strip can change the coefficient of friction. And the test is usually performed with different speeds and different radius of the die. This test is widely used for evaluating the characteristics of lubricants which used during the process of metal forming.
7. The flow of material in die cavity solely depends on the flow-ability of material.
a) True
b) False
Answer: b
Explanation: The flow of material in die cavity not only depends on the flow-ability of material, it also depends on the frictional conditions at the die and material interface. Therefore, a proper study of parameters that affect the friction is required for selecting suitable lubricants for the operation and producing better quality of metal parts.
8. The lubrication is not required when the formability of material is sufficiently large in metal forming.
a) True
b) False
Answer: a
Explanation: A dry condition is mainly used when the material formability is sufficiently large to form desired metal part with simple geometry. In this case, the friction is very high as no any lubricant is used during the operation, but this friction does not significantly affect the metal part quality. A dry condition is usually suitable for hot rolling forming processes.
9. Semi-synthetic fluid is a type of lubricant which is generally insoluble in water.
a) True
b) False
Answer: b
Explanation: Lubricant is a material that is mainly used for reducing friction and for cooling purposes. For example, oils, soluble oils, synthetic and semi-synthetic fluids are widely used in metal forming processes. Semi-synthetic fluid is a kind of lubricant which easily mixed with water to form a fine lubricant because it includes small quantity of mineral oil, usually less than 30% of the total concentrate volume.
10. Additives can be added in a lubricant to enhance its performance during metal forming operations.
a) True
b) False
Answer: a
Explanation: In metal forming process, several types of additives are mixed with lubricant to enhance the performance of the lubricant. The extreme pressure additives are generally used in heavy work metal operations. The temperature dependent EP additives, such as chlorine, phosphorus, and sulphur are mainly used to create chemical films that prevent metal to metal contact during forming operations.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Electromagnetic Forming”.
1. In electromagnetic forming, highly intense magnetic field is used for the forming process.
a) True
b) False
Answer: a
Explanation: In electromagnetic forming, many components like capacitor bank, forming coil, field shaper, conductive material etc. are used to create intense magnetic fields. This magnetic is generally produced by the discharge of capacitors into a coil, which lasts only for a few microseconds. Then further processing is done to perform the metal forming.
2. The magnetic field interacts with metal to generate heat in the metal which causes forming process.
a) True
b) False
Answer: b
Explanation: In the electromagnetic forming process, eddy currents are induced in a conductive material that is placed near to the coil. Then it interacts with a magnetic field to cause mutual repulsion between the metal and the forming coil. This force of repulsion is mainly responsible for inducing stresses in the metal beyond its yield strength which results in plastic deformation of metal.
3. Metal used for electroforming process absorbs energy from the magnetic field to get deform.
a) True
b) False
Answer: a
Explanation: In the electromagnetic forming process, the conductivity of the metal and the eddy currents which makes contact with magnetic field creates a net pressure on the surface of the metal. Then the metal surface moves inward due to the effect of this pressure, this mainly occurs due to the transfer of energy from the magnetic field to the metal.
4. In the electromagnetic forming process, the forming pulse is kept longer to optimize the use of energy.
a) True
b) False
Answer: b
Explanation: In the electromagnetic forming process, the metal absorbs energy from the magnetic field to get deformed. To utilize most of this energy to forming operation, and to reduce the energy loss due to resistance heating, the forming pulse is kept short for better optimization of energy produced by the magnetic field. In general, pulse has duration of between 10 and 100 second.
5. Which of the following methods of forming is not the part of electromagnetic forming?
a) Compression
b) Expansion
c) Shearing
d) Counter forming
Answer: c
Explanation: In the electromagnetic forming process, electromagnetic formation mainly used for three forming methods which can be compression, expansion, and counter forming. For compression, a tubular metal is compressed by a coil, usually against a grooved tube. And shearing is a different process which is not a part of electromagnetic forming.
6. Electromagnetic forming cannot be used for materials of poor electrical conductivity.
a) True
b) False
Answer: b
Explanation: The electromagnetic forming method uses a high intense magnetic field to deform the material. This process is primarily used for the forming of good conducting materials like copper, aluminum, silver etc. This method can also be used for materials of poor electrical conductivity such as stainless steel.
7. The efficiency of electromagnetic forming mainly depends on the resistivity of material being formed.
a) True
b) False
Answer: a
Explanation: The electromagnetic forming method uses a capacitor and forming coil to create intense magnetic field. The efficiency of the magnetic pulse mainly depends on the resistivity of the material being formed. For better output, the resistivity of the material must be less than 15 micro-ohm-centimeters.
8. The process of electromagnetic forming does not require any kind of lubrication.
a) True
b) False
Answer: a
Explanation: In most of the forming processes, tool contacts with the specimen to get the desired output. But in the case of electromagnetic forming, the magnetic field is used to apply the pressure on the surface of a metal, which normally does not require any kind of lubrication. And it leaves no any tool marks on the metal surface.
9. Which of the following is the main advantage of using the electromagnetic forming process?
a) High speed
b) Low maintenance
c) Applicable to all materials
d) No spring-back
Answer: d
Explanation: In the electromagnetic forming process, the metal is loaded and achieve plastic region, which results in plastic or permanent deformation, so that the spring-back associated with the mechanical forming process is completely eliminated because no any mechanical contact is present during the process of metal forming.
10. The joints made by an electromagnetic forming process are much stronger than the parent material.
a) True
b) False
Answer: a
Explanation: In the electromagnetic forming process, the joints made are much stronger than the parent material. This process also allows increased ductility for several alloys because of the lack of stresses and friction which normally encountered with the process. This method is widely used for a high rate of production.
This set of Forming online quiz focuses on “Cooling Curve for Pure Iron”.
1. What is the melting point of pure iron?
a) 1500°C
b) 1535°C
c) 1570°C
d) 1605°C
Answer: b
Explanation: Iron exists in many allotropic forms, and every such allotropic form has a different melting, boiling and solidifying point. But, for pure iron, the melting point is 1535°C.
2. Which iron is formed when the melt is frozen?
a) Alpha
b) Beta
c) Gamma
d) Delta
Answer: d
Explanation: Alpha irons, beta irons or gamma irons cannot be formed when the metal is in the frozen form. When the molten metal is frozen, delta iron is formed.
3. What is the kind of lattice in a delta iron?
a) Face centered cubic
b) Body centered cubic
c) Hexagonal closely packed
d) Tetragonal closely packed
Answer: b
Explanation: The delta form of solid state of iron, which is formed on cooling the melt, has a body centered cubic lattice structure.
4. What is the kind of lattice in a gamma iron?
a) Face centered cubic
b) Body centered cubic
c) Hexagonal closely packed
d) Tetragonal closely packed
Answer: a
Explanation: The gamma form of solid state of iron, which is formed on cooling the melt, has a face centered cubic lattice structure.
5. In transformation in steel, hypo eutectoid steel are heated up to what temperature?
a) 677°C
b) 700°C
c) 723°C
d) 746°C
Answer: c
Explanation: In transformation in steel, the hypo eutectoid steels are heated up to a very high amount of temperature. The temperature to which they are taken is 723°C.
6. What is the Brinell hardness of pearlite?
a) 150
b) 180
c) 210
d) 240
Answer: b
Explanation: Pearlite is not the hardest form. The Brinell hardness of pearlite is only 180. There is a harder material than pearlite, called as martensite, which has Brinell hardness ranging from 650-700.
7. The alpha iron is highly non-magnetic.
a) True
b) False
Answer: b
Explanation: It is one of the properties of alpha irons that alpha irons are highly magnetic and they are found to exist only at room temperature. The alpha iron is the fourth retardation of iron.
8. How much is the Brinell hardness of martensite?
a) 600-650
b) 650-700
c) 750-800
d) 800-850
Answer: b
Explanation: Martensite is a ferro-magnetic substance in nature, and it is known to have Brinell hardness ranging from 650-700.
9. What is the value of ‘a’ in a delta iron lattice?
a) 2.00 Ă…
b) 2.93 Ă…
c) 4.00 Ă…
d) 4.93 Ă…
Answer: b
Explanation: The value of a, which is the distance between two consecutive atoms in the lattice, in delta iron lattice is calculated to be 2.93 Ă…, which is around 2.93 x 10-10 meters.
10. Alpha iron exists only in high temperature and pressure conditions.
a) True
b) False
Answer: b
Explanation: It is one of the properties of alpha irons that alpha irons are highly magnetic and they are found to exist only at room temperature.
This set of Forming Questions and Answers for Experienced people focuses on “Inverse Rate Curves for Steel”.
1. HPF steel is normalized at what temperature?
a) 800°C
b) 900°C
c) 1000°C
d) 1100°C
Answer: b
Explanation: The HPF steel has to be taken to high magnitudes of temperatures. The HPF steel or the hot press forming steel gets normalized at 900°C.
2. What is the Vicker’s hardness of steel before the HPF process?
a) 150 Hv
b) 160 Hv
c) 170 Hv
d) 180 Hv
Answer: c
Explanation: The HPF process in steels is considered to be a very important process, it involves heating the steel to high temperatures. The Vickers hardness of steel before HPF process is 170 Hv.
3. What is the Vickers hardness of steel after the HPF process?
a) 362 Hv
b) 462 Hv
c) 562 Hv
d) 662 Hv
Answer: b
Explanation: The HPF process is a very essential process. The Vickers hardness of the material is found to change after this process is done. The Vickers hardness of steel after HPF process is 462 Hv.
4. What is the amount of carbon used in HPF steel?
a) Less than 0.37%
b) Less than 0.27%
c) Less than 0.47%
d) Less than 0.57%
Answer: b
Explanation: The carbon content which is used in HPF steel is very less in percentage composition. The amount of carbon used in terms of percentage weight is less than 0.27%.
5. What is the amount of silicon used in HPF steel?
a) Less than 0.30%
b) Less than 0.20%
c) Less than 0.40%
d) Less than 0.50%
Answer: d
Explanation: The silicon content which is used in HPF steel is very less in percentage composition. The amount of silicon used in terms of percentage weight is less than 0.50%.
6. What is the amount of boron used in HPF steel?
a) Less than 0.003%
b) Less than 0.007%
c) Less than 0.009%
d) Less than 0.057%
Answer: a
Explanation: The boron content which is used in HPF steel is extremely less in percentage composition. The amount of boron used in terms of percentage weight is less than 0.003%.
7. What is the amount of tungsten used in HPF steel?
a) Less than 0.03%
b) Less than 0.02%
c) Less than 0.04%
d) Less than 0.05%
Answer: d
Explanation: The tungsten content which is used in HPF steel is very less in terms of percentage composition. The amount of tungsten used in terms of percentage weight is less than 0.05%.
8. What is the amount of nitrogen used in HPF steel?
a) Less than 0.03%
b) Less than 0.02%
c) Less than 0.04%
d) Less than 0.05%
Answer: b
Explanation: The nitrogen content which is used in HPF steel is very less in percentage composition. The amount of nitrogen used in terms of percentage weight is less than 0.02%.
9. In an inverse rate curve for steel, steel is heated uniformly.
a) True
b) False
Answer: a
Explanation: In an inverse rate curve for steel, the steel is not just heated uniformly, also its temperature is recorded.
10. In an HPF steel, the amount of manganese used is 3% by weight.
a) True
b) False
Answer: b
Explanation: The manganese content which is used in HPF steel is comparatively more than other substances in percentage composition. The amount of manganese used for HPF steel is less, approximately about, 1.5% to 2.0%.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Transformation in Steel”.
1. Which of the following processes is called as quenching?
a) Slow cooling
b) Slow heating
c) Rapid cooling
d) Rapid heating
Answer: c
Explanation: Among the following, that is, slow cooling, slow heating, rapid cooling and rapid heating, quenching is the name given to the process of rapid cooling.
2. On martensite formation, what is the percentage increase in the volume of the steel?
a) 3%
b) 13%
c) 23%
d) 33%
Answer: a
Explanation: It has been observed that whenever there is a formation of martensite, there is some amount of increase in the volume accompanied by it. This increase in the volume is about 3%.
3. How much is the Brinell hardness of sorbite?
a) 250
b) 350
c) 450
d) 550
Answer: b
Explanation: The cementite in sorbite is known to be very finely divided. The material sorbite is not one of the hardest materials known in casting. The Brinell hardness of sorbite is 350.
4. How much is the Brinell hardness of troostite?
a) 250
b) 350
c) 450
d) 550
Answer: c
Explanation: The cementite in the troostite is very finely divided. The material troostite is not one of the hardest materials known in casting. The Brinell hardness of sorbite is 450.
5. What is the chemical formula of cementite?
a) Fe 3 O 4
b) Fe 2 O 3
c) Fe 3 C
d) FeSO 4
Answer: c
Explanation: None.
6. What is the crystal structure of cementite?
a) Orthogonal
b) Pyramidal
c) Trapeziodal
d) Orthorhombic
Answer: d
Explanation: The crystal structure of the compound cementite or iron carbide is not orthogonal or pyramidal or trapezoidal, but it is orthorhombic.
7. What is the curie temperature of cementite?
a) 480K
b) 500K
c) 520K
d) 540K
Answer: a
Explanation: The compound cementite is also called as Iron Carbide. The chemical formula of the compound cementite is Fe3C. The curie temperature of the compound cementite is approximately about 480K.
8. What is the percentage weight of iron in cementite?
a) 93.3%
b) 94.3%
c) 95.3%
d) 96.3%
Answer: a
Explanation: In the compound iron carbide or cementite, the percentage weight of iron is 93.3% and the rest of the space in the lattice is occupied by carbon. By weight, carbon is present in about 6.67% in the mixture.
9. What is the percentage weight of carbon in cementite?
a) 5.53%
b) 6.67%
c) 7.23%
d) 8.39%
Answer: b
Explanation: None.
10. Cementite is a brittle material.
a) True
b) False
Answer: a
Explanation: Cementite, when in its purest form, is used as a ceramic. Cementite or iron carbide is considered to be a brittle material.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Method of Heat Treatment”.
1. Heat treatment is a process which alters the mechanical properties of metal by changing the product shape.
a) True
b) False
Answer: b
Explanation: Heat treatment is basically a combination of heating and cooling operations applied to a metal in the solid state in a way to alter their physical and mechanical properties. This method enhances the mechanical properties of metal and the whole process is accomplished by without changing the shape of metal which being treated.
2. Case hardening of non-ferrous materials can be done easily as compared to that of ferrous materials.
a) True
b) False
Answer: b
Explanation: In general, all the heat treatment processes are similar as they all include heating and cooling of metals. The heat treatment of ferrous materials normally includes processes like annealing, normalizing, hardening, or tempering. But for nonferrous metals, tempering, normalizing or case hardening cannot be done, they only goes through an annealing process.
3. Proper equipment with close control must be implemented in the heat treatment of metals.
a) True
b) False
Answer: a
Explanation: In heat treatment of materials, it must include proper equipment with close control over the parts relevant to the heating and cooling. For example, the furnace should be of proper shape and size and should be kept within the prescribed limits for each operation. The material used for the heat treatment should be finished and of appropriate size.
4. In heat treatment of metals, quenching is a method which induces ductility in the metal.
a) True
b) False
Answer: b
Explanation: Quenching is a process in which heated metal product interacts directly with cooled water. In heat treatment of metals, this method is used for static load purposes as this process makes the metal hard and brittle. The brittleness basically induced in the metal due to the formation of fine grains on the metal surface.
5. The heating rate of metals mainly depends on the thermal conductivity of metal which being treated.
a) True
b) False
Answer: a
Explanation: In heat treatment of metals, first stage involves heating of metals in which metal is uniformly heated with appropriate heating rate. The heating rate of metal mainly depends on the thermal conductivity of metal and also depends on the metal condition like its size and cross-section.
6. In heat treatment, soaking is a stage in which metal product is cleaned by finishing operation.
a) True
b) False
Answer: b
Explanation: In heat treatment of metals, soaking is a stage which includes holding of metal to the appropriate temperature until the required internal structural changes occur. And soaking period is a term used for the time the metal is held at the specific temperature. For the determination of soaking period, a chemical analysis of the metal is done.
7. In heat treatment of materials, the purpose of annealing is totally opposite to that of hardening.
a) True
b) False
Answer: a
Explanation: In general, the purpose of annealing is just the opposite of hardening. In annealing process, metal is treated to relieve internal stresses and to get soften or ductile by refining their grain structures. And the purpose of hardening is to harden the metal, which also increases its strength by decreasing its ductility.
8. For annealing of ferrous materials, the material is heated with a faster rate to get the desired properties.
a) True
b) False
Answer: b
Explanation: The objective of annealing process is mainly is to induce ductility or softness in the material. To anneal ferrous materials , the metal is slowly heated to its proper temperature. Then after soaking process, the material is cooled very slowly by placing heated metal part in an insulating material.
9. In the heat treatment, normalizing method cannot be applicable for non-ferrous materials.
a) True
b) False
Answer: a
Explanation: The objective of normalizing is to remove internal stresses from the material being treated. Normalizing can be applicable to ferrous materials, but it cannot be used for treating non-ferrous materials. In normalizing, the metal is heated to a higher temperature and then it is removed from the furnace for air cooling.
10. Carburizing is a case hardening process in which carbon is added to the surface of a metal.
a) True
b) False
Answer: a
Explanation: Carburizing is a case hardening process in which carbon is added to the metal surface. In the process of carburizing, when the metal is heated in a container with charcoal, the case becomes very hard and the inside core remains soft and tough. Then the metal part is removed from the furnace for air cooling.
This set of Forming Interview Questions and Answers for Experienced people focuses on “Annealing and Normalizing”.
1. Which of the following is not an objective of annealing?
a) Softening of steel
b) Hardening of steel
c) Increase ductility
d) Relieve internal stress
Answer: b
Explanation: Among the many purposes of treating the steel through annealing is softening of steel, hardening of steel and relieving the internal stresses, but annealing is not used for hardening of the steel.
2. In full annealing, the steel is heated at what temperature?
a) Above critical temperature
b) Above vaporization temperature
c) Above liquefying temperature
d) Above solidification temperature
Answer: a
Explanation: In the process of full annealing, the steel has to be heated slightly above the critical temperature. At this point, the steel has to be held for a considerable amount of time.
3. In annealing process, for the formation of hypereutectoid steel, the steel has to be heated above what point?
a) Ac1
b) Ac2
c) Ac3
d) Ac4
Answer: a
Explanation: For the formation of hypereutectoid steel, in annealing process, the steel has to be heated above the Ac1 point, which is the lower critical line in the temperature versus carbon content graph.
4. In annealing process, for the formation of hypoeutectoid steel, the steel has to be heated above what point?
a) Ac1
b) Ac2
c) Ac3
d) Ac4
Answer: c
Explanation: None.
5. For how long is the heated steel held in full annealing process?
a) 1 minute
b) 3 minutes
c) 6 minutes
d) 9 minutes
Answer: b
Explanation: The heated steel is held at the critical temperature for about 3 to 4 minutes. By doing this, the steel gets enough time to make the internal changes desired.
6. In full annealing, the metal cannot be buried in which of the following materials?
a) Sand
b) Lime
c) Ashes
d) Manganese powder
Answer: d
Explanation: In the process, full annealing, if the metal is removed at high temperatures, they need to be buried. For this, the material cannot be manganese powder.
7. Annealing is a fast process.
a) True
b) False
Answer: b
Explanation: Annealing is considered to be a very slow process, as the part where the steel is cooled, takes up a lot of time for the process to get completed.
8. Which of the following is also called as diffusion annealing?
a) Isothermal annealing
b) Process annealing
c) Homogenizing
d) Spheroidise annealing
Answer: c
Explanation: Homogenising has another name as diffusion annealing. This method is applied to both the ingots, carbon as well as alloy steel.
9. At what temperature is homogenizing carried out?
a) 1150°C
b) 1370°C
c) 1420°C
d) 1320°C
Answer: a
Explanation: Homogenizing is carried out between temperature ranges of 1100°C to 1200°C, but the most optimum temperature is 1150°C, at which the diffusion process goes ahead smoothly.
10. Normalizing process takes a lot of time to complete.
a) True
b) False
Answer: b
Explanation: Normalizing is a comparatively faster process than annealing, as in this process, the cooling rate is supposed to be very high, causing the process to end in lesser time.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Deep Drawing”.
1. Which of the following forming processes is suitable for making utensils and cup shaped objects?
a) Forging
b) Rolling
c) Deep drawing
d) Wire drawing
Answer: c
Explanation: Deep drawing process is also known as cup drawing, which is a part of sheet metal forming process. It is widely used for making products like utensils, cup shaped objects, pressure vessels, gas cylinders, cans etc. In this method, a blank is placed on a die cavity and then held in a position using a holding plate and pressed against the die cavity by using a punch.
2. In the deep drawing process, a clearance is provided between the punch and die to succeed the forming operation.
a) True
b) False
Answer: a
Explanation: During deep drawing operation of metal sheet into the die, there is thickening of the metal sheet up to 12%. Therefore, a clearance is provided between the punch and die to succeed the forming operation. The radial clearance is provided which is almost equal to the thickness of metal sheet plus the thickening of sheet.
3. Deep drawing process can also be possible by having shearing operation instead of bending operation.
a) True
b) False
Answer: b
Explanation: Shearing operations like blanking or punching basically includes cutting of metal sheet, which does not required in deep drawing process. In deep drawing, the flat section of the metal sheet under the holding plate moves towards the die axis and then bending occurs over the die profile. After bending, the metal sheet unbends to flow in downward direction along the side wall.
4. In deep or cup drawing, maximum tensile stress is caused near the end of punch.
a) True
b) False
Answer: a
Explanation: In deep or cup drawing, the tensile stress is generally generated on the sheet at several locations within the die cavity. Maximum tensile stress is induced near the end of punch, at the profile of punch, because the metal sheet bends over the edge of punch due to inducing of tensile stresses in the punch.
5. Necking phenomena do not occur in the process of a cup or deep drawing.
a) True
b) False
Answer: b
Explanation: In deep drawing, necking of metal sheet is a very common phenomena, which occurs near the punch profile due to inducement of tensile stresses in the punch material. The metal sheet under the holding plate experiences compressive hoop stresses and radial tensile stresses due to blank holding plate. In this method, thickness of the cup wall generally increases from the bottom side to the top side.
6. In metal forming, deep drawing process is completely different from wire drawing process.
a) True
b) False
Answer: a
Explanation: Deep drawing process is completely different from wire drawing process. In wire drawing, metallic bar is pulled to form wires, while in deep drawing process; a flat metal sheet is converted into a concave shape part. This operation is basically performed by stretching the metal for which a blank-holder is used to clamp the blank on the die, and then a punch is used which pushes the metal sheet.
7. In deep drawing, the drawing force required decreases as strain increases on the metal.
a) True
b) False
Answer: b
Explanation: In the deep or cup drawing process, the drawing force required generally increases linearly with the punch stroke as the strain increases on the metal. This mainly occurs due to strain hardening of material, which makes the forming material less ductile and the strength of the material substantially increases due to strain hardening.
8. Excessive blank holding force may lead to stretching of sheet metal instead of drawing it.
a) True
b) False
Answer: a
Explanation: In deep drawing, if the blank holding force is too high, then the metal around the punch may start to stretch instead of being drawn. This can cause localized necking or diffuse necking, which basically depends on the sensitivity of strain rate, and lubrication, and geometry of punch. If the blank holding force decreases then it may cause free flow of metal into the die cavity.
9. In deep drawing, the metal at the bottom side of the punch only undergoes longitudinal tensile stresses.
a) True
b) False
Answer: b
Explanation: In deep drawing process, the metal at the bottom of the punch is basically subjected to circumferential tensile stresses and longitudinal tensile stresses also. The punching force applied on the bottom of the cup is transferred to the side of the metal cup. And a narrow ring is present just above the bottom of the metal cup, which undergoes plane strain condition.
10. The difference between the radius of punch and die basically represents occupied length of metal in the die cavity.
a) True
b) False
Answer: a
Explanation: In the deep drawing process, the metal sheet which occupies the length in the die cavity is mainly represented by the difference between the radius of punch and die, which experiences wrinkling and folding due to inducing of hoop compressive stresses in the sheet material. This may be due to the fact that the diameter of the blank becomes small.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Cold Rolling”.
1. In metal forming, cold rolling process is completely different from the work hardening process.
a) True
b) False
Answer: b
Explanation: In metal forming, cold working or rolling process is also known as work hardening process, which basically defined as the process of strengthening a material by plastic or permanent deformation. Plastic deformation occurs when a material is altered after its elastic region, this process makes the material hard and strong.
2. Cold rolling process only affects the tensile strength of the material which being rolled.
a) True
b) False
Answer: b
Explanation: Cold rolling process is a very important process because it allows altering of desired mechanical properties of the material. Cold rolling not only affects the tensile strength, but it also affects the hardness, yield strength, tensile strength and ductility of the material. This process is very economical as the heating cost is excluded from the process.
3. The dislocation density of the material increases during the process of cold rolling or work hardening.
a) True
b) False
Answer: a
Explanation: In cold rolling or work hardening process, dislocations contact with each other and accept configurations which prevent the movement of other dislocations in the material. During the process, the dislocation density increases, this also makes increase in the flow stress of the material. Flow stress is defined as the instantaneous value of stress required to continue the plastic or permanent deformation.
4. The dislocations in the material only act as strong obstacles to the movement of other dislocations.
a) True
b) False
Answer: b
Explanation: In general, the dislocations in the material can be acts as either strong or weak obstacles to the movement of other dislocations of the material, which basically depends on the type of interaction that occurs between the movements of dislocations. This process is mainly considered for strengthening the material which being rolled during the process.
5. The dislocation density of the material is defined as the ratio of total dislocation length per unit volume of the material.
a) True
b) False
Answer: a
Explanation: In general, the dislocation density of a material is defined as the ratio of total dislocation length per unit volume of the material. It is also defined as the number of dislocations that intersect a unit area of a random part of the material. The dislocation density mainly determines the strength of the material.
6. Cold rolling is a process of permanent deformation of material below its re-crystallization temperature.
a) True
b) False
Answer: a
Explanation: Cold rolling or working is a process of permanent or plastic deformation of materials below the re-crystallization temperature, and this process is generally performed at the room temperature. This process is widely used for producing products of better surface finish with superior dimensional control.
7. In cold rolling process, no any residual stresses are induced in the material during the operation.
a) True
b) False
Answer: b
Explanation: In cold rolling process, strain hardening occurs during the expansion or compression of metal plate, which increases the value of flow stress, so that the required rolling force increases, which further lead to inducing of residual stresses in the material. This residual stresses then can be removed from the material by the annealing process.
8. Which of the following methods of heat treatment is best suitable for treating the output of cold rolling?
a) Quenching
b) Case hardening
c) Annealing
d) Cyanide hardening
Answer: c
Explanation: The plastic deformation of metal plate in cold rolling includes changing of grain shape, increase in dislocation density and strain hardening of the material. These changes make the metal plate hard and ductile less. So, annealing is a process of heat treatment in which material regains its softness and relieves all its residual stresses.
9. The cold rolling process requires very heavy forces for the accomplishment of rolling operation.
a) True
b) False
Answer: a
Explanation: In the cold rolling process, the metal plate is compressed between the gaps of two large heavy rollers. This process does not require much of heating the metal plate, so it becomes very difficult to alter the shape of material as the temperature of a material is less than its re-crystallization temperature, and strain hardening also occurs which further makes the metal hard. Hence, this process requires very heavier forces for the accomplishment of rolling operation.
10. Over work hardening of material can induce high brittleness in the material.
a) True
b) False
Answer: a
Explanation: When the material is processed by cold rolling then it loses its ductility by increasing its strength. The process includes strain hardening of the material which induces stresses in the material and when the process is continued and crosses the limit, then the material becomes very hard and brittle, which can only be overcome by annealing process.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Metallurgical Aspects”.
1. In fatigue failure, the behaviour of material under cyclic load generally differs from that under monotonic load.
a) True
b) False
Answer: a
Explanation: The study of behaviour of material in its fatigue failure is very important to understand for the design and manufacturing purpose. The behaviour of material under cyclic load generally differs from that under monotonic load. Fatigue in the form of initiation of a defect is followed by its growth till the operating load is reached to rupture condition.
2. In cyclic loading of material, the crack is generally initiated by a sudden or abrupt failure of the material.
a) True
b) False
Answer: b
Explanation: In a work-piece subjected to cyclic loading, a fatigue crack is generally initiated on a microscopically small scale which further followed by the growth of crack to a macroscopic size. And in last cycle, the material or specimen fails due to fatigue and fracture occurs which defines complete failure of the work-piece.
3. The quality of the metal surface is a very important consideration, which greatly affects the fatigue life of the material.
a) True
b) False
Answer: a
Explanation: The fatigue phenomenon is generally considered as a mechanism which occurs in metallic materials. The study of the fatigue phenomenon is very necessary for considering several technical conditions which affects the fatigue life and fatigue crack growth in the material, such as the material surface quality, residual stress etc.
4. Decarburization is a process which can increase the fatigue limit of the material in case of cyclic loading.
a) True
b) False
Answer: b
Explanation: In case of cyclic loading, decarburization is a process which is defined as the depletion of carbon from the surface of steel alloy. It can significantly reduce the fatigue limit of the steel material. For testing the materials, a batch of similar specimens is selected and then the fatigue strength is determined by considering free surface of the material.
5. Fabrication methods of materials greatly affect the geometry of defects in the material.
a) True
b) False
Answer: a
Explanation: The geometry of defects in the material is greatly influenced by the fabrication methods and also by the quality control procedures which involved the manufacturing of products. Fatigue is a general type of failure, and thus the defect geometry has a significant effect on the fatigue life of the material.
6. The fatigue limit or strength of the material can change with respect to time.
a) True
b) False
Answer: b
Explanation: In many experiments, it has been concluded that the fatigue limit or strength of the material after a long period of time of a metallic material which does not heat up and which surface is not reacted with any other substance chemically during a test remains constant for almost all the practical conditions or purposes.
7. Environmental conditions can affect the fatigue life of material more severely than the sharp stress concentration conditions.
a) True
b) False
Answer: a
Explanation: Environmental conditions can greatly affect the fatigue condition of materials which may be more severe than the sharp stress concentrations conditions. In general, corrosion and temperature are the two main environmental factors which greatly influence the fatigue behaviour of material structures.
8. Corrosion fatigue is very small problem and it has negligible effects on the material properties.
a) True
b) False
Answer: b
Explanation: Fatigue under corrosion is called as corrosion fatigue which is a very complex problem. It mainly refers to the combination of corrosive environment and repeated stress, which can be more detrimental than the other conditions. Repeated stress accelerates the corrosion in material which further accelerates the fatigue conditions in the material.
9. At low temperature condition of the material, its fracture toughness decreases substantially.
a) True
b) False
Answer: a
Explanation: The fracture toughness of the material substantially decreases at low temperature. But at high or elevated temperature, the mean or average stress conditions are extremely complex because of the interactions between fatigue and environmental conditions. At high temperature, the material is plastically deformed with less force.
10. Neutralization of preexisting defects in the material can lower the chances of fatigue failure.
a) True
b) False
Answer: a
Explanation: The fatigue life of material can be improved by various treatments which generally includes grinding, shot peening, spot heating, hammer peening, heat treatment etc. And also by considering strategies like neutralization of preexisting defects and reducing local stress concentration, fatigue life of material can be improved.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Thread Rolling”.
1. Thread rolling is a kind of metal forming which is essentially a hot forging operation.
a) True
b) False
Answer: b
Explanation: Thread rolling is basically a kind of metal forming process which is essentially a cold forging operation. In this process, thread rolls are used which forced onto the component that prepared at the pitch diameter of the required thread. This method is widely used for manufacturing the bolts which combine with nut, and used for temporary joining.
2. In thread rolling, all thread forms can be produced in a single pass.
a) True
b) False
Answer: a
Explanation: In thread rolling, a complete thread is generally formed where the grain of the material follows the form or shape of the thread, which considerably increases the strength of the thread. In this method, all thread forms can be formed in a single pass, which basically includes buttress, knuckle and trapezoidal threads.
3. In general, thread rolling process is very slow and uneconomical process.
a) True
b) False
Answer: b
Explanation: Thread rolling process is very fast and it can produce threads on the bolt extremely fast. So this process can form hundreds of bolts in few minutes. And this process is highly economical for producing threads on the bolts. However, the process is costly, but best suited for large scale production of bolts.
4. Thread rolling process can exceed the length of rolling material during the operation.
a) True
b) False
Answer: b
Explanation: In thread rolling, threaded rollers are used which forces their thread into the rolling material. And the threads are formed on the material, which then comes out from the machine. The thread is formed on the bolt, but this process does not exceed the length of rolling bolt during the operation.
5. The operating speed of thread rolling is much faster than that of thread cutting process.
a) True
b) False
Answer: a
Explanation: In thread rolling process, the process is carried out at much faster rate than the thread cutting process. This basically reduces the machine cycle time. In this process, the blank is produced at the pitch diameter of the thread, but in cut threads the blank is prepared at the major diameter. So, more material is required during the process.
6. Thread rolling process cannot maintain accuracy in producing the threads during the operation.
a) True
b) False
Answer: b
Explanation: In thread rolling process, it has inherent ability to maintain the accuracy in the production of threaded bolts. It can maintain high level of accuracy; this is basically due to well and precise settlement of machine parts during high speed production. Thread rolling also provides better finishing to the formed materials.
7. Thread rolling enables the thread to withstand high tensile and fatigue loads.
a) True
b) False
Answer: a
Explanation: The thread rolling process is also called as cold forging or work hardening process. This process enables the thread to withstand high tensile and fatigue loads. Work hardening is basically done which also improves the wear characteristics of threaded material by inducing the strength and hardness properties in the material.
8. In thread rolling process, the selected blank should be of appropriate diameter.
a) True
b) False
Answer: a
Explanation: In thread rolling, it is very important that the diameter of the selected blank should be correct. If the blank is undersize then the effective diameter of the thread may formed, but the major diameter cannot be formed. And if the blank is oversize, then the excess of material would be forced into the rolls, which may further cause damage to the rolls.
9. In thread rolling, the chamfer diameter should be greater than the core diameter of the thread.
a) True
b) False
Answer: b
Explanation: In general, the selected blank should be straight and possess better surface finish for the process of thread rolling. In this process, a chamfer is used which generally present at the start of the blank and also at the end when the thread is to end at an undercut. The selected chamfer diameter should be slightly less than the core diameter of the thread for taking place of efficient operation.
10. In thread rolling, the rolling speed only depends on the tensile strength of the material being rolled.
a) True
b) False
Answer: b
Explanation: It is very important to select appropriate rolling speed in thread rolling process to produce products of better thread quality and for long life of the rolls. The rolling speed mainly depends on the tensile strength, the speed capabilities of the machine and the thread form to be rolled. In general, the rolling speed kept is very high. But if the speed is too low, then it may cause damage to the rolls.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Stretch Forming”.
1. Stretch forming is a sheet metal forming operation in which shearing is taking place to deform the material.
a) True
b) False
Answer: b
Explanation: Stretch forming is a type of sheet metal forming process in which the metallic sheet is intentionally stretched and bent simultaneously to produce different shapes of the stretched sheet metal. The metal sheet is generally held by jaws at the ends. And then the sheet is stretched by the help of punch.
2. For proper stretching operation, the metal sheet should be stressed above its yield strength.
a) True
b) False
Answer: a
Explanation: In stretch forming, a metal sheet is stretched by the help of stretcher machines. For proper and complete stretching of sheet, the material is deformed plastically which is also called as permanent deformation. The metal sheet is stressed above its yield strength for successfully achieving the plastic deformation of the metal sheet.
3. In stretch forming, spring-back is a very complicated problem which causes trouble in operating machines during the process.
a) True
b) False
Answer: b
Explanation: Spring-back is basically defined as a phenomenon in which the material tries to regain its original shape during elastic loading condition. But in stretch forming process, the stretching and bending operations take place simultaneously which causes permanent deformation of the sheet metal. So, this combined effect results in negligible spring-back in the metal part and hence causes no problem in the operating machines.
4. In stretch forming, forming limit curve is defined as a locus of all the limit strains in different strain paths of the sheet metal.
a) True
b) False
Answer: a
Explanation: In stretch metal forming process, the forming limit curve provides quantification about the formability of sheet metal, which basically gives the details about the quality of material. The forming limit curve is generally defined as a locus of all the limit strains in different strain paths like deep drawing and biaxial stretching, of the sheet metal.
5. Which of the following processes of metal forming is best suited for making products like aircraft wings and window frames?
a) Forging
b) Rolling
c) Drawing
d) Stretch forming
Answer: d
Explanation: Stretch forming is a sheet metal forming process in which the sheet metal is clamped at the edges and stretched by using the dies or form blocks. And no any lubrication is required significantly during the process. This method is best suited for making the products like aircraft wings, window frames, automobile door panels etc.
6. High volume rate of production can be possible by stretch sheet metal forming process.
a) True
b) False
Answer: b
Explanation: In stretch forming, the sheet metal is fixed with stretch gripper with the support of a tool, and then operation takes place in a hydraulic stretching unit. The process consumes too much time as the stretching process takes time to strain hardens the material. So, this process includes low volume rate of production, but the process is very versatile and have economic production.
7. Stretch forming is a process which involves tensile and bending forces during the operation.
a) True
b) False
Answer: a
Explanation: In stretch forming process, stretching of a metal sheet is basically done by holding its edges and bending it on a cylindrical block, simultaneously is known as stretch forming. This process basically involves tensile and bending forces during the operation. In this process, the materials with high ductility are mostly stretched by rigid dies.
8. The stretch forming process is generally performed by using a hydraulic operated ram.
a) True
b) False
Answer: a
Explanation: The stretch forming process is generally performed by using a hydraulic operated ram. In this process, first a single form block is used along with the gripping jaws, and then the metal is gripped and stretched by applying high tensile forces until it deforms plastically. And then the sheet metal is bent and rolled around a form block.
9. Tangential stretch forming and simple stretch forming are quite similar to each other.
a) True
b) False
Answer: b
Explanation: Tangential stretch forming is very different from simple stretch forming. However, the purpose is same. In tangential stretch forming, the metal sheet is gripped from two opposite ends. The main difference to the simple stretch forming is that the form block and gripping jaws both are movable in this process.
10. Rubber forming is a type of forming process in which polyurethane is used as a die material.
a) True
b) False
Answer: a
Explanation: Rubber forming is a type of forming process in which a polyurethane or rubber pad is commonly used as the die material instead of a rigid material. These materials are highly resistance to the abrasion and have a better fatigue life. And pressures of the order of 100 bar are typical of this process. This process is also called as Guerin process.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Rod and Tube Drawing”.
1. Which of the following types of stresses is applied during the process of rod or tube drawing?
a) Shear
b) Direct compressive
c) Tensile
d) In-direct compressive
Answer: c
Explanation: Rod or tube drawing is a deformation process in which the metallic material in the form of cylindrical bar is pulled by the help of a converging die. In general, the tensile stress is applied during the process. The strain hardening occurs which makes the material very hard and strong by reducing its ductility.
2. In rod drawing process, the cross-sectional area of the material remains constant.
a) True
b) False
Answer: b
Explanation: In rod drawing process, a bar or rod is drawn in order to reduce its diameter. The drawing operation results in the reduction in cross-sectional area of the material by increasing its length. This process is basically a kind of cold working process which takes place below the re-crystallization temperature of the material.
3. Which of the following processes of metal forming is widely used for making the raw material for the manufacturing of bolts?
a) Rolling
b) Forging
c) Wire drawing
d) Rod drawing
Answer: d
Explanation: Rod drawing is not completely similar to wire drawing process. Wire drawing is basically a metal forming process which is used for producing wires like electrical wires, cables, welding electrodes, fencing etc. And rod drawing is used for making the raw material for the manufacturing of bolts. The basic difference between rod drawing and wire drawing is the size of the metallic bar used for wire drawing is small.
4. Bar or rod drawing is a process which can be performed in a single draft.
a) True
b) False
Answer: a
Explanation: Bar or rod drawing process can be performed in single draft. A draft is a difference between the initial and final diameter of the metallic bar used. Whereas, for wire drawing process a small diameter metal bar is used. And wire drawing is basically done in multiple steps which use nearly around 4 to 12 dies.
5. In rod drawing process, the final output is coiled on a large metallic form roll.
a) True
b) False
Answer: b
Explanation: In rod drawing process, a draw bench is used instead of a form roll for drawing of rods or bars because rods cannot be coiled on any roll. The rod or bar is usually pointed by swaging operation and then fed into the drawing dies. And the tip of the rod is clamped into the jaws and then drawing process is carried out continuously.
6. Over drawing of the metallic rod can cause poor surface finish of the product.
a) True
b) False
Answer: a
Explanation: Rod drawing is a cold working process in which strain hardening occurs. Over drawing or reduction in cross-sectional area of bar beyond a certain limit can cause poor surface finish of the product. During this stage, the need of tensile stress increases substantially and the material becomes very hard and strong due to the reduction in its ductility.
7. In general, no any lubrication is required during the process of rod or bar drawing.
a) True
b) False
Answer: b
Explanation: In rod drawing process, the metallic rod is fixed into the dies by using a die holder and then a drawing head is used in which the metallic rod is fixed through a jaw mechanism. And then the bar is stretched and slides between the surfaces of the die, which causes friction and wearing. So to avoid such wearing, the rod is first lubricated before going into the process. In general, soap solution or oil is used for the lubrication in rod drawing process.
8. In rod drawing process, intermediate annealing is required for improving the ductility of material.
a) True
b) False
Answer: a
Explanation: Intermediate annealing is basically a kind of heat treatment process in which the material is heated and gradually cooled in order to obtain strength and ductility in the material. During the process of rod drawing, work hardening occurs which causes materials to be hard and less ductile, so for maintaining its mechanical properties, the intermediate annealing is performed.
9. Wet drawing is a process which involves throwing water jets onto the material during the process.
a) True
b) False
Answer: b
Explanation: Wet drawing basically involves dipping of metallic bar inside a lubricant bath before the next processing stage. In this process, the rod is lubricated by using lubricants like soap solution or oil. Lubrication can also be done by applying a coating of sulfate onto the material in order to retain the lubricant on the surface of metallic bar.
10. In rod drawing, a bearing is used which causes frictional drag on the metallic bar.
a) True
b) False
Answer: a
Explanation: In the rod or bar drawing process, the entrance of the die assembly includes a bell assembly which facilitates the entry of lubricant along with the metallic bar during the process. The bearing area causes frictional drag on the metallic bar and generally helps in the movement of the metallic bar inside the die mechanism.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Swaging”.
1. Swaging is a metal forming process in which material is deformed by performing bending operation.
a) True
b) False
Answer: b
Explanation: Swaging is a metal forming process of reducing or shaping the cross-section of metallic rods by means of repeated impacts or blows. This process basically consists of dies which are given the required external shape. These dies intermittently impact the material to produce the deformation.
2. Better surface finish and grain structure of material are the main advantages of using the swaging process.
a) True
b) False
Answer: a
Explanation: In the swaging process, hammering action is produced which provides better surface finish, tensile strength and better grain structure to the material. In this process, the work-piece should be completely clean and dry, and without any kind of lubricant. This method is very simple and can be performed by any unskilled operator.
3. In the swaging process, tubes cannot be swaged without the application of mandrels.
a) True
b) False
Answer: b
Explanation: In the swaging process, tubes can be swaged with or without the application of mandrels. In the case of swaging without mandrels, the surface finish obtained will not be proper and accurate when a blow is applied onto the material during the operation. When the length and thickness of the material increases simultaneously, then the need of mandrel becomes essential.
4. Rotary swaging is a forming process which is used for making tubes of high precision.
a) True
b) False
Answer: a
Explanation: Rotary swaging is a forming process which is mainly used for making tubes with high precision. This process can also be used making rods or bars, and it basically belongs to the group of net-shape forming processes, of which one of the features is that the finished shape of the material is produced without or with only a small quantity of further final processing by finishing.
5. The forming dies of swaging machine are generally arranged in an eccentric manner.
a) True
b) False
Answer: b
Explanation: In the swaging process, the forming dies of the swaging machine are generally arranged concentrically around the material rod. The swaging dies operate with high frequency radial motions and with small strokes. The stroke frequencies commonly range from 1500 to 10000 per minute which basically depends upon the size of machine or equipment.
6. In rotary swaging, a unitary or single die is used during the processing of metallic bar or rod.
a) True
b) False
Answer: b
Explanation: In rotary swaging process, the radial motions of the dies are very important for most of the applications. In general, a die set mainly consists of four die segments which basically depends on the type of application or use, and also depends on the size of the machine tool. In special cases of swaging, the number of die sets can be used up to eight dies.
7. A relative rotational motion between dies and materials is provided to prevent the formation of burrs during the process of swaging.
a) True
b) False
Answer: a
Explanation: In swaging process, the formation of longitudinal burrs at the gaps between the dies is generally prevented by providing relative rotational motion between the dies and the materials. The swaging dies rotate near the material or alternatively, the material rotates between the die segments.
8. Rotary swaging process is also called as incremental forming or oscillating forming process.
a) True
b) False
Answer: a
Explanation: Rotary swaging is basically an incremental forming process which is also called as oscillating forming, because it takes place in many small processing steps. One of the benefits of the incremental forming process compared to the continuous processes is the homogenous forming of the material. High forming ratios can also be achieved by a rotary swaging process in a single processing step.
9. Frictional wearing of dies is the major problem in the process of rotary swaging.
a) True
b) False
Answer: b
Explanation: In rotary swaging, the main benefit of the incremental forming process is the minimum friction, because the time of contact between the dies and material is very small. And the relative movement is very small during the contact, so wearing of dies does not take place easily during the process.
10. In rotary swaging, the lubrication is not required significantly during the process.
a) True
b) False
Answer: a
Explanation: In rotary swaging, the processing of the material is done by minimum relative motion and therefore minimum friction is present between the dies and materials. So the lubrication is not required significantly, but it is enough to use oil in a closed cycle which basically acts as a coolant or can be used for cleaning purpose.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Tube Making”.
1. Tube drawing process is very similar to bar drawing, except the input material is a tube.
a) True
b) False
Answer: a
Explanation: Tube drawing a kind of metal forming process which is very similar to bar drawing process, except the beginning of input material is a tube. This process is used to reduce the diameter, improve the surface finish and improve the dimensional accuracy of the metal tube. In this process, a mandrel may or may not be used, which mainly depends on the purpose.
2. The input of extrusion process is basically the output of tube drawing process.
a) True
b) False
Answer: b
Explanation: In general, the output of extrusion process can be the input of tube drawing process. In tube drawing process, the diameter and thickness of the tubes that have been formed by extrusion or other processes can be further decreased by tube drawing process. This process is almost similar to wire or rod drawing process except that it requires a mandrel to initiate the forming operation.
3. In tube drawing equipment, draw bench type uses multiple dies for completing the forming operation.
a) True
b) False
Answer: b
Explanation: In tube drawing process, the drawing equipment can be of several designs. In general, these designs are mainly classified into two types, which are draw bench and bull block. Draw bench type uses a single die and the pulling force is applied by a chain mechanism or by hydraulic system. It is mainly used for single length drawing of tube or rod.
4. Bull block drawing equipment is mainly used for drawing tubes of very long length.
a) True
b) False
Answer: a
Explanation: In general, the drawing equipment can be of draw bench or bull block type, depending on the purpose or required features in the tube. Bull block drawing equipment design is very similar to a rotating drum, and this equipment is mainly used for drawing the tubes or rods of very long length, which cannot be performed easily by having draw bench design of drawing equipment.
5. In tube drawing process, high dimensional accuracy of tube with close tolerances can be maintained.
a) True
b) False
Answer: a
Explanation: Tube drawing process is very economical and best suitable for producing tubes with thinner walls of high dimensional accuracy and close tolerances. This process is basically a cold working process which takes place at the room temperature or slightly above it. This process also provides better surface finish and enhances certain mechanical properties in the tube material.
6. Mandrel is a part of tube drawing mechanism, which is used for extracting out the tube from drawing mechanism.
a) True
b) False
Answer: b
Explanation: In the tube drawing process, when a hollow tube is drawn through a die, usually a mandrel or plug is used, which basically supports the internal diameter of the tube. The function of the mandrel mainly is to affect the wall thickness reduction and also used for controlling the shape and size of the hole in the tube.
7. The process of drawing a tube without the use of any mandrel is called as tube sinking.
a) True
b) False
Answer: a
Explanation: Tube drawing process can be performed with or without mandrel, depending on the features required in the drawn tube. The mandrel is generally excluded if it is not necessary to make a reduction in the wall thickness, or if the dimensions and surface finish are not important. The process of drawing a tube without the use of any mandrel is basically known as tube sinking.
8. The frictional problems can be increased if a long mandrel is used during the process of tube drawing.
a) True
b) False
Answer: b
Explanation: The tube drawing process can be accomplished by with or without mandrel. Mandrel basically consists of a hard rod or wire that extends over the entire length of the tube and is drawn through the die along with the drawing tube. The frictional problems can be greatly reduced by providing a long mandrel in the tube drawing process.
9. Removing of mandrel after the drawing process may disturb the dimensional tolerances.
a) True
b) False
Answer: a
Explanation: After tube drawing process, the mandrel should be removed from the tube which can be done by the reeling process. The removing process increases the tube diameter and also disturbs the dimensional tolerances. So, great care should be taken while extracting out the mandrel from the inside of tube.
10. In the tube drawing process, no any residual stresses are induced in the tube material.
a) True
b) False
Answer: b
Explanation: In the tube drawing process, the deformation is usually uniform throughout the tube. The process is a cold working process which causes residual stresses in the tube material. In general, the longitudinal residual stresses are tensile on the exterior surface and compressive on the interior surface of the tube.
This set of Forming Multiple Choice Questions & Answers focuses on “Forging Temperatures”.
1. Low carbon steels can be started to forge at what temperature?
a) 1140°C
b) 1270°C
c) 1350°C
d) 1420°C
Answer: b
Explanation: Low carbon soft steels are generally used for making seamless and welded steel pipes, which can be used at very low temperatures. They can be forged at a temperature range of 1250°C to 1300°C.
2. Low carbon steels get forged at what temperature?
a) 670°C
b) 730°C
c) 820°C
d) 950°C
Answer: c
Explanation: None.
3. At what temperature does the high carbon steel get forged?
a) 950°C
b) 1510°C
c) 1150°C
d) 1290°C
Answer: c
Explanation: The high carbon steel is provided heat treatment, after this, the steel is allowed to quench and then tempered. They can be forged at a temperature of 1100°C.
4. At what temperature does alloy steel get forged?
a) 850°C
b) 970°C
c) 1050°C
d) 1200°C
Answer: a
Explanation: For the improvisation of mechanical and physical properties of the materials, a variety of materials are added and to make it alloying steel. The temperature at which alloy steel can be forged is in the range of 825°C to 875°C.
5. At what temperature does wrought irons get forged?
a) Below 1000°C
b) Below 1100°C
c) Below 1200°C
d) Below 1300°C
Answer: d
Explanation: Wrought irons are identified as alloys of iron which contain very low amount of carbon in them. Wrought irons can be forged at a temperature below 1300°C.
6. What is the forging temperature of brass?
a) 450°C
b) 500°C
c) 550°C
d) 600°C
Answer: d
Explanation: Brass is an alloy of mainly two metals being, copper and zinc. These two metals can substitute each other’s place in the structure of the alloy. The temperature at which brass gets forged is about 600°C.
7. What is the forging temperature of bronze?
a) 850°C
b) 900°C
c) 950°C
d) 1000°C
Answer: c
Explanation: Bronze is an alloy that essentially contains copper in it and generally is found to contain about 12% of tin. It may also have some other additives in it like, manganese, zinc or nickel. The temperature at which bronze gets forged is about 950°C.
8. What is the forging temperature of magnesium alloys?
a) 450°C
b) 500°C
c) 550°C
d) 600°C
Answer: b
Explanation: Metals such as zinc, copper, zirconium, silicon or aluminium are mixed with magnesium to form a magnesium alloy. In terms of structure, magnesium is considered to be the lightest metal. The temperature at which magnesium alloys get forged is 500°C.
9. The grain size of steel increases with an increase in temperature.
a) True
b) False
Answer: a
Explanation: With an increase in the temperature, when the temperature goes above the upper critical temperature limit, the grain size of steel also begins to increase. However, on forging, the grain is broken down.
10. Cold working of steel takes place at a temperature below 823°C.
a) True
b) False
Answer: b
Explanation: If the hammering of steel has to take place under the temperature of 723°C, then this working would be considered as cold working. By doing this, one may expect for the occurrence of small hair cracks.
This set of Forming test focuses on “Hand tools and Appliances”.
1. The following figure represents which hand tool appliance?
forming-questions-answers-test-q1
a) Cross peen
b) Ball peen
c) Sledge
d) Straight pin
Answer: a
Explanation: Hand tools are often used when the work needed to be done is very short and can be done in small amount of time without the need of a machine, which would consume more energy and time. The following figure is that of a hand tool called as cross peen.
2. The following figure represents which hand tool appliance?
forming-questions-answers-test-q2
a) Cross peen
b) Ball peen
c) Sledge
d) Straight pin
Answer: d
Explanation: None.
3. The following figure represents which hand tool appliance?
forming-questions-answers-test-q3
a) Cross peen
b) Ball peen
c) Sledge
d) Straight pin
Answer: b
Explanation: None.
4. The following figure represents which hand tool appliance?
forming-questions-answers-test-q4
a) Cross peen
b) Ball peen
c) Set hammer
d) Straight pin
Answer: c
Explanation: The following figure is that of a set hammer. Whenever there are corners that need to be shouldered, it often becomes inconvenient to do it using other tools, here a set hammer plays an important role in shouldering it.
5. The following figure represents which hand tool appliance?
forming-questions-answers-test-q5
a) Cross peen
b) Ball peen
c) Sledge
d) Straight pin
Answer: c
Explanation: The following figure is that of a sledge. Sledges are generally observed to have a very big head area. This large area of the head allows the sledge to distribute its force over a wide area.
6. The following figure represents which hand tool appliance?
forming-questions-answers-test-q6
a) Drift
b) Ball peen
c) Sledge
d) Straight pin
Answer: a
Explanation: The following figure is that of a drift. A punch is a type of a hand tool, when there is a hole to be made in a metal part, and when the metal is experiencing forging heat, a punch can be used, after the making the holes, when it needs to widen apart, a tapered punch is passes through it, called the drift.
7. The following figure represents which hand tool appliance?
forming-questions-answers-test-q7
a) Drift
b) Ball peen
c) Sledge
d) Punch
Answer: d
Explanation: The following figure is that of a punch. A punch is a type of a hand tool, when there is a hole to be made in a metal part, and when the metal is experiencing forging heat, a punch can be used.
8. The following figure represents which hand tool appliance?
forming-questions-answers-test-q8
a) Straight peen
b) Flat tongs
c) Fuller
d) Gad tongs
Answer: c
Explanation: The following figure is that of a fuller. Whenever a piece has to be necked down, a fuller is a highly recommended object. Fullers are made available in various shapes and sizes, according to the requirements.
9. Swages are used for providing smoothness to the articles.
a) True
b) False
Answer: b
Explanation: Swages are used for work where the articles need a good finishing in terms of shapes, such as round, square or pentagonal etc, whereas for the smoothing purposes, flatters are highly used.
10. A flat tong is used for holding bolts.
a) True
b) False
Answer: b
Explanation: For the holding of bolts or rivets or any other circular section, a ring tong is used, whereas a flat tong is used whenever a section having a rectangular shape has to be held.
This set of Forming Mcqs focuses on “Smith Forging Operations”.
1. Which of the following operations involves reduction in length?
a) Upsetting
b) Drawing down
c) Setting down
d) Punching
Answer: a
Explanation: There are a few operations, which are needed for a change of shape of the raw material to its finished form. This can be achieved using smith forging operation. Upsetting is one such operation that involves reduction in length for an increase the thickness.
2. Swaging is another name for which smith forging operation?
a) Bending
b) Punching
c) Drawing down
d) Cutting
Answer: c
Explanation: Swaging is another name for the operation drawing down. In drawing down operation, the length of the material is found to increase at an expense of the width or thickness of it.
3. Which of the following operations involves the reduction in length?
a) Upsetting
b) Drawing down
c) Setting down
d) Punching
Answer: b
Explanation: There are a few operations, which are needed for a change of shape of the raw material to its finished form. This can be achieved using smith forging operation. Drawing down is one such operation that involves increase in length at the cost of its thickness.
4. Which of the following material is not used as a flux in forge welding?
a) 2 parts of borax with one part of sal-ammoniac
b) Quartz sand
c) Calcined borax
d) 3 parts of borax with one part of sal-ammoniac
Answer: a
Explanation: The metal which has to be welded, has to be first covered with flux. By covering it with flux, it cuts the metal from the air around and prevents from oxidation. The fluxes used for this purpose are quartz sand, calcined borax and 3 parts of borax with one part of sal-ammoniac.
5. In which form of weld, are the ends joined?
a) Lap weld
b) Butt weld
c) Jump weld
d) Split weld
Answer: a
Explanation: In lap weld, the ends of the two metals which are to be joined are prepared for welding. In butt welding, the materials are butted are together. In split weld, the metals are kept like a fork in a ‘V’ shape.
6. Which form of weld is also called as ‘T’ weld?
a) Lap weld
b) Butt weld
c) Jump weld
d) Split weld
Answer: c
Explanation: In butt welding, the materials are butted are together. In jump welding, the two pieces are kept at an angle of 90o, in the form of an inverted ‘T’.
7. In cutting smith forging operation, up to what temperature is the steel heated?
a) 700°C – 800°C
b) 850°C – 950°C
c) 900°C – 1000°C
d) 1000°C – 1100°C
Answer: b
Explanation: Cutting is a form of smith forging operation, it is a form of chiseling. For chiseling, a long piece of metal is cut into equal lengths. These equal lengths need to be heated till they are cherry red hot, which makes it a temperature of 850°C to 950°C.
8. Which form of weld is also called as ‘V’ weld?
a) Lap weld
b) Butt weld
c) Jump weld
d) Split weld
Answer: d
Explanation: In butt welding, the materials are butted are together. In split weld, the metals are kept like a fork in a ‘V’ shape.
9. Scarfing is a preparation of metals for welding.
a) True
b) False
Answer: a
Explanation: The shaping of the metal pieces, in order they get united at the center, and a correct shape gets formed, the metal pieces need to be prepared for welding before they actually get welded. This preparation for welding of metals is termed as scarfing.
10. In bending, the layer on the inside gets shortened.
a) True
b) False
Answer: a
Explanation: Bending is a type of process that is most frequently used in forging. It can be done over the edge of the anvil face or the anvil horn. When the metal undergoes bending, the layer which is present on the inside gets shortened and the layer on the outside gets stretched.
This set of Forming Quiz focuses on “Impression Die Forging”.
1. In compressed impression die forging, what is typically the shape of the solid blanks?
a) Cylindrical
b) Conical
c) Spherical
d) Pyramidal
Answer: a
Explanation: In compressed impression die forging, it is generally observed that the shape of solid blanks is either cylindrical or prismatic only. The shape of the solid blanks is similar even in case of stamping industry.
2. Which of the following is not an operation of impression die forging?
a) Broaching
b) Quenching
c) Bending
d) Spreading
Answer: b
Explanation: There are many basic and primary operations in impression die forging, a few of them are, broaching, bending, spreading, sizing and swaging. But, quenching is not any of the operations of impression die forging.
3. Which of the following is not produced using impression die forging?
a) Levers
b) Handles
c) Gears
d) Turbine blades
Answer: b
Explanation: Impression die forging finds itself into variety of applications. They are used in making a few automobile parts also. Among the following, levers, gears and turbine blades can be produced using impression die forging, but not handles.
4. Which of the following are not operated in impression die forging?
a) Hammers
b) Presses
c) Tongs
d) Special purpose machines
Answer: c
Explanation: In impression die forging, there are various such articles which can be forged, but after that need a little working on it. To accomplish that, hammers, presses and some other special purpose machining tools are employed. A tong is not one of them.
5. In forging dies, what is the maximum degree to which the drafts are made?
a) 7 o
b) 10 o
c) 13 o
d) 18 o
Answer: b
Explanation: In impression die forging, there has to be some amount of allowance given to the process, like machining allowance and draft allowance. The drafts are made with a maximum degree deviation of 10 o .
6. In forging dies, what is the minimum degree to which the drafts are made?
a) 1 o
b) 2 o
c) 3 o
d) 4 o
Answer: c
Explanation: There are some types of allowances which have to be given to the system before the operations begin, like, shrinkage allowance, machining allowance and draft allowance. The minimum angle which can be given to the drafts is only 3 o .
7. What is the minimum temperature given before hot forging?
a) 100°C
b) 150°C
c) 200°C
d) 250°C
Answer: c
Explanation: Hot forging is a method of forging articles at an extremely high temperature. But, before putting the article into the hot forging processes, it has to be heated to certain temperatures. The minimum temperature that has to be given to the article should be 200°C.
8. What is the maximum temperature that can should be given before hot forging process?
a) 150°C
b) 200°C
c) 250°C
d) 300°C
Answer: d
Explanation: In impression die forging, when any article has to be hot forged, it has to first be heated to bring at a certain temperature. The maximum temperature that can be provided for hot forging is 300°C.
9. Impression die forging is used only for multiple-pass process.
a) True
b) False
Answer: b
Explanation: In impression die forging, there are two types of pass processes, one is single-pass process and another is multiple-pass process. Multiple-pass process includes final stamping process in it.
10. Cold impression die forging is suited for mass production.
a) True
b) False
Answer: b
Explanation: Cold impression die forging is the most unsuited way of production when it comes to long productions or mass amounts of manufacturing. This is because in cold impression die forging, there is a need of complex and expensive dies, which end up making the process unnecessarily costly.
This set of Welding Questions and Answers for Freshers focuses on “Weldability”.
1. Which of the following is not included in weldability?
a) Ability of mechanical soundness
b) Serviceability of joint
c) Strain relieving brittleness
d) Metallurgical compatibility of metal
Answer: c
Explanation: For the making of good fabricated composition of a structure, metal with good weldability gets readily welded. Weldability includes the ability of the metal or the alloy to be having soundness in its mechanical properties, metallurgical compatibility of metal and serviceability of joint.
2. Which effect is not seen in alloys on weldability?
a) Control of ductile-malleable transformation temperature
b) Provision for oxidation to molten metal
c) Reduction in segregation
d) Grain refinement
Answer: b
Explanation: On weldability, there are some effects seen in the alloying elements. Some of them are Control of ductile-malleable transformation temperature, Reduction in segregation, Grain refinement and provision for deoxidation to the molten metal.
3. On which of the following factor, does weldability not depend?
a) Boiling point
b) Melting point
c) Thermal expansion
d) Thermal conductivity
Answer: a
Explanation: Weldability is dependent on five factors of the metal or alloying element. The factors being, melting point, thermal expansion, thermal conductivity, surface condition and change in the microstructure.
4. Which of the following is not a way of correcting the metal which does not have good weldability properties?
a) Procedure of welding
b) Provision of fluxing material
c) Provision of filler material
d) Procedure of adding filler materials
Answer: d
Explanation: When a particular metal or an alloy does not have desirable welding characteristics, then it can be corrected by proper fluxing material, correct filler material and a perfect welding procedure.
5. What does HAZ stand for?
a) Helium Aerated Zone
b) Heated Area Zone
c) Heat Affected Zone
d) Heat Allowed Zone
Answer: c
Explanation: HAZ stands for Heat Affected Zone. This zone is generally the base of the metal or a thermoplastic material. This zone is not melted but the properties are altered by the welding process.
6. With an increase in the heat input of arc welding method, how does it affect the welding speed?
a) Increases
b) Decreases
c) Remains same
d) No relation
Answer: b
Explanation: In arc welding processes, for calculating the efficiency, we use the formula for heat input. According to the formula, heat input is inversely related to the speed of welding, that is, with an increase in heat input, the welding speed decreases.
7. With an increase in the heat input of arc welding method, how does it affect the voltage applied?
a) Increases
b) Decreases
c) Remains same
d) No relation
Answer: a
Explanation: None.
8. With an increase in the heat input of arc welding method, how does it affect the required current?
a) Increases
b) Decreases
c) Remains same
d) No relation
Answer: a
Explanation: None.
9. In fusion welding, welded pieces are kept together under pressure.
a) True
b) False
Answer: b
Explanation: In fusion welding, the welded pieces are not kept under pressure, instead they are welded first and then allowed for some to cool down. It is in pressure welding, that the welded pieces are kept under pressure for some time.
10. Materials having high thermal conductivity are difficult to melt.
a) True
b) False
Answer: a
Explanation: Materials that have a medium melting point are considered to be welded easily and those materials which have their thermal conductivity very high are the toughest to be melted.
This set of Welding Interview Questions and Answers for freshers focuses on “Types of Welding”.
1. Which of the following is not a type of arc welding?
a) Plasma
b) Electro-slag
c) Submerged
d) Air-acetylene
Answer: d
Explanation: Among the following, plasma arc, electro-slag and submerged arc are few of the types of arc welding. Air-acetylene is one of the forms of gas welding processes.
2. Which of the following is not a type of resistance welding?
a) Seam
b) Projection
c) Electro-slag
d) Spot
Answer: c
Explanation: Among the following, seam, projection and spot are few of the types of resistance welding. Electro-slag is one of the forms of gas welding processes.
3. Which of the following materials are not suited for cold welding?
a) Brass
b) Steel
c) Silver
d) Gold
Answer: b
Explanation: Cold welding process is not very suitable for alloys like steel, the reason being, cold welding cannot take place excellently in ferrous materials. Steel contains high amount of iron, hence it cannot be cold welded.
4. What is the cross-sectional shape of a thermoplastic welding rod?
a) Triangular
b) Hexagonal
c) Square
d) Pentagonal
Answer: a
Explanation: A welding rod or a thermoplastic welding rod is used mainly in plastic welding. The rod should not be very porous or it may catch voids. This rod has a cross sectional shape triangular or circular.
5. Which of the following is not a type of related processes?
a) Soldering
b) Percussion
c) Brazing
d) Hard-pressing
Answer: b
Explanation: Among the following, soldering, pressing and hard-pressing are few of the types of related processes. Percussion is one of the forms of resistance welding processes.
6. Laser is classified under newer beam.
a) True
b) False
Answer: a
Explanation: There are various types of welding processes, one of them is a newer welding process. Under this, there are two types, one is electron-beam and another is the use of laser.
7. Which of the following is not a type of solid state welding?
a) Projection
b) Ultrasonic
c) Friction
d) Diffusion
Answer: a
Explanation: Among the following, ultrasonic, friction and diffusion are a few of the types of related processes. Percussion is one of the forms of resistance welding processes.
8. What is the density of the plastic used in speed tip welding?
a) 916 kg/m 3
b) 923 kg/m 3
c) 946 kg/m 3
d) 982 kg/m 3
Answer: c
Explanation: The plastic which is used in the process of speed tip welding is polypropylene or polypropene. It is classified under thermoplastics materials. The density of polypropylene is 946 kg/m 3 and it starts melting at 130°C.
9. Which of the following could be considered as a related process?
a) Explosive
b) Oxy-Hydrogen welding
c) Oxy-Acetylene cutting
d) Electron-beam
Answer: c
Explanation: Among the following, oxy-acetylene cutting is considered as a related process. Explosive is a type of solid state welding. Electron-beam is a type of newer welding and oxy-hydrogen welding is a form of gas welding.
10. A liquid phase has to be used in cold welding.
a) True
b) False
Answer: b
Explanation: It is hot welding that a liquid or a molten state is used for the joining of two pieces of metal. But in cold welding, there is no use of a liquid phase, that is, joining is done without using heat.
This set of Welding Interview Questions and Answers focuses on “Metallurgy of Weld”.
1. In which run weld, in ordinary steels, the grain refinement takes place?
a) First
b) Second
c) Third
d) Fourth
Answer: b
Explanation: A multi run process causes a good amount of grain refinement. With every proceeding run weld, it normalizes its previous run. In ordinary steels, grain refinement takes place in the second run.
2. What is the minimum strength of mild steel arc welds on addition of microelements in the slag?
a) 43 kgf/mm 2
b) 39 kgf/mm 2
c) 45kgf/mm 2
d) 48 kgf/mm 2
Answer: a
Explanation: When there is an addition of some microelements in the slag along with a few materials being present which are not metals, there is an increase in the strength of the mild steel arc weld. The minimum amount of strength goes up to 43 kgf/mm 2 , which is 430 N/mm 2 .
3. Which of the following is affected by weld contour?
a) Fatigue
b) Creep
c) High pressure property
d) Low pressure property
Answer: a
Explanation: The contour present on the welds form notches. The contours in the form of notches then affect the low temperature properties of the structure and also the fatigue properties.
4. Thermite contains which metal?
a) Zinc
b) Copper
c) Aluminium
d) Manganese
Answer: c
Explanation: The reaction that takes place in between compounds and elements is known welding with solid reactants. These reaction are exothermic, that is give out heat as a product. Thermit reaction is a common example for this, which is mixture of aluminium and rust.
5. Which of the following property is considered for controlling the porosity of the metal?
a) Solid solubility
b) Liquid solubility
c) Gas solubility
d) Flame solubility
Answer: c
Explanation: The amount of solubility of gas in liquid or solid welded metals is considered to be an essential criteria for the control of porosity of the weld. The gas reactions which occur, then regulate porosity.
6. Slag used in fusion welding contains manganese.
a) True
b) False
Answer: a
Explanation: Slags used in welding are generally a combination of silica materials and some carbonate compounds. In fusion welding, some amount of bead control has to be done, which is done by the slags, for this purpose, to improve its performance, microelements like manganese are added.
7. Which of the following property is responsible for weld metal cracking?
a) Stress
b) Strain
c) Temperature conditions
d) Pressure conditions
Answer: a
Explanation: The stresses which get developed in welding during shrinkage are of importance. These stresses are considered to be an important factor which are responsible for the cracking that occurs in metal welds.
8. A thermit reaction produces heat up to what temperature?
a) 4800°F
b) 4000°F
c) 5600°F
d) 5300°F
Answer: b
Explanation: None.
9. What is the maximum strength of mild steel arc welds on addition of microelements in the slag?
a) 53 kgf/mm 2
b) 49 kgf/mm 2
c) 57kgf/mm 2
d) 61 kgf/mm 2
Answer: c
Explanation: When there is an addition of some microelements in the slag along with a few nonmetallic inclusions, there is an increase in the strength of the mild steel arc weld. The maximum amount of strength goes up to 57 kgf/mm 2 , which is 570 N/mm 2 .
10. Slag used in fusion welding has nitrogen.
a) True
b) False
Answer: a
Explanation: Slags used in welding are generally a combination of silica materials and some carbonate compounds. In fusion welding, some amount of bead control has to be done, which is done by the slags, for this purpose, to improve its performance, microelements like nitrogen are added.
This set of Casting, Forming and Welding Multiple Choice Questions & Answers focuses on “Gas Welding”.
1. Which of the following types of fuel gas is commonly used in gas welding?
a) Biogas
b) Coal gas
c) Acetylene
d) Methane
Answer: c
Explanation: Gas welding is usually referred as oxy welding or oxy-fuel welding which is a process of joining metallic materials by application of heat produced by the gas flame. In gas welding, acetylene is commonly used as fuel gas which mixed with proper proportion of oxygen in a mixing chamber of welding torch. Gas welding can produce a hot flame of temperature about 3000-3500 ⁰C.
2. In gas welding, the joint can be made even much stronger than the original.
a) True
b) False
Answer: a
Explanation: In gas welding, various metals like cast iron, steel, aluminium, copper etc. can be used for joining operation. First they brought into a molten state and then a fusion is taking place between two pieces of metal in such a way that the point of fusion closely approaches the strength of the metal fused. In this process, the union or joint can be made even much stronger than the original.
3. Acetylene is a hydrocarbon which molecule is made up of two carbon atoms and four hydrogen atoms.
a) True
b) False
Answer: b
Explanation: In gas welding, acetylene is used as a fuel gas which is a hydrocarbon like other as propane, methane etc. However, it generally differs from those hydrocarbons in a manner that its molecule is made up of two carbon atoms and two hydrogen atoms. And the carbon atoms are joined with hydrogen atoms by making a triple bond.
4. Acetylene is a blue color gas which mixed with oxygen to produce a hot flame.
a) True
b) False
Answer: b
Explanation: In gas welding, acetylene is basically a colorless gas with a very distinctive odour and highly combustible when it is mixed with oxygen. Acetylene gas is formed by mixing the calcium carbide with water and then it is composed, which forms a compound of carbon and hydrogen having the chemical formula C2H2.
5. Gas welding is mainly suited for welding of thin sheets, small diameter pipes and tubes.
a) True
b) False
Answer: a
Explanation: Gas welding process is mainly suited for the welding of a thin sheet, tubes, and small diameter pipe because it cannot provide very high temperature as compared to that provided by the electric arc welding. This method of joining is also used for repairing work, maintenance and in body shops.
6. Acetylene is a non-toxic gas which can be kept or stored in a cylinder at any pressure.
a) True
b) False
Answer: b
Explanation: In gas welding, acetylene is used as a fuel gas which produces hot flame when it is mixed with oxygen. Acetylene may be non-toxic gas, but if it is stored in a cylinder at more than the pressure of 2 bar, then the acetylene becomes self explosive, that’s why the pressure of stored acetylene should be maintained with great care.
7. Single stage gas regulator cannot be used in cold weather for regulating the acetylene or oxygen gas.
a) True
b) False
Answer: a
Explanation: Single stage converter is used to reduce the pressure from the cylinder pressure to the welding pressure, which can take place in a single stage. However, it tends to freeze in cold weather. This is because an abrupt expansion and resulting drop in initial pressure makes rapid cooling of the gas and may cause ice formation in the presence of moisture.
8. In gas welding, the hoses are mainly used for making the connection between gas torch and regulators.
a) True
b) False
Answer: a
Explanation: In gas welding, the hoses are mainly used for making connections between the gas torch and the regulators, which should be made strong, light and flexible enough to make torch movements smooth. In general, welding hose can be of two types that are twin welding hose and double welding hose.
9. A flashback is a condition in gas welding, when the pure methane gas is used as fuel gas instead of acetylene.
a) True
b) False
Answer: b
Explanation: In gas welding, a flashback is a condition in which the flame burns inside the gas torch. Flashback is generally caused by improper mixing of gases, which further increases the rate of flame propagation to high extent that the flame goes back to the mixing chamber. If it is not stopped, the flame may burn the mixture and may travel back into the cylinder.
10. A welding torch is mainly used for mixing and burning the gases in the desired proportions.
a) True
b) False
Answer: a
Explanation: In gas welding, a welding torch is mainly used for mixing oxygen and acetylene in the desired proportions. It is also used for burning the mixture at the end of the tip, and also provides a mean for moving and directing the flame front. Welding torch can be of high pressure type or low pressure type.
This set of Welding Questions and Answers for Experienced people focuses on “Oxy-Acetylene Welding”.
1. Oxy-acetylene process is most suited for which of the following process of joining?
a) Metal wires
b) Metal sheets
c) Metal tubes
d) Metal bars
Answer: b
Explanation: Oxy-acetylene process is most suited for the joining of metal sheets or for joining metal plates which are having a thickness of 2mm to 50mm. While joining, the molten metal flows together to form a continuous joint.
2. For what thickness of a material, in an oxy-acetylene is a welding rod used?
a) 10 mm
b) 15 mm
c) 20 mm
d) 25 mm
Answer: b
Explanation: Oxy-acetylene processes are mainly used for the joining of metal sheets or for joining metal plates which are having a thickness of 2mm to 50mm. When the thickness of the material is more than 15 mm, an additional filler metal is added like a welding rod.
3. What is the flame temperature of city gas?
a) 1500°C
b) 1600°C
c) 1700°C
d) 1800°C
Answer: c
Explanation: City gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 3 mm. The flame temperature of city gas is approximately about 1700°C.
4. In a neutral flame, what is the temperature in the inner core?
a) 3200°C
b) 2100°C
c) 1250°C
d) 2700°C
Answer: a
Explanation: When equal amount of oxygen and acetylene is made to react in a torch, a neutral flame gets produced. The inner core has a temperature of 3200°C, whereas the tip of the neutral flame has a temperature of 1250°C.
5. What is the flame temperature of water gas?
a) 2500°C
b) 2800°C
c) 2300°C
d) 3100°C
Answer: c
Explanation: Water gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 8 mm. The flame temperature of water gas is approximately about 2300°C.
6. Carburising flame has excess of oxygen supply.
a) True
b) False
Answer: b
Explanation: None.
7. What is the flame temperature of methane?
a) 2000°C
b) 1200°C
c) 2700°C
d) 3300°C
Answer: a
Explanation: None.
8. Oxidizing flame has equal volumes of oxygen and acetylene supply.
a) True
b) False
Answer: b
Explanation: A neutral flame is the one in which there is an equal amount of supply of oxygen and acetylene. A carburising flame is the one in which the supply of acetylene is much more than that of oxygen and an oxidizing flame is the one where there is ample supply of oxygen compared to acetylene.
9. What is the flame temperature of acetylene?
a) 1700°C
b) 2200°C
c) 2800°C
d) 3200°C
Answer: d
Explanation: Acetylene gas is a type of fuel gas that is used for the welding of thin sheets of steel which have a thickness of up to 50 mm. The flame temperature of acetylene gas is approximately about 3200°C.
10. What is the flame temperature of hydrogen?
a) 2000°C
b) 1200°C
c) 2700°C
d) 3300°C
Answer: c
Explanation: None.
This set of Welding Interview Questions and Answers for Experienced people focuses on “Arc Welding”.
1. What is the order of temperature of heat produced in an electric arc furnace?
a) 3000°C – 4000°C
b) 4000°C – 5000°C
c) 5000°C – 6000°C
d) 6000°C – 7000°C
Answer: d
Explanation: An electric arc furnace generates a lot of heat when the working metal comes in contact with the electrode. The heat that is generated in this joining process is of the order 6000°C to 7000°C.
2. The distance from the center of arc to the tip of electrode is called what?
a) Arc distance
b) Arc length
c) Arc crater
d) Arc depth
Answer: b
Explanation: The distance from the center of the arc to the tip of the electrode, right till the bottom of the crater is defined to be the arc length. The arc length is considered to be one of the most essential variable in welding process.
3. What is the length of the arc generally?
a) 1mm – 2mm
b) 2mm – 3mm
c) 3mm – 4mm
d) 4mm – 5mm
Answer: c
Explanation: None.
4. In arc welding process, the high quality alternator functions at what frequency?
a) 250 Hz
b) 300 Hz
c) 350 Hz
d) 400 Hz
Answer: d
Explanation: In an arc welding process, there are alternators used for producing high current and function at lower frequency, and there are alternators which are of high quality and work at high frequency. The functioning frequency of these alternators is 400 Hz.
5. Which type of electrode is designed for melting quickly?
a) Fast fill
b) Fast freeze
c) Quick fill
d) Fill freeze
Answer: a
Explanation: Electrodes which are classified into three types, fast fill, fast freeze and fill freeze. Among these, the fast fill electrodes are considered to be able to operate at extremely high welding speeds, and hence fast fill electrodes are designed for quick melting.
6. What amount of electricity gets converted into heat energy in an arc welding process?
a) 0.25 kWh
b) 0.75 kWh
c) 1 kWh
d) 2 kWh
Answer: c
Explanation: In an arc welding process, there is a direct conversion of electrical energy into heat energy. An approximate amount of 1 kilo Watt hour of electrical energy gets converted into heat energy for this process.
7. Arc welding machine uses only D.C. supply.
a) True
b) False
Answer: b
Explanation: Arc welding machines are able of working on both alternating current supply as well as direct current supply. But mainly arc welding machines work on D.C. supply only, where the positive terminal is connected to the welding machine.
8. Which type of electrode is designed for melting quickly?
a) Fast fill
b) Fast freeze
c) Quick fill
d) Fill freeze
Answer: b
Explanation: Electrodes which are classified into three types, fast fill, fast freeze and fill freeze. In fast freeze electrodes, a filler metal is supplied. This filler element gets solidifies and provides a variety in positions of the weld.
9. Which material is not used as an iron coating on the electrode used in arc welding?
a) Cellulose
b) Iron powder
c) Calcium fluoride
d) Steel
Answer: d
Explanation: Materials that are used as coating on the electrode, that are used in arc welding, are cellulose, iron powder, calcium fluoride and rutile. Iron is used for ease of weld, but not steel, though it mainly contains iron.
10. The negative pole of the electrode burns away faster than the positive pole.
a) True
b) False
Answer: b
Explanation: During the operation of the arc welding process, the positive pole of the electrode experiences two third of the heat and the negative pole experiences one third the heat, hence the positive pole burns away faster than the negative pole.
This set of Welding test focuses on “Arc Welding Equipment”.
1. What is the capacity of an automatic welding machine?
a) 100 to 200A
b) 300 to 400A
c) 500 to 700A
d) 800 to 3000A
Answer: d
Explanation: An automatic welding machine has a high amount of capacity. Its capacity ranges in between 800 to 300A. This type of machine is not portable and is suitably used for heavy welding processes.
2. What is the capacity of a light manual welding machine?
a) 100 to 200A
b) 300 to 400A
c) 500 to 700A
d) 800 to 3000A
Answer: a
Explanation: A light manual welding machine has one of the lowest capacity among all types of welding machines. Its capacity ranges in between 100 to 200A. This machine is portable and is best suited for light welding processes.
3. What is the current required in an Oxygen’s INDARC 400 transformer?
a) 20 amp to 100 amp
b) 40 amp to 250 amp
c) 50 amp to 400 amp
d) 60 amp to 500 amp
Answer: c
Explanation: In an Oxygen’s INDARC 400 transformer, there is a hand wheel provided which is used for varying the output, for altering the air gap in the core and results in regulating the current in between 50 amperes to 400 amperes.
4. What is the efficiency of an A.C. welding transformer?
a) 0.6
b) 0.7
c) 0.8
d) 0.9
Answer: c
Explanation: A.C welding is currently gaining considerable ground. The efficiency of an alternating current welding transformer varies from 0.8 to 0.85 and the efficiency of A.C. outfits is in the range of 0.3 to 0.6.
5. What is the amount of electric energy required per kg in dc welding operation?
a) 1-4 kWh
b) 3-7 kWh
c) 4-9 kWh
d) 6-10 kWh
Answer: d
Explanation: The amount of electrical energy consumed required per kg for a D.C. welding operation, is 6 kWh to 10 kWh. Direct current provides the advantage of distribution of the heat needed inside the arc.
6. Which material is not used for making non-consumable electrodes?
a) Carbon
b) Graphite
c) Sodium
d) Tungsten
Answer: c
Explanation: Non-consumable electrodes, are those electrodes which do not get consumed as the welding operation proceeds. These electrodes are primarily made up of materials like carbon, graphite and tungsten.
7. Which of the following characteristic does not define a coated electrode?
a) Maintenance of arc
b) Protection from oxygen
c) Protection from nitrogen
d) Preventing other elements into molten metal
Answer: d
Explanation: A coated electrode is a further classification of a consumable electrode. The purpose of the electrode is to maintain the arc, to shield the molten metal from oxygen and nitrogen present in the air and to provide other alloying elements into the molten metal.
8. What is the amount of carbon contained by a soft steel wire?
a) 0.1% to 0.18%
b) 0.15% to 0.22%
c) 0.18% to 0.26%
d) 0.2% to 0.27%
Answer: a
Explanation: A soft steel wire contains about 0.1% to 0.18% of carbon. Soft steel wire also has other contents in it like phosphorous and sulphur in it. The amount of phosphorous is soft steel is around 0.0025%.
9. What is the percentage of carbon present in low alloy steel?
a) 0.15%
b) 0.2%
c) 0.25%
d) 0.3%
Answer: c
Explanation: The amount of carbon that is present in a soft steel wire is around 0.1% to 0.18% and the amount of carbon in terms of percentage composition in low alloy steels is 0.25%.
10. The presence of arc blower makes good quality welds.
a) True
b) False
Answer: b
Explanation: A flow of large amount of current causes the generation of arc blower. The space around the arc and the metal always experience magnetic fields, causing the currents to get squared. This results in an unstable behavior by the arc blower, which is therefore not desirable for good welds.
This set of Welding Quiz focuses on “Arc Welding Methods”.
1. Why is carbon used in carbon arc welding?
a) Generation of more heat at electrode tip
b) Generation of less heat at electrode tip
c) Provides coating
d) Fixed polarity is maintained
Answer: b
Explanation: Carbon is used in carbon arc welding, at the negative terminal of the cathode. The reason for employing carbon at the negative terminal is that, a lesser amount of heat is generated at the electron tip than at the workpiece.
2. What is the temperature at the negative terminal in carbon arc welding?
a) 3000°C
b) 3100°C
c) 3200°C
d) 3300°C
Answer: c
Explanation: None.
3. The process of carbon arc welding is not used for which of the following material?
a) Copper
b) Bronze
c) Aluminium
d) Iron
Answer: d
Explanation: The process of carbon arc melting is widely used for copper and copper alloys, hence bronze and brass are treated by this method. Aluminium can also be treated likewise, but not iron metal.
4. Which gas is used as a protection in carbon arc welding?
a) Carbon dioxide
b) Carbon monoxide
c) Carbon tetra fluoride
d) Methane
Answer: b
Explanation: In carbon arc welding, there has to be a protection to be provided to the molten weld. This protection is provided in the form of an envelope by using a long arc giving carbon monoxide gas.
5. What is the temperature at the positive terminal in carbon arc welding?
a) 3800°C
b) 3900°C
c) 4000°C
d) 4100°C
Answer: b
Explanation: Carbon is used in carbon arc welding, at the negative terminal of the cathode and the metal which is being worked upon functions as the positive terminal. The temperature of the electrode at the positive terminal is 3900°C.
6. What is the temperature of the negative electrode in metal arc welding?
a) 2200°C
b) 2300°C
c) 2400°C
d) 2500°C
Answer: c
Explanation: In metal arc welding, the temperature of negative electrode is higher than the temperature of positive electrode. The temperature produced in a negative electrode of a metal arc weld is about 2400°C.
7. What is the temperature of the positive electrode in metal arc welding?
a) 2300°C
b) 2400°C
c) 2500°C
d) 2600°C
Answer: d
Explanation: None.
8. Which bead character is seen due to too high welding current?
a) Pilling of metal
b) Pilling of weld metal
c) Excess splatter
d) Small bead formation
Answer: c
Explanation: On provision of too low current, there is pilling of metal seen. When the voltage provided is very high, beads formed are too high. When the speed of weld is less, pilling of weld metal takes place and when welding currents are too high, excessive splatter formation occurs.
9. A smooth and regular bead cannot be formed in metal arc welding.
a) True
b) False
Answer: b
Explanation: Before the welding starts, the machine has to be adjusted very correctly. The current to be supplied and the voltage to be applied should not to be too low or high, and the welding speed should be normal. By doing this, regular and smooth beads will be formed.
10. Carbon is intended to be mixed in small amounts in the weld, in carbon arc welding.
a) True
b) False
Answer: b
Explanation: In carbon arc welding, the carbon is present at the negative electrode, where the electrode temperature is at 3200°C. This temperature is lesser than that at the positive electrode. Carbon electrode is kept at a lower temperature on the negative electrode, to avoid the mixing of carbon in the weld. If the carbon gets mixed with the weld, the weld might end up becoming brittle.
This set of Welding MCQs focuses on “Resistance Welding Methods”.
1. Which kind of resistance is experienced in upset butt welding?
a) Electric resistance
b) Magnetic resistance
c) Thermal resistance
d) Air resistance
Answer: a
Explanation: In the making of an upset butt welding, there are jaws made of copper, into which the part to be welded is put, and hence a solid contact is made. At this point of contact, while the current flows, it gets transformed into heat because of electric resistance.
2. Which of the following can be easily be welded from flash butt welding process?
a) Tin
b) Lead
c) Cast irons
d) Carbon steel
Answer: d
Explanation: In flash butt welding process, the welding of materials like steels and other iron alloys are easy to weld, except for cast iron. The welding of materials like tin, lead, zinc and antimony cannot be welded using flash butt method.
3. Electrodes used in spot welding are made up of which material?
a) Only Copper
b) Copper and tungsten
c) Copper and chromium
d) Copper and aluminium
Answer: d
Explanation: The electrodes that are employed in the spot welding are required to possess a high amount of electrical and thermal conductivity. Hence, they are primarily made up of copper or copper and tungsten or copper and chromium.
4. How are the metals to be welded connected to each other in spot welding?
a) Electric contact
b) Magnetic field
c) Mechanical pressure
d) Direct contact
Answer: c
Explanation: In spot welding process, the metal or the alloy parts which are to be welded, are heated in their in their zones. To bring these parts in contact with one another, mechanical pressure is applied, causing them to connect.
5. Which of the following method is not used in applying pressure in spot welding process?
a) Hand lever
b) Foot lever
c) Air pressure
d) Hydraulic cylinder
Answer: a
Explanation: None.
6. Up to what thickness, can steel be welded using spot welding process?
a) 10 mm
b) 11 mm
c) 12 mm
d) 13 mm
Answer: c
Explanation: In spot welding process, to bring the heated parts in contact with one another, mechanical pressure is applied. This pressure can be of three types, by using foot lever, by providing air pressure or by using a hydraulic cylinder. The use of these methods allows steel or other metal parts to be welded up to a thickness of 12 mm.
7. What is the maximum power supply needed for the working of spot welding process?
a) 135 kVA
b) 140 kVA
c) 145 kVA
d) 150 kVA
Answer: d
Explanation: Spot welding can be used for all types of ductile metals. It can also be employed for structures of sheet metals, and can be applied for making of boxes and cans. For its applications, the maximum power that can be needed for this process is 150 kVA.
8. What is the minimum power supply needed for the working of spot welding process?
a) 10 kVA
b) 14 kVA
c) 6 kVA
d) 22 kVA
Answer: a
Explanation: None.
9. Upset butt welding is majorly used in the making of automobile parts.
a) True
b) False
Answer: b
Explanation: Upset butt welding is mainly used for the manufacture of welding bars, rods, wires or tubing. For the manufacture of automobile parts, such as axles, wheels or frames, flash butt welding is extensively used.
10. In flash butt welding, the forced out metal is called flash.
a) True
b) False
Answer: a
Explanation: In flash butt welding process, there is a light contact between the edges. A high voltage is supplied when the flashing action takes place. In this process, the metal that is forced out, is called as flash.
This set of Welding Multiple Choice Questions & Answers focuses on “Thermit Welding”.
1. In an iron thermit, how many moles of aluminium reacts with three moles of iron oxide to give nine moles of iron?
a) 6
b) 7
c) 8
d) 9
Answer: c
Explanation: The thermit process, which is used for welding depends on the chemical reaction between oxide of iron and aluminium metal. According to this reaction, when 8 moles of aluminium reacts with 3 moles of iron oxide, then, 4 moles of aluminium oxide and 9 moles of iron is formed.
2. In the given figure of thermit welding apparatus, what does the question mark represents which part?
welding-multiple-choice-questions-answers-q2
a) Sand plug
b) Crucible
c) Wax pattern
d) Slag basin
Answer: b
Explanation: Around the parts which are to be united, superheated liquid steel is poured, which then effects in forming the weld. This process, hence, is a fusion welding process. The part represented by the question mark is the crucible.
3. In the given figure of thermit welding apparatus, what does the question mark represents which part?
welding-multiple-choice-questions-answers-q3
a) Sand plug
b) Crucible
c) Wax pattern
d) Slag basin
Answer: d
Explanation: None.
4. In the given figure of thermit welding apparatus, what does the question mark represents which part?
welding-multiple-choice-questions-answers-q4
a) Riser
b) Workpiece
c) Runner
d) Wax pattern
Answer: d
Explanation: In this apparatus of the thermit welding process, the question mark here represents the pattern made up of wax. This process is basically carried out in fusion welding.
5. In the given figure of thermit welding apparatus, what does the question mark represents which part?
welding-multiple-choice-questions-answers-q5
a) Riser
b) Workpiece
c) Runner
d) Wax pattern
Answer: b
Explanation: None.
6. In the given figure of thermit welding apparatus, what does the question mark represents which part?
welding-multiple-choice-questions-answers-q6
a) Riser
b) Workpiece
c) Runner
d) Wax pattern
Answer: c
Explanation: In this figure, the question mark is represented by the runner. This process is carried out at fusion welding.
7. In the given figure of thermit welding apparatus, what does the question mark represents which part?
welding-multiple-choice-questions-answers-q7
a) Riser
b) Runner
c) Sand plug
d) Preheating
Answer: c
Explanation: The part represented by the question mark is the sand plug. Superheated liquid steel is poured, which then effects in forming the weld. This process, hence, is a fusion welding process.
8. After the achievement of welding temperature, electrical connections are established to complete the weld.
a) True
b) False
Answer: b
Explanation: The superheated melt is heated from the crucible gets poured around the metal parts. As the welding temperature is achieved, there is an application of mechanical pressure to the weld.
9. What is the magnitude of temperature produced in a thermit reaction?
a) 2500°C
b) 3000°C
c) 3500°C
d) 4000°C
Answer: b
Explanation: Thermit welding is called as fusion welding. A superheated melt operates in this type of melt. The heat that is produced has the temperature approximately twice than that of the melting point of steel, which is about 3000°C.
10. Thermit welding is used for making rail tracks.
a) True
b) False
Answer: a
Explanation: A superheated melt operates in this type of melt. The production of pipes, rail tracks, shafts or big gears can be done using thermit pressure welding. Thermit welding is called as fusion welding.
This set of Welding online test focuses on “Solid State Welding”.
1. At what temperature, does fusion welding takes place?
a) 850°C
b) 900°C
c) 950°C
d) 1000°C
Answer: b
Explanation: The process of fusion welding can be used for joining metal to a metal or a metal can be joined to a ceramic. For the joining of this process, a temperature of 900°C is provided for the approach.
2. Which of the following is not a type of diffusion welding?
a) Gas-pressure welding
b) Vacuum fusion welding
c) Eutectic fusion bonding
d) Eutectoid fusion welding
Answer: d
Explanation: Diffusion welding is has three basic techniques which are incorporated by it. These three basic techniques are, gas – pressure welding, vacuum fusion welding and eutectic fusion welding.
3. What is the minimum frequency used in ultrasonic welding?
a) 10,000 Hz
b) 20,000 Hz
c) 30,000 Hz
d) 40,000 Hz
Answer: b
Explanation: The process of ultrasonic welding is mainly used for the joining of similar metals or dissimilar metals using vibration energy, by way of high frequency. The minimum frequency needed for this purpose is 20,000 Hz.
4. What is the maximum frequency used in ultrasonic welding?
a) 30,000 Hz
b) 40,000 Hz
c) 50,000 Hz
d) 60,000 Hz
Answer: d
Explanation: None.
5. In what conditions are the parts kept before welding in ultrasonic welding method?
a) Low static pressure
b) High static pressure
c) Low moving pressure
d) High moving pressure
Answer: a
Explanation: In ultrasonic welding method, the parts which are to be joined, are kept clamping to one another in between of supporting member and the welding tip. This clamping is done at a low static pressure.
6. What is the maximum thickness that can be welded in ultrasonic welding?
a) 1.8 mm
b) 2.1 mm
c) 2.3 mm
d) 2.5 mm
Answer: d
Explanation: Weldings such as spot welding or continuous seam welding can be done through ultrasonic welding. The maximum thickness that can be achieved varies depending on the metal. The maximum thickness can be that can be welded is 2.5mm.
7. Electric currents are passed is ultrasonic welding.
a) True
b) False
Answer: b
Explanation: In ultrasonic welding method, the parts which are to be joined, are kept clamping to one another in between of supporting member and the welding tip. In doing this, no current is required to be passed through the metal, and usually, no heat is needed for this too.
8. What is the minimum thickness that can be welded in ultrasonic welding?
a) 0.58 mm
b) 0.21 mm
c) 0.38 mm
d) 0.92 mm
Answer: c
Explanation: None.
9. Which of the following is not a factor for explosive welding?
a) High relative velocity
b) Less amount of plastics
c) Proper orientation
d) High pressure
Answer: b
Explanation: While considering for explosive welding, the factors that one needs to understand is that, there has to be high relative velocity. There should be proper orientation and it needs to be kept under high amount of pressure.
10. ‘α’ is the angle between target plate and flyer plate.
a) True
b) False
Answer: a
Explanation: The workpiece which has its position fixed is called as the target plate and the other plate is called as flyer plate. The distance between the two plates is denoted by ‘d’ and the angle between them is denoted by ‘α’.
This set of Welding online quiz focuses on “Oxygen Cutting”.
1. Which gas is used for the removal of oxygen layer formed on molten iron?
a) Hydrogen
b) Oxygen
c) Carbon dioxide
d) Chlorine
Answer: b
Explanation: In oxygen cutting method, under considerable amount of pressure, when a jet of oxygen gas is made to blow on the particles of molten iron oxide, the oxygen layer present on the molten iron gets removed.
2. Up to what amount of carbon content in steels, can they be treated by oxygen cutting?
a) 0.3%
b) 0.2%
c) 0.7%
d) 0.4%
Answer: c
Explanation: For a steel to be treated by oxygen cutting process, the carbon content that should be available in terms of percentage composition is around 0.7%, that is, the steel that can be treated by this process is a high alloy steel.
3. Up to what temperatures are high alloy steels heated before treating them by oxygen cutting?
a) 675°C
b) 725°C
c) 775°C
d) 825°C
Answer: a
Explanation: In oxygen cutting process, not all steels can be treated by this method. Only high alloy steels can be treated by this method. These steels need to be preheated before oxygen cutting. The temperature range up to which these steels are preheated is about 650°C to 700°C.
4. What are the number of opening available in the cutting torch used in oxygen cutting process?
a) 4
b) 5
c) 6
d) 7
Answer: d
Explanation: Just like any other gas welding equipment, the welding torch gets substituted by a cutting torch in oxygen cutting process. The total number of openings available in the torch are six, with a large opening at the center, making the count to seven.
5. What is the maximum oxygen pressure that can be applied to steel?
a) 13 atm
b) 14 atm
c) 15 atm
d) 16 atm
Answer: b
Explanation: None.
6. What is the minimum oxygen pressure that can be applied to steel?
a) 3 atm
b) 4 atm
c) 5 atm
d) 6 atm
Answer: a
Explanation: In oxygen cutting process, not all steels can be treated by this method. Only high alloy steels can be treated by this method. The pressure supply of oxygen should not be low, as it may lead to the formation of slag on the bottom of the cut. The minimum oxygen pressure that can be applied to steels is 3 atmospheres or 300 kN/m 2 .
7. What is the initial oxygen pressure provided through the lance?
a) 1 atm to 2 atm
b) 2 atm to 3 atm
c) 3 atm to 4 atm
d) 4 atm to 5 atm
Answer: a
Explanation: In oxygen lance cutting, jet of oxygen is passed through steel pipes, and by doing this, holes are produced. For doing this, the jet of oxygen is passed through the lancer under the pressure of 1 atm to 2 atm.
8. What should the outer diameter of a thick-welled lance be, for having good results?
a) 13 mm to 15 mm
b) 15 mm to 17 mm
c) 17 mm to 19 mm
d) 19 mm to 21 mm
Answer: c
Explanation: In oxygen lance cutting, when the lance is made up of a thick wall, with its outer diameter of 17 mm to 19 mm, and possessing an inner diameter of 8 mm to 6 mm, respectively, then good results can be obtained.
9. Cast irons are best treated using oxygen cutting process.
a) True
b) False
Answer: b
Explanation: Cast irons cannot be treated using oxygen cutting process. The reason being that the melting point of cast irons is a lot lower than its ignition temperature. The same cannot be said for high alloy steels.
10. Oxygen cutting process can be applied to metals having a melting point higher than their oxidization temperature.
a) True
b) False
Answer: b
Explanation: It can be counted among one of the drawbacks of oxygen cutting process, that the metal which is to be treated must have its oxidizing temperature higher than its melting temperature, otherwise the metal would get melted before getting oxidized.
This set of Welding Question Bank focuses on “Welding of Various Metals”.
1. Which of the following methods cannot be used for welding carbon steel?
a) Arc welding
b) Gas welding
c) Ultrasonic welding
d) Forge welding
Answer: c
Explanation: For the welding of carbon steel material, one may use the arc welding method. To gas weld carbon steel is also a feasible option and carbon steels can be treated using forge welding also, but it cannot be welded using ultrasonic welding.
2. High alloys steels are preheated up to what temperature?
a) 350°C
b) 400°C
c) 450°C
d) 500°C
Answer: b
Explanation: High alloy steels are those steels which contain high amount of carbon in them. These alloys need to be preheated before welding in order to avoid cracking. The temperature up to which these alloys are preheated is 400°C.
3. Up to what percent of carbon content in steel, it is not required to preheat it?
a) 0.25% – 0.3%
b) 0.3% – 0.35%
c) 0.35% – 0.4%
d) 0.4% – 0.45%
Answer: a
Explanation: Low carbon steels are the ones containing low amount of carbon in them, which does not require preheating. The amount of carbon content needed in low carbon steels, is 0.25% to 0.3%, if preheating is to be avoided.
4. Which of the following material is not used in alloy steels?
a) Molybdenum
b) Nickel
c) Chromium
d) Sodium
Answer: d
Explanation: In alloy steels, there is a big composition used up by iron. Along with iron, there vitally has to be carbon in alloy steels. Along with carbon, there is a presence of other elements such as, molybdenum, nickel and chromium in small amounts.
5. Which among the following methods is best suited for stainless steels?
a) Electric butt welding
b) Seam welding
c) Flux coated arc welding
d) Oxy-hydrogen welding
Answer: a
Explanation: There are a few methods of treating stainless steels for welding, such as, any of the metal arc welding methods or the oxy-acetylene welding method, but the one best suited for this alloy is electric butt welding.
6. Stainless steels are annealed at what temperature?
a) 650°C – 700°C
b) 700°C – 750°C
c) 750°C – 800°C
d) 800°C – 850°C
Answer: c
Explanation: Stainless steels are hardened by constant heating and cooling and the best method suited for this alloy is electric butt welding. As soon as the stainless steel alloy is electric butt welded, it needs to be annealed at a temperature in between 750°C to 800°C.
7. Which of the following is not a material used for making an electrode in metal arc welding, for treating stainless steels?
a) Niobium
b) Columbium
c) Titanium
d) Potassium
Answer: d
Explanation: Stainless steels are best welded using the electric butt welding method and then followed by annealing at around 750°C to 800°C. Stainless steels can also be welded using the metal arc welding methods. For this the electrode which is needed is made up of niobium, titanium and columbium. These materials avoid the occurrence of the defect called weld decay.
8. What is the temperature needed for preheating in cast irons?
a) 550°C
b) 600°C
c) 650°C
d) 700°C
Answer: b
Explanation: Cast irons, upon the removal of welding heat, get solidified very quickly. This solidification takes place due to the surrounding cold mass and the air around. Because of such quick cooling, the carbon gets retained and hard metal stays in the weld. To overcome this, cast irons have to be preheated to 600°C.
9. Low carbon steels need not be preheated before welding.
a) True
b) False
Answer: a
Explanation: Carbon steels which contain carbon in a very low amount are not compulsorily required to be preheated before undergoing welding if the large runs are made. This is because, in low carbon steels, unlike high carbon steels, there is no cracking seen on welding.
10. Carbon steels can be fusion welded.
a) True
b) False
Answer: b
Explanation: Carbon steels are best treated using forge welding, resistance welding, arc welding or by gas welding. Carbon steels essentially cannot be fusion welded, because, of the occurrence of cracks which may cause due to carbon pick up.
This set of Welding Questions and Answers for Entrance exams focuses on “Adhesive Bonding”.
1. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q1
a) Butt unsatisfactory
b) Plain lap good
c) Beveled lap excellent
d) Scarf better
Answer: a
Explanation: Structural adhesives are mainly used when the joint is forced upon by the loads of shear and tensions. To avoid cleavage stresses, an adhesive bonded joint is used. This figure represents a butt unsatisfactory.
2. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q2
a) Scarf better
b) Plain lap good
c) Beveled lap excellent
d) Butt unsatisfactory
Answer: a
Explanation: None.
3. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q3
a) Butt unsatisfactory
b) Plain lap good
c) Beveled lap excellent
d) Scarf better
Answer: b
Explanation: A cleavage stress might result in failures even at low levels of loading. To avoid this, an adhesive bonded joint is used. This figure represents a plain lap good joint.
4. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q4
a) Scarf better
b) Beveled lap excellent
c) Plain lap good
d) Butt unsatisfactory
Answer: b
Explanation: None.
5. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q5
a) Beveled lap excellent
b) Plain lap good
c) Strap good
d) Joggle lap better
Answer: c
Explanation: A cleavage stress might result in failures even at low levels of loading. To avoid this, an adhesive bonded joint is used. This figure represents a strap good joint.
6. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q6
a) Joggle tap better
b) Double lap good
c) Double strap better
d) Scarf better
Answer: c
Explanation: In this figure, there is a double strap better. A cleavage stress might result in failures even at low levels of loading. This is used to avoid cleavage stresses.
7. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q7
a) Beveled lap excellent
b) Plain lap good
c) Strap good
d) Joggle lap better
Answer: d
Explanation: The following figure would here represent a joggle lap better. An apparatus like this is used when the joint experiences loads and tensions.
8. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q8
a) Double butt lap excellent
b) Tongue and groove
c) Double lap good
d) Joggle lap better
Answer: c
Explanation: None.
9. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q9
a) Double butt lap excellent
b) Tongue and groove
c) Double tap good
d) Joggle tap better
Answer: b
Explanation: To remove cleavage stress, structural adhesives are used. To avoid this, an adhesive bonded joint is used. This figure represents a tongue and groove joint.
10. The following figure represents which type of adhesive bonded joint?
welding-questions-answers-entrance-exams-q10
a) Double butt lap excellent
b) Tongue and groove
c) Double tap good
d) Joggle tap better
Answer: a
Explanation: None.
This set of Welding Questions and Answers for Campus interviews focuses on “Riveting”.
1. Which of the following articles is not manufactured using riveting?
a) Rail wagons
b) Coaches
c) Pressure vessels
d) Helmets
Answer: d
Explanation: Riveting is largely used in the manufacture of rail wagons, coaches, pressure vessels, bridges and few types of furnace bodies, but for the manufacture of helmets, riveting cannot be used.
2. The following figure represents which rivet head?
welding-questions-answers-campus-interviews-q2
a) Pan head
b) Conical head
c) Countersunk head
d) Cup head
Answer: d
Explanation: Riveting is a process that is used for fastening a particular joint permanently. The following figure is that of a Cup head riveting or snap head riveting is the most commonly used method of riveting.
3. The following figure represents which rivet head?
welding-questions-answers-campus-interviews-q3
a) Pan head
b) Conical head
c) Countersunk head
d) Cup head
Answer: a
Explanation: For the production of rivets, the most commonly used materials are wrought iron and mild steels. The following figure represents a pan head rivet.
4. Which of the following materials is not used in making rivets?
a) Wrought iron
b) Mild steel
c) Brass
d) Calcium
Answer: d
Explanation: Among the following, calcium is not used the riveting process. For the making of rivets, the used materials are wrought iron and mild steels. There are other materials also used in it, but they are used for small works, such as brass, copper and aluminium.
5. The following figure represents which rivet head?
welding-questions-answers-campus-interviews-q5
a) Pan head
b) Half countersunk head
c) Conical head
d) Snap head
Answer: b
Explanation: Riveting is a process that is used for fastening a particular joint permanently. For the production of rivets, the most commonly used materials are wrought iron and mild steels. The following figure represents a pan head rivet.
6. The following figure represents which rivet head?
welding-questions-answers-campus-interviews-q6
a) Conical head by hammering
b) Snap head
c) Pan head
d) Conical head
Answer: a
Explanation: None.
7. The following figure represents which rivet head?
welding-questions-answers-campus-interviews-q7
a) Conical head by hammering
b) Snap head
c) Pan head
d) Conical head
Answer: d
Explanation: Such an apparatus has a conical head and is produced by hammering. The following figure represents a conical head unlike snap head, pan head and conical head.
8. There can be 4 rows of rivets in lap joint.
a) True
b) False
Answer: b
Explanation: In case of lap joint or butt joint, the riveted joints can be single riveted, double riveted or treble riveted, and when the forces are high, a lozenge joint or a diamond joint can be involved, in that case there can be only one, two or three rows in lap joint, not more.
9. The following figure represents which rivet head?
welding-questions-answers-campus-interviews-q9
a) Conical head
b) Snap head
c) Countersunk head
d) Pan head
Answer: c
Explanation: None.
10. Cup head riveting provides maximum strength.
a) True
b) False
Answer: b
Explanation: Cup head riveting or snap head riveting is the most commonly used method of riveting, but the method that provides the most strength is the pan head riveting method.
