This set of Metal Forming Multiple Choice Questions & Answers (MCQs) 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
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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
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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
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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
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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
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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
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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
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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
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Explanation: The objective of annealing process is mainly is to induce ductility or softness in the material. To anneal ferrous materials (iron is base metal), 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
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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
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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.
Sanfoundry Global Education & Learning Series – Metal Casting, Forming and Welding.
To practice all areas of Casting, Forming and Welding, here is complete set of 1000+ Multiple Choice Questions and Answers.