This set of Heat Treatment of Metals and Alloys Multiple Choice Questions & Answers (MCQs) focuses on “Steels Processes – Annealing”.
1. Which one of the following statements is correct regarding annealing?
a) Rate of cooling is very slow
b) Rate of cooling is more than that of normalizing
c) Rate of cooling is more than that of quenching
d) Rate of cooling is non-uniform
View Answer
Explanation: During the annealing process, steel is heated to a pre-determined temperature, holding at this temperature and then followed by slow cooling. The temperature may vary according to the type of cooling.
2. Which one of the following statements is incorrect regarding annealing?
a) It improves ductility
b) It improves machinability
c) It improves brittleness
d) It relieves internal stresses
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Explanation: Annealing heat treatment has various advantages. Annealing process improves ductility and machinability. It also relieves the internal stresses produced during processes like solidification, forging, rolling, etc. It therefore reduces brittleness.
3. Which one of the following statements is incorrect regarding annealing?
a) It increases the gaseous content in steel
b) It reduces chemical non-uniformity
c) It refines grain size
d) It enhances machinability
View Answer
Explanation: Annealing process reduces chemical non uniformity. It also refines grain size and enhances machinability. It also reduces the gaseous content in steel thus improving the mechanical properties.
4. Which one of the following statements is incorrect regarding annealing?
a) Phase transformation takes place during full annealing
b) Phase transformation takes place during partial annealing
c) Phase transformation takes place during subcritical annealing
d) Phase transformation does not take place during full annealing
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Explanation: Unlike full annealing and partial annealing, phase transformation does not take place during subcritical annealing. The reason is that during subcritical annealing steel is heated below a lower critical temperature. Therefore no phase transformation takes place at that temperature.
5. Which one of the following statements is incorrect regarding annealing?
a) On the basis of phase transformation features annealing can be classified into 3 types
b) On the basis of phase transformation features annealing can be classified into 2 types
c) On the basis of phase transformation features annealing can be classified into 4 types
d) On the basis of phase transformation features annealing can be classified into 5 types
View Answer
Explanation: On the basis of phase transformation features annealing can be classified into 2 types. The first type of annealing is done with the sole purpose of achieving some properties with no microstructural changes. The second type is mainly concerned with phase transformation.
6. Which one of the following statements is correct regarding annealing?
a) For first order annealing there is a wide range of temperature available
b) For second order annealing there is a wide range of temperature available
c) For first order annealing temperature should be more than upper critical temperature
d) For second order annealing temperature should be less than lower critical temperature
View Answer
Explanation: The first order annealing is done with the sole purpose of achieving some properties with no microstructural changes. No phase transformation is involved in this; therefore the temperature required is less than lower critical temperature giving a wide range of temperatures. The second type is mainly concerned with phase transformation.
Sanfoundry Global Education & Learning Series – Heat Treatment of Metals and Alloys.
To practice all areas of Heat Treatment of Metals and Alloys, here is complete set of Multiple Choice Questions and Answers.
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