25) What is the main purpose of annealing ?

To improve machinability

To improve magnetism

To increase hardness

To increase toughness

Answer is:

To improve machinability

Explanation:

Purpose of Annealing process is to
- To soften the steel.
- To improve the machinability.
- To increase the ductility.
- To relieve the internal stresses.
- To refine the grain size and to prepare the steel for subsequent heat treatment process.

Heat Treatment MCQ - Machinist(Set-1) with Answers

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Related Heat Treatment MCQ - Machinist(Set-1) with Answers

26) During heat treatment when carbon is dissolved to form solid solution, it is known as

Ferrite

Pearlite

Austenite

Cementite

Answer is:

Austenite

27) Which one of the following is the solid carburizing material ?

Charcoal

Petrol

Ammonia

Kerosene

Answer is:

Charcoal

28) While hardening, after heating the steel to the required temperature, it is held at that temperature as soaking time for normally

5 minutes for 10 mm thickness

10 minutes for 5 mm thickness

2 minutes for 20 mm thickness

20 minutes for 2 mm thickness

Answer is:

5 minutes for 10 mm thickness

29) Which one of the following quenching media is used for hardening H.S.S. tool ?

Water

Brine solution

Oil

Soda water

Answer is:

Oil

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