HEAT TREATMENT MCQ FOR SEM 3

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

Ferrite

Pearlite

Cementite

Austenite

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

Petrol

Ammonia
Charcoal

Kerosene

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

10 minutes for 5 mm thickness
5 minutes for 10 mm thickness

2 minutes for 20 mm thickness

20 minutes for 2 mm thickness

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

Water

Brine solution

Oil

Soda water

5) What is the hardening temperature for H.S.S. tool?

950°C
1250°C

850°C

750°C

6) Which one of the following is the purpose of tempering a hardened steel component?

To increase ductility

To increase hardness
To increase toughness

To reduce hardness

7) While normalizing the steel should be cooled

in oil

by forced air

in water
in still air to room temperature

8) The process of increasing carbon percentage on the surface of low-carbon steel is known as

Hardening

Nitriding

Tempering

Carburizing

9) The process of producing a component with tough and ductile core and a hard outer surface is known as

Hardening

Tempering

Case hardening

Annealing

10) The process of heating steel to about 40°C above the upper critical temperature and cooling it in still air to room temperature is known as

Hardening

Annealing

Normalizing

Tempering

11) Which one of the following heat treatment processes produce a scale-free surface on the component?

Induction Hardening

Flame Hardening

Case hardening

Nitriding

12) In heat treatment process annealing is done to

increase the toughness

increase the hardness
increase the softness

increase the brittleness

13) After the hardening process, the metal becomes more hardened and also will become more

Ductile

Malleable
Brittle

Tough

14) For case hardening, the first stage is carburizing. By carburizing, it s meant...

Increasing the percentage of carbon of the steel piece.

Increasing the percentage of carbon of the core of the piece.

Increasing the percentage of carbon on the surface.

Decreasing the percentage of carbon of the steel piece.

15) For annealing hypereutectoid steel according to the carbon content, it should be heated to

30°C to 50°C above the lower critical point.

600°C to 630°C.
30°C to 50°C above the upper critical point.

1000°C to 1030°C.

16) Liquid carburizing is done in a heated salt bath. Which one of the following is not a carburizing salt?

Sodium carbonate

Sodium cyanide
Sodium sulphate

Barium chloride

17) For best result of annealing, the heated steel piece is cooled

by removing the piece from the furnace and allowing it to cool in open air.

be removing the piece from the furnace and placing it under a blast of air.
slowly in the furnace itself by switching off the heat supply.

by removing the piece from the furnace and dipping it in a tank containing water.