1. 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.
2. Which one of the following quenching media is used for hardening H.S.S. tool ?
Oil .
3. What is the hardening temperature for H.S.S. tool ?
1250°C .
4. Which one of the following is the purpose of tempering a hardened steel component ?
To increase toughness.
5. While normalizing the steel should be cooled
in still air to room temperature.
6. The process of increasing carbon percentage on the surface of low-carbon steel is known as
Carburizing.
7. The process of producing a component with tough and ductile core and a hard outer surface
is known as
Case hardening.
8. 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
Normalizing.
9. Which one of the following heat treatment processes produces a scale-free surface on
the component ?
Induction hardening.
10. In heat treatment process annealing is done to
increase the softness.
11. After hardening process, the metal becomes more hardened and also will become more
Brittle.
12. For case hardening the first stage is carburising. By carburising it is meant...
Increasing the percentage of carbon on the surface.
13. For annealing hypoeutectoid steel according to the carbon content, it should be heated to
30°C to 50°C above the upper critical point.
14. Liquid carburising is done in a heated salt bath. Which one of the following is not a
carburising salt ?
Sodium sulphate.
15. For best result of annealing, the heated steel piece is cooled
slowly in the furnace itself by switching off the heat supply.
5 minutes for 10 mm thickness.
2. Which one of the following quenching media is used for hardening H.S.S. tool ?
Oil .
3. What is the hardening temperature for H.S.S. tool ?
1250°C .
4. Which one of the following is the purpose of tempering a hardened steel component ?
To increase toughness.
5. While normalizing the steel should be cooled
in still air to room temperature.
6. The process of increasing carbon percentage on the surface of low-carbon steel is known as
Carburizing.
7. The process of producing a component with tough and ductile core and a hard outer surface
is known as
Case hardening.
8. 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
Normalizing.
9. Which one of the following heat treatment processes produces a scale-free surface on
the component ?
Induction hardening.
10. In heat treatment process annealing is done to
increase the softness.
11. After hardening process, the metal becomes more hardened and also will become more
Brittle.
12. For case hardening the first stage is carburising. By carburising it is meant...
Increasing the percentage of carbon on the surface.
13. For annealing hypoeutectoid steel according to the carbon content, it should be heated to
30°C to 50°C above the upper critical point.
14. Liquid carburising is done in a heated salt bath. Which one of the following is not a
carburising salt ?
Sodium sulphate.
15. For best result of annealing, the heated steel piece is cooled
slowly in the furnace itself by switching off the heat supply.
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