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
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
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
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 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
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 softness
increase the brittleness
13) After the hardening process, the metal becomes more hardened and also will become more
Ductile
Malleable
Brittle
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.
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
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.
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.
No comments:
Post a Comment