Forming Interview Questions on “Annealing and Normalizing”.
1. Which of the following is not an objective of annealing?
a) Softening of steel
b) Hardening of steel
c) Increase ductility
d) Relieve internal stress
Answer: b
Clarification: Among the many purposes of treating the steel through annealing is softening of steel, hardening of steel and relieving the internal stresses, but annealing is not used for hardening of the steel.
2. In full annealing, the steel is heated at what temperature?
a) Above critical temperature
b) Above vaporization temperature
c) Above liquefying temperature
d) Above solidification temperature
Answer: a
Clarification: In the process of full annealing, the steel has to be heated slightly above the critical temperature. At this point, the steel has to be held for a considerable amount of time.
3. In annealing process, for the formation of hypereutectoid steel, the steel has to be heated above what point?
a) Ac1
b) Ac2
c) Ac3
d) Ac4
Answer: a
Clarification: For the formation of hypereutectoid steel, in annealing process, the steel has to be heated above the Ac1 point, which is the lower critical line in the temperature versus carbon content graph.
4. In annealing process, for the formation of hypoeutectoid steel, the steel has to be heated above what point?
a) Ac1
b) Ac2
c) Ac3
d) Ac4
Answer: c
Clarification: None.
5. For how long is the heated steel held in full annealing process?
a) 1 minute
b) 3 minutes
c) 6 minutes
d) 9 minutes
Answer: b
Clarification: The heated steel is held at the critical temperature for about 3 to 4 minutes. By doing this, the steel gets enough time to make the internal changes desired.
6. In full annealing, the metal cannot be buried in which of the following materials?
a) Sand
b) Lime
c) Ashes
d) Manganese powder
Answer: d
Clarification: In the process, full annealing, if the metal is removed at high temperatures, they need to be buried. For this, the material cannot be manganese powder.
7. Annealing is a fast process.
a) True
b) False
Answer: b
Clarification: Annealing is considered to be a very slow process, as the part where the steel is cooled, takes up a lot of time for the process to get completed.
8. Which of the following is also called as diffusion annealing?
a) Isothermal annealing
b) Process annealing
c) Homogenizing
d) Spheroidise annealing
Answer: c
Clarification: Homogenising has another name as diffusion annealing. This method is applied to both the ingots, carbon as well as alloy steel.
9. At what temperature is homogenizing carried out?
a) 1150°C
b) 1370°C
c) 1420°C
d) 1320°C
Answer: a
Clarification: Homogenizing is carried out between temperature ranges of 1100°C to 1200°C, but the most optimum temperature is 1150°C, at which the diffusion process goes ahead smoothly.
10. Normalizing process takes a lot of time to complete.
a) True
b) False
Answer: b
Clarification: Normalizing is a comparatively faster process than annealing, as in this process, the cooling rate is supposed to be very high, causing the process to end in lesser time.