Questions and Answers Section 5

Questions and Answers

Question :

41.Which of the following is a case hardening process?

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Carburising

Cyaniding

Nitriding

all of these

Note:-

Cyaniding

Most liquid carburizing baths contain cyanide, which introduces both carbon and nitrogen into the case.

nitriding

heat (steel) in the presence of ammonia or other nitrogenous material so as to increase hardness and corrosion resistance.

Question :

42.The process used for relieving the internal stresses previously set up in the Metal and for increasing the machinability of steel, is

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process annealing.

Note:

Annealing is a heat treatment process which alters the microstructure of a material to change its mechanical or electrical properties. Typically, in steels, annealing is used to reduce hardness, increase ductility and help eliminate internal stresses.

Question :

43.Steel containing up to 0.15% carbon, is known as

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dead mild steel.

Note:-

Dead Mild Steel has a carbon content of between 0.05% and 0.15%. This gives Dead Mild Steel the property of good Ductility and the ability to be easily formed. Some of the uses of Dead Mild Steel are : Tinplate, Car Bodies, Chains, Nails, Thin Wire, etc.