The purpose of heat treatment is to

A. Relieve the stresses set up in the material after hot or cold working

B. Modify the structure of the material

C. Change grain size

D. Any one of these

Answer: Option D

Solution(By Examveda Team)

Heat treatment process effect on material structure and grains.
Most carbon steels and carbon alloy steels can be heat treated for the purpose of improving mechanical properties such as tensile and yield strength.
This is accomplished due to the heat treatment fundamentally altering the microstructure of the steel.