Heat Treatment of steel castings

Steel castings are heat treated for the following purposes;

1)      To soften

2)      To harden and toughen

3)      To diffuse carbon and other alloying elements.

4)      To improve machinability

5)      To increase resistance to wear

6)      To remove hydrogen

7)      To stress relieve the castings.

Different heat treatment operations:

a)      Homogenization

b)      Annealing

c)      Normalizing

d)     Stress-reliving:

a)      Mechanical means

b)      Thermal means

e)      Quench hardening