02
Quenching and Tempering Processing
03
Technology for heating processing
General steel heat treatment includes the following techniques:
Quenching
Steel is heated to a temperature higher than its transformation point to form austenite; then the steel is quickly cooled to form martensite. This process increases the hardness and strength of the steel without changing its shape, but the steel becomes more brittle.
Tempering
Heating the steel again after quenching adds elasticity and toughness, transforming the steel to a structure with high resistance to wear. However, the hardness is slightly reduced when compared with the state after quenching..
Annealing
This process is used to improve the structure and soften the steel since semi-hard steel, hard steel and alloy steel are difficult to cut due to their hardness.
Normalizing
This process is used to make the structure finer, uniformize carbides and remove residual stresses, thus making the steel easier to cut. Since hardenability also improves, normalizing is sometimes used as a pre-process before quenching.