Heat treatment

Heat treatment is a group of industrial, thermal and metal working processes used to change physical and sometimes chemical properties of a material. It is most often used in metallurgy.

Heat treatment is also used to produce many other materials such as glass. Heat treatment involves the use of heating or cooling, usually to extreme temperatures, to achieve a desired result such as curing or softening the material. 

Heat treatment methods include annealing, cementation, dispersion peening, tempering, carburizing, normalization and hardening. Although the term heat treatment only applies to processes in which heating and cooling are performed for the specific purpose of intentionally changing properties, heating and cooling often occurs accidentally during other manufacturing processes such as hot stamping or welding.

Heat treatment of gears