Thermo-chemical heat treatments are applications where a diffusion takes place between the facade of the material subjected to heat treatment and the furnace atmosphere. During this diffusion, while the thermocouple is solid, the heat treatment medium can be solid, liquid or gas. Surface chemical analysis changes from another treatment process. Cementation is performed when enriched with carbon, and nitration process when enriched with nitrogen.
In this process, the main goal is to make the surface more resistant to factors such as fatigue and corrosion. Depending on the type of surface treatment, an increase in the hardness of the material can also be observed.