A surface hardening process used on ferrous metals by heating the metal in contact with ammonia gas or other nitrogenous material.

A thermochemical treatment in which nitrogen is diffused into the steel. The treatment is usually carried out at a temperature around 500C, in either a gas or salt bath atmosphere, or with the use of a plasma.

The process of adding nitrogen to the surface of a steel usually from dissociated ammonia as the source. Nitriding develops a very hard case after a long time at comparatively low temperature, without quenching.

Also known as Case Nitriding, it involves infusing nitrogen into the surface layer of the part at a specific temperature, changing the alloy at that layer.