Plasma nitriding (also known as ion nitriding, plasma ion nitriding or glow-discharge nitriding), is an industrial surface hardening treatment for metallic materials.
In plasma nitriding, the reactivity of the nitriding media is not due to temperature but to the gas ionized state. In this technique intense electric fields are used to generate ionized molecules of the gas around the surface to be nitrided. The gas used for plasma nitriding is usually pure nitrogen, since no spontaneous decomposition is needed.
This process permits the close control of the nitrided microstructure, allowing nitriding with or without compound layer formation. Not only is the performance of metal parts enhanced, but working lifespans also increase, and so do the strain limit and the fatigue strength of the metals being treated. The nitrided surface enhances seal performance since it reduces surface friction.