Plasma nitriding is a process which makes use of the properties of the gas plasma, of an ionized gas.

The advantage is that a low process temperature of about – or under – 500° C is well suited for plasma nitriding and there is thus no drop in the core hardness of hardened steel. Another special feature is that in plasma nitriding even high-porosity sintered steels as well as cast iron and high-alloy tool steels can be treated.

Very often, this method is used before coating with PVD or CVD, since in plasma nitriding the possibility of forming a diffusion layer without compound layer can be produced.