Ion Nitriding

Standard – UNI 5478
Typical Materials – 42CrMo4, 39NiCrMo3, 41CrAlMo7, AISI 304, AISI 420, etc.
Achievable Metallurgical Characteristics – Maximum achievable depths:
– Low-alloy steels: 0.30mm
– Martensitic stainless steels: 0.20mm
– Austenitic stainless steels: 0.10mm

Plasma nitriding is a thermochemical process similar to conventional gas nitriding that enhances the surface hardness and wear resistance of components. Compared to gas nitriding, plasma nitriding allows for greater control over the thickness of the white layer deposited and is applicable to steels that are otherwise not nitridable, such as stainless steels.

The process takes place at temperatures between 350-500°C, with nitrogen enrichment achieved through the dissociation of ammonia introduced into the treatment chamber. During the treatment, a potential difference is created between the parts (acting as the cathode) and the treatment chamber (anode); this high potential difference generates a stable luminous discharge (plasma) that envelops the components, allowing nitrogen to diffuse into the surface. The components are then slowly cooled in the furnace to room temperature.

Due to the nature of the process, particular care must be taken with sharp edges, which may experience partial melting, and with deep holes, which often do not achieve uniform nitriding across their surface.