Ferritic Nitrocarburizing

Standard – UNI 10931
Typical materials – 42CrMo4, 39NiCrMo3, 41CrAlMo7, C40, etc.
Metallurgical characteristics obtainable – Surface hardness varies depending on the material and the pre-treatment hardness level. Values range between 450-1200HV.
Effective nitriding depth: 0.10-0.60mm

Ferritic nitrocarburizing is typically applied to finished parts at the end of all mechanical processing. In some cases, depending on the application and level of finish, subsequent lapping may be required after the treatment.

Nitrocarburizing provides components with high surface hardness without affecting the core mechanical properties. Additionally, the process ensures high wear and corrosion resistance. It is widely used in the automotive industry, particularly for transmission shafts, where fatigue resistance is significantly improved.

The process involves heating the components to temperatures below austenitization, typically between 540-580°C, in a controlled atmosphere that allows the diffusion of nitrogen and carbon into the surface of the components. By varying the exposure time, the required depth can be controlled according to the design specifications. Since the diffusion process is slow, the achievable depths are much shallower compared to thermochemical processes like carburizing. After nitrocarburizing, the components are cooled in a controlled manner within the furnace to ambient temperature.

The lower processing temperatures greatly minimize deformations, particularly if the process is preceded by pre-treatment quenching and/or stabilizations at temperatures of at least 600°C.