Ferritic Nitrocarburizing (FNC)
Process in which both nitrogen and carbon are absorbed into the surface layers of a ferrous material at temperatures below the lower critical temperature (AC3) and, by diffusion, create a compound layer on the surface and diffused case. FNC is a low distortion heat treat process because it is performed at temperatures less than the AC3 critical temperature, so no phase change takes place, and it is slow-cooled rather than oil quenched. Nitrocarburizing is done mainly to provide a wear resistant surface, improve corrosion resistance, and to enhance fatigue properties. FNC can be used on low, high carbon, alloy steels, and cast irons. Ferritic Nitrocarburizing (FNC), like nitriding and plasma (ion) nitriding, is more environmentally friendly compared to chrome plating.
Related term: Gas soft nitriding (GSN)
