Nitrocarburizing is a case hardening process, similar to nitriding, involving the introduction of nitrogen and carbon into a solid ferrous alloy by holding below the lower critical temperature (Ac1) in contact with a suitable nitrogenous and carbonaceous material. A thin nitrogen and carbon enriched layer, possibly with accompanying carbonitrides and nitrides is produced. The compound layer (or white layer) with an underlying diffusion zone contains dissolved nitrogen and iron (alloy) nitrides. Quenching is not required to produce a hard case.
Other common names and related subjects are case hardening, ferritic nitrocarburizing (FNC) and austenitic nitrocarburizing (ANC) the latter two designations referring to temperature below or slightly above the lower critical temperature.
Gasbarre specializes in the design and manufacture of custom-engineered ferritic nitrocarburizing furnaces specific to the thermal processing industry.
Source: Gasbarre and Daniel H. Herring, “The Heat Treat Doctor.” The HERRING GROUP, Inc.