An evelated-temperature process (similar to carburizing) by which a ferrous metal absorbs both carbon and nitrogen into the surface when exposed to an atmosphere high in carbon and nitrogen. The carbon and nitrogen atoms diffuse into the metal to form a high-carbon and high-nitrogen zone near the surface.
A process in which a ferrous alloy is case hardened by first being heated in a gaseous atmosphere of such composition that the alloy absorbs carbon and nitrogen simultaneously, and then being cooled at a rate that will produce desired properties.
A thermochemical method of surface hardening a steel in which the steel is heated into the austenitic region and carbon and nitrogen diffused into the steel surface, following which, the steel is quenched.
A heat treatment for steel which adds carbon and nitrogen from an atmosphere rich in such elements.
A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere of such composition as to cause simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, create a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the workpiece.
Similar to Carburising (see below). Diffusion of carbon and nitrogen at about 900oC (by pack, gas, salt bath or plasma process) into low carbon steel, followed by quenching and tempering to produce martensitic case (typically 1mm thick).
Thermo-chemical case hardening. Steels with carbon content of approximately 0.1 to 0.25% are carburized up to approximately 0.8 to 0.9% and case hardened. The surface layer is more resistant to wear.
Carbonitriding is a modification of gas carburizing, as opposed to a form of nitriding. This modification describes the addition of ammonia molecules into the gas carburizing atmosphere, and will therefore add nitrogen to the carburized case. Atomic Nitrogen is formed at the surface which thereafter diffuses into the steel with the carbon.