Gas Nitriding of Steels,Gas Nitriding of Steels,Gas Nitriding of Steels,Gas Nitriding of SteelsGAS NITRIDING is a case-hardening process whereby nitrogen is introduced into the surface of a solid ferrous alloy by
holding the metal at a suitable temperature (below Ac1, for ferritic steels) in contact with a nitrogenous gas, usually
ammonia. Quenching is not required for the production of a hard case. The nitriding temperature for all steels is between
495 and 565 °C (925 and 1050 °F).
Application Factors
Principal reasons for nitriding are:
· To obtain high surface hardness
· To increase wear resistance and antigalling properties
· To improve fatigue life
· To improve corrosion resistance (except for stainless steels)
· To obtain a surface that is resistant to the softening effect of heat at temperatures up to the nitriding
temperature
Because of the absence of a quenching requirement, with attendant volume changes, and the comparatively low
temperatures employed in this process, nitriding of steels produces less distortion and deformation than either carburizing
or conventional hardening. Some growth occurs as a result of nitriding, but volumetric changes are relatively small.
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