Low-Temperature Carburization of Austenitic Stainless Steels

LOW-TEMPERATURE CARBURIZATION is a gaseous carburization process performed at atmospheric pressure, at temperatures where the kinetics of substitutional diffusion are very slow. Low-temperature carburization hardens the surface of austenitic stainless steels through the diffusion of interstitial carbon, without the formation of carbides. The surface must be activated, by modification and removal of the naturally occurring chromia layer, for the process to work. The process results in a hardened diffusional case on the surface, typically 20 to 35 mm thick, with carbon content at the surface in excess of 10 at.%. The process is conformal and can be applied to finished components without change in dimension. Property enhancements include: