Technological importance of plasma-induced nitrided and carburized layers on steel

Abstract

The principles of plasma thermochemical processing for both nitriding and carburizing are described. Limitations of existing plant for high temperature treatments are briefly discussed from both a metallurgical and an energy standpoint. The technological acceptance of plasma ferritic thermochemical treatments within the U.K. is identified and illustrated by a number of case histories. Attention is focused on conditions for controlling the formation of compound layers and the production of bright nitrided material. Although the technology of plasma carburizing has not yet been developed fully, laboratory studies have shown that the treatment is technically feasible. The carbon profiles which can be generated from methane-H 2 mixtures, with no auxiliary heating, are presented to illustrate the rapid rate of formation of carburized layers when the plasma technique is used.