Effect of processing temperatures on characteristics of surface layers of low temperature plasma nitrocarburized AISI 204Cu austenitic stainless steel

The influence of processing temperatures on the surface characteristics of AISI 204Cu austenitic stainless steel was investigated during a low temperature plasma nitrocarburizing. The resultant layer was a dual-layer structure, which comprises a N-enriched layer on the top of C-enriched layer. The surface hardness and the layer thickness increase up to about HV0.05 1000 and 20 μm with increasing temperature. The specimen treated at 400 °C shows a much enhanced corrosion resistance compared to the untreated steel. A loss in corrosion resistance was observed for specimens treated at temperatures above 430 °C due to the formation of Cr2N.