Surface Modification of SUS304 Stainless Steel Using Carbon Push-Ahead Effect by Low Temperature Plasma Nitriding

Low temperature nitriding can harden the steel surface. However, the consequent thickness is limited because it depends on the formation of non-equilibrium phase at low temperature diffusion treatment. The hardness drops abruptly at the interface between the treated layer and the substrate as a result of nitriding. In this paper, duplex surface layers produced by combinations of carburizing and nitriding were developed using the carbon push-ahead effect of nitriding using relatively low-temperature plasma treatment. The location of the low-temperature carburized layer was pushed ahead following nitriding to form a support layer for a hard nitrided surface layer. The treatment combination was optimized for a thicker hard layer with good corrosion resistance.