Surface material design of 316 stainless steel by combination of low temperature carburizing and nitriding

Combinations of carburizing and nitriding were plasma processed both sequentially and simultaneously to AISI 316 substrate at 723 K. All samples treated by combined carburizing and nitrizing show carbon accumulation beyond the nitrided layer. Depth of the combined treated layer was deeper than that of the nitrided-only specimen. In addition, hardness depth profiles of these samples show gentle slopes from the surface to substrate. Sequentially carburised then post-nitrided specimen showed corrosion resistance as well as untreated substrate, however, the corrosion resistance of simultaneously carburized and nitrided specimen was obviously inferior to those of samples of untreated steel. It was found that the surface design with hardness and corrosion resistance is possible by sequential plasma process.