Temperature effect on microstructure and wear property of 316L stainless steel by high-voltage DC plasma glow-discharge nitriding

By applying the different high-voltage DC plasma glow-discharge nitriding (DCPN) temperatures, the microstructure and wear resistance of the surface-nitrided 316L stainless steel were investigated. The phase composition, thickness, micro-hardness and element profile were examined by X-ray diffractometer, Optical microscopy, Hardness tester and EDS (Energy dispersive spectrometer), respectively. The results showed that a homogenous layer S-phase was produced between 350 degree C and 400 degree C and a single layer CrN at 480 degree C. The nitrided layer depth was approximately 5-9 μm. Both the thickness and the surface-hardness of the nitrided layer increased with the temperature increasing. It also revealed that the wear resistance of the DCPN stainless steel can be improved by one times or more. Wear of the untreated 316L was severe and characterized by strong adhesion wear, whilst wear of the DCPN-treated 316L was mild and dominated by oxidation wear. (authors)