Electrolyte-Plasma Nitriding of Austenitic Stainless Steel under Cathodic and Anodic Polarity

Abstract—The article presents the results of surface modification of austenitic stainless steel by electrolyte-plasma nitriding under anodic and cathodic polarity of the product being treated. The morphology and surface roughness, phase composition, and microhardness of diffusion layers, as well as tribological and corrosion properties, were studied. The effect of physicochemical processes during anodic and cathodic treatments on the features of the formation of a modified surface and its operational properties is demonstrated. The anodic treatment increased the hardness of the nitrided layers up to 1150 HV, halved the surface roughness, improved the wear resistance by a factor of 166, and decreased the coefficient of friction by a factor of 1.6. The cathodic treatment increased the hardness only to 580 HV and improved the wear resistance by a factor of 13.6. Both treatments were shown to decrease pitting corrosion in a sodium chloride medium.