A model to predict the s-phase thickness and the change in corrosion behavior toward H2SO4 of 316L austenitic stainless steel after plasma nitriding

Abstract

Austenitic steels are known for their high corrosion resistance, but at the same time exhibit low hardness and wear resistance. While plasma nitriding improves tribological properties, it also affects corrosion behavior depending on the electrolyte. In this paper, a model should be present, that allows to predict the thickness of the s-Phase and the change of the corrosion behavior in plasma nitriding processes for austenitic stainless steels. For this purpose, different processes under specific variation of the temperature ranging from 360 °C to 450 °C and duration of 10 h to 24 h were performed. Other process parameters such as the voltage or gas mixture remained constant. There are two stages in the developed model: the first one allows the prediction of the s-Phase thickness by isothickness curves. The second stage implements an evaluation system of the corrosion resistance. By assigning numerical values for the observed corrosion, a quantitative comparison is allowed, which is represented by a color scaling.