Nitriding behavior and corrosion properties of AISI 304L and 316L austenitic stainless steel with deformation-induced martensite

In this study, AISI 304L and AISI 316L were solution annealed and afterwards work hardened with a cold rolling degree of 38%. The surfaces were polished and shot-peened, respectively. The amount of deformation induced martensite depends on the material and this, in turn influences the nitriding behavior. It will be shown, that a highly deformed microstructure promotes the growth of the S-phase. Furthermore, the resulting surface hardness and corrosion resistances in saline solution were examined. The corrosion properties are highly dependent on the surface topography. Shot-peening increases the roughness and also induces crack like artifacts which accelerate corrosion kinetics. The results were evaluated statistically to derive correlations between the microstructure, the plasma nitriding behavior and the resulting properties.