Anisotropy changes in hardness and indentation modulus induced by plasma nitriding of 316L polycrystalline stainless steel

The changes in anisotropic hardness and indentation modulus induced by plasma nitriding at 400 °C of a 316L polycrystalline austenitic stainless steel are analyzed. The dependence of hardness and elastic modulus modifications on the crystallographic orientation is investigated through instrumented indentation and electron backscattering diffraction. Both hardness and indentation modulus exhibit an inverted anisotropy compared to the untreated 316L, likely associated with the presence of the N atoms in interstitial sites.