Plasma nitriding of 316L austenitic stainless steel: Experimental investigation of fatigue life and surface evolution

AISI 316L austenitic stainless steel is widely used in nuclear and chemical industries for structural components that are submitted to cyclic deformation and stresses. The influence of low temperature (~ 400 °C) plasma nitriding on the crystallographic texture and fatigue durability of 316L has been investigated. Electron back-scattering diffraction measurements show that nitriding enhances the <001> and <111> texture components while the <110> one vanishes. Series of fatigue tests carried out in air at room temperature in the low cycle fatigue range show a significant improvement of the fatigue life. Results are discussed taking into account the residual compressive stresses in the nitrided layer.