The Effects of Oxygen Impurities on Fretting Fatigue of Austenitic Stainless Steel in Hydrogen Gas

To clarify the effect of O₂ addition as an impurity in a H₂ environment on the fretting fatigue strength of JIS SUS304 austenitic stainless steel, a control method to add ppm-level O₂ to a H₂ environment was established. The experiments were then carried out in H₂ environments with O₂ concentrations of 0.088, 5, 35 and 100 vppm. The fretting fatigue strength in the H₂ was significantly reduced by the addition of a small amount of O₂. The reduction was caused by the change in the stress conditions at the contact part due to the addition of O₂ that changed the oxidation and fretting wear behavior on the fretted surface.