Effect of high-pressure H2 gas on tensile and fatigue properties of stainless steel SUS316L by means of the internal high-pressure H2 gas method

For prohibiting a global warming, fuel-cell systems without carbon dioxide emissions are a one of the promising technique. In case of a fuel-cell vehicle (FCV), high-pressure H2 gas is indispensable for a long running range. Although there are lot of paper for studying a hydrogen embrittlement (HE), there are few paper referred to the effect of high-pressure H2 on the HE phenomenon. In this study, an effect of high-pressure H2 gas on tensile & fatigue properties of stainless steel SUS316L were investigated by means of the internal high-pressure H2 gas technique. Main findings of this study are as follows; 1) Although there are almost no hydrogen embrittlement effect on the 0.2 % proof stress and tensile strength, elongation and reduction of area decrease in H2 gas environment, 2) For case of low Nieq material, fatigue life and fatigue limit decrease in H2 gas environment, 3) For case of low Nieq material, not a few α’ martensitic phase generated on the fatigue fractured specimen.