Effects of hydrogen and stress on the electrochemical and passivation behaviour of 304 stainless steel in simulated PEMFC environment

This work investigates the effects of hydrogen and stress on the electrochemical and passivation behaviour of 304 stainless steel in 0.5 M sulfuric acid with 2 ppm sodium fluoride. Three major results are revealed: hydrogen and stress significantly increase the critical current density (icrit) and passive current density (ipass); hydrogen has a more obvious impact on icrit than that on ipass; a high synergistic effect between hydrogen and stress on current densities is observed at the intermediate hydrogen charging current densities range. •Effects of hydrogen and stress on passive and critical current densities were compared.•Hydrogen has a more obvious impact on critical current density than on passive current density.•A high synergism effect between hydrogen and stress on current densities was observed.