In order to realize sustainable society using hydrogen for main energy source, hydrogen embrittlement is big issue to be solved. As hydrogen embrittlement is accelerated near crack tip region where tensile stress exists, improvement of residual stress, i.e., change of residual stress from tension to compression, might suppress the hydrogen embrittlement. In the present paper, the crack propagation of stainless steel exposed to hydrogen was examined considering the residual stress on the surface. The tensile residual stress was introduced by an angle grinder, then the residual stress was improved by cavitation peening. Cavitation peening was a peening method in the same way as shot peening using cavitation impacts produced by a cavitating jet, i.e., a submerged water jet. It was revealed that the crack propagation rate of the specimen in which tensile residual stress was introduced and exposed to hydrogen was suppressed by improving residual stress using cavitation peening.
