The hydrogen transport behavior together with hydrogen embrittlement (HE) in hydrogen-charged type 304 and 316 stainless steels during deformation was investigated by combined tension and outgassing experiments. The specimens were thermally hydrogen-charged in 30 MPa hydrogen at 473 K for 48 h. HE of hydrogen-charged type 304 steel decreases with increasing prestrain and almost no HE is observed in hydrogen-charged type 316 steel. Prior strain-induced alpha' martensite formed by the prestrain at 208 K has little relation with HE, while dynamic alpha' martensite formed during deformation after the prestrain shows obvious HE. The differences in hydrogen diffusivity and solubility between alpha' martensite and austenite (gamma) induce hydrogen diffusion from dynamic alpha' martensite and then its accumulation at the boundary between the alpha'-rich and gamma-rich zones, resulting in crack initiation at the boundary between the alpha'-rich and gamma-rich zones. Copyright (c) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.