The high strength and hydrogen embrittlement resistance of selective laser melted 304 austenitic stainless steel

3D printing technology can be used to produce a variety of complex parts for hydrogen service. In this study, 304 austenitic stainless steel (ASS) sample was manufactured by selective laser melting (SLM), one of the 3D printing technologies, then its high strength and hydrogen embrittlement resistance were discovered in comparison to traditional solution-treated 304 ASS. The unique high-density dislocation cellular structure of SLM sample remarkably restrained the nucleation of α'-martensite and slowed down the diffusion of hydrogen. Moreover, the possibility of hydrogen induced intergranular fracture was significantly reduced because of the alleviated hydrogen segregation at the grain boundary.