Hydrogen embrittlement of additively manufactured austenitic stainless steel 316 L

Additive manufacturing (AM) is a promising means of production of austenitic stainless steel (SS) parts for hydrogen service. The hydrogen embrittlement resistance of SS 316 L parts manufactured by powder-bed-fed selective laser melting (SLM) and directed energy deposition (DED) was examined using slow strain rate tensile testing. The influence of the hierarchical AM microstructures on mechanical response, microstructural evolution, and void formation were analyzed using multiscale electron microscopy. The presence of hydrogen reduced ductility in as-built DED materials, but did not significantly influence the response in as-built SLM material or heat-treated materials. Microstructural features driving these different responses are discussed. • Stainless steels additively manufactured with different methods exposed to hydrogen. • Hydrogen reduced ductility in only as-built directed energy deposited material. • Hydrogen enhanced dislocation cells and texture in directed energy deposited material. • Hydrogen interactions with dislocations, segregation, and precipitates are explored. • Hydrogen-dislocation interactions appear most closely linked to tensile response.