• Journal of the Korean Society for Heat Treatment
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• v.35 no.4
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• pp.203-210
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• 2022

In this study, hydrogen embrittlement in Inconel 718 fabricated by selective laser melting (SLM) was investigated. To focus on the effect of the SLM-induced solidification substructure, hydrogen embrittlement behavior of SLM as-built (SLM-AB) sample and that of conventionally produced (Con-S) sample were systematically compared. The detailed microstructural characterization showed that the SLM-AB sample exhibited a solidification substructure including a high density of dislocations and Laves phase, while the Con-S sample showed completely recrystallized grains without any substructure. Although the intrinsic strength in the SLM-AB sample was higher than the Con-S sample, the resistance to hydrogen embrittlement was higher in the SLM-AB sample. Nevertheless, a statistical analysis of the hydrogen-assisted cracks (HACs) revealed that the predominant HAC type of SLM-AB and Con-S samples was similar, i.e., intergranular HAC. The difference in the resistance to hydrogen embrittlement between the SLM-AB and Con-S samples were discussed in terms of the relation between the microstructural feature and its effect on hydrogen accumulation.