2020/03/31 by Dong‐Hyun Lee, Lee, Dong-Hyun, Binhan Sun +10 · 1 citation
Engineering · Materials Science · #Additive Manufacturing Materials and Processes #FOS: Physical sciences #Hydrogen embrittlement and corrosion behaviors in metals #Materials Science (cond-mat.mtrl-sci) #Welding Techniques and Residual Stresses
paper · pdf · doi:10.48550/arxiv.2004.00085
openalex publication_date 2020/03/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Hydrogen embrittlement in 304L (18wt.% Cr, 8-10wt.% Ni) austenitic stainless\nsteel (ASS) fabricated by laser powder-bed-fusion (LPBF) was investigated by\ntensile testing after electrochemical hydrogen pre-charging and compared to\nconventionally available 304L ASSs with two different processing histories, (i)\ncasting plus annealing (CA) and (ii) CA plus thermomechanical treatment (TMT).\nIt was revealed that hydrogen-charging led to a significant reduction in\nductility for the CA sample, but only a small effect of hydrogen was observed\nfor the LPBF and CA-TMT samples. Hydrogen-assisted cracking behavior was found\nto be strongly linked to strain-induced martensitic transformation. In\naddition, the amount of alpha' martensite was much higher in the CA sample than\nin other samples, suggesting that severe hydrogen embrittlement can be\ncorrelated with the low mechanical stability of austenite. Detailed\nmicrostructural characterization showed that low austenite stability of the CA\nsample was mainly attributed to the retained content of delta ferrite and the\nchemical inhomogeneity inside the gamma matrix (gamma close to delta has ~2\nwt.% higher Cr but ~2 wt.% lower Ni), but TMT enhanced the chemical homogeneity\nand thus austenite stability. By contrast, the LPBF process led directly, i.e.\nwithout any thermomechanical treatment, to a fully austenitic structure with\nhomogeneous elemental distribution in the ASS. These results confirmed that the\npresence of delta and the chemical inhomogeneity inside gamma matrix, which\npromoted the deformation-induced martensitic transformation and the associated\nH enrichment at the gamma-alpha' interface, was the primary reason for the\nsevere H-assisted failure.\n