Effect of grain boundary engineering on hydrogen embrittlement in Fe-Mn-C TWIP steel at various strain rates

Abstract The influence of strain rate (10 −3  ≤  e ˙  ≤ 10 −5  s −1 ) on hydrogen embrittlement behavior of Fe−17Mn − 0.8C (wt.%) TWIP steel was investigated. Two types of specimens were tested; one (AR) was hot-rolled, and the other (GBE) was further processed by grain boundary engineering. After hydrogen charging, the fracture strength (FS) and ductility of AR samples decreased as e ˙ decreased, because increasing numbers of H atoms accumulated near crack tips. However, after hydrogen charging, the FS and tensile ductility of GBE samples were not decreased much even at low e ˙ , because special boundaries suppressed hydrogen-induced crack initiation and propagation.