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) <= (epsilon)over dot <= 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 (epsilon)over dot 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 (epsilon)over dot, because special boundaries suppressed hydrogen-induced crack initiation and propagation.