Origin of deformation twins and their influence on hydrogen embrittlement in cold-rolled austenitic stainless steel

The effect of cold rolling on hydrogen embrittlement in stable 18Cr-1Mn-11Ni-0.15 N austenitic stainless steels was investigated. Alloy plates were cold-rolled to 15% or 30% reduction, then pre-charged with hydrogen and subjected to tensile testing with slow strain rate. Hydrogen-induced degradation of tensile elongation became increasingly severe with the increase in the degree of cold rolling. During cold rolling, deformation twins with various orientations were actively generated, and twins with specific orientations were vulnerable to hydrogen-induced cracking. Cold rolling also increased the density of defects, and thereby facilitated penetration of hydrogen into the steels. The combination of cracks generated at the twin boundaries, and the promoted hydrogen diffusion caused severe hydrogen embrittlement in the cold-rolled steels. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.