The role of reverted transformation in hydrogen embrittlement of a Cu-containing low carbon high strength steel
Xiaohui Xi, Tong Wu, Yuwan Tian, Jun Hu, Shuntian Huang, Tingxin Xie, Jin‐Liang Wang, Liqing Chen
Abstract
This work presents an investigation on the role of reverted transformation in hydrogen embrittlement, aiming at revealing the influencing mechanism of austenite and grain boundary characteristics on hydrogen embrittlement (HE) susceptibility during reverted transformation. The results showed that HE susceptibility decreased with the annealing temperature increasing from 680 ºC to 720 ºC, which attributed to a combined effect of austenite and grain boundary distribution. Both the fractions of austenite and high angle grain boundary (HAGB) increased with the annealing temperature increasing from 680 ºC to 700 ºC, which resulted in a lower HE susceptibility at 700 ºC due to strong H storage of austenite and HAGB. As the annealing temperature further increased to 720 ºC, the fraction of austenite exhibited a decline, but the fraction of HAGB monotonously increased. As a result, a lower HE susceptibility was achieved at 720 ºC. This indicated that grain boundary distribution played a determining role in the resistance to HE. We ascribed this to the variant selection and Bain/CP grouping.