Effect of nanosized NbC precipitates on hydrogen-induced cracking of high-strength low-alloy steel

• 作者: En-dian Fan Shi-qi Zhang Dong-han Xie Qi-yue Zhao Xiao-gang Li Yun-hua Huang
• 来源期刊: 矿物冶金与材料学报
• 年，卷（期）: 2021,（2）
• 页码范围: 249-256
• 页数: 8页
• 语种: 英文

摘要

We investigated the effect of nanosized NbC precipitates on hydrogen-induced cracking (HIC) of high-strength low-alloy steel by conducting slow-strain-rate tensile tests (SSRT) and performing continuous hydrogen charging and fracture analysis. The results reveal that the HIC resistance of Nb-bearing steel is obviously superior to that of Nb-free steel, with the fractured Nb-bearing steel in the SSRT exhibiting a smaller ratio of elongation reduction (Iδ). However, as the hydrogen traps induced by NbC precipitates approach hydrogen saturation, the ef-fect of the precipitates on the HIC resistance attenuate. We speculate that the highly dispersed nanosized NbC precipitates act as irreversible hydrogen traps that hinder the accumulation of hydrogen at potential crack nucleation sites. In addition, much like Nb-free steel, the Nb-bear-ing steel exhibits both H-solution strengthening and the resistance to HIC.