The hydrogen-induced delayed fracture (HIDF) behavior of a 1300-MPa-grade high-strength bolt steel 42CrMoV containing 0.42 wt.% Cu was investigated by constant load tensile test in a pH 3.5 Walpole solution. It is shown that the addition of Cu is beneficial to enhance the HIDF resistance by ~ 13%. The observation of the fracture surface revealed that the area fraction of brittle crack initiation zone decreased remarkably for the Cu-added steel. Both the corrosion pit depth and the corrosion rate of the Cu-added steel in the Walpole solution are notably decreased, which is primarily because of the formation of a Cu-rich protective compact rust layer and slightly higher corrosion potential. As a result, the absorbed hydrogen content in that solution was also decreased by ~ 21%. It is concluded that the improvement in the HIDF resistance of the tested steel is primarily due to the increase in corrosion resistance and resultant decrease in the absorbed diffusible hydrogen content in the acidic condition.

通过在 pH 值为 3.5 的 Walpole 溶液中进行恒载荷拉伸试验，研究了含 0.42 wt.% Cu 的 1300 MPa 级高强度螺栓钢 42CrMoV 的氢致延迟断裂 (HIDF) 行为。结果表明，添加 Cu 有利于将 HIDF 电阻提高约 13%。断口观察表明，添加Cu的钢脆性裂纹萌生区的面积率显着降低。加铜钢在 Walpole 溶液中的腐蚀坑深度和腐蚀速率均显着降低，这主要是由于富铜保护致密锈层的形成和略高的腐蚀电位所致。结果，该溶液中吸收的氢含量也降低了约 21%。