1 Materials Science and Engineering Research Center, School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China 2 School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, Jiangsu, China
Hydrogen-induced delayed fracture of Cu-containing high-strength bolt steel
1 Materials Science and Engineering Research Center, School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China 2 School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, Jiangsu, China
摘要 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.
Abstract: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.
Xiao-li Zhao,Cheng-xiang Zhang,Yong-jian Zhang, et al. Hydrogen-induced delayed fracture of Cu-containing high-strength bolt steel[J]. Journal of Iron and Steel Research International, 2023, 30(02): 375-383.