Relationship between Hydrogen Embrittlement Sensitivity and Hydrogen Content for 40CrNiMoA High Strength Steel

Stress corrosion performance of 40CrNiMoA high strength steel was studied in wet air environment. The fracture morphology and mechanical properties of the samples before and after dehydrogenation were investigated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), tensile test and impact test. The results show that intergranular stress corrosion cracking occurred in the wet air environment, and the fracture morphology was hydrogen embrittlement. The results of Auger electron spectroscopy showed that grain boundary segregation was not the main reason of hydrogen embrittlement. After the process of dehydrogenation, the tensile strength and yield strength decreased significantly, and the section shrinkage increased significantly, and the impact of work has also increased.