Improvement of Resistance to Hydrogen Embrittlement for 1300MPa Ultra-high Strength Steel by Introducing Nano-sized Cu-rich Phase Precipitation

Cu-bearing and conventional martensite ultra-high strength steels with tensile strengths of 1300 MPa were investigated to explore the effect of the precipitation of Cu-rich particles on hydrogen embrittlement (HE). The results showed that the Cu-bearing steel strengthened by 9R Cu-rich precipitates had nanoscale and coherent properties and exhibited a higher resistance to HE than the conventional martensite steel. The Cu-rich precipitates served as irreversible hydrogen traps, leading to a low diffusible hydrogen content and hydrogen diffusivity for the Cu-bearing steel, thereby providing an effective approach to improve the hydrogen embrittlement of ultra-high strength steels.