Research on Corrosion Fatigue Crack Growth of Marine Engineering Equipment Material E690 High-Strength Steel

摘要

In this paper, taking E690 high-strength steel as the research object, the crack growth experiments under different environment and stress ratio were carried out. In addition, the crack propagation parameters of E690 high strength steel under different conditions were calculated, which were used to established the equation of Paris formula, and the mechanism was analyzed. The results show that: (1) the crack growth rate of E690 high strength steel in air and brine increase with the increase of stress intensity factor range. Moreover, in the initial stage of crack growth, the crack growth rate in brine environment is larger than that in air, and the corrosion environment has an obvious effect on accelerating crack growth; (2) the corrosion fatigue crack growth rate of E690 high strength steel increases with the increasing of stress ratio, and the crack growth threshold Kth decreases.