Research on Calculation Method for Hydrogen Induced Stress Corrosion Fracture Toughness of Metal in Deep Sea

Focusing on the hydrogen induced stress corrosion cracking（HISCC） of titanium alloy in deep sea,this paper calculated hydrogen diffusion in metal with the stress induced diffusion method and introduced the hydrogen reducing surface energy model into HISCC process to simulate the cycling of the material embrittlement of crack tip and crack propagation by finite element software ABAQUS combined with the secondary development of Python.Calibrated with the experiment in existing literature,the calculation error is 11%,which proves that the method for updating the critical fracture surface energy of the crack tip at the beginning of each crack is effective and feasible.The results show that,hydrogen will concentrate on the crack tip where the stress is relatively higher,and the environmental pressures will intensify this process.The HISCC fracture toughness of a titanium alloy at 5 000 and 10 000 depth reduces to 31.16%and 22.28% of that in the indoor environment,respectively.