This study establishes a three-dimensional stress-induced hydrogen diffusion model by using finite element analysis and simulates the plastic strain at the defects and its influence on the diffusion and aggregation behaviour of hydrogen atoms under large deformation conditions by using the nonlinear hardening function. The results show that the plastic strain significantly increases the local stress, the equivalent plastic strain, and the hydrogen concentration in the corrosion defect region. Plastic strain increases the overall von Mises stress in the specimen, while the significant increase in hydrostatic stress and equivalent plastic strain is mainly concentrated in the central region of the corrosion defect. In the absence of plastic strain, the diffusion of hydrogen atoms is mainly driven by the concentration gradient, and the flow direction is from the region of high concentration to the region of low concentration, which ultimately leads to a steady state of hydrogen atom concentration inside the specimen. However, when plastic strain exists, the diffusion behaviour of hydrogen atoms is driven by the hydrostatic stress gradient, which is manifested by the aggregation of hydrogen atoms towards the stress concentration region （i.e., at the corrosion defect）. In addition, narrow and deep corrosion defects are more likely to lead to local accumulation of hydrogen atoms, while the shape of the defect has relatively little effect on the distribution of hydrogen concentration.

hydrogen energy  /  hydrogen embrittlement  /  plastic strain  /  numerical simulation  /  X65 pipeline steel  /  corrosion defects  /  hydrogen diffusion