Offshore wind turbine support structures and the related transformer platform are particularly corrosive-prone,and corrosion flaws can result in stress concentration,which adversely affects the wind turbine equipment’s service life.Using Q345 steel as the research object,a finite element model for the growth prediction of surface corrosion defects in Q345 steel was established using COMSOL coupling Multi-physics simulation software,and the stress corrosion behavior of Q345 steel in different states in the marine environment was simulated.The Tafel relation of Q345 steel was determined using an electrochemical corrosion test,the impact of stress on electrochemical corrosion at corrosion defects was predicted using multi-physics coupling,and corrosion defect increase prediction was performed in conjunction with Faraday’s law.The results indicate that as the tensile strain and defect depth increase,the stress at the defect is increased,and the failure at the defect is accelerated.When stress causes plastic deformation at the defect site,local corrosion activity is significantly enhanced.The mechanical and electrochemical effects at the defect site alter the stress distribution at the defect center,enhancing the corrosion rate at the defect center.