Fatigue failure analysis of high-strength steel in seawater corrosion environment

High-strength steel, widely used in marine engineering, is prone to corrosion fatigue due to seawater corrosion and cyclic loading. This study experimentally investigates the effects of stress ratio, loading frequency, and temperature on its corrosion fatigue performance, and analyzes fracture morphology and crack propagation to clarify damage mechanisms. Separate corrosion and fatigue damage models are developed and integrated into a coupled corrosion fatigue equation. Using UMESHMOTION and UMAT subroutines in Abaqus, numerical simulations of the coupled process are implemented and validated against experimental results. The findings reveal that higher stress ratios and temperatures significantly reduce fatigue life, while increased loading frequency alleviates corrosion effects. Under coupled corrosion fatigue conditions, although the contribution of corrosion to the overall damage accumulation is relatively small, it substantially accelerates crack initiation, which accounts for over 50% of the total fatigue life, while crack propagation constitutes less than 50%.