Investigation of the pitting-to-crack transition in corrosion-fatigue of high-strength steel wires based on the phase-field method

This study develops a coupled corrosion-fatigue phase-field model to investigate the pitting-to-crack transition in high-strength steel wires by integrating chemical–electrochemical processes and cyclic loading effects within a unified computational framework. The corrosion-fatigue life (CFL) of high-strength steel wires was determined through coupled corrosion-fatigue experiments, and the phase-field model replicated the observed CFL trends, demonstrating its accuracy and reliability in predicting material degradation. The model effectively captures the entire evolution from pit nucleation to crack propagation. Simulation results show that pit geometry plays a critical role in the transition from corrosion-driven degradation to mechanically dominated crack propagation, with narrower pits generating higher stress concentrations that accelerate crack initiation. Additionally, the interfacial kinetic coefficient significantly influences pit evolution and crack nucleation, underscoring its importance in the progression of corrosion-fatigue damage. The study also identifies the critical energy release rate ($G_c$) as a key mechanical parameter that governs the transition from pitting to fatigue crack growth, providing a quantitative criterion for assessing damage evolution. The proposed phase-field model offers a comprehensive tool for predicting structural degradation in high-strength steel wires and provides fundamental insights into corrosion-fatigue mechanisms.