Fatigue life evolution of steel wire considering corrosion-fatigue coupling effect: Analytical model and application

The fatigue life of steel wire is affected not only by fatigue load, but also by corrosion environment in service period. Specially, the corrosion pit will lead to stress concentration on the surface of steel wire inducing the formation of fatigue cracks, and the fatigue cracks will accelerate the corrosion process. Therefore, the corrosion fatigue of steel wire is a coupling effect. In this study, the corrosion -fatigue coupling life curve is derived with considering corrosion -fatigue pitting stage, corrosion -fatigue short crack stage and corrosion -fatigue long crack stage. In addition, the stress concentration factors of different corrosion pits are calculated by COMSOL software. Furthermore, the effect of corrosion environment factors, that is, corrosion rate, corrosion pit morphology, frequency and action factor of fatigue load, on fatigue life of steel wire is analyzed. And then, the corrosion -fatigue coupling life curve is compared with the fatigue life curve and fatigue life curve with precorrosion. The result showed that the anti -fatigue performance of the steel wire with considering corrosion -fatigue coupling is 68.08% and 41.79% lower than fatigue life curve and fatigue life curve with pre -corrosion. Therefore, the corrosion -fatigue coupling effect should be considered in the design of steel wire.