Influence of roughness on surface instability of medical grade cobalt-chromium alloy (CoCrMo) during contact corrosion-fatigue

► We investigated influence of residual stress of implant surface on environmental corrosion. ► Localized stress developed during contact fatigue accelerates preferential corrosion pit at surface troughs. ► A new method was suggested to evaluate thermodynamic driving forces of implant surface. ► We developed predictive model of roughness evolution by contact corrosion-fatigue.