The role of surface chemistry and fatigue on tribocorrosion of austenitic stainless steel

Tribocorrosion is combined with fatigue (multi-degradation) in many engineering applications. In the present study, the effect of surface chemistry and electrochemical conditions on multi-degradation of austenitic stainless steel has been investigated. Mechanical and chemical wear loss has been calculated by modeling and measuring anodic current at open circuit potential and passive potential respectively. Surface and subsurface structure and chemistry has been investigated by SEM/FIB and XPS. Observations showed that cyclic and static 4-point bending affect the composition of the passive film and concentration of Mo and Cr cations in the oxide layer as well as formation of subsurface voids and cracks at different electrochemical conditions. Formation Cr(OH)3 is found to have significant effect on multi-degradation.