Mild corrosion behavior on sulphurized steel surface during friction

After treatment by low temperature ion sulphuration, the solid lubrication sulphuration layers (FeS films) were produced on the AISI 1045 and stainless steel. A mass of corrosion peeling pits occurred on the worn scars of 1045 steel sulphuration layer after wear test, whereas none of them on the stainless steel one. AFM was used to observe the morphology of sulphuration layer, SEM equipped EDS was utilized to analyze the morphologies and compositions of worn scars. XPS and XRD were employed to detect the valence states of sulphuration layer and its worn scars, as well as the phase structures. The results showed that during friction, under the frictional heat, the sulfate radical with mild corrosion was produced, so that the 1045 steel without any anti-corrosion was corroded in some certain, meanwhile the stainless steel was not corroded depending on its excellent corrosion resistance.