The effects of microstructures and repassivation kinetics on the tribocorrosion resistance of ferrite and ferrite-martensite stainless steels

Abstract

The study addresses the tribocorrosion behavior of a ferritic stainless steel and a ferrite-martensite stainless steel under two passive potentials. The dual phase microstructure was produced by a specific heat treatment applied to the ferritic stainless steel. Since both materials have the same chemical composition, their tribocorrosion resistances are discussed in terms of microstructure benefit. This benefit concerns the determination of the wear rate, as well as the identification of the wear mechanism from surface and sub-surface observations. In parallel, current transients recorded during sliding are analyzed to quantify the kinetics of repassivation and evaluate the impact of the rebuilding of oxide film on wear.The results show that the hardness of the material is the main parameter that controls wear for the sliding conditions selected in this work. In a second order of magnitude, the nature of the oxide layer plays a role in the damage mechanism. Finally, if the oxide growth rate is affected by both the applied potential and the microstructure, it mainly affects the subsurface microstructure of the wear track with a thickening of the grain refined layer, as the repassivation is faster.