Adhesion, friction and wear analysis of a chromium oxide scale on a ferritic stainless steel

The aim of this study is to explore the potential engineering application of a thermally grown chromium oxide scale on a ferritic stainless steel. The friction and wear behaviour of the oxide scale were investigated by scratch and pin-on-disk tests. The failure mechanisms of the oxide scale subjected to scratch tests under both progressive and constant loading were investigated. It shows that the oxide scale adheres well to the steel substrate and is in a ductile failure. The oxide scale leads to an increase in the coefficient of friction (COF) under different constant loads when compared to what occurs when there is no oxide scale in the scratch test. The pin-on-disk tribological tests show that the chromium oxide scale on the ferritic stainless steel causes abrasive wear of the high-speed steel (HSS) pin, but it enhances the wear resistance of the ferritic stainless steel disk. The COF is slightly lower when there is oxide scale on the disk which is different from that by the scratch test. The ferritic steel substrate fine wear particles generated during the dry sliding and the formation of new compound layers on the surface can stabilise the COF. The wear mechanism is proposed and the tribological properties of the thermally grown chromium oxide by the two techniques are discussed.