Friction behaviour and self-lubricating mechanism of low alloy martensitic steel during reciprocating sliding

Abstract

The study of metal-ceramic sliding wear is important as it occurs in many industrial mechanical systems. The friction behaviour and self-lubricating mechanism of low alloy martensitic steel during reciprocating sliding wear against the WC ceramic ball under an ambient atmosphere and at room temperature were investigated. The reciprocating sliding wear process was characterised using a commercial friction and wear testing machine and a scanning electron microscope. The results showed that there was a self-lubricating phenomenon during reciprocating sliding wear between the experimental steel and the tungsten carbide ceramic ball, and the friction coefficient decreased to 0.3 from 0.53. This is attributed to the high hardness of the subsurface, the lubricating effect of the surface oxide film, and the removal mechanism of layer-by-layer peeling. The evolution of the friction coefficient corresponded to the change in the wear mechanism. During the initial stage of sliding wear, adhesive wear was the primary wear mechanism, while fatigue spalling occurred during steady-state wear. In addition, during the self-lubricating process, the wear growth rate of the experimental steel decreased correspondingly, and the wear surface roughness also showed a decreasing trend.