The effect of dynamic frictional heating on the dry sliding behaviors of M2 steel against GCr15 steel

The tribological behaviors depend significantly on the dynamic contact temperature of the frictional surfaces, thus, many triologiests pay their attention to the surface temperature evaluation as well as the surface temperature measurements. In order to study thermal effects and dynamic thermal process induced by mechanical friction, a special testing device was adopted with M2 steel pin against GCr15 bearing steel disk. The experimental results show that the fluctuation of transient friction temperature gradually decreased, even disappeared with the measuring points towards the far end of sliding surface. By using SEM, EDS and TEM, the composition and worn surface morphologies analysis results indicate that the oxidation rate of M2 steel increased with contact temperature increase and more oxides were formed on the worn surface of the M2 steel. The secondary carbides separated out from the M2 steel may play an important part in the observed tribological variations. The quantity of the secondary carbide grains formed increased with the contact temperature increase, and the friction coefficient of the couple also increased.