Friction-Reducing Performance of Serpentine on 45^#Carbon Steel Surfaces with Different Roughnesses

The 45^# carbon steel pair surfaces with three different roughnesses were prepared. The friction-reducing performance of serpentine on the three surfaces was investigated by an MMW-1A universal friction and wear tester. The worn surfaces were analyzed by three-dimensional video microscopy, scanning electron microscopy and energy dispersive spectroscopy, respectively. The results show that the friction-reducing effect of serpentine is more remarkable to smooth surface. When the surface roughness R_a was 0.742 μm, the worn surface was repaired effectively, the friction coefficient was decreased, the wear mass loss was no more than 1.3 mg, and the surface roughness was reduced by 72.1%. Nevertheless, the friction and wear behavior obeyed the wear feature of normal metallic materials when the R_a was 1.424 and 3.706 μm. The self-repairing film could smooth the worn surface, and there was a dynamical equilibrium between wear and the formation of self-repairing film.