Abstract:Using a self made impact test rig of heavy load,under working condition of lubricated contacts with greases,the impact wear experiments of a steel ball on a GCr15 steel sample were carried out at certain impact rate.The damage behaviors of the surfaces of samples and plastic deformation were analyzed and observed with the Scan Electronic Microscope(SEM)and surface profiler.The results indicate that the surface of GCr15 steel has undergone plastic deformation and wear by impacting,with plastic deformation existing in each stage of the impact.The losses of surface layer under different contact conditions are different,accompanying with the formation of small spherical particles.When the number of impact times is small,the larger viscosity of the grease has,the greater the depth of dent and the higher the shoulder bump of dent forming after impact wear will be.Along with increasing of the number of impact times,the depths of the dents using different greases tend to be identical.