Abstract:
The dry and wet two-stage continuous rolling contact wear tests were carried out on U75V rail samples without surfacing and with local surfacing. The rolling contact characteristics and wear behavior of the two rail samples were compared and analyzed.The results show that the adhesion coefficients of the two rail samples were both about 0.60 in the dry wear stage, and decreased sharply to about 0.25 into the wet wear stage; the adhesion coefficient of the local surfacing rail sample in the dry wear stage was slightly higher than the un-surfacing rail sample, and the wet wear stage was the opposite. The surfacing layer of the local surfacing rail sample mainly consisted of martensite and had the highest hardness. The wear surface damage of surfacing layer was slight, and no obvious cracks and plastic deformation were found. The heat affected zone was composed of ferrite, pearlite and martensite and the hardness was in the middle. After wear, the surface roughness of the heat affected zone was the largest, the plastic deformation was large and there were many cracks with large expansion angles. The non-surfacing zone was mainly composed of pearlite and the hardness was the lowest. After wear, the surface of the non-surfacing zone was flat, and obvious plastic deformation and a small amount of cracks were found.