Influence of microstructure on rolling contact wear in high carbon steels

It has been reported that the characteristic of rolling contact wear of rail steels varies depending on the microstructure of steels. However, the reasons for such variations have not been fully elucidated yet. Accordingly, a two cylinder rolling contact wear test was conducted by using pcarlitic steels, tempered martensite steels, spheroidal carbide steels and pro eutectoid cementite steels which contain pro-eutectoid cementite structures in pearlite structure. The relation between micro-structures and wear in high carbon steels was investigated, and the dominating factor of the rolling contact wear and the wear mechanism in high carbon steels was discussed. The main findings are as follows: (1) The wear property of high carbon steels is greatly influenced by the micro-structural morphology, and the wear resistance of pearlitic steels and pro eutectoid cementite steels with the lamella structure as pearlite are higher than the tempered martensite steels and spheroidal carbide steels with the carbide dispersion structure (the carbide are distributed in the matrix ferrite). (2) The reason why the wear resistance of steels with the lamella structure as pearlite improves compared with steels with the carbide dispersion structure is attributable to the prevention of adhesive wear due to increasing hardness (strength) of the rolling contact surface and to the prevention of the occurrence of fatigue wear due to flaking in the rolling contact surface.