<p>The critical wear rate, surface damage, deformation layer, crack initiation and propagation of U76CrRE heavy rail steel samples of two different cooling conditions (rolled rail, and heat-treated rail) under intermittent load were measured and observed by friction and wear tester, laser confocal microscope, scanning electron microscope and EBSD. The experimental results show that when the same kind of rail is matched with wheel steel with low hardness and high hardness successively, the critical wear rate of rail moves to the right. Moreover, when the rolled rail is matched with wheel steel with low hardness, the deformation layer and wear amount are larger than those of heat-treated rail are, while when it is matched with wheel steel with high hardness, the deformation layer and wear amount are smaller than those of heat-treated rail. When the rolled rail and heat-treated rail are matched with the same kind of wheel steel successively, the critical wear rate moves down, and the wear deformation layer of heat-treated rail is smaller than that of rolled rail. The failure life of the heat-treated rail is better than that of the rolled rail, which is due to the increase of the hardness of the heat-treated rail and the refinement of pearlite lamellae. With the increase of the distance from the surface layer, the proportion of large-angle grain boundaries of ferrite grains gradually increases of rolled rail and heat-treated rail, but the rolled rail presents the characteristics of large crack angle, deep depth and small length, mainly due to wear failure. While the heat-treated rail has the characteristics of small crack angle, shallow depth and long length, the crack propagation trend is obvious, and the failure form of the heat-treated rail is mainly fatigue failure. Moving the critical wear rate to the right and down is beneficial to inhibit the formation and propagation of fatigue cracks.</p>