Abstract: Laser dispersed quenched process was carried out on steel rail surface in order to improve the service life of the rail. Three different distribution patterns for the laser dispersed quenched were used, and rolling contact fatigue wear test machine was used to measure the fatigue wear property of the rail, and the wear surface morphology, cross-sectional morphology and wear mechanism were analyzed. The results show that the wear loss of original state specimen is 1.102 g, and fatigue spall and plastic deformation with severe corrugation occur on the surface of the original specimen. After laser dispersed quenched process, the corrugation is eliminated, and the wear loss of rail specimen reduces significantly, but cracks occur at the edge of contact zone and the interface of laser hardened region. The cracks at the center of contact zone can be effectively removed when the hardened regions are distributed with 1 mm spacing and 60° inclination, and the lowest wear loss is acquired at this condition, which decreases by 63% compared with that of the original state specimen. It can effectively improve the cracking resistance and wear property of the laser dispersed hardened layer by combination of reducing the spacing and increasing the tilt angle of laser hardened region.

Key words: steel rail, laser dispersed quenched, rolling contact fatigue, wear