This work presented a study on the improvement of laser surface treatment on rolling contact fatigue resistance of gray cast iron. Sample surface covered with carbon powder was coupled with localized treatment by high-energy laser beam—a process defined as “laser cladding (LC).” With this method, the optimum precoating thickness was experimentally studied. Compared to the region treated by laser remelting, the crystal in LC region was finer, more compact, and uniform. Mechanical property testing showed not only high micro-hardness of LC region, but also improved tensile and compressive resistance of treated material. Fatigue wear tests and thorough analysis of fatigue detects suggested that LC treatment significantly improved fatigue wear resistance (FWR). Improved FWR was likely facilitated by delayed initiation and propagation of cracks, as well as the reduction of contact stress on substrate. Additionally, formations of fatigue defects on sample surface were thoroughly discussed.
