9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems
In order to meet the challenges arising from a growing loads and passenger traffic, high speed train and heavy load railway have been developed rapidly in recent years in China. The rail/wheel is frequently required to sustain service conditions more severe than their original design.Many attempts have been made to improve wear resistance of wheel/rail steels under rolling-sliding wear conditions. However all of these attempts are based on wholly treatment of the materials and require post-treatment operations. Due to the failure of rolling-sliding wear is primarily determined by the surface properties of a material, appropriate surface technique, is one of feasible methods forimproving the wear resistance of wheel/rail. Laser surface treatment, such as laser hardening, laser melting or laser cladding, have been widely used in many industrial sectors to protect the components from wear and fatigue damage. Generally, for a large area required to be treated, the multiple passes with overlapping laser tracks is indispensable, but this process is harmful due to the development of soft zones in the overlapped region by tempering effect or the introduction of cracks in the treated layer by stress concentrations. To avoid the above limitation, a pulse laser beam is adopted by forming a regular scattered melting/hardening pattern distributed on the surface. In the present study, the wear rate of wheel steel by laser dispersed treatment was evaluated by twin-disc wear testing machine in comparison with the untreated counterpart. The relevant wear and fatiguemechanism are discussed based on the analysis of the microstructure evolution of laser dispersed treated zone during the process of rolling sliding wear.
Li ZY,Xing XH,Yang MJ,et al. Investigation on rolling sliding wear behavior of wheel steel by laser dispersed treatment[C]Proceedings of 9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems(CM2012),2012.