美国铁路激光熔凝钢轨的在线试验  

Online Test on Laser Glazing Rail of American Railway

作　　者：张准胜[1] 

机构地区：[1]郑州铁路局,郑州450052

出　　处：《铁道工程学报》2012年第11期38-42,共5页Journal of Railway Engineering Society

摘　　要：研究目的:我国重载货运线路年运量目前已接近5亿吨,利用激光表面工程技术来改善轮轨关系,延长钢轨大修周期,已成为一个迫切的任务。当今我国该领域在实验室和现场研究应用较多的是激光相变硬化技术、激光熔覆技术,轮轨表面激光熔凝技术的研究应用在国内还鲜有资料。本文详细介绍美国联邦铁路局研究发展处2007年5月公布的激光熔凝钢轨的环线铁路试验及事后分析研究报告,以供给国内研究者参考和借鉴。研究结论:(1)激光熔凝钢轨失效的原因是源于激光加工引起的裂纹在疲劳条件下的不断扩展;(2)激光重熔搭接带是残余应力促进裂纹形成和传播最敏感的区域;(3)激光熔凝钢轨上道前一定要进行完整的金相评价以决定它们的完整性。Research purposes： At present, the annual traffic volume of the heavy - haul railway in China has been approach to 500 million tons. Using the laser surface engineering technology to improve the wheel/rail relationship and prolong the rail overhaul interval has already become a pressing task. Nowadays, in this field, the laboratory test and the on- site research and application in China mainly include the laser transformation hardening technology and laser cladding technology have been more frequently used, while there is little information on the laser glazing technology and its application in glazing the wheel/rail surface. This paper in detail introduces the research on the laser glazing rail test in FAST at TI＇C and its ex - post analysis report announced by the office of federal railway administration in May 2007 for the purpose of giving the reference to domestic researchers. Research conclusions ： （ 1 ） The reason for failure of laser glazing rail is the continuous extension of cracks induced by laser glazing in fatigue conditions. （2） The laser re -melting overlapping zone is the most sensitive area where the residual stresses promote crack formation and spreading. （3） The laser glazing rails must undergo a complete metallurgical evaluation to determine their integrity before installation on track.

关 键 词：激光熔凝 激光熔覆 激光相变硬化 钢轨 试验 

分 类 号：U216.424[交通运输工程—道路与铁道工程]