高速铁路钢轨表面伤损分析  

Analysis on surface damage of hot rails for high-speed railway

作　　者：李继康[1] 王春芳[1] 张银花[2] LI Jikang;WANG Chunfang;ZHANG Yinhua(Center Laboratory,Central Iron and Steel Research Institute,Beijing 100081,China;China Academy of Railway Sciences,Beijing 100081,China)

机构地区：[1]钢铁研究总院中心实验室,北京100081 [2]中国铁道科学研究院,北京100081

出　　处：《物理测试》2021年第4期18-24,共7页Physics Examination and Testing

摘　　要：某路段高速铁路钢轨发生伤损,主要表现为浅层状龟裂掉块。采用金相显微镜、扫描电镜、背散射电子衍射取向成像技术、透射电镜、显微硬度计等对钢轨的正常部位和伤损部位进行了分析。结果表明:钢轨踏面龟裂掉块是由于列车启动时车轮短时打滑空转,致使钢轨表面承受巨大的摩擦力,表层金属发生剧烈塑性变形,温度瞬时升高到奥氏体化温度以上进而又快速冷却,踏面局部形成厚度不大于1.0 mm的白层马氏体。白层马氏体在轮轨接触应力的反复作用下发生断裂,形成龟纹状裂纹;然后裂纹沿白层与基体界面扩展,最终导致基体浅层剥落。The rails in a high-speed railway was damaged,which mainly showed superficial punctate craquelure chipping.The normal and damaged parts of the rail were analyzed by means of metallographic microscope,scanning electron microscope,backscatter electron diffraction orientation imaging,transmission electron microscope and microhardness tester. The results showed that the fallen pieces of the rail tread were caused by the short time skidding and idling of the wheels during the start of the train,which resulted in the huge friction force on the rail surface and the severe plastic deformation of the surface metal. The temperature rose instantaneously above the austenitizing temperature and then cooled down rapidly.White layer martensite with thickness not more than 1. 0 mm was formed on the rail tread. Under the repeated action of wheel-rail contact stress,the white layer martensite broke to form craquelure cracks. Then the crack propagated along the interface between the white layer and the matrix,resulting in the superficial peeling of the matrix.

关 键 词：高速铁路 钢轨 表面伤损 白层马氏体 裂纹 

分 类 号：U213.4[交通运输工程—道路与铁道工程]