钢轨现场焊打磨工艺对接头质量的影响  

Influence of grinding procedure for the quality of rail field welded joint

作　　者：贾春 戴虹[2] 汪鹏举 钟元[2] 李正浩[2] 

机构地区：[1]西宁工务机械段,青海西宁810006 [2]西南交通大学材料科学与工程学院,四川成都610031

出　　处：《电焊机》2016年第8期76-79,共4页Electric Welding Machine

基　　金：中国铁路总公司科技开发项目(2012G004-D)

摘　　要：针对无缝线路换铺工程中的钢轨焊接接头踏面上出现的纵向裂纹问题,采用现代材料分析方法分析该类裂纹的特征和组织形貌;采用数控钢轨仿形精磨机进行打磨工艺的模拟对比试验,探讨该类裂纹的形成原因。结果表明,纵向裂纹的产生原因是焊后打磨操作违规导致焊接接头轨顶面打磨发蓝,形成了薄壳状马氏体硬化层,在列车车轮碾压作用下形成了沿纵向的表面裂纹,致使钢轨接头损伤。打磨压力越大,砂轮硬度越高,焊头表面越容易发生打磨发蓝现象。For the problem of longitudinal crack has appeared on the rail surface when laying continuously welded rails （CWR）,this article analyzes the characteristic and structure morphology of the cracks by the modem methods for material analysis. The simulation contrasts test for the grinding procedure has been done to discuss the factor of forming such cracks with the CNC rail profiling refiner. The result shows that the incorrect grinding operation after welding,which causes the top surface of the welding joint to become blue and form the hardened layer of the thin martensite,and then the longitudinal crack forms on the surface under tile pressure from the train wheels causing the damage to the joint. That is why the longitudinal crack appears. The greater the pressure is,the higher hardness will be. the more chance of becoming blue.

关 键 词：钢轨焊接接头 表面裂纹 马氏体硬化层 打磨工艺 

分 类 号：TG441.8[金属学及工艺—焊接]