稀土轨焊接热标凸字断裂原因分析  

Study on the thermal convex word fracture reason of the Rare earth rail welding

作　　者：芦建峰[1] 

机构地区：[1]呼和浩特铁路局焊轨段,内蒙古呼和浩特010051

出　　处：《电焊机》2016年第2期94-96,共3页Electric Welding Machine

摘　　要：服役半年的稀土钢轨焊缝,在京包线发生两处轨腰断裂,经分析两处断裂原因相同,均以钢厂轧制热标凸字(V)与焊缝交汇处为裂纹源,向内部扩展后造成钢轨断裂。通过模拟试验得知,因钢轨制造部门热标凸字的存在,在钢轨焊接后推凸过程中,焊筋边缘的热态金属与迎向焊瘤的凸字挤压在一起,形成一个夹缝,经放大观察为表面裂纹。在后续生产、运输和线路使用后,裂纹向内部扩展最终发生断裂。夹缝最大深度为热标凸字厚度,机加工可消除此裂纹。Service for half a year of rare earth welding occur two rail waist fractures in Jingbao railway,after the analysis, two faults are very similar, the source of crack by convex word（V）to welding to expand the rail fracture. Through the simulation test, because of the convex word of steel manufacturer exsit, in the process of rail welding after pushing convex, weld reinforcement on the edge of the hot metal is embraced by the flash of extrusion convex word together, forming a gap, the magnification for surface crack. After the subsequent transport and line using,crack propagates inwards and breaks in the end. The maximum depth of gap is the thickness of convex word,and machining can eliminate the crack.

关 键 词：钢轨 凸字 断裂 稀土 

分 类 号：TG457.1[金属学及工艺—焊接]