放热焊接钢轨温度分布及预热保温研究
Research on temperature distribution, preheating and heat preservation of rail under exothermic welding

轨道交通线路施工过程中,有很多导线接头需要焊接在钢轨上。放热焊接时温度处理不好导致钢轨中马氏体的存在,使钢轨结构脆化以及韧性变差,影响行车安全。通过试验和仿真对比验证分析,建立钢轨有限元计算模型,从不同的预热工况下分析焊接钢轨的温度分布情况以及马氏体温度点的影响范围,最后提出放热焊接钢轨的预热和保温措施,为轨道交通线路现场施工提供理论依据。
In the construction process of Rail transit lines, a lot of wire connectors will be welded on the rail. When heat treatment can not be handled properly, Martensite will exist in the rail, and that will make the rail structure embrittlement and poor toughness. At last, it will affect the safety of the vehicle. In this paper, experiment and simulation analysis are compared for mutual proof. After finite element model of rail has been built, temperature distribution of welded rail and the influence range of Martensite temperature point are got from different preheating condition. In this paper, the exothermic welding rail preheating and heat preservation measures are proposed. These findings can provide a theoretical basis for the rail transit line construction