钢轨铝热焊预热参数对焊前预热温度的影响  

The Influence of Preheat Parameters on the Preheat Temperature of Rail Thermit Welding

作　　者：高松福 任金雷 石孟雷 宋宏图 GAO Songfu;REN Jinlei;SHI Menglei;SONG Hongtu(Metals and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited)

机构地区：[1]中国铁道科学研究院集团有限公司金属及化学研究所,北京100081

出　　处：《高速铁路新材料》2023年第1期54-57,共4页Advanced Materials of High Speed Railway

基　　金：中国铁道科学研究院集团有限公司金属及化学研究所科研项目(2021XC0104)。

摘　　要：通过设计测量钢轨铝热焊接头温度的专用方法,研究了60 kg/m钢轨铝热焊接预热过程中,预热参数对钢轨预热温度的影响。结果表明:钢轨端面预热温度呈现轨底、轨腰部位温度较高,轨头部位温度较低的分布特点,且随预热时间增加而增加;轨缝宽度较宽(30 mm)时,钢轨端面的预热温度较低,预热温度不均匀程度较为明显;随着丙烷流量的降低,轨底预热温度达到1 100℃的时间越短,丙烷流量为48 L/min时,加热时间为2.7 min。数值模拟研究发现,较高的火焰流速和较大的轨缝宽度均加剧预热的不均匀程度,与试验测温所得规律一致。现场钢轨铝热焊接宜根据轨缝宽度和钢轨温度的不同,采用有差别的预热工艺,以达到钢轨端面预热温度适当且分布均匀的目标。The influence of preheat parameters on preheat temperature of rail thermit welding was investigated.The results show that,when the rail gap width is 30 mm,the preheating flame can flow through the rail gap more smoothly,and the heating effect on the rail head is weak,which leads to lower preheating temperature of the rail end and uneven distribution of preheating temperature.When the propane flow rate is 48 L/min,the temperature and heating rate of the preheating flame are higher due to the higher proportion of oxygen in the preheating gas.As a result,the temperature of rail bottom is higher than that of rail head,and the heating effect on rail end is stronger.When preheating time is 2.7 min,the temperature of rail bottom exceeds 1 100 ℃.The propane gas flow rate should be optimized according to the width of the rail gap in order to achieve uniform distribution of the preheating temperature of the rail end.

关 键 词：钢轨焊接 铝热焊 预热参数 预热温度 

分 类 号：U213.92[交通运输工程—道路与铁道工程] TG457.1[金属学及工艺—焊接]