高海拔环境下钢轨铝热焊预热工艺研究

Study on Preheating Technology of Rail Thermit Welding in High Altitude Environment

通过制作钢轨铝热焊预热测温试验模型,研究了海拔高度对预热气体质量流量和预热温度的影响。试验结果表明:采用相同的预热气体压力时,高海拔环境下预热气体质量流量减少,导致钢轨的预热温度增加缓慢,影响预热效果。为保证与平原地区相近的预热效果,高海拔环境下应采用较高的预热气体压力。高海拔环境下进行钢轨铝热焊接时,采用调整气体压力后的预热工艺,焊接接头性能满足TB/T 1632.3—2019《钢轨焊接第3部分:铝热焊接》技术要求及现场验收要求。

The effect of altitude on preheating gas flow rate and preheating temperature was studied by making preheating experimental model.The results of preheating test show that the output flow of preheating gas decreases at high altitude.The preheating temperature of rail increases slowly due to less gas output at high altitude,which affects the preheating effect.In order to ensure the preheating effect similar to that in the plain area,high preheating gas pressure should be adopted at high altitude.The preheating process after adjusting gas pressure should be adopted to meet the requirements of TB/T 1632.3—2019 standards and on site joints inspection.