既有线铝热焊焊接质量控制技术

Controlling technology of thermit welding quality of rail on existing railway line

铝热焊在既有线铁路无缝线路的铺设、钢轨断轨修复、应力放散等维修作业中多有应用。针对在铝热焊过程中存在的问题,提出了应对措施:焊接前应检查焊接设备及机具,封锁方案应完备,焊接时应对齐两钢轨端面,预留焊缝间隙应适中,封箱工作和焊头表面打磨要适当,控制好预热温度和时间,焊后应进行热处理及探伤检测。实践证明,将工序按标准控制,不断改进工艺,就能保证焊接质量达到规定的标准。

Thermit welding is often used for the continuous welded rail, broken rail repair, stress releasing, and other maintenance operations of the existing railway line. According to the quality problems in thermit welding process, this paper put forward a series of quality control measures before and after welding, such as welding equipment or machine check and exhaustive blockade program application before the welding, two rail ends alignment, moderate welding gap reservation, fine sealing work, appropriate welding head surface polishing, preheating temperature and time control, low temperature preheating during the welding, and heat treatment and flaw detection after the welding. The practice proved that the quality of welding can reach the required standard by the standard process control and continuous technique improvement.