U75V钢轨闪光焊焊后热处理冷却工艺优化研究  

Research on Optimization of Cooling Process in the Post-weld Heat Treatment of U75V Rails Flash Butt Welding Joints

作　　者：杜吉康 詹新伟 王树青 DU Jikang;ZHAN Xinwei;WANG Shuqing(Metals and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

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》2022年第6期47-52,共6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青年基金项目(2020SJ07)。

摘　　要：钢轨经闪光焊接后,为提高接头性能,需进行焊后正火热处理。针对U75V钢轨闪光焊接头正火热处理后,轨底三角区发现马氏体组织的问题,提出了2种解决对策,并在2个焊轨厂开展了焊后热处理冷却工艺试验,试验结果验证了解决对策的可行性:通过调整喷风方式、减小喷风压力来直接降低轨底三角区冷却速度,或通过减少喷风时间来间接减小冷却速度,均能够有效抑制轨底三角区马氏体的产生。同时优化了喷风冷却方式及工艺参数,采用优化后的参数所生产的接头不仅轨底三角区显微组织未出现马氏体,焊缝硬度也能与母材很好地匹配。In order to improve the performance of the welding joint, normalizing heat treatment is required after flash butt welding. Aiming at the problem that abnormal martensite structure was found in the triangle area at the bottom of rail after normalizing beat treatment of U75V rail flash butt welding joint, two kinds of solutions were proposed, and the cooling process test of the heat treatment was performed in two rail welding factories. The process test verifies the feasibility of the aolutions: By adjusting the air injection mode and decreasing the air injection pressure, it can directly reduce the cooling speed of the triangular area at the bottom of the rail, or to indirectly reduce the cooling speed by reducing the time of the air injection,which can effectively suppress the formation of martensite in triangular area. At the same time, the air injection mode and cooling process parameters are optimized, and the effect verification is passed, indicating that the microstructure of the joint produced by the optimized parameter are normal, and the other performances meet the TB/T 1632. 2—2014 standard.

关 键 词：U75V钢轨 闪光焊 马氏体 喷风冷却 工艺参数优化 

分 类 号：U213.93[交通运输工程—道路与铁道工程]