铁道建筑

针对重载线路钢轨焊接接头磨耗低塌严重等问题，本文通过现场勘查、测量和长期监测，分析了接头区域硬度分布与相对磨耗规律，提出了降低重载线路钢轨焊接接头磨耗的量化指标。结果表明：焊接接头服役中的相对磨耗与轨顶面硬度密切相关，焊缝的软化区比其他位置磨耗更严重；闪光焊和铝热焊接头相对磨耗均随接头与母材硬度比值(H_j/H_b)的增加而减小，H_j/H_b为0.98时，接头与母材的相对磨耗最小；接头软化区相对磨耗随软化区宽度增加而增大。建议适当提高接头轨顶面硬度质量控制指标，改进闪光焊热处理工艺中冷却速度，加强高硬度铝热焊剂的研究及应用。

In response to the problems of serious low and collapse wear of welded joints on heavy haul railway lines, through on-site investigation, measurement, and long-term monitoring, the hardness distribution and relative wear law of the joint area were analyzed, and quantitative indicators for reducing the wear of welded joints on heavy haul railway lines were proposed. The results indicate that the relative wear of welded joints during service is closely related to the hardness of the rail top surface, and the softening zone of the weld seam has more severe wear compared to other positions. The relative wear of flash welding and aluminum thermal welding joints decreases with the increase of the hardness ratio(H_j/H_b) between the joint and the base metal. When the H_j/H_b value is 0.98, the relative wear between the joint and the base metal is the smallest. The relative wear of the joint softening zone increases with the width of the softening zone increasing. It is recommended to appropriately increase the quality control indicators for the hardness of the joint rail top surface, improve the cooling rate in the flash welding heat treatment process, and strengthen the research and application of high hardness aluminum thermal flux.