重载曲线钢轨滚动接触疲劳时变规律及治理优化  

Evolution of rail rolling contact fatigue on heavy-haul curves and treatment optimization

作　　者：张昕[1] 赵鑫[1] 彭峰 李静伟 张凯 李涛 ZHANG Xin;ZHAO Xin;PENG Feng;LI Jinwei;ZHANG Kai;LI Tao(State Key Laboratory of Rail Transit Vehicle System,Southwest Jiaotong University,Chengdu 610031,China;Manufacturing Dept.of Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,China;Steel Works.of Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,China;Jining Maintenance Department,China Railway Hohhot Group Co.,Ltd.,Ulanqab 012000,China)

机构地区：[1]西南交通大学轨道交通运载系统全国重点实验室,四川成都610031 [2]内蒙古包钢钢联股份有限公司制造部,内蒙古包头014010 [3]内蒙古包钢钢联股份有限公司炼钢厂,内蒙古包头014010 [4]中国铁路呼和浩特集团有限公司集宁工务段,内蒙古乌兰察布012000

出　　处：《铁道科学与工程学报》2024年第8期3153-3165,共13页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52375130,U21A20167)。

摘　　要：为探明某重载铁路小半径曲线钢轨因滚动接触疲劳提前失效机理及优化现有打磨策略,针对该重载线曲线段发生的U75V热处理钢轨滚动接触疲劳损伤,开展不同半径、运量曲线钢轨的现场试验、室内试验、数值仿真,揭示现场不同圆曲线段钢轨疲劳随服役时间的演化规律。研究结果表明:钢轨疲劳随服役时间的演化大致分为裂纹萌生与快速扩展和裂纹-磨耗共生2个阶段。在进入裂纹-磨耗共生阶段后,R600 m、R800 m重载圆曲线段随着服役时间累计会因钢轨显著失形导致轮轨匹配恶化,虽对轨距角裂纹产生了一定抑制作用,但轨面部分区域产生了严重剥离掉块,可能会威胁到安全行车,究其根本原因是钢轨失形到一定程度后轮轨接触点向轨肩集中所致;所跟踪的其余曲线因钢轨磨耗较小未明显失形,故不会出现严重剥离掉块。在实验室内通过对下道钢轨失效分析后发现,涡流探伤仪测量到的最大深度与真实最大深度间存在误差;测量深度一般大于真实深度,真实深度在变大的同时测量深度与真实深度间的误差会越来越大。基于钢轨滚动接触疲劳时变规律,为进一步延长R600 m、R800 m重载钢轨的使用寿命,建议加大打磨频率(特别是在新轨上道6个月内),优先将廓形打磨为标准廓形,兼顾磨去疲劳裂纹;对于更大半径曲线考虑到经济性等,保持当前的打磨策略即可。To reveal the failure mechanism of heavy haul rails on sharp curves by rolling contact fatigue and optimize the existing grinding strategies,field and laboratory tests and numerical simulations were conducted in consideration of different radii and gross traffic tonnages to investigate the evolution of the RCF on U75V HT rail installed on the heavy haul curves with different radii.It is found that the evolution of rail RCF with service time can be roughly divided into two stages:crack initiation and rapid propagation,and crack-wear symbiosis.After entering the crack-wear symbiosis stage,rail profiles deteriorate significantly on R600 m and R800 m curves,resulting in worsened wheel-rail match and severe spalling on the rail contact surfaces and threatening the running safety.The root cause is that the wheel-rail contact point moves to the rail shoulder once the rail is worn to a certain extent.For monitored curves with larger radii,no severe profile deterioration by wear was observed due to low wear rates,and no severe spalling was present.Failure analysis of replaced rails were performed in the laboratory.It is found that the maximum depth measured by the eddy current crack detector considerably different from the actual ones,the measured depth is generally larger,and the difference increases with the crack depth.To further extend the service life of heavy haul rails on R600 m and R800 m curves,it is recommended to increase the grinding frequency(especially within the first six months in service)to remove/control the cracks,for which the standard profile is preferred.For rails on curves with larger radii,the current grinding strategy seems to be sufficient.

关 键 词：重载铁路 曲线钢轨 滚动接触疲劳 涡流检测 钢轨打磨 

分 类 号：U213.422[交通运输工程—道路与铁道工程]