滚动方向对CL60车轮材料接触疲劳损伤的影响  

Effect of Rolling Direction on Contact Fatigue Damage of CL60 Wheel Steel

作　　者：胡月 李群 刘启跃[1] 郭俊[1] 王文健[1] HU Yue;LI Qun;LIU Qiyue;GUO Jun;WANG Wenjian(Tribology Research Institute,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学摩擦学研究所

出　　处：《西南交通大学学报》2020年第1期84-91,共8页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(51775455,51975489,51475393)

摘　　要：为研究车轮滚动方向对车轮材料接触疲劳损伤的影响机制,利用WR-1滚动磨损试验机进行了车轮单向和双向运行滚滑磨损试验,使用光镜和扫描电镜分析了试验后车轮试样的表面磨损形貌、剖面疲劳裂纹形貌及磨屑尺寸,探究了换向运行工况下车轮表面损伤、裂纹扩展、磨屑尺寸随反向循环次数的演变规律.研究结果表明:车轮表面损伤以起皮剥落为主,反向循环次数从1万次增加到12万次时,初始剥落逐渐消失,继而形成与原滚动方向相反的新剥落,相同循环次数下改变车轮滚动方向有利于减轻车轮材料疲劳损伤;车轮换向改变了表面微裂纹的扩展方向,形成4°~8°的反向疲劳裂纹,并出现了裂纹扭曲和分支现象;单向滚动时,随循环次数增加,磨屑尺寸先增大后减小,反向后磨屑厚度先增大后减小,反向1万次时,磨屑厚度增大到10~12μm,为单向时的两倍.In order to investigate the effect of wheel rolling direction on rolling contact fatigue(RCF)damage of wheel steel,the rolling-sliding wear experiments under both unidirectional and bidirectional conditions were carried out on a rolling wear testing apparatus(WR-1,China).The wheel surface damage,section fatigue crack morphology and wear debris size were observed by optical microscope and scanning electron microscope,the evolution law of wheel surface damage,fatigue crack propagation and debris size with the number of reverse cycles under reversing operating conditions were investigated.The results show that the wheel surface damage is mainly caused by peeling.As the number of reverse cycles increases from 10000 to 120000,the initial peelings gradually wear off and then new peelings are formed opposite to the original rolling direction,changing wheel rolling direction is beneficial to reduce the RCF damage of wheel materials under the same test cycles.The propagation direction of surface microcracks is changed after wheel reverse rolling,forming reverse fatigue cracks of 4°−8°,and crack distortion and branching occur on the wheel samples.As the number of cycles increases,the debris size increases firstly and then decreases under unidirectional condition,after wheel reverse rolling,the debris thickness increases firstly and then decreases,the thickness increases to 10−12μm after reversing 10000 cycles,which is twice as much as under the unidirectional condition.

关 键 词：车轮钢 滚动方向 疲劳损伤 裂纹扩展 磨屑尺寸 

分 类 号：TH117.1[机械工程—机械设计及理论]