中国铁道科学2025，Vol.46Issue(2)：60-71,12.DOI:10.3969/j.issn.1001-4632.2025.02.06
U75V钢轨微观晶粒结构对滚动接触疲劳损伤行为影响
Effect of the Microscopic Grain Structure of U75V Rail on Rolling Contact Fatigue Damage Behavior
摘要
Abstract
Microstructural properties such as grain topology,size,and orientation of rail materials have a significant effect on early rolling contact fatigue(RCF)crack evolution.To analyze the influence of grain structure on RCF cracks,a microscopic model reflecting the geometric structure and orientation of grains in U75V rail materials was established based on crystal plasticity theory and the Voronoi principle.The model was further enhanced by modified cohesive elements to forge a link between the microstructure of the material and fatigue damage,facilitating the simulation of RCF crack evolution at the microscopic scale and establishing a microscopic RCF crack evolution model for rails.Based on this model,the effects of rail microstructure on the initiation locations and propagation paths of surface RCF cracks under cyclic loading were investigated.The results show that under cyclic loading,RCF cracks mostly initiate at grain boundaries.While the microcrack initiation locations and lifetimes exhibit randomness,the initiation locations show a tendency to be concentrated in specific regions.The growth rate of RCF cracks varies across different stages,with the increase of growth length,the overall trend of early slow late gradually become faster,which can be divided into stages I and II.Stage I is the initiation stage,where microcracks propagate over a length equivalent to several grain sizes.The crack growth behavior during this stage is mainly governed by the grain orientation and the interaction between grain boundaries,and the crack growth rate is around 0.002 5 μm·r-1,which is lower than the crack growth expansion rate of 0.010 3 μm·r-1.When the microcracks that are closely spaced at the initiation position are attracted to each other and polymerize during the growth process to form a new crack,they enter into stage II.The growth behavior of new cracks is mainly governed by external loading,and the crack growth rate increases significantly to 0.018 7 μm·r-1.The simulated crack morphology matches the structure observed in the twin-disc test.关键词
U75V钢轨/滚动接触疲劳/微观结构/晶体塑性/裂纹扩展/微观模型Key words
U75V Rail/Rolling contact fatigue(RCF)/Microstructure/Crystal plasticity/Crack propagation/Microscopic model分类
交通工程引用本文复制引用
李骏鹏,周宇,梁旭,华建兵,刘思磊,翁之意..U75V钢轨微观晶粒结构对滚动接触疲劳损伤行为影响[J].中国铁道科学,2025,46(2):60-71,12.基金项目
中央高校基本科研业务费项目(2022-5-ZD-04) （2022-5-ZD-04）
上海市科委基金资助项目(20dz1203100) （20dz1203100）
浙江省交通运输厅科技计划项目(2023024) （2023024）
中国国家铁路集团有限公司科技研究开发项目(N2022G011,K2023G013) （N2022G011,K2023G013）
中国铁道科学研究院集团有限公司院基金课题(2023YJ052) （2023YJ052）
安徽省城市轨道交通安全与应急管理重点实验室开放课题(2024GD0008) （2024GD0008）
2024年度合肥大学人才科研基金项目(24RC24) （24RC24）
