Wang Yanpeng, Xiang Pengcheng, Ding Haohao, Wang Wenjian, Zou Qiang, Liu Xuehua, Guo Jun, Liu Qiyue
Tribology Research Institute, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China.
Technology Center, Ma'anshan Iron and steel Co., Ltd., Ma'anshan 243000, China.
Materials (Basel). 2020 Sep 25;13(19):4282. doi: 10.3390/ma13194282.
Rolling contact fatigue (RCF) damages often occur, sometimes even leading to shelling on locomotive wheel treads. In this work, the RCF damage behaviors of two locomotive wheel materials with different molybdenum (Mo) contents were studied, and the influence of depth of wheel material was explored as well. The result indicates that with the increase in the Mo content from 0.01 wt.% (wheel 1, i.e., a standard wheel) to 0.04 wt.% (wheel 2, i.e., an improved wheel), the proeutectoid ferrite content and the interlamellar spacing of pearlite decreased, the depth and length of the RCF cracks increased and the average RCF live of locomotive wheel steel improved by 34.06%. With the increase in the depth of material, the proeutectoid ferrite content and the interlamellar spacing of pearlite increased, the depth of RCF cracks increased, the length of RCF cracks of wheel 1 increased and then decreased whereas that of wheel 2 decreased, the RCF live showed a decrease trend for wheel 1, while the RCF life increased and then decreased for wheel 2. The processes of shelling can be divided into three patterns: cracks propagating back to the surface, crack connection and fragments of surface materials.
滚动接触疲劳（RCF）损伤经常出现，有时甚至会导致机车车轮踏面出现剥落。在这项工作中，研究了两种不同钼（Mo）含量的机车车轮材料的RCF损伤行为，并探讨了车轮材料深度的影响。结果表明，随着钼含量从0.01 wt.%（车轮1，即标准车轮）增加到0.04 wt.%（车轮2，即改进型车轮），先共析铁素体含量和珠光体片层间距减小，RCF裂纹的深度和长度增加，机车车轮钢的平均RCF寿命提高了34.06%。随着材料深度的增加，先共析铁素体含量和珠光体片层间距增加，RCF裂纹深度增加，车轮1的RCF裂纹长度先增加后减小，而车轮2的则减小，车轮1的RCF寿命呈下降趋势，而车轮2的RCF寿命先增加后减小。剥落过程可分为三种模式：裂纹扩展回表面、裂纹连接和表面材料碎片。
