Abstract In this study, the effect of surface defect on the rolling contact fatigue (RCF) of railway wheel steel was investigated. Artificial defects with different dimensions were produced on unprerolled and prerolled wheel discs to simulate defects appearing in actual wheels. Subsequently, twin-disc tests were conducted under the typical contact stress and slip ratio. Finally, a novel method was used to investigate the RCF crack initiation of the wheel disc. Results show that the prerolling promotes RCF crack initiation for wheel steels with surface defects. The critical defect dimension resulting in the RCF crack initiation of the prerolled wheel disc is 100–200 μm. Considering the scaling factor between the actual wheel and test wheel disc, the predicted critical defect dimension is 2–4 mm for the actual wheel, which agrees with field observations. For the prerolled wheel steel, RCF cracks initiate from the region near the middle edge of the defect, where the most significant stress concentration appears. An increase in defect dimension increases the stress concentration, thereby reducing the RCF life. The Fatemi–Socie multiaxial fatigue parameter in conjunction with the theory of critical distances can predict the effect of defect dimension on variation in RCF life.

中文翻译：

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含表面缺陷铁路车轮钢滚动接触疲劳研究

摘要 在本研究中，研究了表面缺陷对铁路车轮钢滚动接触疲劳（RCF）的影响。在未预卷和预卷轮盘上产生不同尺寸的人工缺陷，以模拟实际车轮中出现的缺陷。随后，在典型的接触应力和滑移率下进行了双盘试验。最后，使用一种新方法来研究轮盘的 RCF 裂纹萌生。结果表明，预轧促进了具有表面缺陷的车轮钢的 RCF 裂纹萌生。导致预轧轮盘 RCF 裂纹萌生的临界缺陷尺寸为 100-200 μm。考虑到实际车轮和测试轮盘之间的比例因子，实际车轮的预测临界缺陷尺寸为 2-4 mm，与实地观察一致。对于预轧车轮钢，RCF 裂纹从缺陷中间边缘附近的区域开始，该区域出现最显着的应力集中。缺陷尺寸的增加会增加应力集中，从而降低 RCF 寿命。Fatemi-Socie 多轴疲劳参数结合临界距离理论可以预测缺陷尺寸对 RCF 寿命变化的影响。