Surface integrity is critical for gear contact fatigue performance. The relation between gear surface integrity and contact fatigue remains unclear, which is a challenge for gear anti-fatigue design. This study investigates the relation between surface integrity and contact fatigue of 18CrNiMo7-6 carburized gears through fatigue experiments and data-driven modeling. A series of gear contact fatigue tests, with approximately 110 × 10⁶ running cycles in total, has been conducted. P-N curves and fatigue limits of the tested gears are investigated for four typical manufacturing processes: carburizing and grinding, shot peening, barrel finishing, and barrel finishing after shot peening. The influence of different surface integrity components on contact fatigue is explored with a Pearson correlation coefficient analysis and a random forest algorithm. Formulae of gear contact fatigue life and fatigue limit considering surface integrity are proposed. Results show that a high surface integrity state with surface hardness of 686.5 HV, maximum compressive residual stress of −1162 MPa, and surface roughness Sa of 0.36 μm, exhibits the highest gear contact fatigue limit, which is 15.1% higher than the carburizing and grinding state, indicating the benefits of improving surface integrity. For both the gear contact fatigue life and fatigue limit, the most significant surface integrity components are surface hardness, maximum compressive residual stress, and surface roughness. The proposed formulae considering surface integrity illustrate reasonable prediction accuracy, with 1.5 times dispersion band for the predicted fatigue life and a maximum relative error of 2.1% for the predicted fatigue limit.

表面完整性对于齿轮接触疲劳性能至关重要。齿轮表面完整性与接触疲劳之间的关系尚不清楚，这对齿轮抗疲劳设计是一个挑战。本研究通过疲劳实验和数据驱动建模研究了 18CrNiMo7-6 渗碳齿轮的表面完整性与接触疲劳之间的关系。已经进行了一系列齿轮接触疲劳测试，总共大约 110 × 10 ^{6 个}运行循环。PN研究了四种典型制造工艺的测试齿轮的曲线和疲劳极限：渗碳和磨削、喷丸、滚桶精加工和喷丸后滚桶精加工。通过 Pearson 相关系数分析和随机森林算法探索不同表面完整性成分对接触疲劳的影响。提出了考虑表面完整性的齿轮接触疲劳寿命和疲劳极限公式。结果表明，表面硬度为 686.5 HV，最大压缩残余应力为 -1162 MPa，表面粗糙度为Sa为 0.36 μm，表现出最高的齿轮接触疲劳极限，比渗碳和磨削状态高 15.1%，表明提高表面完整性的好处。对于齿轮接触疲劳寿命和疲劳极限，最重要的表面完整性分量是表面硬度、最大压缩残余应力和表面粗糙度。所提出的考虑表面完整性的公式说明了合理的预测精度，预测疲劳寿命的分散带为 1.5 倍，预测疲劳极限的最大相对误差为 2.1%。