中文摘要：

为提高18Cr2Ni4WA钢齿轮的服役性能，研究了渗碳与喷丸强化复合处理对18Cr2Ni4WA钢表面完整性及常规疲劳和接触疲劳性能的影响规律。利用X射线应力仪、粗糙度仪、扫描电子显微镜、显微硬度计等测试和分析了表面组织结构、残余应力场、表面粗糙度、表面形态特征及表面加工硬化作用。结果表明：合理的喷丸强化工艺与渗碳复合处理能够显著提高18Cr2Ni4wA齿轮钢的旋弯弯曲疲劳性能和接触疲劳性能，但并不是喷丸强度越高，疲劳性能越好，而是存在较佳的喷丸强化参数，此条件下可获得良好的表面完整性，因而常规机械疲劳抗力和接触疲劳抗力均可协调提高。过高强度的喷丸处理会破坏渗碳钢的表面完整性，不利于疲劳性能。此外，复合改性对常规疲劳行为和接触疲劳行为的影响规律有所不同，此归于二者失效机制及控制因素的差异。

英文摘要：

In order to improve the service performance, the effects of carburizing combined with shot peening on plain fatigue and contact fatigue properties of 18Cr2Ni4WA steel were investigated. Metallographic structure, resid- ual stress, roughness, morphology and hardness on the modified surface were measured and analyzed by using X- ray diffraction analysis, surface profile measurement, scanning electron microscopy and microhardness instrument, etc. The results show that the rotating bending fatigue and contact fatigue properties of 18Cr2Ni4WA steel can be remarkably improved by optimized carburizing and shot peening process. But it is not the higher the shot peening intensity, the better the fatigue properties. The surface integrity, plain fatigue resistance and contact fatigue resist- ance can be synchronously improved under an optimum shot peening parameters, whereas they will be decreased by exorbitant shot peening intensity. In addition, the effects of complex modification on plain fatigue and contact fa- tigue are different due to the difference of their failure mechanisms and control factors.