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通过显微硬度、化学成分、扫描电镜和能谱仪等方法对接触疲劳试验样品进行了分析。结果表明,试样经过一定周次的循环加载,滚道表面出现点蚀、微裂纹和剥落等现象。疲劳裂纹主要从滚道表面萌生,并与表面呈一定角度向内部扩展。材料内部的非金属夹杂物对裂纹的萌生和扩展发生影响。次表面疲劳裂纹优先在Al2O3·Mg O颗粒周边萌生和扩展,并没有在Ti N颗粒周围萌生。
Contact fatigue test samples were analyzed by microhardness, chemical composition, scanning electron microscopy and energy dispersive spectroscopy. The results show that the sample after a certain cycle of loading, raceway surface pitting, micro-cracks and spalling phenomenon. Fatigue cracks mainly from the raceway surface initiation, and with the surface at an angle to the internal expansion. Non-metallic inclusions within the material affect the initiation and propagation of cracks. Sub-surface fatigue cracks preferentially germinate and expand around the Al2O3 · MgO particles, and do not sprout around TiN particles.