【摘要】 采用光学显微镜和扫描电子显微镜等手段 ,对某轻型汽车 4 0Cr后桥半轴断裂件的组织及断口特征进行了分析结果表明 :半轴在调质处理时的淬火温度不够高 ,使其表层和心部组织中存在较多的铁素体相 ,造成了工件最终的硬度和疲劳强度不足 ,导致半轴在使用中发生扭转疲劳断裂 .更多还原

【Abstract】 The microstructure and fracture features of 40Cr rear half-axle used in a car were analyzed by optical metalloscope and SEM. The results show that too much ferrite phase is remained in the microstructures of the half-axle after quenching in a lower temperature, which lowers hardness and fatigue strength. This leads to the twisting fatigue failure of the half-axle in use.更多还原