一种液环真空泵转轴断裂的失效分析

The Fracture Analysis on Drive Shaft Faliut of Liquid-ring Vacuum Pump

针对一种液环真空泵转轴的断裂失效进行了分析。该轴除了径向断裂外还存在轴向裂纹。对径向断口的宏观和微观分析均显示了疲劳损伤的特征,强度校核也表明该轴的疲劳安全系数过低,存在疲劳断裂的风险。对轴向裂纹的金相检测排除了淬火裂纹的可能,微观分析显示过载裂纹的特征,分析表明径向裂纹破坏了轴的结构完整性,加剧了应力集中,从而导致了轴向过载裂纹。根据分析结果,从材质和热处理方面提出了改进措施。

For a liquid-ring vacuum pump drive shaft failure, a failure analysis is conducted. The shaft exists axial cracks in addition to the radial fracture. Through the macroscopic and microcosmic analysis of radial fracture, the characteristics of fatigue damage is showed. Then the intensity checking also showed that the fatigue safety coefficient of the shaft is too low, so there is a risk of fatigue fracture. The metallographic detection of axial crack excluded the possibility of quenching crack, and the microscopic analysis showed the characteristic of overload crack. The analysis showed that the structural integrity of the shaft was damaged by the radial crack, thus the stress concentration is enhansed, which leaded to the axial overload crack. According to the analysis results, the improvement measures are proposed from the aspects of material and heat treatment.