某发动机总管支架销轴在使用过程中出现脱落和裂纹。通过断口的宏微观分析、金相检验与结构分析等,对销轴脱落和产生裂纹的原因进行了分析。结果表明:在发动机工作振动应力的作用下,销轴与支架连接的焊点产生疲劳裂纹,进而引起总管支架销轴脱落,脱落原因为支架组件的设计结构和连接工艺不合理、焊接强度低。 An engine mast support pin peels and cracks during use. Through the macro-micro fracture analysis, metallographic examination and structural analysis, the reasons for the pin off and cracks occurred. The results show that under the action of the vibration stress of the engine, the fatigue cracks occur on the solder joint between the pin and the bracket, which leads to the pin of the bus bracket falling off. The reason for the drop is that the design of the bracket component and the connection process are not reasonable and the welding strength is low.