导弹舵机汇流线断裂失效分析

某型号导弹在空中进行发射试验时失控，检查发现舵机汇流线断裂。本文对断裂的汇流线进行了断口宏、微观观察，化学成分分析以及硬度检测，并结合汇流线焊接工艺参数进行了分析试验和验证。结果表明，该汇流线在焊接时，因焊接温度和时间参数控制不当，导致汇流线疲劳抗力下降，在导弹挂飞振动时发生疲劳断裂。焊接工艺对比试验以及故障再现试验结果表明，通过严格控制汇流线焊接工艺参数，将焊接温度控制在350±5℃，时间≤3s，可以有效提高产品的质量可靠性。

Failure Analysis of a Bus Wire of a Missile Helm Gear

The bus wire of a missile helm gear fractured during the launch test. The facture cause of the bus wire was analyzed by faeture surface observation, chemical composition analysis, and hardness testing. Then based on the welding parameters of the bus wire, simulation tests were carried out. The results show that the fatigue resistance of the bus wire declined because of the improper welding temperature and time. As a result, the bus wire fractured under the effect of vibration during the launch test. Simulation test results show that the quality reliability of the bus wire can be effectively improved by properly controlling the welding parameters keeping the welding temperature in the range from 345 ℃ to 355 ℃ and the welding time shorter than 3 s.