开口销断裂分析

Fracture Analysis of Split Pin

发动机在分解检查时发现,顺航向左侧α1作动筒与支架固定销轴上的开口销发生断裂。通过外观检查、断口宏微观分析、表面检查、成分分析、组织检查、硬度检查等手段和有限元分析,对故障开口销的断裂性质和断裂原因进行分析。结果表明:故障开口销材质硬度值偏高,不符合标准要求;故障开口销断裂的性质为疲劳断裂;故障开口销在发动机工作过程中与作动筒支架侧表面发生周向摩擦,开口销内弧表面产生弯曲应力,再加上源区附近表面的磨损影响,最终导致其疲劳断裂。

Fracture was found in the split pin of the engine,which joint alone the course left α1 cylinder and the bracket fixed pin. After the check of an engine breakdown,the mode and cause of the fracture were analyzed by appearance observation,macro and micro observation on the fracture surface,chemical composition analysis,metallographic examination,hardness test,and finite element analysis. The results show that the material hardness value of fault split pin is too high,which does not meet the standard requirement; the fracture of the split pin is fatigue fracture,and the reason for fatigue fracture is in the process of the engine working,and there is circumferential friction on the surface of the fault split pin and the side surface of the cylinder,the inner act surface of the split pin creates the bending stress and the wear on the surface near the source area.