钛合金高锁螺栓断裂原因分析

Cause Analysis on Fracture of Titanium Alloy High Lock Bolts

某飞机用钛合金高锁螺栓在装配过程中发生断裂。通过宏观分析、微观分析、金相检验、力学性能复查和装配现场调查等方法对螺栓的断裂原因进行了分析。结果表明:该钛合金高锁螺栓为单边弯曲应力造成的过载断裂,与螺栓制造质量无关。螺栓装配区域操作空间狭小,安装时扳手的转动平面易发生倾转,从而在螺栓上形成弯曲应力,建议改进装配工具。

The titanium alloy high lock bolts of an aircraft fractured during assembly.The causes of bolts fracture were analyzed by means of macro analysis,micro analysis,metallographic examination,mechanical property recheck and assembly site investigation.The results show that the bolts were an overload fracture caused by single side bending stress,which has nothing to do with the bolts manufacturing quality.The operation space of the bolts assembly area was narrow,and the rotation plane of the wrench was prone to tilt during installation,thus formed bending stress on the bolt.It is suggested to improve the assembly tool.