某型机接头裂纹分析

Crack Analysis of Some Plane Joint

某型机在进行地面检查时,发现有4个同图号接头的螺纹处存在4～10 mm长度不等的磁痕显示。用化学分析、金相检验、扫描电镜、能谱分析等方法对接头裂纹进行了分析。结果表明:故障接头裂纹性质属过载引起的多源疲劳,裂纹产生的时间应在表面处理之前的机加工过程中,且在表面处理后的使用过程中没有进一步扩展。

When carrying on ground inspection for some plane,was found that 4 to 10 mm length of magnetic particle indication appeared in thread of four joints with the same drawing number.Chemical composition analysis,metallographic examination,SEM and EDS analysis were used to analyze the joint crack reason.The results show that,the joint crack was multiple source fatigue caused by overload,cracking time should be produced during machining before surface-treatment process,and the crack doesn't extend in the use later.