紧固件折叠缺陷的开裂失效典型案例分析

Analysis of cracking failure typical cases of folding defect on fastener

采用宏观观察、金相检验、扫描电子显微镜观察及能谱分析的方法对4种航天用紧固件折叠缺陷导致的开裂失效模式进行了分析。结果表明:合金钢30CrMnSiA、不锈钢1Cr18Ni9Ti、高温合金GH4169、钛合金TA1紧固件折叠缺陷大多具有尖端圆钝或分叉、脱碳、氧化层、偏析、流线阻断、晶粒粗大等典型的失效特征,并提出实际生产中的改进措施,对航天紧固件产品的质量保障具有一定的实际指导意义。

The cracking modes caused by folding defects in four kinds of aerospace fasteners were analyzed by means of macroscopic observation,metallographic examination,scanning electron microscopy observation and energy spectrum analysis.The results showed that the folding defects of alloy steel 30 CrMnSiA,stainless steel 1 Cr18 Ni9 Ti,superalloy GH4169 and titanium alloy TA1 fasteners mostly had typical failure characteristics such as blunt or bifurcate tip,decarburization,oxide layer,segregation,streamline blocking and coarse grain.The improvement measures in actual production were put forward,which had a certain practical guiding significance for the quality assurance of aerospace fasteners.