大型薄壁铸件铆接裂纹原因分析

Analysis on Riveting Crack of Large Thin-Wall Casting Part

某飞机上的一大型薄壁铸件在与蒙皮铆接时多次发生开裂,造成严重的安全隐患。通过对故障件进行的断口宏、微观检查,金相组织分析以及相关工艺试验,经综合分析讨论,明确了铸件铆接时出现裂纹的原因。结果表明:该零件铸造时变质处理不充分,材质塑性差,降低铆接时承受冲击的能力是导致开裂的主要原因,零件装配存在应力也是导致开裂的重要因素。

A large thin-wall casting part for aeroplane cracked many times when it was riveted with the skin and resulted in serious security risk. The cause of the riveting crack was analyzed synthetically by macro and micro obser- vation of fracture surface, metallographic microstructure analysis and other relative tests. The result shows that the in- sufficient modification, the low plasticity which reduces the ability of bearing concussion when riveting of this casting part are the main causes of cracking. Meanwhile, the pressure produced after the assembling is also the important cause of riveting crack.