2219铝合金箱底法兰焊缝条状缺陷产生原因

Causes of strip defects in flange weld of 2219 aluminum alloy box bottom

在对某型号箱底法兰焊缝进行射线检测时,发现焊缝区域存在条状裂纹缺陷,采用宏观观察、化学成分分析、力学性能测试、金相检验、扫描电镜和能谱分析等方法对裂纹缺陷产生的原因进行分析。结果表明:在法兰焊接过程中,局部焊接线能量输入过大,使得位于熔合线、紧邻母材近焊缝区的低熔点共晶相出现晶间液化,在结构应力和热应力的共同作用下,焊缝产生条状缺陷。

In the radiographic testing of a certain type of box bottom flange weld,it was found that there were strip crack defects in the weld area.The causes of the crack defects were analyzed by means of macroscopic observation,chemical composition analysis,mechanical property test,metallographic examination,scanning electron microscope and energy spectrum analysis.The results show that in the process of flange welding,the local welding line energy input was too large,which made the low melting point eutectic phase located in the fusion line and adjacent to the base metal near the weld zone appeared intergranular liquefaction.Under the combined action of structural stress and thermal stress,strip defects were produced in the weld.