6082-T6铝合金双丝MIG焊接头裂纹的研究  

Study of weld cracks in double-wire MIG welded joints of 6082-T6 Al-alloy

作　　者：阮野[1] 孙立权[1] 王毅[1] 袁帅[1] 

机构地区：[1]长春工程学院机电学院,吉林长春130012

出　　处：《焊接技术》2015年第10期70-72,6,共3页Welding Technology

基　　金：吉林省科技发展基金资助(20070309)

摘　　要：采用扫描电镜和能谱仪等方法分析了6082-T6铝合金双丝MIG焊焊接接头裂纹的形貌以及形成机制。研究结果表明,双丝MIG焊焊接接头中裂纹主要是热裂纹,裂纹位于焊缝中部,沿焊缝中心长度方向开裂;裂纹断口表面密排着由枝晶端头组成的颗粒状凸起,枝晶的凸起处圆滑并且无损伤痕迹;裂纹产生的原因主要在于焊接过程中成分偏析导致发生共晶转变,在晶界处形成α-Al-Mg2Si低熔点共晶液态薄膜状组织和6082-T6铝合金有高的线膨胀系数,焊缝金属在凝固过程中产生极大拉伸应力。The morphologies and mechanism of weld cracks in double-wire MIG welded joints of 6082-T6 Al-alloy were studied by using SEM and EDS. The results showed that the type of cracks in welded joints was mainly hot cracks. The cracks lied in the center of the weld seam and extended in the direction of length. There were a lot of dendrite knobs at the fracture surfaces. Moreover, these knob surfaces were smooth and didn′ t show the damage mark. The mainly reasons of cracks were the forming of α-Al-Mg2 Si low melting liquid films at the grain boundaries result from the component segregation and effect of tensile stress during the weld process.

关 键 词：6082-T6铝合金 双丝MIG焊 焊接裂纹 组织 

分 类 号：TG406[金属学及工艺—焊接]