铝合金双丝MIG焊焊接接头组织与耐腐蚀性能

Microstructures and corrosion-resistant performance of Al twin wire MIG welded joint

采用扫描电镜、X射线衍射和电化学分析仪等测试方法研究了6082-T6铝合金双丝MIG焊焊接接头的组织及其耐腐蚀性能.结果表明,6082-T6铝合金双丝MIG焊接头组织主要由α-Al,少量的α-Al+Mg2Si共晶和Mg2Si组成,其中Mg2Si主要分布于晶界;对焊缝与母材的动电位极化曲线与盐雾腐蚀后的腐蚀形貌分析表明,6082-T6铝合金双丝MIG焊焊缝的耐腐蚀性低于母材,Mg2Si相的大量析出降低了焊缝的耐腐蚀性.

Microstructures and corrosion-resistant performance of 6082-T6 Al twin wire MIG welded joint are studied by SEM and XRD technology.Experiments show that the welded seam is composed of a lot of α-Al,α-Al+Mg2Si and a few Mg2Si;moreover,Mg2Si largely presents in the grain boundary.Corrosion-resistant performance is studied by measuring the potentiodynamic polarization curves and corrosion surface morphologies of twin wire MIG welded joint,and the results show that corrosion-resistant performance of the matrix is better than that of the weld seam,and precipitated Mg2Si decreases the corrosion-resistant performance of the weld seam.