5083铝合金搅拌摩擦焊与MIG焊缝腐蚀性能对比

Comparision of corrosion properties for 5083 aluminum alloy friction stir welding and metal inert-gas welding weld

对5083铝合金FSW(搅拌摩擦焊)和MIG(熔化极氩弧焊)焊缝的微观显微组织和腐蚀性能进行了分析.结果表明,FSW焊缝由细小的等轴再结晶组织构成,而MIG焊缝晶粒粗大,组织不均匀.电化学腐蚀试验表明,主轴旋转频率为300 r/min,焊接速度为160 mm/min,搅拌头倾角为3°的FSW焊缝与MIG焊缝相比,腐蚀电位Ecorr正向移动,平均腐蚀速率和腐蚀电流密度J变小,极化电阻Rp增大.腐蚀形貌分析显示,FSW焊缝表面上只出现少量较浅的点蚀坑,而MIG焊缝表面的点蚀现象较为严重.

The microstructures and corrosion properties of 5083 aluminum alloy friction stir welding(FSW) and MIG(metal inert-gas) weld were analyzed.The results showed that the FSW weld was characterized by its much finer grains,contrasting with the grains of MIG weld.Electrochemical corrosion test demonstrated that the corrosion potential of the FSW weld at the rotation rate of 300 r/min,and the traverse speed of 160 mm/min with 3°tool tilt was more positive than that of the MIG weld,meanwhile,the corrosion rate and the corrosion current density were less than those of the MIG weld,Rp(polarization resistance) of the FSW weld was larger than that of the MIG weld.The corrosion morphologies analysis showed that few shallow pits presented on the surface of the dissimilar weld.However,a large number of deeper pits emerged on the surfaces of two parent materials.