随焊冲击抑制6061-T6铝合金接头软化行为研究

Study on restraining softening behavior of 6061-T6 aluminum alloy joint by welding impact

6061-T6铝合金焊后软化最严重的区域为焊接热影响区,易造成铝合金构件整体强度下降。为了抑制焊接接头的软化现象,通过新参数直流反接TIG焊以及随焊冲击实验对焊接接头进行强化,并通过维氏硬度计、扫描电子显微电镜、能谱分析仪和电化学工作站对冲击试样进行分析。结果发现:随焊冲击后焊接热影响区软化行为减弱,晶界析出的G.P区、Mg2Si、CuAl2以及β相的尺寸和聚集程度变小,晶粒得到细化。焊接热影响区冲击区腐蚀电流小于未冲击区,塔菲尔斜率大于未冲击区,抗腐蚀性能增强。

The most serious softening area of 6061-T6 aluminum alloy after welding is the welding heat-affected zone,which causes the overall strength of aluminum alloy components to decrease.In order to suppress the softening phenomenon of welded joints,new parameters of DC reverse TIG welding and welding impact experiments were used for strengthening.The impact samples were ana-lyzed using a Vickers hardness tester,scanning electron microscopy,energy spectrum analyzer,and electrochemical workstation.The results show that the softening behavior of the welding heat-affected zone weakens after welding impact,and the size and aggrega-tion degree of G.P zone,Mg2Si,CuAl2 andβphase decrease,and the grains are refined.The corrosion current in the impact zone of the welding heat-affected zone is less than that in the non impact zone,and the Tafel slope is greater than that in the non impact zone,so the corrosion resistance is enhanced.