6082铝合金搅拌摩擦焊焊缝的电化学腐蚀行为

Electrochemical corrosion behavior of friction stir welding weld of 6082 aluminum alloy

通过室温静态挂片试验以及动电位极化曲线测试,在室温0.2 mol/L NaHSO3+0.6 mol/L NaCl溶液中,对6082铝合金搅拌摩擦焊(FSW)焊缝以及6082铝合金母材的电化学腐蚀行为进行了研究。结果表明,主轴转速为1 200 r/min,焊接速度为200 mm/min,搅拌头倾角为3°时的焊缝与母材相比,平均腐蚀速率较小,腐蚀电位Ecorr正向移动,腐蚀电流密度J变小。同时使用扫描电子显微镜(SEM)对室温静态挂片试验试样的表面形貌进行了观察,发现焊缝表面上只出现少量较浅的点蚀坑,而母材表面的点蚀现象较为严重。

In the ambient temperature solution of 0.2 mol/L NaHSO3 and 0.6 mol/L NaCl,the electrochemical corrosion behavior of friction stir welding weld of 6082 aluminum alloy and parent material were investigated by static weight loss experiment(gravimetric test) and potentiodynamic polarization curve.With the rotation rate of 1 200 r/min,the traverse speed of 200 mm/min and 3° tool tilt,the corrosion rate of the weld was less than that of the parent material,and the corrosion potential of the weld was more positive than that of the parent material,the corrosion current density was less than that of the parent material.SEM observation showed that a few shallow pits appeared on the surface of the weld,however,a large number of deeper pits emerged on the surface of the parent material.