化工学报 ›› 2008, Vol. 59 ›› Issue (5): 1223-1227.

• 表面与界面工程 • 上一篇    下一篇

钼酸盐对镁合金在模拟冷却水中腐蚀的抑制作用

李凌杰,雷惊雷,于生海,赵川,张胜涛,潘复生   

  1. 重庆大学化学化工学院;重庆大学材料科学与工程学院
  • 出版日期:2008-05-05 发布日期:2008-05-05

Inhibition of corrosion of magnesium alloy by molybdate in simulated cooling water

LI Lingjie, LEI Jinglei, YU Shenghai, ZHAO Chuan, ZHANG Shengtao, PAN Fusheng   

  • Online:2008-05-05 Published:2008-05-05

摘要:

采用Tafel极化曲线、电化学阻抗谱方法研究了钼酸钠对AZ40镁合金在模拟冷却水中腐蚀的抑制作用,利用扫描电子显微镜(SEM)和能量色散谱(EDS)表征了试样的形貌及组成。结果表明,钼酸钠对镁合金在模拟冷却水中的腐蚀具有一定的抑制作用,钼酸钠浓度为1000 μg·g-1时缓蚀效果最佳。钼酸钠的加入减弱了腐蚀性Cl-在试样/介质界面的吸附,同时参与镁合金试样在模拟冷却水中表面膜的生成,使表面膜变得致密,从而较好地抑制镁合金的腐蚀;其缓蚀作用属于阳极抑制型缓蚀作用。

关键词:

镁合金, 模拟冷却水, 钼酸盐, 腐蚀, 缓蚀作用

Abstract:

Tafel polarization curves and electrochemical impedance spectroscopy (EIS) techniques were used to study the inhibition of corrosion of AZ40 magnesium alloy by molybdate in simulated cooling water.The surface morphology and elemental composition of AZ40 magnesium alloy exposed in the simulated cooling water with or without molybdate were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).The results showed that the corrosion of magnesium alloy in simulated cooling water was inhibited by addition of molybdate.The highest inhibition efficiency was achieved when the concentration of molybdate was 1000 μg·g-1.Molybdate mainly inhibited the anodic reactions of magnesium alloy through weakening the adsorption of aggressive Cl- on the alloy/medium interface and forming a compact protective layer that covered the magnesium alloy surface active sites.

Key words:

镁合金, 模拟冷却水, 钼酸盐, 腐蚀, 缓蚀作用