Electrochemical Investigation of the Synergistic Effect Between Molybdate and Tungstate on Surface Passivation of Carbon Steel
Electrochemical Investigation of the Synergistic Effect Between Molybdate and Tungstate on Surface Passivation of Carbon Steel
复制标题
钼酸盐和钨酸盐对碳钢表面钝化协同作用的电化学研究
DOI：
10.20964/2021.01.49
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发表时间：
2021
影响因子：
1.5
通讯作者：
Pei Zhang
中科院分区：
文献类型：
--
作者：
Pei Zhang
本文的目的是了解钼酸盐和钨酸盐对碳钢表面钝化的协同作用，特别是寻找钼酸盐和钨酸盐的最佳配比。针对不同MoO 42- 和WO 42- 比例的Na 2 MoO 4 和Na 2 WO 4 混合溶液中的Q235碳钢，采用动电位极化、莫特肖特基和电化学阻抗谱(EIS)等电化学方法。总浓度为0.2 mmol/L时,MoO 42- 和WO 42- 的配比变化对Q235碳钢的腐蚀行为没有影响,主要腐蚀参数包括腐蚀电位(E c )、腐蚀电流密度(i c )、平带电位(U f )和内层钝化膜电阻(R i )与配比变化无关;然而，MoO 42- 和WO 42- 的比例变化对Q235碳钢的钝化行为影响明显，并且当MoO 42- 和WO 42- 的比例为1:1时，主要钝化参数，包括跨钝化电位(E t )、施主密度(N D )和外层钝化膜电阻(R o )，呈现最佳水平。同时还讨论了腐蚀和钝化的相关机理。
The purpose of this paper was to understand the synergistic effect between molybdate and tungstate for the surface passivation of carbon steel, particularly to find the optimum ratio of molybdate and tungstate. For Q235 carbon steel in mixed Na 2 MoO 4 and Na 2 WO 4 solutions with different ratios of MoO 42- and WO 42- , the electrochemical methods, including potentiodynamic polarization, Mott-Schottky and electrochemical impedance spectroscopy (EIS), were applied. Under the total concentration of 0.2 mmol/L, the ratio variation of MoO 42- and WO 42- did not affect the corrosion behavior of Q235 carbon steel, and the main corrosion parameters, including corrosion potential (E c ), corrosion current density (i c ), flat band potential (U f ) and inner-layer passive film resistance (R i ) were independent of the ratio variation; however, the ratio variation of MoO 42- and WO 42- affected the passivation behavior of Q235 carbon steel obviously, and the main passivation parameters, including transpassive potential (E t ), donor density (N D ) and outer-layer passive film resistance (R o ), presented the optimum level when the ratio of MoO 42- and WO 42- was one to one. At the same time, the related mechanisms of corrosion and passivation were also discussed.