Investigation on inhibition of CrO42- and MoO42- ions on carbon steel pitting corrosion by electrochemical noise analysis
Investigation on inhibition of CrO42- and MoO42- ions on carbon steel pitting corrosion by electrochemical noise analysis
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DOI：
10.1023/a:1016340421529
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发表时间：
2002-04-01
影响因子：
2.9
通讯作者：
Xu, LM
中科院分区：
文献类型：
--
作者：
Dong, ZH;Guo, XP;Xu, LM
采用电化学噪声分析（ENA）和动电位极化法研究了CrO_（42-）和MoO_（42-）对16 Mn碳钢在0.1MNaCl碳酸氢盐溶液中的缓蚀作用。实验结果表明，碳钢表面在浸泡4-6 h后，一旦出现点蚀，增加CrO 42-和MoO 42-离子的浓度会加速再钝化过程，降低亚稳点蚀的持续时间和形核速率。进一步的分析表明，噪声电阻R-n可能不适用于评价CrO_（42-）和MoO_（42-）对点蚀的抑制效果。而瞬态电荷q（pit）是一段时间内所有电流瞬态的积分，可以表征缓蚀剂对点蚀的抑制性能。给出了基于q（pit）的缓蚀效率的新定义。
The inhibition effect of chromate (CrO42-) and molybdate (MoO42-) anions on the pitting corrosion of 16Mn carbon steel in 0.1 M NaCl containing bicarbonate solution was studied based on electrochemical noise analysis (ENA) and the potentiodynamic polarization method. The experimental results indicated that, once the pits occur on the surface of the carbon steel after 4-6 h of immersion, increasing the concentration of CrO42- and MoO42- ions accelerate the repassivation process, and attenuate the duration and the nucleation rate of metastable pits. Further analysis demonstrated that noise resistance R-n might not be suitable for the evaluation of the inhibition efficiency of CrO42- and MoO42- anions on pitting corrosion in the present system. However, the transient charge q(pit), which is an integral of all current transients during a certain period, can characterize the inhibition performance on pitting corrosion. A new definition of inhibition efficiency based on q(pit) is given.