Abstract The corrosion process of a Q235 carbon steel/B10 copper-nickel alloy couple under epoxy coating with artificial defect in 3.5 wt.% NaCl solution was investigated using the wire beam electrode (WBE) and electrochemical impedance spectroscopy (EIS) techniques. The causes of the difference in the degree of coating delamination at the carbon steel area and the copper-nickel alloy area were discussed. The results showed that the anodic reaction of the electrode at the artificial defect was accelerated, while other electrodes of the WBE were protected to some extent in the whole test period. There were electrochemical inhomogeneities of carbon steel and copper-nickel alloy under epoxy coating during galvanic corrosion. The degree of cathodic delamination of the coating at the carbon steel area was obviously higher than that at the copper-nickel alloy area, which was mainly dominated by the electrochemical activity of the metal and the location of the coating defect on the WBE. Polarity reversals of the single carbon steel electrodes under the coating was found, the reasons for the phenomena were different from each other.

中文翻译：

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使用 WBE 和 EIS 技术研究具有人工缺陷的环氧树脂涂层下碳钢/铜镍合金对在 3.5 wt.% NaCl 溶液中的腐蚀行为

摘要 采用线束电极（WBE）和电化学阻抗谱（EIS）技术研究了带有人工缺陷的环氧树脂涂层下Q235碳钢/B10铜镍合金对在3.5 wt.% NaCl溶液中的腐蚀过程。探讨了碳钢区和铜镍合金区镀层分层程度不同的原因。结果表明，人工缺陷处电极的阳极反应加速，而WBE的其他电极在整个测试期间都得到了一定程度的保护。在电偶腐蚀过程中，环氧涂层下的碳钢和铜镍合金存在电化学不均匀性。碳钢区镀层阴极脱层程度明显高于铜镍合金区，主要受金属电化学活性和WBE上镀层缺陷位置的影响。发现镀层下单碳钢电极发生反极性现象，其原因各不相同。