Abstract

In this paper, the growth process of T2 brass passive film in generator cooling water was studied, the effect of CO₂’s leakage on the crystal structure and anti-corrosion performance of passive film was analyzed, and we were trying to repair the passive film by adjusting pH of solution. Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization (PP), Potentiostatic Scan (PS), Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) were used in this paper. The test results showed that a thin and dense Cu₂O passive film was formed on the surface of T2 brass after immersed in the cooling water for 2 days. And then a loose CuO outside layer was formed gradually, during this period the Cu₂O was further oxidized to be CuO, the dense structure of the inner Cu₂O layer was thus damaged. Finally a double-layer passive film consisted by Cu₂O and CuO was formed at the 24th day of immersed. Corrosion pits and cracks appeared on the outside passive film after erosed by CO₂. The anti-corrosion performance of the passive film cannot be completely restored by self in alkaline solution.

中文翻译：

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T2黄铜在电厂发电机定子冷却水中的腐蚀行为

抽象的

本文研究了T2黄铜钝化膜在发电机冷却水中的生长过程，分析了CO ₂泄漏对钝化膜晶体结构和防腐性能的影响，并试图修复钝化膜。通过调节溶液的pH值来成膜。本文使用了电化学阻抗谱（EIS），恒电位极化（PP），恒电位扫描（PS），扫描电子显微镜（SEM）和X射线光电子能谱（XPS）。测试结果表明，将T2黄铜浸入冷却水中2天后，在T2黄铜的表面上形成了一层致密的Cu ₂ O钝化膜。然后逐渐形成疏松的CuO外层，在此期间Cu ₂O进一步被氧化成CuO，从而破坏了内部Cu ₂ O层的致密结构。最后在浸入第24天形成了由Cu ₂ O和CuO组成的双层钝化膜。CO ₂腐蚀后，在钝化膜的外部出现腐蚀坑和裂纹。在碱性溶液中，钝化膜的抗腐蚀性能无法完全恢复。