The Corrosion Behavior of T2 Brass in Power Plant Generator Stator Cooling Water

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.