The Corrosion Behavior of T2 Brass in Power Plant Generator Stator Cooling Water
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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.
Keywords:T2 brass generator cooling water CO2 passive film EIS
This work was supported by Science-Technology Innovation Platform and Talents Program of Hunan Province, China (2016TP12027).
CONFLICT OF INTEREST
The authors declare that they have no conflict of interest.
- 1.Wang, S., Research on Corrosion Protection of Inner Cooling Water System in Generator, Changsha: Changsha Univ. of Science and Technology, 2010.Google Scholar
- 2.Svoboda, R. and Plamer, D.A., Behavior of copper in generator stator cooling-water systems, Power Plant Chem., 2009, vol. 11, pp. 70–76.Google Scholar
- 3.Duffeau, F., Aspden, D., and Coetzee, G., Guide on stator water chemistry management, Study Comm., 2010, vol. 4, pp. 37–41.Google Scholar
- 4.Prevention of Flow Restrictions in Generator Stator Water Cooling Circuits, EPRI, 2002.Google Scholar
- 5.Schleithoff, K. and Emshoff, H.W., Optimization of the conditioning of generator cooling water, VGB Kraftswerktechnik, 1990, vol. 70, pp. 677–681.Google Scholar
- 6.Robert, S. and Donald, A.P., Behaviour of copper in generator stator cooling-water systems, Proc. 15th ICPWS, Berlin, Sept. 2008, pp. 8–11.Google Scholar
- 7.Syrett, B., Electrochemical Corrosion Potential (ECP) of Hollow Copper Strands in Water Cooled Generator, EPRI, 2007.Google Scholar
- 9.Svoboda, R. and Seipp, H.G., Flow restrictions water cooled generator stator coils-prevention, diagnosis, and removal. Part 1: behavior of copper in water cooled generator coils, Power Plant Chem., 2004, vol. 6, pp. 7–14.Google Scholar
- 11.Sharon, P.M. and Felix, W.R.M., Operating experience gained during the copper oxide plugging incident in Koeberg Unit1 generation stator, Power Plant Chem., 2001, vol. 3, pp. 262–269.Google Scholar
- 14.Rui, Y.Z. and Shun, A.C., Copper corrosion behavior in stator cooling water, Mater. Perform., 2016, vol. 55, pp. 46–50.Google Scholar
- 15.Ye, C.S., Zhang, J., and Qian, Q., Quasi-dynamicsimulation test of corrosion control for generator copper conductors, Corros. Sci. Protect. Technol., 2004, vol. 16, pp. 41–43.Google Scholar
- 16.Zha, F.L., Feng, B., and Xu, S., Electrochemical corrosion behavior of copper in soil extract solution, Corros. Sci. Protect. Technol., 2014, vol. 26, pp. 446–450.Google Scholar
- 17.Xu, Q.J., Zhu, L.J., and Qi, H., Photoelectrochemical study of the corrosion and inhibition on Cu, Acta Metallurg. Sin., 2008, vol. 44, pp. 1360–1365.Google Scholar
- 19.Dai, J., Hu, L.H., and Liu, W.Q., Study on the flat band potential of nanoporous TiO2 film electrode, Acta Phys. Sin., 2008, vol. 57, pp. 5310–5316.Google Scholar
- 20.Q, D.Z., Rohwerder, M., and Zhao, Z., Semiconducting behavior of temporararily protective oil coating on the surface of AISI 304 stainless steel in 5% Na2SO4 solution during its degradation, J. Electrochem. Soc., 2004, vol. 151, pp. B446–B452.Google Scholar
- 23.Kuleshova, N.E., Vvedenskii, A.V., and Bobrinskaya, E.V., Anodic oxidation of serine anion on smooth and platinized platinum, Russ. J. Electrochem., 2018, vol. 54, pp. 529–597.Google Scholar