Passivity breakdown of 13Cr stainless steel under high chloride and CO2 environment
- 15 Downloads
Herein, the effect of high chloride ion (Cl−) concentration on the corrosion behavior and passive film breakdown of 13Cr martensitic stainless steel under CO2 environment was demonstrated. The Cl− concentration was varied from 30 to 150 g/L and cyclic potentiodynamic polarization was conducted to investigate the influence of the Cl− concentration on the corrosion potential (Ecorr), passive breakdown potential (Epit), and repassivation potential (Erep). The results of the polarization curves revealed that 13Cr stainless steel is susceptible to pitting under high Cl− concentration. The passive breakdown potential and repassivation potential decreased with the increase of Cl− concentration. The semiconducting behavior of the passive film was investigated by Mott-Schottky analysis and the point defect model (PDM). It was observed that the iron cation vacancies and oxygen vacancies were continuously generated by autocatalytic reactions and the higher Cl− concentration resulted in higher vacancies in the passive film. Once the excess vacancies condensed at the metal/film interface, the passive film became locally detached from the metal, which led to the breakdown of the passive film.
Keywords13Cr stainless steel electrochemical characterization pitting corrosion high chloride concentration passive film breakdown
Unable to display preview. Download preview PDF.
This work was financially supported by the National Science and Technology Major Project of China (No. 2016ZX05028–004).
- M.J. Ke and J. Boles, Corrosion behavior of various 13 chromium tubulars in acid stimulation fluids, [in] SPE International Symposium on Oilfield Corrosion, Aberdeen, 2004, art. No. 87561.Google Scholar
- K. Krishnan, Sulfide stress cracking (SSC) resistance of AISI 420 modified (13Cr) martensitic stainless steel bar stock, [in] Corrosion 2017, New Orleans, 2017, art. No. 9645.Google Scholar
- J.J. Zou, F.Q. Xie, N.M. Lin, X.F. Yao, W. Tian, and B. Tang, Formation of chromium coating and comparative examination on corrosion resistance with 13Cr steel in CO2-saturated simulated oilfield brine, Surf. Rev. Lett., 20(2013), No. 3–4, art. No. 50041.Google Scholar
- Z.J. Liu, X.Q. Cheng, S.J. Lu, and X.G. Li, Effect of chloride ions on 316L stainless steel in cyclic cooling water, Acta Metall. Sin. Engl. Lett., 23(2010), No. 6, p. 431.Google Scholar