Passivity breakdown of 13Cr stainless steel under high chloride and CO2 environment
来源期刊：International Journal of Minerals Metallurgy and Materials2019年第3期
论文作者：Hui-xin Li Lei Zhang Ya-wen Wang Min-xu Lu
文章页码：329 - 336
摘 要：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.
Hui-xin Li1，Lei Zhang1，Ya-wen Wang3，Min-xu Lu1
1. Institute for Advanced Materials and Technology, University of Science and Technology Beijing3. CRRC Beijing Locomotive Co., Ltd.
摘 要：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.
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