Double effects of O2 on passive film of super 13Cr stainless steel in CO2 saturated environment

Abstract

Abstract Herein, a comprehensive suite of electrochemical methods, including cyclic polarization, Mott-Schottky (M-S), and electrochemical impedance spectroscopy (EIS) tests, were employed to investigate the effects of O2 on passivation and pitting behavior of Super 13Cr in CO2-saturated environment. Our findings reveal that O2 plays a dual role: O2 substantially enhances the stability of passive film by diminishing point defeat density, thereby improving the resistance to local corrosive attacks. Conversely, within the stable pitting domain, O2 exacerbates the severity of the corrosive environment, undermining the repassivation capabilities of super 13Cr stainless steel. The study elucidates the intricate interplay of O2 and the passive film, offering valuable insights for the strategic application of Super 13Cr in the demanding conditions of modern oil and gas extraction processes where CO2 and O2 coexist.