Influence of oxygen on metastable pitting behavior of super 13Cr stainless steel in CO2-saturated environment

This study investigates the effect of oxygen on the metastable pitting corrosion behavior of Super 13Cr martensitic stainless steel in a CO2-saturated environment, which is pertinent to challenging extraction conditions of oil and gas industry. Potentiostatic polarization and comprehensive statistical analysis to assess the corrosion dynamics. The results indicate that the presence of oxygen significantly influences the initiation and progression of metastable pitting. In the 50 % O2 + 50 % CO2 environment, a decrease in the frequency and size of metastable pitting events was observed, along with a reduction in the peak current, pit radius, and stable product, suggesting that oxygen inhibits the transition from metastable to stable pitting. •The presence of O2 reduces frequency and size of metastable pitting.•O2 does not alter the growth rate of metastable pitting.•O2 inhibits metastable to stable pitting transition, stabilizing the passive film.