Effect of O2 on corrosion of 3Cr steel in high temperature and high pressure CO2–O2 environment

• DOI: 10.1016/j.apsusc.2014.12.109
• Publication Date: 2014-12-25T02:02:34Z
• Authors: Xueqiang Lin; Wei Liu; Fei Wu; Chuanchuan Xu; Juanjuan Dou; Minxu Lu
• Keywords: Pitting Corrosion

Abstract The development of corrosion scale of 3Cr steel in an aqueous environment containing 95% CO 2 –5% O 2 was characterized and analyzed by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), X-ray diffraction (XRD) and in situ electrochemical impedance spectroscopy (EIS). The results show that the corrosion of 3Cr steel was promoted by dissolved oxygen. Fe(OH) 3 precipitation formed at local areas, leading to the nonuniform distribution of Cr element and pitting corrosion. With the increase of corrosion time, Cr-rich area formed at the bottom of pits, where the pitting corrosion process was inhibited. The importance of Fe(OH) 3 and Cr-rich area on the formation of corrosion pits and pits development was emphasized.