X80 管线钢在H2S/CO2环境中的短期腐蚀行为研究

X80 steel has been widely used in oil and gas pipelines along with the rapid development of international and domestic oil and gas industry. Effective research of the corrosion behavior of X80 steel in service is a problem that must be solved. In this study, the corrosion behavior of X80 steel in CO2 saturated solution containing different content of H2S was investigated by electrochemical impedance spectra, polarization curves, etc. The results showed that X80 steel generated compact corrosion product film at the early stage of the corrosion, in the H2S free solution, corrosion product film gradually dissolved and corrosion rate increased gradually with progress of the test. The surface of working electrode formed a thin corrosion product film gradually with H2S, and the corrosion rate decreased with the increase of immersion time. Besides, the performance of the corrosion product film of X80 steel in low H2S content(79mg/L) is better and corrosion rate decrease degree is greater than that of high H2S content(158mg/L). While in high H2S content codition, H2S dissolved to form acid and the depolarization effect began to dominate the corrosion, making X80 steel are more likely to be corroded. The work will contribute to a better understanding of the role of H2S in the H2S/CO2 environment and provides a meaningful exploration of corrosion behaviour and mechanism of X80 high strength pipeline steel in H2S/CO2 environment.