Effects of CO2 gassy-supercritical phase transition on corrosion behaviors of carbon steels in saturated vapor environment

Corrosion behaviors of P110 and N80 tubular steels in CO2 gas phase and supercritical (S-CO2) phase in a saturated water vapor environment were explored in corrosion weight loss experiments by SEM, EDS, XRD, XPS and cross-section analysis techniques. With the increase in CO2 partial pressure, the average corrosion rate increased first and then decreased. The average corrosion rate reached the maximum value under the near-critical pressure. When CO2 partial pressure further increased to be above the critical pressure, the average corrosion rate gradually decreased and local aggregation of molecules was weakened.

Automated summary

The corrosion behaviors of P110 and N80 tubular steels in CO2 gas phase and supercritical (S-CO2) phase were studied in a saturated water vapor environment using corrosion weight loss experiments and analytical techniques such as SEM, EDS, XRD, XPS, and cross-section analysis. The average corrosion rate initially increased and then decreased with increasing CO2 partial pressure, reaching a maximum value near the critical pressure. Subsequently, as the CO2 partial pressure exceeded the critical pressure, the average corrosion rate gradually decreased and local aggregation of molecules weakened.