Effect of O2 and H2S impurities on the corrosion behavior of X65 steel in water-saturated supercritical CO2 system

The corrosion behavior of X65 steel in water-saturated supercritical CO2 containing O2 and/or H2S impurities was investigated by means of weight loss measurements and surface characterization. The results showed that the addition of O2 or H2S impurities increased the corrosion rate of X65 steel in water-saturated supercritical CO2 system. The effect of H2S on the corrosion of X65 steel was greater than that of O2. The corrosion was more severe with the coexistence of O2 and H2S. The change in corrosion behavior was attributed to the fact that low concentrations of O2 and/or H2S can notably change the corrosion mechanism.