Flow dependence of steel corrosion in supercritical CO2 environments with different water concentrations

The corrosion behavior of mild steel in water contaminated supercritical CO2 fluids was investigated by weight-loss measurements and surface morphology observations. It is found that a higher flow rate induces a higher corrosion rate in various water containing conditions, which becomes much obvious with increasing the water concentration. By a detailed comparison of the surface corrosion morphologies formed in different supercritical CO2 fluids, the flow dependence is attributed to a mechanism of water droplet entrainment and its impact on steel surfaces. This observation is helpful for the understanding and the control of steel corrosion in CO2 transportation and injection conditions.