Corrosion of Mild Steel in High CO2 Environment: Effect of the FeCO3 Layer

Abstract

Abstract In the oil and gas industry, transportation of the hydrocarbons may involve high concentrations of CO2 and significant amounts of liquid water which will provide the electrolyte for the corrosion of mild steel to take place. The consequent damage can be in the form of general corrosion or localized – pitting attack. However at these conditions, an iron carbonate (FeCO3) layer may form which can provide some level of protection. The current works undertakes a study of the corrosion behavior of mild steel in high partial pressure CO2 system, which covers all three states of CO2: gas, liquid and supercritical. The transient behaviors of the CO2 corrosion process is revealed, with corrosion rates changing from extreme initial values to very low corrosion rates due to a FeCO3 layer forming.