Influence of Aluminum Addition on the Corrosion of 304 Stainless Steel in High Temperature Water

The influence of Al3+ addition on the corrosion of 304 stainless steel (SS) in high temperature water has been investigated by gravimetric analysis, potentiodynamic polarization and Mott-Schottky plots. After Al3+ addition, the amount of oxidized metal on 304 SS was reduced, the open circuit potential was shifted towards positive direction, the passive current density was declined, and the donor density of the oxide film formed on 304 SS surface was decreased. The corrosion kinetics of 304 SS in this work was curved to be parabolic with a 25% reduction of the parabolic rate constant by Al3+ addition. The activation energy of the corrosion process was increased due to the presence of Al which slowed down the 304 SS corrosion. The structure and composition of oxide film formed on 304 SS in high temperature water may be changed by Al3+ addition. The work may give a decent route for radiation field or consumption control in the essential circuit water of PWR.