The Effect of Minor Elements on Corrosion Resistance of Carbon Steel for High Level Nucler Waste Disposal Container

Abstract

Controlling the reduction of Fe₃O₄ film is an important factor to improve corrosion resistance of carbon steel for geological disposal of radioactive waste. In the present study, the effect of alloying elements on the reduction reaction of Fe₃O₄ film was examined using sputter-deposited complex oxide films and low alloy steels containing the alloying elements. Fe₃O₄ films containing a small amount of another oxides were cathodically polarized in the simulated solution of bentonite-contacting water. It showed that the addition of Cr₂O₃, TiO₂, Al₂O₃ and MoO₂ to Fe₃O₄ is effective on the suppression of the reductive reaction. Fe₃O₄ films formed on the steels containing small amount of Cr, Ti, Al and Mo by alkaline solution treatment at high temperature also showed a high resistance against the reductive dissolution. The steels containing these alloying elements showed excellent corrosion resistances in the simulated solution of bentonite-contacting water.