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

摘要

Controlling the reduction of Fe_3O_4 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 Fe_3O_4 film was examined using sputter-deposited complex oxide films and low alloy steels containing the alloying element. Fe_3O_4 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 Cr_2O_3, TiO_2, Al_2O_3 and MoO_2 to Fe_3O_4 is effective on the suppression of the reductive reaction. Fe_3O_4 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.