Role of oxidizers in the active dissolution and passivation of metals

It was established that addition of hydrogen peroxide to a solution of sulphuric acid leads to acceleration of the active dissolution of chromium and to the shift of its passivation potential in negative direction. Similar data were obtained for Fe-28% Cr alloy in H₂SO₄ solution containing H₂O₂ and for iron in sulphuric acid with K₂Cr₂O₇ additions. The conclusion was made that depending on the potential the molecules of oxygen-containing oxidizers can undergo different transmissions on the surface of the metal, including transformations connected with the direct participation of the oxidizer in the anodic dissolution of the metal or in the building of inhibiting or passivating layers on the metallic surface.