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Improving stability of the passive state of metals. Experiments were carried out to study the effects of cathode aftercharges of Ag, Pt and Pd upon the corrosion stability of stainless steel (approximately 18% Cr and 9% Ni) in H2SO4 and in a mixture of HCl and HNO3. In H2SO4 the state of passivity sets in more easily and increasingly improved resistance to corrosion of stainless steel becomes evident when the steel is treated with cathode aftercharges. In media containing high concentrations of active Cl ions, aftercharges of noble metals did not have any marked effect upon the corrosion resistance of stainless steel. In sulphuric acid, corrosion takes place mainly at the expense of cathode processes of H depolarisation. But, at the potential of H liberation, Fe, Cr and Ni change into the active state, and the stainless steel, which is not treated with cathodic aftercharges, in sulphuric acid, cannot be passivated. The passive state sets in more quickly if the material of aftercharges uses an effective cathode.—(N. D. Tomashev and G. P. Chernova, Dokl. Akad. Nauk, 1953, 89 (1), 121–124.)