Mechanism of Electrochemical Corrosion Of Metals Under Insulating Coatings. II. Kinetics of Cathodic Processes On Insulated Metals in Electrolytes

1. Investigations were made of the kinetics of the cathodic process on metal surfaces coated with thin insulating films. It was established that enhancement of the cathodic reaction on insulated electrodes at definite potential values is connected with the emergence of electronic conductivity of the film. Along with this, there can also be observed a nonreversible process of electrochemical perforation of the protective film by the active ions in the electric field. 2. Studies were made of the mechanism possibly involved in the corrosion of metals under porous insulating films. It was shown that on metals with a static potential in the region of emerging electronic conductivity in the film, the cathodic process is active not only on the metal surfaces exposed by the film pores but also on the very thin sections of the insulating film.