Zin I. Scientific basis of inhibiting pigment selection for increase of protection of galvanized steel

It was studied mechanism of corrosion protection of galvanized steel by inhibited epoxy coatings with aim to improve their exploitation properties and replace chromate pigments by ecologically safe inhibitors. Methods of impedance, electron microscopy, surface analysis, atomic-absorption spectroscopy and others were used. New technical approaches with using scanning reference electrodes and electrochemical element for modeling cut edge corrosion were proposed. It was shown that corrosion underneath damaged epoxy coating occurs with a separation of anodic and cathodic reactions, which rates depend on electrochemical conditions in defect area and coating composition. It was established synergetic protective effect of a mixture of zinc phosphate and calcium containing ion exchange pigment in epoxy coating on galvanized steel, caused by deposition of adsorbed film consisting calcium and zinc phosphates, which influence is equal to chromate. Content of pigments in epoxy coatings was optimized. Scientificfundamentals of epoxy coating modification by functional petroleum resins for increase of their protective properties were defined. Results are used by VAT "Gallak", GIC "Lvivanticor" and GEIC "Techno-resurs" in paint technology and corrosion protection of equipment and metal constructions.