EFFECT OF SURFACE TREATMENT OF STEEL SUBSTRATE TO THE CORROSION RESISTANCE FOR ORGANIC COATINGS

Mechanical and chemical surface treatment of steel structures is an integral part of the process before application of paints. The purpose of mechanical surface treatment is mainly to get rid of the surface material impurities that are bound to the metal surface chemisorption (corrosion products, mill scales and rust), to obtain a technically clean surface. Furthermore, to create conditions for anchoring the coating, creating conditions for increased corrosion resistance and / or improve the mechanical properties of the steel substrate. Chemical surface treatment serves primarily to remove of adherent impurities, especially residues of fatty substances, abrasives and polishing, adhering to the surface of the steel substrate during the production process itself. The quality of the steel substrate surface treatment is one of the important factors affecting the adhesion of the coating and thus its corrosion resistance and thus of steel structures life. This paper is focuses on the steel surfaces mechanically cleaned with abrasive blast-cleaning and grinding. Then there are the surfaces of hot rolled and cold rolled. The chemical surface treatment is an organic degreasing in a degreasing agent. Each surface pre-treatment has own specific and therefore may have a different effect on the corrosion resistance of coatings in terms of purity of surface anchor profile and residual stress to the prepared steel substrate. We can say that the more closely the surface, this adjustment is made, the better the conditions for application of paints, resulting in improved corrosion resistance of the final coating.