May 20 th - 22 nd 2020, Brno, Czech Republic, EU STUDYING THE SELF-ORGANIZATION OF MACROMOLECULES ON THE SURFACE OF TEXTURED POLYMER COATING OF METAL SHEET 1 Olga MAKSIMOVA, 2 Valentin SMIRNOV, 2 Stepan OSIPOV, 1 Evgenii MENSHIKOV, 2 Andrei MAKSIMOV, 1 Vladislav EGOROV, 2 Alena TRIFANOVA, 1 Aleksander BAIDZHANOV, 2 Nadezhda OSIPOVA 1 Cherepovets State University, Laboratory of Mathematical and Computer Modeling, Cherepovets, Russian Federation, og62@mail.ru 2 Cherepovets Stste University, Department of Physics, Cherepovets, Russian Federation https://doi.org/10.37904/metal.2020.3566 Abstract To describe a surface morphology of textured polymer coatings, the model of polymer chains attached to spherical granules was developed. By means of the model, we revealed the influence of coating density on its surface morphology. Diffuse reflection coefficient was calculated for polymer coatings with different morphologies. Keywords: Textured polymer coating, associate, corrosion resistance, diffuse reflection coefficient 1. INTRODUCTION The corrosion destruction is one of the main reasons for reduced efficiency of metal products [1,2]. One of the effective methods to prevent the corrosion is applying a polymer coating to steel sheets. The determination of corrosion resistance is an expensive procedure and requires a long test interval for its test (e.g., about 1 month in a salt spray chamber). The main indicator of the coating quality is the thickness of the polymer film. However, the production test data and the simulation results [3] show that there are manufacturing regimes which increase the polymer coating thickness for a given depth of the raw layer. It is economically profitable for a manufacturer to reduce the raw layer depth of polymer material and decrease artificially its density using special temperature conditions for the coating formation. Thus, the cost of production is reduced and it satisfies the quality requirements for polymer coating thickness [4]. However, an excessive decrease in the coating density leads to reduced corrosion resistance [5]. Therefore, the development of simple methods that allow determining the deviation of the polymer coating density from the standard one is a relevant task. The objects of research in this paper are the surfaces of textured polymer coatings of the “Steel Velvet” type produced in PAO Severstal (Cherepovets, Russia). The texture of these coatings is created due to the presence of the filler consisting of polyacryl or polyamide granules in the paint material. During the drying process, polymer molecules are adsorbed on the particles surface, forming associates of the radial “viscous fingers” type [5], which are collected in star-shaped clusters scattered over the entire surface of the metal sheet (Figure 1). The surface morphology of such coatings depends on their formation regime and chemical structure of the paint material. If the temperature regime is violated, the sizes of associates change, they may be observed by means of an optical microscope. The aim of this work is to develop an optical method for detecting deviations of the polymer coating density from the standart one.