St. Petersburg Mining University of Empress Catherine II, St. Petersburg, Russia
E. I. Pryakhin, Dr. Eng., Prof., Head of the Dept. of Mazerials Science and Technology of Art Products, e-mail: Pryakhin_EI@pers.spmi.ru
D. A. Pribytkova, Postgraduate Student, Dept. of Materials Science and Technology of Art Products, e-mail: pribytda@gmail.com

This study presents experimental data that assess the physico-mechanical properties of a two-layer protective coating designed to enhance the corrosion resistance of district heating pipelines. The coating consists of polyurethane and epoxy enamels, each offering specific advantages. Epoxy coatings are characterized by high adhesion to metal surfaces and excellent chemical resistance, while polyurethane enamels exhibit high elasticity, resistance to ultraviolet radiation, and mechanical damage. To improve the coating’s performance characteristics and simplify the application process, a combined approach is proposed, where the first layer consists of epoxy enamel and the second of polyurethane enamel. This method integrates the benefits of both materials, ensuring reliable protection against external influences, improved operational properties, and an extended service life. The experimental results confirmed that the two-layer coating outperforms single-component alternatives in quality. The study examines key parameters such as continuity, adhesion, and mechanical resistance to impact and bending for two coating combinations: one with an epoxy base layer and a polyurethane top layer, and the other with the layers applied in reverse order.

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