Hybrid protective coating for metallic surfaces, particularly water wall tubes in power boilers

摘要

Hybrid protective cover of metallic surfaces, especially of water-wall tubes of power boilers, which includes the anticorrosive agent X, which is a water solu­tion, including phosphate, dichromate, magnesium, chromium and aluminum ions and spherical aluminum powder with oxidized surface, with grain size below 8 µm in the concentration of up to 1600 g per decimeter of solution., and where the pro­portion of dichromate to phosphate ions is 0,25-0,35, and the protective agent Y, which consists of dispersions of spherical and/or flakes powders of aluminum, sili­con and aluminum-silicon compounds in silicon resins and mixtures of organic solvents, characterized in that it comprises internal layer (A), directly adhering to protected metallic surface (1), containing the anticorrosion agent (X), and inter­connected outer layer (B), containing the protective agent (Y).