a. Powder coating, which is a new type of coating that does not contain solvent and is formed by melting powder. Epoxy powder coating is commonly used in anti-corrosion engineering. Compared with traditional solvent-based anti-corrosion coatings, it has the advantages of no solvent pollution, convenient coating, rapid curing, and excellent performance. It has been widely used in chemical and petroleum pipeline anti-corrosion since the 1960s. With the development of the petrochemical industry, the anti-corrosion requirements for pipes, especially buried pipes, are getting higher and higher, and epoxy powder coatings have received attention.
b. Zinc-rich coating is a kind of coating containing a large amount of magnesium powder, its zinc powder content is between 85-95%, the coating film thickness is only 100 microns, the cost is low, and the performance is excellent.
c. Fluorine-containing coatings, such as the GSC-CS system in the United States, is a new type of fluororesin coating, which has three times longer life than general coatings, is resistant to various chemical media, and can be used at a temperature of 260 ℃. Equipment surface coating.
d. Flake coating, composed of glass phosphor and corrosion-resistant thermosetting resin, has excellent anti-corrosion performance and impermeability. For example, glass flake polyester and vinyl coatings are used in flue gas desulfurization devices abroad, with good results, and can also be used as sealing materials for equipment joints. The Japanese patent introduces an epoxy resin coating containing flake stainless steel powder, which is coated on the metal surface, and the durability of the coating is three years, which is better than other coatings.
e. Conductive coatings, some equipment should be both anti-corrosion and anti-static, such as gasoline tanks. The research on conductive coatings abroad is very active. Many companies in Japan and the United States produce such coatings. The main direction of research on conductive coatings is to develop new conductive fillers with high conductivity and low cost to reduce costs.
The application of anti-corrosion coatings in steel pipe is very extensive. In order to improve its service life and application range, the research and application of foreign coatings are mainly two aspects: materials and construction methods. According to statistics, 75% of the coating corrosion damage is caused by improper treatment of the substrate. Therefore, it is equally important to research and develop new materials and strengthen construction quality management. According to a Japanese survey, among the existing coatings, epoxy polyurethane coatings, zinc-rich coatings, coal tar enamels, etc., as long as the grassroots treatment is qualified and the construction is organized in strict accordance with the requirements, the use effect is still very ideal.