For steel structures, how to do a good job of anti-corrosion and fire prevention, the following describes the common anti-corrosion methods of steel structures:
Steel structures are usually sprayed with zinc or aluminium, and heavier corrosion coatings form long-term anticorrosive structures, or coated with matching heavy-duty anticorrosive coatings. Zinc and aluminium have great atmospheric corrosion resistance. When spraying zinc or aluminium on steel components, zinc and aluminium are negative potential and form sacrificial anode to protect steel. At present, spraying aluminium coating is used to prevent the corrosion of industrial atmosphere and marine atmosphere. Its characteristics are as follows:
(1) Flexible technology, suitable for long-term protection of important large and difficult-to-repair steel structures, and can be constructed on site;
(2) Aluminum sprayed coating has strong bonding force with iron and steel matrix, long coating life and good long-term economic benefits.
(3) Zinc or aluminium spraying coatings sealed with anticorrosive coatings can greatly prolong the service life of coatings. From the effect of theory and practical application, zinc or aluminium spraying coatings are the best bottom of anticorrosive coatings. The protective life of the composite coatings of metal spraying coatings and anticorrosive coatings is longer than that of the combined coatings of metal spraying coatings and anticorrosive coatings, which is several times longer than that of the single coatings.
Heavy anti-corrosion long-acting paint consists of primer, intermediate paint and topcoat.
Considering the long-term economy, spraying aluminium coating is the most economical, but the one-time investment is too large, and the coatings with good construction can be maintained in 10 years. Epoxy zinc-rich primer + epoxy mica iron intermediate paint and acrylic polyurethane long-term protection system have better economy.