Arc spraying is the most widely used anticorrosive technology of aluminum spraying and zinc spraying for steel structure, and its application prospect is also more extensive. The anti-corrosion principle of arc spraying is to use arc spraying equipment to heat, melt, atomize and spray two charged wires (such as zinc, aluminum, etc.) to form an anti-corrosion coating, plus a long-term anti-corrosion composite coating of organic sealing coating. The remarkable features of the coating are as follows:
With a long corrosion resistance life, the anticorrosion life can reach more than 50 years, and the anticorrosion coating does not need any other anticorrosion maintenance within the service life of 30 years; for maintenance after 30 years, only the sealing coating shall be brushed on the arc spraying layer; no need to spray again, so as to achieve one-time anticorrosion and the coating is durable and effective.
The arc spraying layer and the metal substrate have excellent coating adhesion (up to 10MP). The metal spraying layer is combined with the base metal by mechanical inlay and micro metallurgy. Under slight bending, impact or collision, it can also ensure that the anti-corrosion coating does not fall off, peel off, bond firmly, and anti-corrosion is long and effective, which can not be achieved by any other surface anti-corrosion coating.
The principle of anti-corrosion coating is cathodic protection. In corrosive environment, even if the anti-corrosion coating is partially damaged, it still has the effect of sacrificing itself to protect the steel substrate. The area ratio of coating (anode) to steel substrate (cathode) is ≥ 1, while the ratio of zinc rich coating (anode to cathode) is < 1, and its protection effect and binding force are far lower than that of arc spraying anti-corrosion coating.