Among the anti-corrosion techniques of aluminum and zinc spraying on steel structures, arc spraying is most widely used, 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 metal wires (such as zinc and aluminum) to form an anti-corrosion coating, plus a long-term anti-corrosion composite coating with organic closing coating. The obvious characteristics of the coating are:
It has long-lasting corrosion-resistant life, and its anti-corrosion life can reach more than 50 years. The anti-corrosion coating does not need any other anti-corrosion maintenance within the 30-year service life; For maintenance in the future 30 years, only the closing coating must be brushed on the arc spraying layer; It does not need to be sprayed from scratch to complete one-time anti-corrosion, and the coating is durable and useful.
The arc spraying layer has excellent coating contact force with the metal substrate (up to more than 10MP). The metal spraying layer is connected with the base metal by mechanical inlay and micro metallurgy. Under slight twists, impacts or bumps, it can also ensure that the anti-corrosion coating will not fall, peel, contact firmly and be durable and useful for anti-corrosion, which can not be reached by any other external anti-corrosion coating.
The principle of aluminum spraying and zinc spraying anti-corrosion coating on steel structure is cathode maintenance. In corrosive environment, even if the anti-corrosion coating is partially damaged, it still has the role of dedicated maintenance of steel matrix. Area ratio of coating (anode) to steel substrate (cathode) ≥ 1; The ratio of anode to cathode of zinc rich coating is 1, and its maintenance function and contact force are far lower than that of arc spraying anti-corrosion coating.
