VCI powder bimetallic coating for steel structure surface protection and preparation method thereof

The invention provides a VCI (Vapor Corrosion Inhibitor) powder bimetallic coating for steel structure surface protection and a preparation method thereof. The ofpowder bimetallic coating comprises the following components in parts by weight: a binder, a filler, a VCI vapor corrosion inhibitor and an auxiliary, wherein the binder comprises 15-25 parts of powdered epoxy resin, 15-25 parts of powdered polyester resin, 5-15 parts of polytetrafluoroethylene resin, and 5-15 parts of organic silicon resin; the filler comprises 30-60 parts of flake zinc powder, 1-5 parts of flake aluminum powder, 5-10 parts of aluminum triphosphate, and 5-10 parts of zinc phosphate; the auxiliary is selected from one or more of a flatting agent, a conductive agent, a degassing agent and a light stabilizer; the mass ratio of the binder to the filler is 3:1 to 1:2.5; the mass of the VCI vapor corrosion inhibitor is 5-10% of the total mass of the binder and the filler; the mass of the auxiliary is 2-10% of the total mass of the binder and the filler. The coating plays a good shielding role as a powdered coating, further plays a cathode protection role as a common zinc-rich coating, and meanwhile takes a corrosion inhibition effect as the VCI vapor corrosion inhibitor, so as to achieve the excellent protection effect for the metal binder. In addition, the powdered coating disclosed by the invention is prepared by mixing different weather-resistant resins, so that the powdered coating has better weather resistance than the common powdered coating.