An improved anti-corrosion coating for steel

Using zinc-based coatings to protect galvanized steel from corrosion has been standard practice in the steel industry for decades, but these processes have several key disadvantages. First, achieving longer corrosion performance requires thicker layers of zinc, which raises costs and also limits the ability to shape and bend the steel subsequently. Also, the coating processes often involve compounds containing hexavalent chromium, which presents serious health and environmental risks. A series of coating formulations, known collectively as Intercoat ChemGuard, developed by Chemcoaters Inc. (Gary, Ind.; www.chemcoaters.com), overcomes these limitations. Using a reverse roll-coating process, the anti-corrosion coatings are applied over a steel substrate that has been coated with low levels of zinc. The coatings generate covalent bonds with the zinc on the steel surface, forming a layer of reacted material. Meanwhile, the outermost layer of the coatings remains unreacted, allowing the coating to have self-healing properties, which allows the corrosion protection to persist after the steel is cut or punctured. “When Intercoat ChemGuard is applied over the lightest possible coating of zinc that is commercially available in flat-rolled…