An Active Coating and New Protection Technology for Weathering Steel Structures in Chloride Containing Environments

A new coating that allows formation of the correct protective patina on weathering steel structures located in regions of high chlorine and/or high time-of–wetness, has been developed. The coating controls the time-of-wetness at the steel surface, allowing correct wet/dry cycling required for protective patina formation. It also binds chloride ions, and prevents them from reaching the steel surface and forming the incorrect, non-adherent rust. The active coating is not a paint, but rather accelerates correct patina formation to about 1-2 years compared with 8-16 years needed for bare weathering steel in nonpolluted atmospheric exposures. Corrosion rates have been decreased by a factor of 10 in high chloride locations.