Polyoxometalate and Zirconium-Phosphate Conversion Coating for Steel Piping

The proposed polyoxometalate conversion coating will find application in reducing life-cycle costs of piping systems subject to microbial-influenced corrosion in the presence of untreated or brackish water. The environmentally friendly chrome-free conversion coating is expected to perform not only as a corrosion inhibitor to microbially induced corrosion, but also function as a smart coating that will passivate metal exposed in organic-coating topcoats and at defects in the conversion coating. The removal of toxic materials and reduction in operation and maintenance costs would be welcomed for control of material degradation in the nation's spaceport and propulsion test-facility infrastructure and ground and flight assets. Other areas supported by NASA, such as the Air Transportation & Safety, Structures and Waste Storage/Treatment, could also make use of the conversion-coating technology.

In the Federal Highway Administration (FHWA) 2001 report on corrosion costs in the United States it is estimated that Corrosion costs U.S. industry and government agencies an estimated $276 billion/year. Chrome-free environmentally friendly conversion coatings will find application in a variety of industrial sectors in reducing worker exposure to toxic materials and reduction of waste-treatment costs. The corrosion inhibition of ferrous metals will lead to decreased failures due to microbial corrosion in pipelines and in manufacturing and construction materials in highly corrosive salt and acid environments. It is expected that the coatings can be used in field applications for large structures at ambient temperatures rather than higher temperature alternatives that need to be applied in controlled environments. More »