President, Dean Corrosion Technology, Allentown, Pennsylvania
Lead Materials Engineer, Air Products and Chemicals, Inc., Allentown, Pennsylvania
Pages: 16 Published: Jan 2002
A series of regression analyses was made on the multi-year corrosion losses of panels of steel, zinc, copper, and aluminum in the ISO CORRAG program. In every case, the only sites selected for the analyses were sites with all four exposures reported and complete data sets on the time of wetness, sulfur dioxide, and chloride deposition. The regressions with significant R values were then selected for further analyses. The time exponent and one-year corrosion coefficient were regressed against the environmental variables. None of the exponent regressions showed large environmental effects. The steel exponent was increased by chloride deposition and time of wetness. The copper exponent was increased by increasing time of wetness and decreased by increasing chloride. Neither zinc nor aluminum exponents showed significant effects from the environmental data. The best environmental regressions were only able to predict the measured corrosion losses to within a factor of two for steel, zinc, and copper. The aluminum loss predictions were worse. Some other environmental variables will need to be found to improve this approach to predicting atmospheric corrosion.
atmospheric corrosion, time of wetness, chloride deposition, sulfation, sulfur dioxide deposition, ISO CORRAG program, regression analysis, time exponent
Paper ID: STP10879S