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Determination of the Phosphate Quality of Automotive Organic Coatings on Different Steel Substrates by Electrochemical Impedance Spectroscopy
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Abstract
Various steel substrates which were processed under different pretreatment conditions and coated with automotive paint systems, were investigated by electrochemical impedance spectroscopy (EIS). The impedances of damaged and undamaged organic coatings on cold rolled steel were measured in an aqueous sodium chloride solution. These results were compared with two conventional accelerated exposure tests, the High Temperature Chipping Corrosion Test (HTCCT), and the modified Volvo outdoor exposure test. The chipped organic coatings on cold rolled steel, electrogalvanized zinc, ZnFe electrogalvanized, and ZnFe hot dip galvanized were then investigated by EIS. An inhomogeneous three-dimensional surface model was used to analyze the EIS data and characterize the corrosion protection of the paint/phosphate/metal system. The fraction of the total test area which had undergone paint delamination and corrosion was calculated from the model results. Agreement with the paint loss results from HTCCT and Volvo tests was obtained. The EIS is shown to be a useful and reliable tool to evaluate phosphate quality, and the corrosion performance of painted automotive sheet steels.
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Ruiz, K. and Davidson, D., "Determination of the Phosphate Quality of Automotive Organic Coatings on Different Steel Substrates by Electrochemical Impedance Spectroscopy," SAE Technical Paper 912299, 1991, https://doi.org/10.4271/912299.Also In
References
- Hess J. C. Soreide L. E. Automotive Corrosion and Prevention Conference Proceedings Dec. 1989 17
- Shastry C. R. Towsend H. E. Automotive Corrosion and Prevention Conference Proceedings Dec. 1989 7
- Bacon R. C. Smith J. J. Rugg F. M. Ind. Chem. 40 1948 161
- Brasher D. M. Kingsbury A. H. J. Appl. Chem. 4 1954 62
- Brasher D. Nurse T. J. J. Appl. Chem. 9 1959 96
- Touhsaent R. E. Leidheiser H. Corrosion 28 1972 435
- Mansfeld F. Kendig M. W. “Electrochemical Impedance Tests for Protective Coatings” Laboratory Corrosion Tests and Standards Haynes G.S. Baboian R. American Society for Testing and Materials Philadelphia 1985 122 142
- Scantlebury J. D. Ho K. N. Eden D. A. “Impedance Measurements on Organic Coatings on Mild Steel in Sodium Chloride Solutions,” Electrochemical Corrosion Testing Mansfeld Florian Bertocci Ugo American Society for Testing and Materials 1981 187 197
- Haruyama S. Asari M. Tsuru T. “Impedance Characteristics during Degradation of Coated Steel” Corrosion Protection by Organic Coatings Kendig M. Leidheiser H. 87-2 Pennington, NJ Electrochemical Society 1987
- Mansfeld F. Jeanjaquet S. Kendig M. “An Electrochemical Impedance Spectroscopy Study of Reactions at the Metal/Coating Interface” Corrosion Protection by Organic Coatings Kendig M. Leidheiser H. 87-2 Pennington, NJ Electrochemical Society 1987
- Mansfeld F. Kendig M. Tsai S. Metallic Corroison Proceedings - 8th International Congress on Metallic Corrosion 7th Congress of the European Federation of Corrosion (111th Event) Sept. 1981 1014
- Kendig M. Mansfeld F. Tsai S. Corrosion Science 23 4 1983 317
- Kendig M. Scully J. Corrosion Science 46 1 1990 22
- Titz J. Wagner G. H. Spahn H. Ebert M. Juttner K. Lorenz W. J. The Journals of Science and Engineering Corrosion March 1990 221
- Boukamp B. A. Equivalent Circuit Users Manual University of Twente 1989
- Piens M. Verbist R. Vereecker J. International Conference in Organic Coatings Science and Technology, Proceedings 7 July 1981 249 262