- Author
- Nguyen, T. | Hubbard, J. B. | McFadden, G. B.
- Title
- Mathematical Model for the Cathodic Blistering of Organic Coatings on Steel Immersed in Electrolytes.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
- Journal of Coatings Technology, Vol. 63, No. 794, 43-52, March 1991
- Keywords
- steels | mathematical models | blisters | coatings | corrison
- Abstract
- A physical/mathematical model which describes blistering resulting from the corrosion of coated metals containing defects exposed to electrolytes has been developed. The model is based on the two-dimensional diffusion of cations through some arbitrary medium. Cations migrating along the coating/metal interface from the defect to the cathodic sites are assumed to be responsible for the formation of highly water-soluble corrosion products, leading to blistering. Solutions of the model were expressed in terms of dimensionless parameters. Concentration profiles between the blister and defect and cation flux into the blister as functions of time, blister size, distance between the blister and defect, ion diffusivity, and potential gradient were calculated. The predictions were related to available experimental data in the literature on cation uptakes and blistering rates for coated steel panels exposed to metal chloride solutions.