Mesoscopic Modeling Of Corrosion Processes: Pitting Morphology Evolution
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A. Taleb, C. Vautrin-Ul, H. Mendy, J. Stafiej & A. Chausse
We use cellular automata simulations at a mesoscopic scale to describe the phenomenon governing the morphology of pitting corrosion. We show that spontaneous separation of anodic and cathodic reaction zones plays a major role in determining the shape of the corroded space. The location of these zones versus the corroded surface is a stochastic event that influences strongly the direction of the corrosion propagation. Keywords: cellular automata, corrosion, pitting morphology. 1 Introduction The corrosion phenomena lead to a strong modification of the metal surface properties. Both physical and chemical aspects of the surface are affected by this change. Depending on the corrosive environment properties in terms of pH, temperature, aggressive ion concentration and potential, the metal surface is covered by an oxide film or not. In certain conditions, the presence of the film leads to a passivation of the surface that is separation of the corrosive media from the metal greatly reducing the rate of corrosion. The local breakdown of this protecting layer induces local corrosion named pitting corrosion or crevice corrosion if the site is occluded.
cellular automata, corrosion, pitting morphology.