Monte Carlo simulation of uniform corrosion process under potentiostatic conditions

• Published in: Corrosion science Vol. 49; no. 7; pp. 2880 - 2904
• Main Authors: Guessasma, S., Elkedim, O., Nardin, Ph, Hamzaoui, R., Grosdidier, T.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2007; Elsevier Science; Elsevier
• Subjects: A. Alloy; A. Metal coatings; Applied sciences; B. Modelling studies; B. Potentiostatic; Chemical Sciences; Condensed Matter; Corrosion; Corrosion environments; Cristallography; Engineering Sciences; Exact sciences and technology; Materials Science; Mechanics; Mechanics of materials; Metallic coatings; Metals. Metallurgy; Physics; Production techniques; Surface treatment; A. Metal coatings; B. Potentiostatic; B. Modelling studies; A. Alloy; Monte Carlo method; Metal coating; Simulation; Uniform corrosion; Modeling; Surface treatment; Operating conditions
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2006.10.041

The aim of this paper is to study the corrosion resistance of industrial coatings of metallic alloys including certain amount of process-induced porosity. Surface damages during a simulated corrosion process are investigated using Monte Carlo simulation technique and compared to corrosion response (dissolution currents). In this simulation, a 3D grid of the coating is subject to an electrolyte attack under potentiostatic conditions. The surface damages are related to a controlled dissolution process governed by dissolution probability, roughness, porosity size and fraction. In order to validate the model results, theoretical I = f( t) curves are compared to corrosion behaviour of Fe–40Al samples pointing out critical parameters affecting current density and exposed area. Predictions relating the porosity level to corrosion behaviour are established and discussed. The main conclusions focus on a primary effect of pore size and connectivity and a secondary effect of porosity level in the considered process window (porosity levels between 5.8% and 7.8%). The experimental work shows that the porosity effect could not explain all observed trends and a deeper examination of the microstructure reveals another candidate (unmolten particles) which is expected to vary both pore connectivity and dissolution events.