Marine corrosion of iron: mathematical modelling of the processes and measurement of lost mass

espanolHemos derivado el modelo matematico de Melchers para la difusion de oxigeno a traves de la capa de herrumbre formada en la superficie de aceros sometidos a procesos de inmersion total, mediante un principio mas fundamental: la ley de Planck-Nernst. Para esto se ha despreciado las corrientes convectivas asi como la migracion de las moleculas de oxigeno. Tambien, ademas de considerar un flujo unidimensional, se asume que el consumo de oxigeno, debido a reacciones quimicas con el hierro, unicamente ocurre en la interfase metal-herrumbre. Por ultimo, se ha determinado experimentalmente un valor para el parametro a que aparece en el modelo de Melchor, el cual es una medida de la cantidad de hierro convertida en herrumbre adherente. EnglishWe have derived the Melchers? mathematical model of the oxygen diffusion across the rust layer formed on the surface of the steels submitted to total immersion, by a most fundamental principle: the Planck-Nersnt law. To achieve it, we have neglected the convection and migration of the oxygen molecules, and we have assumed both that this problem is 1-D and that oxygen consumption, due to chemical reactions, can only occur at the interface between the metallic surface and the rust. Furthermore, we have experimentally determined an a value for Melchers?s model, which accounts for the amount of iron coming from the steel which is converted into adherent rust.