Numerical modeling of iron corrosion due to an acidic aqueous solution Original Research Article

We attempt to tackle the problem of the direct numerical simulation of the chemical corrosion of iron through the solution of an evolutive system of partial differential equations based on the electrochemistry laws. The process is described in terms of the concentrations of the chemical species appearing within the chemical reactions and the electric potential. In fact in the literature corrosion processes have been object of microscopic descriptions built upon ‘ab initio’ molecular dynamics and of phenomenological models based on data fitting techniques. In the first case, the simulation procedures are too lengthy and not suitable for applicative purposes, whereas in the second case, the validity of the models is obviously restricted to the experimental set-up. Interesting, but necessarily a posteriori, descriptions have been developed based on inverse modeling. Here we present the simulation of the primary reactions occurring during the corrosion of the irony bottom of a closed vertical slot filled with an acidic solution and whose top and bottom, which are connected by an external conducing wire, work respectively as a cathode and an anode of a galvanic cell. The curves of the evolution of the concentration of the ions, of the pH of the solution and of the electric potential are discussed.