A mathematical model simulating CO2 corrosion is presented in the form of a set of non-linear, coupled differential equations. For different values of the parameters (pH, pCO(2) and flow velocity) that influence the solution, the problem is numerically solved by the network method, which provides all the concentrations of the species from the steel surface to the bulk. Although the model is strongly sensitive to the above parameters, no assumptions are considered as regards the linearization of species fluxes, chemical reaction rates and current densities of the electrochemical reactions. The design of the model is explained in detail and it is run on standard electrical circuit simulation software. As expected, the corrosion rate, an important parameter to know in chemical utilities, increases for lower values of pH and higher values of flow velocity, while changes in pCO(2) hardly influence this quantity. The results are very close to the experimental data. (c) 2011 Elsevier Ltd. All rights reserved.