A quantitative method of describing ionic transfer processes in electrolytes under metal corrosion

Abstract

A quantitative iterative method is described for the transport of ions in solutions under steady-state conditions. This method assumes that electrochemically inactive species are not submitted to transport in the absence of convection, if they do not participate in homogeneous chemical reactions. The set of equations for ionic transfer can be transformed to a system of transfer equations involving transport by diffusion and convection which can be solved with existing procedures, in particular those for convection heat transfer problems. This method requires calculation of the electric field strength or current density for each iteration step according to an explicit expression given in this article. If only one species particpates in the charge transfer reaction at the electrode surface, the set of ion transfer equations can be reduced to Laplace's equation. Examples of the application of the method are given for metal dissolution in a channel and in a hemispherical pit.