Mathematical Studies on Galvanic Corrosion

Abstract

Extensive numerical evaluation was performed on a Fourier series derived for the potential distribution in an electrolyte lying above a plane containing infinitely long, narrow electrodes juxtaposed and arranged in an infinitely alternating array with even symmetry. In contrast to the previous studies in this series, the limitation that the electrolyte has finite depth was imposed. Four perspective drawings of the reduced potential function were made to scale to illustrate the potential variation throughout the solution. From this study a practical rule was established for deciding from the behavior of the electrochemical system what effectively is an "infinite thickness" of the electrolyte. Current density variation over the anode was evaluated for several different combinations of relative thickness and of relative polarization parameter /c. When is small, the major part of the corrosion current is concentrated in the vicinity of the anode‐cathode junction, provided that the electrical resistance of corrodent is not too high or the polarization too strong, i.e., provided that is relatively small in comparison with c. Several graphs of were included to illustrate the effects of the dimensionless groups , , and ( /c). Comparison with published experimental data was made, and the agreement is reasonably good. Detailed discussion of the influence of several factors is also presented.