ガルバニック腐食およびカソード防食における電位・電流密度分布予測 Prediction of Potential and Current Density in Galvanic Corrosion and Cathodic Protection Systems
A three dimensional boundary element method was developed for predicting electro-galvanic field responses due to anodic-cathodic interaction. Although the governing equation is linear (Laplace), the boundary condition, which is enforced based on experimentally determined polarization curves, is generally non-linear. Therefore, Newton-Raphson iterative procedure was employed in the present prediction method. An experiment was also conducted on galvanic corrosion of a cylindrical vessel which was made of cast iron and stainless steel, and filled with 0.0165 % NaCl solution. In addition, the effect of cathodic protection by placing a small piece of aluminum plate on the cylindrical vessel was examined experimentally. The validity and usefulness of the present prediction method were de- menstruated by comparing the calculated results and the experimental data.