Galvanic Corrosion and its Analysis of Aluminum Wire for Overhead Transmission Line

Abstract

The corrosion behavior of aluminum wire which is galvanically coupled with copper in 5mass% NaCl solution was studied by surface observation and polarization curve measurements. The corrosion rate of the aluminum and copper coupled specimen was estimated by using polarization resistance method and it is about 0.03mAcm^-2 which is roughly correspondent with the limiting diffusion current density of dissolved oxygen in the NaCl solution. It is shown and considered that morphological characteristics of the galvanic corrosion of aluminum wire specimen showed deep but narrow mouth of pitting cavities.