Electrochemical evaluation of dissolution characteristics of Al-based sacrificial anodes in seawater

The surface dissolution characteristics of Al-based sacrificial anodes in seawater have never been expressed numerically except in words such as uniform dissolution, non-uniform dissolution, serious localized dissolution, etc. An electrochemical method was developed in our laboratory to evaluate the above mentioned characteristics quantitatively. The Al anode samples are polarized to −1000 mv (vs. Ag/AgCl reference electrode) in seawater at 25±1°C, and anodic current-time curves are recorded simultaneously. Then the coulometric density was calculated with the aid of a planimeter. By comparing the coulometric densities of these samples, the surface dissolution characteristics of anodes can be evaluated quantitatively. Contribution No. 1447 from Institute of Oceanology, Academia Sinica