A Study on the Influence of Al Alloy Sacrificial Anode Efficiency due to Marine Environmental Variation

J. Ocean Eng. Technol. 2000;14(2):106-111.

해양환경 변화가 알루미늄합금 희생양극의 효율에 미치는 영향에 관한 연구

김도형

한국해양대학교 기관시스템공학부

Keywords: Al sacrificial anode, Current density, Flow rate, Electrochemical characteristics, Anode current efficiency

핵심용어: 알루미늄희생양극, 전류밀도, 유동, 전기화학적 특징, 양극전류효율

Abstract

Recently it was reported that the life of Al Sacrifical anode is being used in port piers has been significantly shortened compared with the original design life (e.g. average life shortened from 20 years to 13-15 year) Those factors involving these problems mentioned above were seemed to be a quality of anode material and diverse environmental factors such as pH flow rate temperature Dissolved oxygen Chemical oxygen demand and resistivity etcm In this study flow rate and contamination degree(pH) of sea water affecting to sacrificial anode life hve been investigated in terms of electrochemical characteristics of Al alloy sacrificial anode It was known that the lifetime of Al alloy anode was shortened not only by increasing of self-corrosion quantity by varying flow rate of sea water but also by increasing corrosion current density due to the potential difference increment between Al anode and steel structure cathode by varying contamination degree of sea water. Especially when anode current density is from 1mA/cm2 to 3mA/cm2 and flow rate of sea water is under 2m/s anode current efficiency is 90% above However flow rate is over 2m/s anode current efficiency fell down sharply due to erosion corrosion as well as galvanic corrosion.