Analysis on Protection Failure of Zinc Sacrificial Anodes

After a year of service in steel ship,the zinc sacrifical anodes was discovered dissolving unevenly and failure in protection of the ship.The cause of the uneven dissolving and protection failure is investigated through chemical composition analysis,metallographic observation,SEM analysis, resistance detection and infrared analysis.The results reveal that mispainting on the anodes is the main cause to bring about the failure of the sacrifical anode protection.