EFFECTIVENEES OF USING SACRIFICIAL ANODE OF ALUMINUM ALLOY FOR SHIP STEEL PLATE OF AISI E 2512 ON CORROSION RATE IN THE MEDIA OF SEA WATER

Abstract

Hull plates are part of construction of the first affected by sea water corrosion. Corrosion of hull plates may decrease the strength and life of the ship, thus reducing the safety program can reduce the load cargo and passenger ships. To avoid greater losses due to sea water corrosion, we need a corrosion protection on the hull plate. Until now, one way to protect the hull plate from corrosion is cathodic protection method.Cathodic protection method often used is the sacrificial anode system. Sacrificial anode types used in this study is aluminum alloy. The research aims determine the effectiveness of the use of aluminum alloy as sacrificial anode for cathodic protection of hull plates and knows the needs of sacrificial anode that is used to slow the average rate of corrosion in the hull plates in seawater. This research method is field observation and laboratory experiments. Object of observation is a general cargo ship, which under replating repairs and replacement of sacrificial anode. Test speciment for experimental laboratory is a steel plate AISI E 2512, three kinds of aluminum alloy sacrificial anode products are different (the product A, Al = 86.118%, the product B Al = 85.097% and the product C Al = 97.665%) and use of sea water media with a salinity of 37 o / oo The results showed that the aluminum alloy sacrificial anode mounted on the hull plate can work optimally with the corrosion rate of ship hull plates of 0.304 mm/year in the vertical direction and 0.327 mm/year in the longitudinal direction of the ship and in compliance with applicable standards and met the eligibility safe condition Results of corrosion testing in the laboratory can also prove that among of the three aluminum alloy sacrificial anode mounted on steel plates of AISI E 2512 ships haven is the most optimal performance is the product of aluminum alloy sacrificial anode C, because it has the average corrosion rate of the lowest vessel steel plate at 0.065 mm/year. From this research it is known that aluminum alloy sacrificial anode product C has the optimal performance, meaning it slows the rate of corrosion of steel plate AISI E 2512 that can truly serve as the sacrificial anode. Key words: Ship steel plate , Aluminum alloy sacrificial anode, Corrosion rate