Pengaruh Penggunaan Dan Penempatan Anoda Korban Paduan Zn Pada Pelat Astm A36 Terhadap Laju Korosi

Abstract

This study is motivated by the high corrosion rate of ASTM A36 steel plates, which are widely used in ship structures, especially in aggressive marine environments. Cathodic protection using sacrificial anodes is a commonly applied method to control corrosion; however, its effectiveness is strongly influenced by the anode placement. This research aims to evaluate the effect of zinc alloy sacrificial anode placement on corrosion rate and microstructural changes of ASTM A36 steel plates. An experimental method was conducted using the weight loss approach over an 8- week immersion period in natural seawater. The tested variations included vertical anode placement (X1), horizontal anode placement (X2), and a control sample without anode (X3). Observations were carried out periodically through mass measurements and metallographic testing to examine microstructural changes. The results show that the use of sacrificial anodes significantly reduces the corrosion rate compared to the control sample. The lowest corrosion rate was consistently observed in the horizontal configuration (X2), followed by the vertical configuration (X1). The corrosion trend indicates three main phases: initial activation, stabilization, and protection degradation. Furthermore, metallographic analysis reveals more severe microstructural damage in specimens without anode protection. It can be concluded that anode placement plays a crucial role in the effectiveness of cathodic protection. The horizontal configuration provides a more uniform current distribution, resulting in more optimal corrosion control.