The Performance Of Coupled Mild Steel-Zinc Sacrificial Anode In Simulating Marine Fouling Environment

Corrosion is no longer common in daily live, it is a natural process that cause severe failure problems which been receiving focus from worldwide including Malaysia Navy and marine fouling is one the biggest contributor to this concern matters. Hence sacrificial anode cathodic protection is selected to overcome the problems. This research studies the performance of coupled mild steel-zinc sacrificial anode in simulating marine fouling environment. The parameters are three type seawater (Pasir Gudang, India and Artificial seawater), marine fouling (cockles, clams and seaweed) and pH (6.5, 7.5 and 8.5). Immersion testing, linear polarization and electrochemical impedance spectroscopy (EIS) were conducted in this research and for characterization SEM and EDX analysis was used. Coupled mild steel and zinc with seaweed showed the highest weight gain due to calcareous deposit, which is 1.66 g for immersion testing. DOE was used to design the experiment for both linear polarization and electrochemical impedance spectroscopy. For linear polarization, the 3 parameters chosen are immersion days, type of seawater and type of fouling. The highest corrosion rate is 2.715 mm/year for 9 days of immersion, using India seawater and cockle which was expected to give significant effect on corrosion rate. Whereas the lowest corrosion rate is 0.48041 mm/years after 3 days immersed in Pasir Gudang seawater and seaweed. From EIS, cockles was chose as the marine fouling and the two parameter that being considered are pH and immersion days. It can be observed that the lowest bulk capacitance is 0.9971μF which is for 6.5 pH and 9 days. Whereas the highest bulk capacitance is 0.98969 μF for 7.5 pH and 6 days of immersion