The efficiency of moringa leaf (Moringa Oleifera) as green material carbon steel corrosion inhibitor for different concentration of sea water.

Abstract

Carbon steel as materials of pipe is used in the plural oil and gas industry in Malaysia, but the corrosive working environment conditions create this type of pipe prone to corrosion. In electrical industries, Aluminum-conductor steel-reinforced (ACSR) are the most commonly used in transmission line systems due to aluminum’s light weight and cost, and carbon steel’s strand is high mechanical strength. Corrosion is an absolute phenomenon that occurs in carbon steel, but the rate of corrosion can be controlled by certain techniques. One of which is the use of environmentally friendly corrosion inhibitors or so-called green corrosion inhibitors. Moringa Leaf (Moringa Oleifera) is known to have a high content of antioxidant compounds and the use of this benefit only limited to water purification and as a food ingredient. From this issue, research was carried out on the use of Moringa leaf extract as green corrosion inhibitor on carbons steel. This research uses variations Moringa leaf powder concentration in 200 ml static seawater conditions (0 rpm) give the concentration of 200, 400, and 600, 800 and 1000 ppm to get optimal work. The linear polarization method used to determine the performance of Moringa leaf powder to reduce the corrosion reaction. In the tafel test, it was found that moringa leaf powder that is added suitable to work as inhibitor. Addition of the concentration able to reduce the corrosion rate up to 0.124 mmpy with efficiency from polarization resistance of 49.69 %, while efficiency from corrosion rate and corrosion current of 70.5% in static seawater conditions. Consequently, in inhibited solutions, the corrosion rate is indicative of the number of the free corrosion sites remaining after some sites have been blocked by inhibitor adsorption. Tafel test results found that a protective passive layer is formed on the surface of the steel make contact between the metal and sea water is reduced with existing of moringa leaf powder so that corrosion can be inhibited.