Keywords: Red palm oil; natural corrosion inhibitor; temperature; steel

Abstract

Red palm oil was studied as a corrosion inhibitor for mild and carbon steel in an acidic medium at different temperatures. It was shown that the steel weight loss was directly proportional to the increase of temperature. Mild steel lost about 1.34 mg of weight at 25°C and reached a maximum weight loss at 60°C was 2.41 mg. Carbon steel underwent about 1.41 mg weight loss (25°C) until 2.47 mg (60°C). The rate of corrosion was also increased as the temperature increased. The maximum corrosion rate for both mild and carbon steel at 60°C was 15.71 mpy and 16.10 mpy, respectively. The maximum rate of corrosion inhibitor efficiency for mild and carbon steel was found to be 91.1% and 80.1% at 25°C. The percentage of corrosion inhibitor efficiency gradually decreased when the temperature increased. SEM-EDX results showed both surfaces of mild and carbon steel were smoothed and no holes at 25°C. However, at 60°C corrosion effect occurred on the surface of both types of steel. Based on the percentage of chlorine, oxygen, and ferum atom mass, the oxidation and corrosion impacts were lower for mild steel compared to carbon steel.