Banana Trunk as Green Corrosion Inhibitor for Carbon Steel in Subsea Applications

摘要

Corrosion is a serious problem in every industry and can cause losses in production leading to large financial losses. International legisation body has drawn offshore chemical into several categories based on biodegradation, bioaccumulation and toxicity. Otherwise, the inhibitor is not accept to be used as they are harmful to environment. Therefore, most industries are looking for green inhibitor as it will fulfill the environment legislation. An electrochemical test has been carried out to determine the corrosion rate of carbon steel. This research aimed to investigate the potential corrosion of carbon steel in seven different immersion periods (1 day, 2 days, 7 days, 14 days, 21 days, 28 days, 35 days) using seawater 3.5% NaCl. The pH values were set in neutral in static condition. The materials were run for tafel polarization with a scan rate of 0.5mV/sec. Each sample will be tested when achieve a predetermined time. This experiment was carried out to compare the corrosion rate of 3.5% NaCl and with NaCl added 25% inhibitor. Inhibitors used were from banana trunk. The experiments were carried out at four different temperatures (5°C, 10°C, 20°C and 30°C). Before and after testing, the microstructures of each sample were observed by using Optical Microscope (OM). The results show the highest corrosion rate occurring in the shortest period of immersion for 1 day. However, the corrosion rate decreases when the longer period of immersion. The corrosion rate for 3.5% NaCl will increase with added 25% inhibitor and decrease for 3.5% NaCl when temperature decreases.