Corrosion Resistance of API 5L Grade B Steel with Taro Leaf (Colocasia esculenta) Addition as Corrosion Inhibitor in HCl 0.1 M

摘要

Taro leaf (Colocasia esculenta) has the potential to be used as a corrosion inhibitor because it has a substance called polyphenol that binds to the hydroxyl group and essential amino acids . Taro leaf extract is taken by maceration method . In this study, the specimen was steel API 5L grade B that would measured the corosivity in 0.1 M HC1 solution + taro leaf extract with a specific concentration (in ppm). Tests conducted by FTIR method taro leaves, potentiodynamic polarization (Tafel) and Electrochemical Impedance Spectroscopy (EIS). Based on the results revealed that there is a phenolic group in taro leaves, which has polyphenol content 0.053 % (mg/100 mg). The optimum composition of taro leaf extract is 4000 ppm which generate corrosion rate value of 30.22 mpy and efficiency inhibitor performance of 72.7 %. In this study, the Kads value of taro leaf extract ranged from 0.885 to greater than Kads value of ginger extract in hydrochloric acid solution. The high Kads values indicate a more efficient process of adsorption and better value of inhibition efficiency.