Electrochemical Evaluation of the Corrosion Rate Inhibition Capacity of Eugenol, o-Eugenol and Diphenol, on AISI 1020 Steel Exposed to 1M HCl Medium

Abstract

Due to corrosion damages, petrochemical industry invests millions of dollars in the mitigation of this problem, which is presented basically in equipment and metal pipes, both externally and internally. A possible solution to the different consequences caused by corrosion is the use of green corrosion inhibitors. In the present research project, the inhibition capacity of the eugenol, o-eugenol and diphenol, on AISI 1020 carbon steel exposed to a 1M HCl acid medium is evaluated. Hence, the corrosion rate of the material in solutions with and without green corrosion inhibitor was calculated under the influence of two operating variables: temperature and immersion time; applying techniques such as Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization. In addition, the surface of AISI-1020 carbon steel was characterized by Scanning Electron Microscopy (SEM) in combination with Energy Dispersive X-ray Spectroscopy (EDS). Experimental tests show that the diphenol-based inhibitor obtained a corrosion rate inhibition efficiency of96.24 % for AISI 1020 steel, compared to 76.87 % for Eugenol and 71.01 % for o-eugenol. The experimental results have shown that the percentage of inhibition increases as the temperature and immersion time of the electrochemical cell increase in the system, achieving a maximum percentage of inhibition in the corrosion rate of AISI 1020 steel of 92.23 % for a temperature of 80 °C and 6 h of immersion time.