The Role of Echium Angustifolium Mill Extract in The Corrosion Mitigation of Carbon Steel in Sulfuric Acid Solution

Abstract

The role of Echium angustifolium Mill extract for advancing corrosion resistance of carbon steel in 1.0 M H2SO4 solution was discussed in this research. Weight loss (WL), open circuit potential (OCP), potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) methods were applied to monitor the corrosion behavior of carbon steel in 1.0 M H2SO4 solution. The influence of temperature was studied from 25–45°C and some thermodynamic parameters were computed. The Surface morphology of the carbon steel surface was examined via different techniques. These measurements confirmed that the existence of Echium angustifolium Mill extract reduces the corrosion rate (CR), corrosion current densities (icorr), and double layer capacities (Cdl), simultaneously increase the polarization resistance (Rp) values. Tafel plots observed that the Echium angustifolium Mill extract play as a mixed type inhibitor. Electrochemical impedance confirmed that the existence of the applicable extract reduced the double layer capacitance and enhanced the charge transfer resistance. The extract molecules adsorbed on the metal surface follow Langmuir adsorption isotherm. The gained data confirmed that the inhibition efficiency (η%) increase with the increase of extract concentration.