Effect of avocado (persea americana) leaf extracts on the corrosion behavior of stainless steel in acidic environment

In this study, the inhibitory activity of avocado (Persea Americana) leaf extracts on the corrosion of stainless steel in acidic environment was investigated depending on the concentration, temperature and waiting time in corrosive environment. Potentiodynamic polarization, linear polarization resistance, electrochemical impedance spectrometry (EIS) and scanning electron microscopy (SEM) methods were used to obtain the experimental data. Inhibition efficiency (%IE1), corrosion current (icor) and polarization resistance (Rp) values of stainless steel in acidic medium with and without avocado leaf extract were obtained. According to the results obtained, it was observed that the inhibition efficiency increased as the extract concentration and the exposure time to the acidic environment increased. The highest inhibitory activity (64%) was obtained at the highest concentration of (10g/L). According to the results obtained at different temperatures (25°C, 35°C, 45°C and 55°C), it was determined that the corrosion resistance decreased with the increase in temperature. The surface images of the stainless steel were taken by scanning electron microscope (SEM) and it was observed that a protective film layer was formed on the surface. It was determined that the adsorption process of the inhibitor on stainless steel surface in acidic environment conformed to Langmuir adsorption isotherm. The adsorption free enthalpy (ΔG°ads) value was calculated and it was determined that the physical adsorption of the inhibitor occurred spontaneously.