Corrosion inhibition effect of magnolia grandiflora leaves extract on mild steel in acid solution

Abstract

The corrosion inhibition performance of Magnolia grandiflora leaves extract (MGLE) on mild steel in 0.5 M H2SO4 solution was investigated through electrochemical technology, weight-loss experiment and scanning electron microscope (SEM). The results showed that MGLE was a mixed corrosion inhibitor with a predominantly cathodic inhibition for mild steel in H2SO4 solution, which could effectively inhibit the corrosion of mild steel in H2SO4 solution, under the experimental conditions, the max corrosion inhibition efficiency was up to 91%. The corrosion inhibition performance of MGLE enhanced with the increase of concentration and weakened with rising temperature, but the decrease was not significant, especially at high concentration. The thermodynamic and kinetic parameters were calculated and discussed, it was found that the adsorption of MGLE on the surface of mild steel was an exothermic process and obeyed the Langmuir isothermal equation.