Electrochemical And Weight Loss Studies Of Extract From Mint As Green Corrosion Inhibitor For Carbon Steel In H_2SO_4 Solution

摘要

The inhibitive action of extract from mint leaves (EML) on Q235A hot rolled carbon steel (HRCS) in 0.5mol/L H_2SO_4 solution was studied using weight loss measurement, electrochemical polarization and scanning electron microscope (SEM) characterization. The results indicate that the extract functions as a good inhibitor. The inhibition efficiency of EML increases with rise in temperature and concentration. The max value of inhibition efficiency reaches 94.01% with addition of 320mg/L EML inhibitor in 0.5mol/L H_2SO_4 solution, at 50°C. Chemical adsorption of EML components occurs on the surface of carbon steel according to the thermodynamic theoretic analysis. It is shown that the extract of mint leaves acts as a mixed type inhibitor according to the analysis from electrochemical polarization curves. The adsorption of the extract on hot rolled carbon steel obeys Langmuir's adsorption isotherm.