矿物冶金与材料学报
礦物冶金與材料學報
광물야금여재료학보
INTERNATIONAL JOURNAL OF MINERALS,METALLURGY AND MATERIALS
2014年
11期
1083-1095
,共13页
steel corrosion%mild steel%sulfuric acid%corrosion inhibitors
The ethanolic extract ofKleinia grandifloraleaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M H2SO4 medium using mass-loss analysis, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and X-ray diffraction analysis. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 308 to 328 K. The inhibition efficiency was observed to increase with increasing concentration of the extract. Polarization curves revealed that theKleinia grandiflora leaf extract is a mixed inhibitor. Impedance diagrams revealed that an increase ofKleinia grandiflora leaf extract concentration increased the charge transfer resistance and decreased the double-layer capacitance. The adsorption process obeys Langmuir’s model, with a standard free energy of adsorption (?Gads) of?18.62 kJ/mol. The obtained results indicate that theKleinia grandiflora leaf extract can serve as an effective inhibitor for the corrosion of mild steel in a sulfuric acid medium.