Corrosion inhibition of carbon steel in hydrochloric acid solution by rice bran extracts

Abstract

Purpose

The paper reports an investigation into the use of aqueous extracts of rice bran as a green inhibitor for corrosion of carbon steel in hydrochloric acid (HCl) solution.

Design/methodology/approach

Extracts from the rice bran were used as the main component of an environmentally friendly corrosion inhibitor for use in HCl pickling processes. Inhibition behavior on carbon steel in HCl was investigated by means of mass‐loss tests, polarization curves, electrochemical impedance spectroscopy and atomic force microscopy.

Findings

The results show that the extract exhibited good inhibition performance in 1 M HCl. The inhibition efficiency increased with increase in the concentration of the inhibitor and was only moderately affected by temperature variations in the range 303‐363 K. The inhibitive action was due to adsorption on the A3 steel and the adsorption process was consistent with the Langmuir isotherm. The free energy of adsorption (ΔG_ads.) was −4.192 kJ/mol. The negative value of ΔG_ads. indicated spontaneous adsorption of the inhibitor occurred on the surface of A3 steel.

Practical implications

Rice bran extract is an effective inhibitor and can be used to protect carbon steel from corrosion in HCl solution.

Originality/value

The rice bran extracts are an effective green inhibitor and can be widely used in the pickling of metals.

Citation

Dong, L., Yuanhua, L., Yigang, D. and Dezhi, Z. (2011), "Corrosion inhibition of carbon steel in hydrochloric acid solution by rice bran extracts", Anti-Corrosion Methods and Materials, Vol. 58 No. 4, pp. 205-210. https://doi.org/10.1108/00035591111148920