Acid cleaning of steel using Arghel echo friendly corrosion inhibitor

Abstract

Acid cleaning of mild steel dissolution by 1M sulfuric acid/10 % methanol (test solution) in presence of Arghel herb extract as green inhibitor were monitored by potentiodynamic and electrochemical impedance techniques in the temperature range 30-60°C. At all temperature, the corrosion rate decreased with increasing inhibitor concentration. Potentiodynamic polarization measurements indicated mat the inhibitor has strong effect on the corrosion behavior of the steel and behave as mixed type inhibitor. Impedance results indicate that the charge transfer controls the dissolution mechanism of steel across the phase boundary in the absence and the presence of the inhibitor. The inhibition efficiency obtained from various employed methods is in good agreement. Thermodynamic and activation parameters obtained from this study indicated that the presence of the Arghel increases the activation energy, and the adsorption process of the inhibitor on the metal surface is spontaneous. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.