Abstract
The corrosion and corrosion inhibition of Pb and Pb-In alloys in HCl solution, were investigated. The study was performed in the absence and presence of the phytic acid (PA) inhibitor using potentiodynamic polarization and electrochemical impedance spectroscopy measurements, and complementary by scanning electron microscope (SEM) and X-ray spectroscopy analysis (EDX) investigations. The obtained outcomes showed that the PA is efficient corrosion inhibitor for Pb and Pb-In alloys in HCl solution. The inhibition efficiency (%) for Pb and its investigated alloys increases with an increase in the concentration of PA and decreases with increasing temperature. The maximum inhibition efficiency (approximate to 80%) was obtained at 1x10(-3)M of the PA inhibitor. Langmuir adsorption isotherm fits well the experimental data. SEM/EDX observations of the electrode surface confirmed the existence of an adsorbed film. One can conclude that the increase in activation energy with increasing additive concentration, in addition to the decrease in % in the presence of inhibitor with temperature, is suggestive of physical adsorption of the inhibitor molecules on the surface of Pb and Pb-0.5In alloy.