Corrosion Inhibition of Mild Steel in 1 mol L-1 HCl Using Gum Exudates of Azadirachta indica

Abstract

The ability of gum exudates of Azadirachta indica (GAI) to inhibit corrosion on mild steel in 1 mol L-1 HCl has been studied using mass loss, polarization, and impedence measurements. The effect of temperature (303-323 K) and immersion time of 1, 2, 4, 6, and 12 hours on corrosion behavior of mild steel was examined. Gum exudates decrease the corrosion rate up to a concentration of 80 ppm and at 323 K temperature. GAI adsorb chemically onto the surface of the mild steel while it obeys Langmuir adsorption isotherms. Polarization studies show GAI as mixed mode inhibitor. Surface studies ascertain that a shielding layer was formed on the mild steel surface.