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.