Gravimetric and quantitative surface morphological studies of Mangifera indica peel extract as a corrosion inhibitor for mild steel in 1 M HCl solution

Mangifera indica peel extract was evaluated as a corrosion inhibitor for mild steel in 1 M HCl using gravimetric and depth of attack techniques. The extract was characterized using gas chromatography–mass spectrometry and the corrosion film solution by Fourier transform infrared spectroscopy. Scanning electron microscopy, arithmetic mean deviation of the surface profile ( R a ), and the maximum height of irregularities ( R z ) were used to characterize mild steel coupon surfaces. Effects of temperature, concentration, and time on the corrosion rate of the coupon with and without M. indica peel extract were evaluated. The adsorption of this inhibitor was found to obey the Freundlich model, and thermodynamic parameters were Δ G ads o (−8.39 kJ/mol), ∆ H a o (16.21 kJ/mol), and ∆ S a o (−70.41 J/mol·K). Maximum inhibition efficiencies were 95.75% and 95.76% using weight loss and depth of attack methods, respectively.