Corrosion Inhibition of Pipeline Steel in 0.5 M HCL Using Cotyledon of Chrysophyllum cainito

Abstract

The corrosion inhibition characteristics of Chrysophyllum cainto cotyledon aqueous extract was studied for the corrosion of pipeline steel in 0.5 M HCl using gravimetric technique. The corrosion surface morphology and corrosion surface film were studied using Scanning electron microscope and Fourier transform infrared spectroscopy respectively. The results obtained showed Chrysophyllum cainto aqueous extract as a good corrosion inhibitors of pipeline steel corrosion in acidic environment, recording an average corrosion inhibition efficiency above 90% at 303 K. The Scanning electron micrograph showed a smoother corrosion surface morphology in the presence of the extract while the Fourier transform infrared spectroscopic data showed the corrosion inhibition mechanism to be through adsorption.

CORROSION INHIBITION CHARACTERISTICS OF Vernonia Amygdalina STEM EXTRACTS ON MILD STEEL IN ACIDIC MEDIUM

“…Figure 1.0 shows the weight loss pattern increased directly with time and temperature from 303 K to 333 K as the lines are near straight line. This has been previously reported in literature [13]. The slight deviation from linearity maybe attributed to imperfection of the method and the impaction of corrosion surface.…”

“…The fact that Ea values in the presence of the extract are higher than in the absence of Vernonia amygdalina stem extract revealing that test extract increased the energy barrier for the continued oxidation of mild steel in 1.0 M HCl, implying increased inhibition of mild steel corrosion with increase in concentration of Vernonia amygdalina stem extract. This also suggests that the anti-oxidation process is exothermic [13].…”

“…As the concentrations of extract increased, the rate of mild steel dissolution in the acid decreases they by decreasing the corrosion rate values. This might be as a result of an increase in the distribution of the probable adsorbed extract molecules on the steel surface, which probably resulted in the formation of a better coat film between the metal's surface and the acidic solution, decreasing the acidic effect [10,12,13]. It can deduce that Vernonia amygdalina stem extract has improved efficiency in lowering mild steel corrosion [19][20].…”

“…Adsorption isotherms provides foundational understanding of the inhibitor molecules -mild steel surface interaction [5,13]. The results of Vernonia amygdalina stem extract action on mild steel in 1.0 M HCl were applied to a variety of adsorption isotherms.…”