Anti-Corrosion and Computational Study of Mild Steel in Hydrochloric Acid Using Calcium Gluconate as Inhibitor

摘要

The inhibiting effect of calcium gluconate on the electrochemical behaviour of mild steel in dilute hydrochloric acid was evaluated through weight loss technique, open circuit measurement and potentiodynamic polarization tests at specific concentration of the organic compound. Corrosion rate were calculated from the potentiodynamic polarization measurements. The surface morphology of the mild steel was examined using scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). A molecular dynamics simulations with Forcite quench molecular dynamics was used for the computational study of the system. The results revealed that corrosion rate of the mild steel decreased with addition of the inhibitor. Equally, increasing inhibitor concentration led to significant reduction in the corrosion rate of the mild steel with inhibitor efficiency values above 80 %. The potentiodynamic polarization data showed that calcium gluconate acts as mixed type corrosion inhibitor. The inhibition occurs by adsorption of films on the metal surface. The adsorption of calcium gluconate has been found to obey Langmuir adsorption isotherm at all the concentrations of calcium gluconate.