The Inhibitive Action of Some Diazole Derivatives on the Corrosion of 304 Stainless Steel in HCl Solution

Abstract

The effect of the addition of some diazole derivatives on the corrosion of stainless steel 304 (SS 304) in hydrochloric acid (HCl) was investigated using such methods as weight loss (WL), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) measurements. The inhibition efficiency (% IE) increases with increasing the inhibitor concentration, but decreases with increasing the temperature. The studied compounds are adsorbed chemically on the SS 304 surface following the Langmuir adsorption isotherm. Potentiodynamic polarization studies showed that those compounds are mixed type inhibitors. The quantum chemical calculation was applied to elucidate the adsorption mode of the inhibitor molecule onto the SS 304 surface. The results obtained from different techniques are in good agreement.