Antibacterial drugs as inhibitors for the corrosion of stainless steel type 304 in HCl solution

The effect of three antibacterial drugs (3-thiazinonyl-bicyclo [4.2.0] octene-carboxylate derivatives) on the corrosion behavior of stainless steel type 304 in 1.0 M HCl solution has been investigated using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency increased with increase in inhibitor concentration but decreased with increase in temperature. The thermodynamic functions of corrosion and adsorption processes were evaluated. The potentiodynamic polarization measurements indicated that the inhibitors are of mixed type. The adsorption of these inhibitors was found to obey Langmuir’s adsorption isotherm. Synergism between iodide ion and inhibitors was proposed. The inhibitive action was satisfactory explained by using both thermodynamic and kinetic models. The results obtained from the three different techniques were in good agreement.