The inhibition of corrosion of steel by 3,8-bis(4-chlorophenyl)-2,6-dioxo-2,3,4,6-tetrahydro-1H-pyrido[1,2- b][1,2 ,4]triazine-7,9-dicarbonitrile (CTPTC) in hydrochloric acid has been investigated at various temperatures using electrochemical techniques (impedance spectroscopy (EIS), potentiodynamic polarization). Inhibition efficiency (E%) increased with HCl concentration. Adsorption of inhibitor on the steel surface in 1.0 M HCl follows the Langmuir isotherm model. EIS measurements showed that the dissolution process of steel occurred under activation control. Polarization curves indicated that inhibitor tested acted as mixed inhibitor. The temperature effect on the corrosion behavior of steel in 1.0 M HCl without and with the inhibitor was studied in the temperature range from 303 to 333K. The adsorption free energy and activation parameters for the steel dissolution reaction in the presence of triazine derivative were determined.
