Title of article :
Investigation of 4-Amino-3-Hydrazino-5-Mercapto- 1,2,4-Triazole as Corrosion Inhibitor for C38 Steel in Hydrochloric Acid Medium
Author/Authors :
ZARROK, Hassan Université Ibn Tofail - Faculté des Sciences - Laboratoire des procèdes de séparation, Morocco , OUDDA, Hassan Université Ibn Tofail - Faculté des Sciences - Laboratoire des procèdes de séparation, Morocco , ZARROUK, Abdelkader Université Mohammed Premier - Faculté des Sciences - LCAE-URAC18, Morocco , SALGHI, Rachid Ecole Supérieure de Technologie d’Agadir - Equipe d’Analyse Agroalimentaire, Morocco , HAMMOUTI, Belkheir Université Mohammed Premier - Faculté des Sciences - LCAE-URAC18, Morocco , EBN TOUHAMI, Mohamed Université Ibn Tofail - Faculté des Sciences - Laboratoire d électrochimie, de corrosion et d environnement, Morocco , AL-DEYAB, Salem Salem King Saud University - Department of Chemistry, Saudi Arabia
Abstract :
The inhibition effect of 4-Amino-3-hydrazino-5-mercapto-1,2,4-triazole (AHMT) against the corrosion of C38 steel in 1 M HCl solution was studied by weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Inhibition efficiency increased with inhibitor concentration and it attains an efficiency of more than 87% at 10^-2 M at 308K. Polarization curves show that AHMT is a mix-type inhibitor. As the inhibitor concentration increased, the charge transfer resistance of C38 steel increased and double layer capacitance decreased. The adsorption of AHMT molecules on the C38 steel surface obeys Langmuir adsorption isotherm. The adsorption free energy of AHMT on C38 steel (-34.88 kJ / mol) involves two types of interaction, chemisorption and physisorption of the inhibition on the metal surface. The results obtained from the different methods are in good agreement.
Keywords :
Steel , Hydrochloric acid , Triazole , Polarisation curves , Impedance , Langmuir
