Experimental and Theoretical Study of Corrosion Behaviour of Maraging Steel in 1 M HCl in Presence of 5-Methyl-4-[(E)-(thiophen-2-ylmethylidene)amino]-4H-1,2,4-triazole-3-thiol

Abstract

The inhibitory action of a synthesized Schiff base (5-methyl-4-[(E)-(thiophen-2-ylmethylidene)amino]-4H-1,2,4-triazole-3-thiol) [MTATT] on the corrosion behaviour of maraging steel in 1 M HCl was investigated by electrochemical techniques like Tafel polarization studies and electrochemical impedance spectroscopy. According to experimental data, inhibition efficiency increased with increase in temperature and concentration of the inhibitor where MTATT acts as a mixed type inhibitor. The mode of inhibitor adsorption on maraging steel follows Langmuir adsorption isotherm. The calculated thermodynamic and activation parameters suggested chemisorption mode of inhibitor adsorption. Scanning electron microscope technology with energy dispersive X-ray spectroscopy (SEM-EDX) studies confirmed the adsorption of inhibitor molecule on the surface of maraging steel. Several global reactivity parameters were calculated using DFT method at B3LYP/6-311++(d,p) basis set. Theoretical calculations are in good concurrence with the experimental results.