Corrosion Protection of Mild Steel in 1 M HCL Solution Using the Triazole Derivative

Abstract

Mild steel (MS) is a cost-effective engineering material known for its versatility and strength. The mild steel has good ductility and weldability, making it suitable for various applications like automobile, and aerospace industries. We investigated the inhibition performance of 5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol (PyTT) as an inhibitor for mild steel in 1 M hydrochloric acid at varying temperatures. The study employed conventional weight-loss along with potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS). As the concentration of PyTT increased, the inhibition efficiency increased; however, it declined with higher temperatures. PyTT confirmed mixed inhibition behavior and adhered to the Langmuir isotherm. The highest inhibitory efficiency observed was 85.50% at 100 ppm and 303 K. Notably, there was strong correlation between the results obtained from PP and EIS. A probable mechanism for preventing the MS corrosion was suggested. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) were used to examine the morphological and roughness investigations of MS with, and without inhibitor (PyTT). The SEM results showed a significant adsorption between MS-PyTT inhibitor. The structure of PyTT was correlated with its ability to suppress the corrosion using Monte Carlo simulation (MCS) and density function theory (DFT) techniques. The results of this investigation showed good agreement between experimental and theoretical data. The activation energy and thermodynamic parameters were calculated, and the findings were evaluated.