Anti-corrosion performance of dehydroacetic acid thiosemicarbazone on XC38 carbon steel in an acidic medium

Abstract

Dehydroacetic acid thiosemicarbazone (DHATSC) was tested for its ability to suppress corrosion on mild steel XC38 (MS XC38) by measuring its effects by electrochemical impedance spectroscopy (EIS), weight loss (WL), and potentiodynamic polarization (PDP). Using weight loss tests and potentiodynamic polarization, the corrosion inhibiting efficiency (IE) of DHATSC for MS XC38 in 1.0 M HCl solution was calculated. The data showed that DHATSC was highly inhibitory, with increasing effectiveness as the inhibitor concentration increased. In 1 M HCl, the PDP curves showed that DHATSC was a mixed-type inhibitor. In addition to the EIS findings, the adsorption of DHATSC was also validated by analyzing the charge transfer resistance (Rct) values of the MS XC38 surface. At room temperature, the most outstanding corrosion inhibition efficiency as determined by weight loss was 78%; however, the PDP method obtained 94% at a concentration of 200 ppm. With a standard free energy (Gads) of −6.90 KJ.mol-1 for the adsorption stage, the Langmuir isotherm offered the most accurate description of DHATSC adsorption. The inhibitor has a nanocrystalline structure, measured by X-ray diffraction (XRD), with a mean crystallite size (D) of 56.11 nm. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses verified the mild steel's surface analysis. The theoretical calculations generally agreed with the experimental findings to a high degree.

Keywords

• Mild Steel
• Electrochemical tests
• Corrosion inhibition
• Schiff base DHATSC
• Inhibition efficiency
• DFT