Electrochemical Behavior of N1-(3-Methylphenyl)Piperidine-1,4-Dicarboxamide as a Corrosion Inhibitor for Soft-Cast Steel Carbon Steel in 1 M HCl

The electrochemical corrosion behavior of N1-(3-methylphenyl)piperidine-1,4-dicarboxamide soft-cast steel in 1 M HCl was investigated at the temperature range of 303–333 K. The experiments used for this investigation are electrochemical potentiodynamic polarization and impedance spectroscopic measurements. The results found from this investigation suggested that N1-(3-methylphenyl)piperidine-1,4-dicarboxamide acts as a good corrosion inhibitor for soft-cast steel in 1 M HCl. We found 94% of inhibition efficiency at optimized inhibitor concentrations of 100 ppm. The inhibition efficiency of inhibitor increases with the increasing inhibitor concentration as well as the temperature of corrosive media. The polarization measurement suggested that the N1-(3-methylphenyl)piperidine-1,4-dicarboxamide inhibits the corrosion of soft-cast steel by the adsorption process and it acts as a mixed-type inhibitor. The adsorption of the inhibitor compound is determined, which obeys the Freundlich’s adsorption isotherm model. Surface investigation of surfaces of soft-cast steel was examined by scanning electron microscopic measurements.