Corrosion Inhibition of Novel Prepared Cationic Surfactants for API N80 Carbon Steel Pipelines in Oil Industries

Abstract

The objective of this study is to investigate the corrosion inhibition of API N80 steel pipelines in 1M HCl solution by a synthesized compound (N-(3-(dimethyl octyl ammonio) propyl) palmitamide bromide, subjected to four different modes of measurements. Weight loss (WL) was investigated at five different temperatures: 25–60°C, while potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) were tested at 25°C. The result showed that the synthesized inhibitor was good and its protection efficiency (%η) significantly increased by increasing both the dose and the temperature. The polarization curve revealed that the studied inhibitor acts as mixed-type of inhibitor. Adsorption of the investigated inhibitor led to a reduction in the double layer capacitance and an increase in the charge transfer resistance. The adsorption of this inhibitor was found to obey the Langmuir adsorption model. The thermodynamic parameters were calculated and discussed. A clear correlation was found between corrosion protection efficiency and theoretical parameters obtained using density functional theory.