The incidence of chromium-rich corrosion products on the efficiency of an imidazoline-based inhibitor used for CO2 corrosion prevention

Inhibition of CO2 corrosion of carbon steel with 1% Cr

“…The electrochemical data were analyzed using Gamry Ò software and Zview 2 Ò software. Corrosion rates (CR) were calculated with polarization resistance (Rp) values obtained from LPR measurements, using the SterneGeary equation with a proportionality factor B ¼ 0.022 V [6]. To characterize the inhibited surfaces, a scanning electron microscope JEOL Ò JSM-6390 with EDS was used.…”

“…%. The nature of the chromium-rich corrosion products found in the corroded surfaces of 1Cr steel is discussed elsewhere [6]. The surface of samples inhibited at 2500 rpm ( Fig.…”

“…However, other authors tested various inhibitors on carbon steels with and without 0.5% Cr and found that all the employed compounds achieved acceptable efficiencies on both steels [5]. Recently, it has been shown that the addition of 1% Cr in carbon steel has a negative effect on the adsorption of a commercial imidazoline-based inhibitor, leading to localized corrosion, more or less severe, depending on steel microstructure and pre-corrosion period [6]. It needs to be noted that the latter set of results were obtained under low flow rate (glass cells with low speed magnetic stirring), thus experimentation under more representative hydrodynamic conditions would be valuable.…”

“…This improvement is based on the formation of a stable protective chromium containing oxide film [17,18]. Nevertheless, some researchers have found an adverse behaviour particularly for Cr contents from 0.5 to 1.5% [5,6,12,16,19].…”

Inhibition of carbon steel corrosion by imidazoline in carbon dioxide saturated oilfield brine solution

“…Testing of imidazoline based corrosion inhibitors in the protection of carbon steel immersed in the carbon dioxide saturated solution with chlorides (or oilfield brine), performed by electrochemical methods, have been described in many papers [22][23][24][25][26][27][28]. In this paper electrochemical impedance spectroscopy (EIS) measurements, linear polarization measurements and anodic and cathodic polarization measurements (Tafel extrapolation method) were done in order to test imidazoline based corrosion inhibitor for the protection of carbon steel in carbon dioxide saturated oilfield brine solution.…”