Abstract

The present study is focused on evaluating the corrosion resistance of 1018 carbon steel and the influence of using a corrosion inhibitor in its corrosion behavior. In particular, the corrosion inhibitor prepared in the present study consists in an organic compound of hydroxyethyl-imidazoline derivate based on avocado oil. A mixture of brine-diesel saturated with CO₂ was used as a corrosive medium at 70°C. The electrochemical techniques employed to evaluate the performance of the inhibitor were polarization curves, open circuit potential, linear polarization resistance and electrochemical impedance spectroscopy. The results revealed that a high efficiency was obtained when the inhibitor was added in 25 ppm. This fact was supported by scanning electron microscopy, where a uniform corrosion process was observed with the formation of an iron carbonate film. This film was formed when the inhibitor was added in 5, 10 and 25 ppm. However, when the concentrations used were 50 and 100 ppm, a localized corrosion process was promoted. In the present study, some calculations were performed to determinate the chemical adsorption process energy (\(\Delta G_{{{\text{ads}}}}^{0}~\) = –50.89 kJ/mol) through isotherm adsorption of Langmuir.

中文翻译：

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使用鳄梨油基绿色缓蚀剂评估1018碳钢的缓蚀性能

摘要

本研究的重点是评估1018碳钢的耐腐蚀性以及使用缓蚀剂对其腐蚀行为的影响。特别地，在本研究中制备的腐蚀抑制剂由基于鳄梨油的羟乙基-咪唑啉衍生物的有机化合物组成。饱和CO ₂的盐水柴油混合物在70℃下用作腐蚀性介质。用于评估抑制剂性能的电化学技术是极化曲线，开路电势，线性极化电阻和电化学阻抗谱。结果表明，当以25ppm添加抑制剂时，获得了高效率。扫描电子显微镜证实了这一事实，其中观察到均匀的腐蚀过程并形成了碳酸铁膜。当以5、10和25ppm添加抑制剂时形成该膜。但是，当所用浓度为50和100 ppm时，会促进局部腐蚀过程。在本研究中，进行了一些计算以确定化学吸附过程的能量（\（\ Delta G _ {{{\ text {ads}}}} ^ {0}〜\ = –50.89 kJ / mol）通过Langmuir的等温吸附。