曼尼希碱缓蚀剂在盐酸中对N80钢缓蚀性能

目的制备一种新型曼尼希碱缓蚀剂并研究其性能。方法利用失重法研究缓蚀剂缓蚀效率与缓蚀剂的质量浓度、盐酸质量分数、腐蚀温度、腐蚀时间的关系,确定缓蚀剂的吸附曲线。通过动电位极化曲线法和交流阻抗法研究缓蚀剂的综合性质。利用扫描电镜观察腐蚀前后N80钢片的表面形态。结果缓蚀剂缓蚀效率随缓蚀剂添加量的增大而增大,随测试温度的升高而下降,随盐酸质量分数的升高先增大后减小,随腐蚀时间的延长先增大后减小。60℃时,在质量分数为15%盐酸中浸入4 h、缓蚀剂添加量在1.0 g/L的条件下,缓蚀剂缓蚀效率为99.18%,腐蚀反应的活化能由56.34 k J/mol提高到了86.54 k J/mol。缓蚀剂在N80钢表面符合Langmiur吸附模型,吸附吉布斯自由能为-29.94 k J/mol。极化实验结果显示该缓蚀剂为以阴极抑制为主的混合型缓蚀剂。阻抗谱图显示添加缓蚀剂后,阻抗明显增大。扫描电镜结果显示缓蚀剂有效抑制了盐酸对N80钢片的腐蚀。结论所制备的缓蚀剂在质量分数为15%的盐酸中对N80钢片有良好的缓蚀效果。

Mannich Base as Corrosion Inhibitor for N80 Steel in HCl Solution

The work aims to prepare a novel Mannich base inhibitor and study its performance. The relationship among corrosion efficiency of corrosion inhibitor and mass concentration of corrosion inhibitor, mass fraction of hydrochloric acid, corrosion temperature and corrosion duration was studied by weight loss method. Adsorption curve of the corrosion inhibitor was verified. Comprehensive properties of the corrosion inhibitor were studied by electrochemical impedance spectroscopy and scanning electron microscopy. The surface morphology of N80 sheet steel was observed by SEM. Efficiency of the inhibitor in-creased as addition of the inhibitor increased, decreased as temperature increased, increased firstly and then decreased as the HCl concentration and corrosion time increased. At 60℃, the efficiency of corrosion inhibitor was 99.18 % provided that it was immersed in 15% HCl for 4 h and 1.0 g/L of inhibitor was added. The activation energy of corrosion reaction increased from 56.34 kJ/mol to 86.54 kJ/mol. The adsorption of inhibitor on N80 steel surface followed the Langmuir adsorption isotherm model.?29.94 kJ/mol of Gibbs free energy was absorbed. The obtained results of polarization experiment indicated that the in-hibitor acted as a mixed-type inhibitor mainly featuring in cathodal depression. The SEM observations showed that the corrosion inhibitor can inhibit corrosion of N80 sheet steel effectively. The inhibitor prepared provides good corrosion inhibition effects for N80 sheet steel in 15% HCl solution.