目的 了解在 HCl 介质中,三聚氰胺对碳钢的缓蚀作用和缓蚀机理。 方法 在 1 mol/ L HCl 溶液中添加不同浓度的三聚氰胺,测试碳钢在溶液中的动电位极化曲线和电化学阻抗谱,获得电化学参数和缓蚀效率。 再结合量子化学计算结果,分析其缓蚀机理。 结果 针对碳钢在 1 mol/ L HCl 溶液中的腐蚀,三聚氰胺是一种混合抑制型缓蚀剂,随其浓度的增加,缓蚀效率增大。 三聚氰胺通过分子中 Mulliken电荷相对较负的氮原子吸附在碳钢表面起到缓蚀作用,吸附过程为自发过程,以物理吸附为主,且符合Langmuir 吸附等温方程。 结论 在 HCl 介质中,三聚氰胺对碳钢具有一定的缓蚀作用。

Objective To investigate the corrosion inhibition of carbon steel in HCl medium by melamine and the mechanism. Methods The electrochemical parameters and inhibitive efficiencies were obtained by measuring the potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) for carbon steel in the solution containing different concentrations of melamine, and then combined with the result of quantum chemical calculations, the inhibition mechanism of melamine was discussed and analyzed. Results Melamine was a mixed-type inhibitor for the corrosion of carbon steel in 1 mol/ L HCl solution, and its inhibitive efficiency increased with increasing inhibitor concentration. The inhibition effect of melamine was produced by the adsorption of melamine molecules onto the carbon steel surface through nitrogen atoms, the Mulliken charges of which were relatively more negative. The adsorption process was a spontaneous process, mainly physical adsorption, and obeyed the Langmuir isotherm equation. Conclusion Melamine could inhibit the corrosion of carbon steel in HCl medium.