通用气相防锈薄膜的制备及其缓蚀机理的研究

发布时间：2018-07-03 14:00

  本文选题：气相缓蚀剂 + 复配　； 参考：《西安理工大学》2017年硕士论文

【摘要】：本文针对金属在大气中的腐蚀,制备通用型气相防锈薄膜,并研究气相缓蚀剂在液膜下对金属的缓蚀机理。首先采用电化学工作站(Tafel极化曲线)和交流阻抗仪(EIS)进行电化学试验,对气相缓蚀剂进行复配并研究其在NaCl溶液中对Q235钢和黄铜的缓蚀效率,得到最佳配方的气相缓蚀剂。其次将气相缓蚀剂的最佳配方用涂覆法制成气相防锈薄膜,在模拟高温高湿环境的恒温恒湿箱内进行湿热试验,计算出其缓蚀率。表征金属电极表面,研究气相缓蚀剂的缓蚀机理,以及温度和Cl-浓度对气相缓蚀剂的影响。电化学试验结果表明,当钼酸铵、三乙醇胺、苯甲酸钠与硫酸锌四元复配气相缓蚀剂的配比浓度为2g/L: 8g/L: 10g/L: 4g/L时,气相缓蚀剂对Q235钢缓蚀率达到90.78 %,对黄铜缓蚀率达到87.65%,四元复配气相缓蚀剂在NaCl溶液中(质量分数3.5%)对Q235钢和黄铜的腐蚀速率明显降低,有很好的缓蚀效果。湿热试验与电化学实验结果一致,四元复配气相缓蚀剂对Q235钢的缓蚀率达到87.63%,对黄铜的缓蚀率达到86.56%,缓蚀效果较好。四元复配气相缓蚀剂配方中的各组分之间存在协同效应,较单一气相缓蚀剂的缓蚀效果有了显著的提高。金属表征结果表明,对于Q235钢,复配气相缓蚀剂是混合型缓蚀剂,抑制碳钢阴阳极的电化学反应,复配气相缓蚀剂的N、O原子上的孤对电子与Fe的d轨道配位成键,在Q235钢表面形成吸附膜,从能谱图中可以看出气相缓蚀剂会阻止Q235钢表面形成Fe2O3等腐蚀产物,吸附膜具有一定的疏水性,缓蚀率随着温度升高略微增大,而Cl-浓度越低,缓蚀率越大。对于黄铜,复配气相缓蚀剂主要抑制阳极腐蚀反应具有缓蚀效果。在黄铜表面,复配气相缓蚀剂挥发出的N原子与Cu相互作用并形成一层很薄的保护膜,从能谱图中可以看出气相缓蚀剂会阻止黄铜表面形成Cu(I),Cu2O等腐蚀产物,保护膜具有一定的疏水性。当温度在50～60℃时,气相缓蚀剂对黄铜的缓蚀率达到最大,缓蚀率随Cl-浓度的降低而增高。
[Abstract]:In this paper, a general gas phase anticorrosive film is prepared for the corrosion of metals in the atmosphere, and the corrosion inhibition mechanism of the gas phase corrosion inhibitor on the metal under the liquid film is studied. Firstly, electrochemical experiments were carried out by using an electrochemical workstation (Tafel polarization curve) and an alternating current impedance meter (EIS). The gas phase corrosion inhibitor was compounded and its corrosion inhibition efficiency to Q235 steel and brass in NaCl solution was studied. The optimum formulation of gas phase inhibitor was obtained. Secondly, the best formulation of gas phase corrosion inhibitor was coated to form gas phase antirust film, and the corrosion inhibition rate was calculated in a constant temperature and humidity chamber under simulated high temperature and high humidity environment. The corrosion inhibition mechanism of gas phase inhibitor and the effect of temperature and Cl- concentration on gas phase corrosion inhibitor were studied by characterizing the surface of metal electrode. The electrochemical test results show that when the concentration of the compound gas phase corrosion inhibitor of ammonium molybdate, triethanolamine, sodium benzoate and zinc sulfate is 2 g / L: 8 g / L: 10 g / L: 4 g / L, The corrosion rate of Q235 steel and brass was 90.78 for gas phase inhibitor and 87.65 for brass respectively. The corrosion rate of Q235 steel and brass was obviously decreased by four-element gas phase inhibitor in NaCl solution (3.5% by mass fraction), and the corrosion rate of Q235 steel and brass was very good. The results of hygrothermal test and electrochemical experiment were consistent. The corrosion inhibition rate of Q235 steel was 87.63 for four-component gas phase corrosion inhibitor and 86.566.56 for brass. The corrosion inhibition effect was better. There is a synergistic effect among the components in the composition of the four-component compound gas phase corrosion inhibitor, which is significantly improved than that of the single gas phase inhibitor. The results of metal characterization show that for Q235 steel, the compound gas phase inhibitor is a mixed corrosion inhibitor, which inhibits the electrochemical reaction of the cathode and anode of carbon steel, and the coordination bond between the lone pair electrons on the N2O atom of the compound gas phase inhibitor and the d orbital of Fe. The adsorption film was formed on the surface of Q235 steel. The gas phase corrosion inhibitor can prevent the formation of Fe _ 2O _ 3 and other corrosion products on the surface of Q235 steel. The adsorption film has a certain hydrophobicity, and the corrosion inhibition rate increases slightly with the increase of temperature, while the concentration of Cl- is lower. The higher the corrosion inhibition rate is. For brass, the compound gas-phase inhibitor mainly inhibits the anodic corrosion reaction. On the surface of brass, the N atoms volatilized by the compound gas phase inhibitor interact with Cu and form a thin protective film. It can be seen from the energy spectrum that the corrosion products such as Cu (I) and Cu _ 2O can be prevented from forming on the brass surface by the gas phase corrosion inhibitor. The protective film has a certain hydrophobicity. When the temperature is 50 ~ 60 鈩，

本文编号：2093893