摘要在酸洗等过程中,不可避免会造成金属材料的腐蚀,向酸洗液中加入缓蚀剂是减缓金属腐蚀最为经济、可行的办法。本文选用1-羟基苯并三氮唑(BTAOH)作为缓蚀剂,研究了其在1 mol/L盐酸溶液中对低碳钢腐蚀行为的影响,并进一步探讨了BTAOH/钼酸钠复合体系对同一试样在相同环境下腐蚀行为的影响。具体研究内容包括以下几个方面:① 利用电化学工作站测量了30 ℃时低碳钢在含有不同浓度BTAOH的盐酸溶液(1 mol/L)中的极化曲线与交流阻抗谱,并计算出了各浓度条件下的腐蚀电流密度、缓释效率和覆盖率;② 考察了BTAOH浓度为200 ppm 时,温度对其在盐酸溶液(1 mol/L)中电化学行为的影响,并根据所测数据拟合的结果得出了加入缓蚀剂前后腐蚀过程的活化能;③ 选取200 ppm BTAOH,研究了不同浓度钼酸钠与BTAOH协同缓释的效果,并利用扫描电镜和原子力显微镜等手段对所观察到的现象进行了进一步的验证。86796
结果表明,30 ℃下BATOH对低碳钢的缓释效率随BATOH浓度的增加而增加;BTAOH浓度为200 ppm 时,其覆盖率随温度的升高而下降,说明BTAOH在本实验条件下对低碳钢表面的吸附为物理吸附;同时根据温度对BATOH在低碳钢表面吸附行为的影响,本文计算得到吸附表观活化能Ea为75。50 ,同时得出、、分别为-26。76、-26。58、0。59;在协同缓释作用的研究中,随钼酸钠浓度的提高,复合体系缓蚀性能出现先升高后降低的现象,并在5:2(钼酸钠比BTAOH)表现出最高缓蚀效率和最大覆盖率;不同钼酸钠/BTAOH条件下低碳钢表面腐蚀形貌的结果证实了上述电化学测试的结果。
毕业论文关键词:1-羟基苯并三氮唑;钼酸钠;缓蚀剂;吸附;协同作用
Abstract In order to forbid the corrosion of metallic materials in the acid pickling process, the addition of corrosion inhibitor is considered as the one of the most economical and feasible approaches。 In this thesis, the effects of 1-hydroxy benzotriazole (BTAOH) on corrosion behavior of mild steel in HCL solution (1 mol/L) had been investigated in details, as well as the synergistic inhibition effect of sodium molybdate/BTAOH composite in the similar situation。 The contents of this thesis including following aspects:
First, we had measured polarization and EIS curves of mild steel in the 1 M HCL with different BTAOH concentrations at 30℃ by using an electrochemical workstation, and we also calculated corrosion current density at each concentrations, as well as the inhibition efficiency and coverage ratio。 Second, the apparent activation energy (Ea) had been determined by investigating the effects of temperature on the corrosion behavior of mild steel in 1 M HCL at the consist BTAOH concentration 200 ppm。 Third, by changing the concentration of sodium molybdate, synergistic inhibition effect of sodium molybdate/BTAOH composite also had been studied, and the the interesting phenomena had been verificated by the relative scanning electron microscopy and atomic force microscopy results。
The results showed that, the coverage ratio increases with the increasing of the BTAOH concentration at the temperature 30 ℃。 With fixed 200 ppm BTAOH, coverage ratio decreases with the increasing of temperature, which means the BTAOH molecules are physical adsorpted to the mild steel surface in this experiment。 Meanwhile, according to the effects of temperature on the adsorption behavior on the BTAOH, we have calculated the Ea, , and as 75。50, -26。76, -26。58, 0。59 kJ/mol respectively。 In the synergistic inhibition effect of sodium molybdate/BTAOH composite research, we found a non-monotonic sodium molybdate concentration dependence of inhibition efficiency of the composite, and when the sodium molybdate/BTAOH ration is 5:2, it appears the highest inhibition efficiency。