甲基紫与溴离子在硫酸溶液中对冷轧钢的协同缓蚀研究.doc

甲基紫与溴离子在硫酸溶液中对冷轧钢的协同缓蚀研究


目录
摘要 1
ABSTRACT 2
1 绪论 3
1.1 引言 3
1.2缓蚀剂 3
1.3 缓蚀剂的分类 4
1.4缓蚀剂的特点 5
1.5缓蚀剂性能的研究方法 5
2 实验方法 6
2.1化学试剂及仪器 6
2.2实验溶液配制 6
2.3实验方法 6
3结果及讨论 7
3.1失重法 7
3.2电化学 18
3.2.1 极化曲线 18
3.2.2阻抗 20
3.3缓蚀机理分析 23
4 结论 23
参考文献 24
致谢 26
 
摘要：在现代经济建设中，金属材料有着举足轻重的作用，而钢铁作为一种常用的金属材料更是必不可少，然而目前钢铁的腐蚀越来越严重，尤其在酸性环境下。因此，本文研究了在30℃、35℃、40℃、45℃下，甲基紫以及甲基紫与0.01 mol/L Brˉ 共同存于0.5 mol/L硫酸溶液中对冷轧钢的缓蚀行为。结果表明单独甲基紫对冷轧钢的缓蚀率最高为50%左右，但是在与Brˉ复配后，缓蚀率最高能达到90%左右。同时还获得了ΔG，ΔH，ΔS及K等相关热力学常数，结果表明缓蚀剂吸附是自发进行的化学吸附；单独甲基紫存在时吸附过程是在吸热情况下进行的，而甲基紫与0.01 mol/L Brˉ复配后为放热过程；反应活化能及指前因子也计算得到，单独甲基紫及与Brˉ复配后在硫酸体系中对冷轧钢表面的吸附均符合 Langmuir 吸附模型。同时用电化学法研究了在30℃时甲基紫以及甲基紫与0.01 mol/L Brˉ 配比后对冷轧钢的缓蚀行为。结果表明，在0.5mol/L H2SO4中，甲基紫及甲基紫与0.01mol/LBrˉ复配后均属于以抑制阴极为主的混合型缓蚀剂。电化学的结果与失重法的表现出一致的规律性。

关键词：缓蚀、甲基紫、硫酸、冷轧钢、溴离子。
 
Synergistic Inhibition of Methyl Violet with Brˉ for the Corrosion of Cold Rolled Steel in H2SO4 Solution

Abstract: In the modern economic construction, metal materials have a pivotal function, and it is essential that steel taken a commonly used as metal material. However, the corrosion of steel becomes increasingly serious, especially under sour environment. Therefore, in these experiments weight loss method was used to study inhibition behaviors of the methyl violet and methyl violet with 0.01 mol/L Br- on cold-rolled steel in 0.5mol/L sulfuric acid solution at separately 30 ℃, 35 ℃, 40 ℃, 45 ℃.  The inhibition efficiency of separate the methyl violet is over 50%, yet after Brˉ ion added, the highest inhibition efficiency can reach at around 90%. Simultaneously the ΔG, ΔH, ΔS, and K have been obtained.  The ΔG values are negative and it”s absolute values are than 40 kJ/mol, which means the adsorption process of methyl violet is spontaneous chemical adsorption. In the presence of separate methyl violet, the ΔH value is positive, which presents the adsorption process is an endothermic process；The ΔH is negative after methyl violet and 0.01 mol/L Brˉ ion added, which shows the adsorption process is an exothermic process; Then the active energy and refers to the factor have been calculated, the system of separately methyl violet and methyl violet with Brˉ ion were consistent with Langmuir adsorption isotherm on the cold rolled steel in sulfuric acid. At the same time, the inhibition behaviors of methyl violet and methyl violet with 0.01 mol/ L Br- have also been studied by electrochemical methods on cold rolled steel in H2SO4 Solution at 30C. The results indicate that in 0.5mol/L H2SO4 solution the methyl violet and methyl violet with 0.01mol/L Brˉ ion is a mixed type inhibitor mainly in cathode inhibition. the Electrochemical results are similar with the outcome of weight loss.

Keywords:  corrosion inhibition, methyl violet, sulfuric acid, cold rolled steel, Brˉ