低比例甲醇汽油对金属的腐蚀研究

目的减轻甲醇汽油的腐蚀性。方法以汽车油路系统常用的紫铜、黄铜、钢、铁、铝等金属材质为研究对象,采用金属试片的腐蚀度和颜色变化相结合的方法,分析判断甲醇汽油的腐蚀性,通过考察不同金属试片在不同含量甲醇汽油、含水甲醇汽油以及添加缓蚀剂甲醇汽油中的腐蚀情况,分析甲醇汽油腐蚀的主要原因,并根据缓蚀机理筛选缓蚀剂。结果低比例甲醇汽油对不同金属材质都有明显的腐蚀作用,与93#汽油相比,加入5%(体积分数)的甲醇就能使紫铜、黄铜、钢、铝的腐蚀度增加一倍以上。少量水分可加剧甲醇汽油的腐蚀,但当水含量达到一定程度时,腐蚀度减小。缓蚀剂B对铜系金属材质的腐蚀有较好的抑制作用,缓蚀剂C对铁片腐蚀有较好的抑制作用,复配缓蚀剂H对所选金属材质都有良好的缓蚀效果,可使紫铜、黄铜、铁和铝的缓蚀率分别减小82.1%、81.5%、85.3%和89.5%。结论复配的缓蚀剂能够有效地减缓甲醇汽油对金属的腐蚀。

Corrosion of Low Proportional Methanol Gasoline on Metal

Objective In order to mitigate the corrosion of methanol gasoline. Methods Commonly used metal materials such as copper, brass, iron, steel and aluminum in the automotive oil system were studied as the objects. A method combining degree of metal corrosion and color change was developed to determine corrosion performance of methanol gasoline. The corrosion effects of metal slice immersed in methanol gasoline with different contents, water-added methanol gasoline and inhibitor-added methanol gasoline were investigated. Main reasons for corrosion in methanol gasoline were analyzed. Corrosion inhibitor was screened according to corrosion mechanism. Results Low proportional methanol gasoline had obvious corrosion effect on all kinds of metal materials. Compared with 93# gasoline, addition of 5% methanol would double the degree of corrosion for copper, brass, iron, steel and aluminum. Adding small amounts of water would exacerbate corrosion of methanol gasoline. But when the water content reached a certain level, the degree of corrosion became less. Inhibitor B had a good corrosion inhibition effect on copper-based metal material, while inhibitor C had a good corrosion inhibition effect on iron-based metal material. Combined inhibitor H had a good corrosion inhibition effect on all selected metal materials, which could reduce the corrosion rates of copper, brass, iron and aluminum by 82.1%, 81.5%, 85.3% and 89.5% respectively. Conclusion Combined inhibitor can effectively reduce the corrosion of methanol gasoline on metal materials.