热海水中高效铝基牺牲阳极的研制

IOCAS-IR > 海洋环流与波动重点实验室

	热海水中高效铝基牺牲阳极的研制
	刘学庆
学位类型	博士
	2001
学位授予单位	中国科学院海洋研究所
学位授予地点	中国科学院海洋研究所
学位专业	海洋化学
关键词	铝基牺牲阳极灰箱分析关联度
摘要	随着社会的高速发展和人口急剧增加，淡水资源危机问题已引起世界各国的普遍关注。我国属于贫水国家，部分地区淡水资源严重缺乏，沿海城市尤为严重。据统计，城市用水中约80%为工业用水，工业用水中约80%为工业泠却用水。针对这种情况，人们试图在工业生产中用海水代替淡水做工业冷却水，以节约淡水资源。然而，在海水冷却系统中，换热器的出口及其后续部位的钢铁设施由于海水温度较高，一般50℃左右，有的还大于55℃，腐蚀特别严重。因此，解决该部位的腐蚀防护问题是直接利用海水代替淡水做工业冷却用水中不可缺少的一环。牺牲阳极法是防止海水中钢铁设备腐蚀的一种行之有效的方法，但是常用的几种牺牲阳极在该温度下电流效率明显降低。因此研究一种能在较高温度下（50℃左右）使用的新型高效牺牲阳极是一项很有意义的工作。这也是本课题的研究目的。本文自制了28种Al-Zn-In系牺牲阳极，按国标GB 4950-85的要求测试了开路电位、工作电位；计算了电流效率；观察了腐蚀产物脱落情况及腐蚀均匀性，结果表明腐蚀均匀性是影响高温铝基牺牲阳极性能的最主要因素。进一步测试了三种试样的恒电流阳极极化曲线，结果表明，牺牲阳极阳极极化时，在开始的0.2（或0.4）mA/cm~2较小的阳极极化电流下，极化程度最大，随后尽管增加阳极极化电流，极化电位基本维持稳定；随着温度的升高，极化程度也越来越大，说明温度升高，会使牺牲阳极的工作电位正移，不利于提供足够的保护电位。用灰箱分析法研究了各元素与工作电位、电流效率、腐蚀产物均匀性的关联性。结果表明，对提高牺牲阳极的腐蚀均匀性来说，在20℃、40℃时，Mg是合适的添加元素；在60℃时，Ga是合适的添加元素。根据灰箱分析结果，建议牺牲阳极配方：20℃、40℃时，为Al-Zn-In-Ga-Mg；60℃时为Al-Zn-In-Ga。
其他摘要	With the development of society and the increase of its population, the absence of fresh water has aroused the whole world's attention. China belongs to the countries of deficiency of water, especially its cities along the sea. According to data, water for industry, 80% of which is water for cooling, covers 80% of water for the city. To save fresh water, people want to replace freshwater with seawater for cooling in industry. However, in seawater cooling system, the corrosion of the outlet of heat-exchanger and its following steel implements, whose temperatures are about 50 ℃ or even up to 55 ℃, is very serious. Thus it is important to solve the problem. Application of sacrificial anode is one effective method to present steel equipment in seawater from corrosion, but at 50 ℃, the current efficiency of the types of sacrificial anodes in common use is much lower. So it is significant to study and make one new type of sacrificial anode, which can apply at 50 ℃. Twenty-eight types of sacrificial anodes were made and according to the standard of GB 4950-85, their potentials were tested, their current efficiencies were calculated and their corrosion products' falling off and corrosion uniformity were observed. It was shown that the corrosion uniformity was the most important factor of affecting the performance of sacrificial anodes at high temperature. Three samples' anodic polarization curves were drawn. It showed that the polarization degree of sacrificial anodes was great when anodic polarization current density was 0.2 or 0.4 mA/cm~2, that the potential would keep stable in spite of increasing polarization current density, and that with the temperature rising, the degree is higher and higher so that the anodes are unfavorable to offer enough protect potential. Mathematical grey interrelation analysis method was used to study the correlation between Al anode elements and working potential, current efficiency, corrosion uniformity. It showed that Mg was the good element to increase corrosion uniformity of sacrificial anodes at 20 ℃ and 40 ℃, and Ga good at 60 ℃. According to the conclusion of grey interrelation analysis, it was proposed that Al-Zn-In-Ga-Mg is good at 20 ℃ and 40 ℃, and Al-Zn-In-Ga good at 60 ℃.
页数	80
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/1115
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	刘学庆. 热海水中高效铝基牺牲阳极的研制[D]. 中国科学院海洋研究所. 中国科学院海洋研究所,2001.

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