典型钢材在黄东海离岸海水中电化学腐蚀行为研究

发布时间：2018-05-31 22:02

本文选题：东黄海 + 离岸海水腐蚀　；参考：《中国科学院大学(中国科学院海洋研究所)》2017年硕士论文

【摘要】：随着人类对海洋开发的日益深入,海洋结构用钢被广泛应用于各项海洋事业,但是由于海洋环境的复杂性,使这些材料面临着严重的腐蚀问题。目前有关海洋腐蚀的研究多集中在室内或海滨、岸基试验站,缺少对离岸海水腐蚀行为和腐蚀过程的研究。因此,充分了解典型环境因素对海水,尤其是离岸海水中钢材腐蚀行为的影响,对海洋工程有重要的参考意义。基于以上背景,本文分别进行了四种钢材春季、夏季、秋季、冬季在黄、东海海域共四个航次的调查;应用动电位极化曲线、电化学阻抗(EIS)技术在科学三号及东方红二号科考船船载实验室现场对四种钢材在黄、东海离岸海水中的腐蚀电化学行为进行了初步研究并结合形貌分析研究了其季节变化规律。获得的具体实验数据包括:45#中碳钢、Q235低碳钢、X80管线钢及316L不锈钢在2016年夏季和冬季在黄海海域各20个站位的开路电位、动电位极化曲线、电化学阻抗数据;上述四种钢材2016年在东海海域春季18个站位和秋季20个站位的开路电位、动电位极化曲线、电化学阻抗数据。本论文的主要结论如下:(1)在黄海海域,45#中碳钢、Q235低碳钢和X80管线钢的腐蚀速率空间分布基本呈近岸低、远岸高及明显的南低北高的趋势,这种分布趋势明显与黄海海域溶解氧的分布一致;316L不锈钢的腐蚀速率在黄海海域的分布基本均匀,无明显的空间变化。45#中碳钢、Q235低碳钢和X80管线钢在黄海海域的腐蚀行为季节变化明显,冬季腐蚀较夏季严重,在近岸海域三种钢材的腐蚀情况与低氧区的形成及消亡密切相关,中部海域的腐蚀情况则受到黄海冷水团(夏季)及黄海暖流(冬季)系统的影响;而316L不锈钢腐蚀情况在黄海海域没有显著的季节变化。(2)在东海海域,45#中碳钢、Q235低碳钢和X80管线钢的腐蚀速率空间分布基本呈近岸低、远岸高的趋势,这种分布趋势主要受温度、盐度、溶解氧的共同影响;316L不锈钢的腐蚀速率在东海海域的分布基本均匀,无明显的空间变化。45#中碳钢、Q235低碳钢和X80管线钢在东海海域的腐蚀行为季节变化明显,秋季腐蚀较春季严重,在近岸海域三种碳钢的腐蚀情况与低氧区的形成及消亡和东海沿岸水的性质密切相关,中部海域腐蚀情况则受台湾暖流的影响,而316L不锈钢腐蚀行为在东海海域无明显的季节变化。(3)在东海及黄海海域,45#中碳钢、Q235低碳钢和X80管线钢的腐蚀速率空间分布都呈现出近岸低、远岸高的共同趋势,316L不锈钢的腐蚀速率则无明显的空间变化。就耐蚀性而言,316L不锈钢的耐腐蚀性能最好,其次为X80管线钢和45#中碳钢,Q235低碳钢的耐蚀性最差,这主要与它们的微观组织结构有关。
[Abstract]:With the development of ocean, steel for marine structure is widely used in various marine undertakings. However, due to the complexity of marine environment, these materials are faced with serious corrosion problems. At present, the researches on marine corrosion mainly focus on indoor or coastal, shore-based test stations, and lack of research on the corrosion behavior and corrosion process of offshore seawater. Therefore, understanding the influence of typical environmental factors on the corrosion behavior of steel in seawater, especially offshore seawater, has important reference significance for marine engineering. Based on the above background, four kinds of steel in spring, summer, autumn and winter were investigated in the Yellow Sea and East China Sea, and the potentiodynamic polarization curve was used. Electrochemical impedance spectroscopy (EIS) technique was used to study the corrosion electrochemical behavior of four kinds of steels in offshore waters of the Yellow Sea and East China Sea at the site of the Shipboard Laboratory of Science No.3 and Dongfanghong No. 2. The seasonal variation of four steels in the offshore waters of the Yellow Sea and the East China Sea was studied by means of morphological analysis. The specific experimental data obtained include the open-circuit potential, potentiodynamic polarization curve and electrochemical impedance data of 20 stations in the Huang Hai sea area in summer and winter of 2016, respectively, for 1: 4 medium carbon steel, Q235 low carbon steel, X80 pipeline steel and 316L stainless steel in the summer and winter of 2016. The open circuit potential, dynamic potential polarization curve and electrochemical impedance data of 18 stations in spring and 20 stations in autumn in the East China Sea in 2016. The main conclusions of this paper are as follows: (1) the corrosion rate spatial distribution of Q235 and X80 pipeline steels in the Huang Hai sea area is basically low in the near shore, low in the far shore and high in the south and north. This distribution trend is obviously consistent with the distribution of dissolved oxygen in the Huang Hai sea area. The corrosion rate of stainless steel 316L is basically uniform in the Huang Hai sea area. The corrosion behavior of Q235 low carbon steel and X80 pipeline steel without obvious spatial variation is obvious in Huang Hai, and the corrosion in winter is more serious than that in summer. The corrosion of three kinds of steels in coastal waters is closely related to the formation and extinction of low oxygen zone. The corrosion in the central sea area is affected by the Huang Hai cold water mass (summer) and the Huang Hai warm current (winter) system. However, the corrosion rate of 316L stainless steel has no significant seasonal variation in Huang Hai. 2) in the East China Sea, the corrosion rates of Q235 low carbon steel and X80 pipeline steel show a trend of low near shore and high in far shore, which is mainly affected by temperature. The distribution of corrosion rate of stainless steel in the East China Sea is basically uniform, and the corrosion behavior of Q235 low carbon steel and X80 pipeline steel in the East China Sea is obviously different from that of medium carbon steel, Q235 low carbon steel and X80 pipeline steel in the East China Sea, and there is no obvious spatial change in the corrosion behavior of Q235 low carbon steel and X80 pipeline steel in the East China Sea. The corrosion in autumn is more serious than that in spring. The corrosion of three kinds of carbon steels in the coastal area is closely related to the formation and extinction of the low oxygen zone and the nature of the coastal water in the East China Sea, while the corrosion situation in the central sea area is affected by the Taiwan warm current. However, the corrosion behavior of 316L stainless steel has no obvious seasonal variation in the East China Sea. The corrosion rate of 316L stainless steel has no obvious spatial variation. In terms of corrosion resistance, the corrosion resistance of stainless steel was the best, followed by X80 pipeline steel and 4medium carbon steel Q235 low carbon steel, which was mainly related to their microstructure.
【学位授予单位】：中国科学院大学(中国科学院海洋研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG172.5;P755.3

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