东黄海海水中典型结构材料的腐蚀行为对比研究

The studies of corrosion behavior and corrosion process in the seawater have been mostly concentrated in coastal and shore-based test station for a long term, which result in the lack understanding of corrosion behavior and corrosion process in offshore seawater. It is not clear how the seasonal variation and annual changes affecting the offshore seawater corrosion, which has seriously restricted the understanding of the corrosivity and potential risk of structural materials in seawater in different sea zones. Therefore, a comparative study on the corrosion in the different stations in the Yellow Sea and the East China Sea is proposed in this application. In-situ corrosion parameters at different depths is measured, together with the in-situ environmental parameters of the seawater. Variation of corrosion potential and corrosion rate under the in-situ environmental conditions and its temporal and spatial characteristics are analyzed in details. The influences of temperature, salinity, dissolved oxygen, flow current, redox potential on the corrosion behavior of typical structural materials are investigated, in addition, the influence of the initial corrosion products is considered. Combined with the comparison of indoor experimental data, inshore experimental data and offshore in-situ data, the corrosion mechanism of these materials is investigated using correlation analysis and numerical simulation methods. The internal reasons of the seawater corrosiveness and its variety is further recognized to reveal the electrochemical corrosion and dynamic mechanism of structural materials under offshore seawater conditions.

长期以来对海水腐蚀行为和腐蚀过程的研究，多集中在海滨或岸基试验站，缺少对离岸海水腐蚀行为和腐蚀过程的了解，不清楚季节变化、年度变化等对离岸海水腐蚀性能的作用机制，严重制约了对结构材料在不同海域海水中的腐蚀破坏性和潜在风险性的认识。因此，本申请拟以黄海和东海海域的不同海水站位作为研究对比，以走航式现场测量不同深度腐蚀参数为主要研究手段，同时观测海域海水的各项环境参数，重点分析现场环境条件下腐蚀电位和腐蚀速率等的变化规律及其时空特点，探讨典型结构材料在温度、盐度、溶解氧、流速、氧化还原电位等因素变化时对其腐蚀行为的影响以及初期腐蚀产物形成后表面状态变化的影响情况。同时结合这些材料的近岸实验数据和室内测试数据与离岸观测数据进行对比，采用相关性分析和数值模拟试验等方法探讨其腐蚀作用机理，进一步理解影响海水腐蚀性的各种因素及其变化的内在原因，揭示离岸海水条件下结构材料的腐蚀电化学及动力学机制。

本项目选用了Q235低碳钢、316L不锈钢、X80管线钢、EH36船用钢和45#中碳钢等5种典型钢材作为我们的研究对象，分别于2016至2018年间在中国东海和黄海区域进行了不同季节、不同站位、不同深度等多维度的腐蚀数据监测，首次取得了大量具有代表性的相关实海测试数据。项目执行期间还成功研制了深海腐蚀监测仪，并依托南海海试航次成功进行了3000m水深的海试，远远超过了东黄海海域所能达到的水深；同时还搭载“科学号”，获得了“科学号”在西太平洋航次沿线表层腐蚀数据，超额完成了计划书中承诺的任务。完成了离岸海水条件下腐蚀电化学及动力学数值模型的模拟计算；依据四年的监测结果初步建立了典型钢材在东黄海海域腐蚀特性数据库，丰富了我国腐蚀大数据库的内容，为我国腐蚀事业的发展做出贡献。同时还多次参加大型国际会议，向交叉学科的同行宣传介绍本项目工作，寻求学术交流，扩大影响。