碳钢材料在高放射性核废液浸泡区、气液界面区和气相区的局部腐蚀特性研究

项目名称： 碳钢材料在高放射性核废液浸泡区、气液界面区和气相区的局部腐蚀特性研究

项目编号： No.51501180

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 徐玮辰

作者单位： 中国科学院海洋研究所

项目金额： 21万元

中文摘要： 随着核能的广泛使用，核废料的处理成为越来越重要的问题。高放射性液态核废料的永久性（深层地下）存储需要相当长的准备时间，因此目前的高放废液采用临时存储的方法。碳钢是一种有应用前景的临时存储罐材料。高放废液是一种含有大量硝酸根、亚硝酸根离子以及少量氯离子的碱性溶液，由于衰减能量的释放，温度较高。碳钢在该环境中最具有危害性的腐蚀是局部腐蚀。亚硝酸根离子是一种有效的缓蚀剂，但其抑制点蚀诱发和生长的机理并不明确；硝酸根和亚硝酸根离子对局部腐蚀的综合作用比较复杂，可以解释实验现象并被广泛认可的机理没有提出。另外，碳钢在高放废液环境中的气液界面和气相区腐蚀也开始成为关注的热点，但是其对碳钢的危害也不明确。本项目通过系统研究硝酸根和亚硝酸根离子对点蚀的影响，探索其作用机理；通过对浸泡区、气液界面区和气相区的腐蚀特性研究，得到使碳钢钝化的实验条件范围，并为碳钢材料在该环境中的可靠性评估提供参考依据。

中文关键词： 局部腐蚀；点蚀；核废料存储；同步辐射

英文摘要： Since nuclear power is used widely, the nuclear waste disposal has become an increasingly important issue. Permanent (deep geological) disposal of high-level liquid radioactive waste requires a long time preparation, so interim storage of the liquid waste is currently applied. Carbon steel is a promising material for the tanks used for interim storage. High-level liquid radioactive waste is alkaline solution containing large amounts of nitrate and nitrite ions and trace chloride ions, and its temperature is high due to the release of radioactive decay energy. Localised corrosion is the most detrimental for carbon steel in this environment. Nitrite is a very effective corrosion inhibitor, but the mechanism for inhibiting the initiation and growth of corrosion pits is not clear; the combination effect of nitrate and nitrite on localised corrosion is complicated, and the mechanism, which is well acknowledged and which can clearly explain experimental results, has not been published. In addition, liquid air interface and vapor phase corrosion of carbon steel has become particular concerns, but the damage it may cause is still unclear. In this project, the effects of nitrate and nitrite on pitting corrosion of carbon steel will be systematically investigated to explore the mechanism; the corrosion of carbon steel in full immersion, liquid air interface and vapor phase area will be studied to determine the conditions where carbon steel is completely passivated, and to provide sufficient solid basis for the evaluation of the material durability in this environment.

英文关键词： localised corrosion;pitting corrosion;nuclear waste storage ;synchrotron