轻水堆包壳锆材服役环境下延寿策略及研究进展

Life Extension Strategy and Research Progress of Zirconium Alloy Cladding Applied to Light Water Reactors

综述了核反应堆用锆合金的涂层研究现状。主要论述了非金属类涂层、金属类涂层以及MAX相涂层。其中MAX相既具有金属的性质,又具有陶瓷的性质。分析了包壳材料服役环境下的腐蚀行为,包括正常工况下的过热水氧化腐蚀和含锂离子的水溶液腐蚀行为,同时也关注了离子辐照行为以及事故工况下的高温蒸汽腐蚀行为。现有涂层材料普遍具有局限性,研究多侧重于高温蒸汽腐蚀。出现了一些新材料,比如可形成致密氧化膜的MAX相、硅涂层等,但是其正常工况下的应用前景不明。相比而言,金属类涂层在抗腐蚀方面更具优势,然而其抗辐照行为和中子经济性尚待研究。目前单一涂层技术在满足抗辐照和中子经济性的基础上尚不足以同时满足正常工况和高温蒸汽下的抗腐蚀性和高稳定性。组合涂层或者多层膜技术逐步受到重视。多元涂层氧化过程中的元素迁移动力学行为以及涂层基体界面的微合金化对结合力的影响具有深远意义,目前该方面的研究有待突破。

The research status of coating technology for zirconium alloys applied to nuclear reactors was summarized.Non-metallic coatings,metal coatings and MAX coatings were discussed.Among them,the MAX phase combined the advantages of metal properties and ceramic properties.The corrosion behavior of the cladding materials in normal service environment was analyzed,including the superheated water corrosion under normal conditions and the corrosion behavior in aqueous solution containing lithium ions.Moreover,the ion irradiation behavior and the high temperature steam corrosion behavior under accident conditions were also considered.The researches on existing coating materials generally have limitations,which mainly focuses on high-temperature steam corrosion.Some new materials have emerged,such as MAX phase and silicon coatings that can form dense oxide film in the oxidation process.However,the application under normal conditions is unknown.Metal coatings have better advantages in corrosion resistance,but their anti-irradiation behavior and neutron economy need to be studied.At present,single layer coatings can not meet the corrosion resistance and high stability under normal conditions and high temperature steam on the basis of satisfying the radiation resistance and neutron economy.The composite coatings or multilayer coating technologies gradually begin to gain attention.The kinetic behavior of element migration in multi-component coatings during oxidation process and the micro alloying of the interface between coating and substrate have far-reaching significance.At present,the research in this area remains to be broken through.