摘要
以V-(4-5)Cr-(4-5)Ti合金为代表的钒合金具有高温性能优异、抗辐照肿胀性能好、中子辐照活化性低等诸多优点,被视为先进核聚变反应堆最有潜力的候选包层结构材料之一.然而,钒合金在较高温度下的氧化腐蚀及吸氧脆化问题仍是目前制约其实际应用和长寿命服役的重要因素.因此,提升钒合金的抗高温氧化腐蚀性能,对于提高其服役温度、延长其服役寿命以及拓宽其应用领域均具有重要意义.本文综述了国内外有关提升钒合金抗高温氧化腐蚀性能的三种主要方案,即添加抗氧化性元素、应用扩散型涂层和包覆型涂层,并对这些方案的主要特点、应用实例以及存在的问题进行了分析和讨论.上述三种方案中,包覆型涂层由于可以将钒合金基体和服役环境完全隔离,因而具备更大的应用潜力.根据钒合金的应用特点,对先进包覆型抗氧化腐蚀涂层的发展趋势和技术需求进行了展望,以期为钒合金抗高温氧化腐蚀研究工作的深入开展提供借鉴.
Vanadium alloys are an attractive candidate material for advanced fusion reactors’ structural components.Some leading vanadium alloys,such as V-(4-5)Cr-(4-5)Ti alloy,exhibit several important advantages,including excellent strength at elevated temperatures,high resistance to neutron irradiation damage,inherently low long-term activation,as well as good fabricability and weldability.However,the corrosion and embrittlement via oxygen pickup during the high-temperature oxidation process of vanadium alloys remains a key issue,restricting their operation conditions and long service life.In a high-pressure oxygen environment,the main oxidation product VO,with a low melting point of ~680 ℃,is formed on the vanadium alloy surface,which cannot offer reliable protection to mitigate further oxidation over 650 ℃.However,despite being exposed to a very low-pressure oxygen environment,it is still unlikely for vanadium alloys to form an effective oxidation film to retard the oxygen absorption at temperatures over 450 ℃,mainly due to the high solubility of oxygen in vanadium.When the oxygen concentration reaches 0.2% in the matrix of V-4Cr-4Ti alloy,it can cause severe oxygen embrittlement,possibly due to oxygen accumulation and formation of fine oxidation precipitates at the grain boundaries and the adjacent matrix.Therefore,it is significantly important to enhance the high-temperature oxidation-resistant performance of the vanadium alloy to broaden the operation conditions.In this work,this research progress on the high-temperature oxidation resistance of vanadium alloys is systematically reviewed.In summary,three main methods for enhancing the oxidation –corrosion resistance of vanadium alloys at elevated temperatures are elaborated,i.e.,oxidation-resistant element addition,diffusion coating,and overlay coating.Additionally,the characteristics and existing problems of these methods and the responding examples are also analyzed and discussed in detail.In the first two methods,it is impossible to completely isolate the alloy substrate from the service environment;thus,the typical oxidation product VOis easily formed in the high-pressure oxygen environment,leading to severe oxidation corrosion and embrittlement,especially at elevated temperatures.Expectedly,the dense overlay coating presents a greater potential application mainly because of the thorough protection from the service environment.Finally,the development trend in the modification and technical requirements of the advanced overlay coatings on high-performance oxidation resistance are prospected in this paper as per the practical application demands for vanadium alloys,aiming to provide a beneficial reference for further research.
作者
张高伟
韩文妥
刘平平
易晓鸥
詹倩
杨善武
万发荣
ZHANG Gao-wei;HAN Wen-tuo;LIU Ping-ping;YI Xiao-ou;ZHAN Qian;YANG Shan-wu;WAN Fa-rong(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2022年第11期1868-1880,共13页
Chinese Journal of Engineering
基金
广东省基础与应用基础研究基金资助项目(2021A1515110488)
国家重点研发计划专项资助项目(2017YFE0301400)。
关键词
聚变堆
钒合金
高温氧化腐蚀
抗氧化性元素
扩散型涂层
包覆型涂层
fusion reactor
vanadium alloy
high-temperature oxidation corrosion
oxidation-resistant element
diffusion coating
overlay coating
