摘要
Li_(4)SiO_(4)小球与ODS钢的化学相容性对聚变反应器的安全运行具有重要意义。研究了在500、600、700℃的氩气环境中保温300 h后ODS钢与小球接触界面组织和成分的变化。结果表明,在600~700℃时,Li_(4)SiO_(4)小球与ODS钢的界面发生了严重的元素互扩散和反应。在Li_(4)SiO_(4)小球表面,由于ODS钢中Fe和Cr的扩散,出现了一层薄薄的反应层,这也导致了密度的增加,破碎负荷从51 N(500℃)下降到32 N(700℃)。XRD图谱显示,ODS钢表面出现了LiCrO_(2)和LiFeO_(2)新相,说明Li_(4)SiO_(4)小球中的Li和O原子可以扩散到ODS中,与Fe、Cr元素在高温下发生反应形成腐蚀层。在700℃时,腐蚀层可分为2个氧化层。最外层是LiFeO_(2)和LiCrO_(2)的混合物,下一层主要是LiFeO_(2)。在ODS钢的表面,700℃/300 h条件下氧扩散系数为2.2×10^(-14) cm^(2)/s,这说明ODS钢作为一种包层结构材料,在未来的包层设计中需要一层耐腐蚀涂层。
The chemical compatibility between Li_(4)SiO_(4) pebbles and ODS steel is important for the safe operation of the fusion reactor.In the present paper, the transformation of microstructure and component for contact interface between ODS steel and pebbles after 300 h heat preservation in an argon atmosphere at 500, 600, and 700 ℃ was investigated. The results show that serious element interdiffusion and reaction can be observed at the interface between Li_(4)SiO_(4) pebbles and ODS steel at temperatures of 600~700 ℃.For the surface of Li_(4)SiO_(4) pebbles, a thin reaction layer appears due to the diffusion of Fe and Cr from ODS steel, which also causes the increase of density and decrease of crush load from 51 N(500 ℃) to 32 N(700 ℃). XRD patterns show that the new phase of LiCrO_(2) and LiFeO_(2) appears on the surface of ODS steel, which suggests that the Li and O atoms in Li_(4)SiO_(4) pebbles can diffuse into ODS, and react with Fe and Cr elements to form corrosion layers at high temperature. The corrosion layers can be divided into two oxide sub-layers at 700 ℃. The outermost layer is a mixture of LiFeO_(2) and LiCrO_(2), and the next layer is mainly LiFeO_(2). For the surface of ODS steel, the oxygen diffusion coefficient is 2.2×10^(-14) cm^(2)/s at 700 ℃ for 300 h. It suggests that the ODS steel as a blanket structure material steel needs a resisted corrosion coating in the design of a blanket in the future.
作者
李光彬
王曼
谭广繁
向茂乔
张迎春
Li Guangbin;Wang Man;Tan Guangfan;Xiang Maoqiao;Zhang Yingchun(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第8期2663-2669,共7页
Rare Metal Materials and Engineering
基金
National Magnetic Confinement Fusion Energy Research Project of China (2015GB121006)。
