摘要
利用锂化还原技术处理乏燃料时,形成了LiCl-Li2O混合熔盐,这将造成反应容器和传送装置材料的加速腐蚀.为了解此类腐蚀的腐蚀机理,采用浸没法腐蚀实验研究了纯铁在750℃不同含量熔融LiCl-Li2O中的腐蚀行为.腐蚀产物的相结构采用X射线衍射(XRD)分析,用电子探针(EPMA)观察截面形貌和分析腐蚀产物的元素分布.实验结果表明,随着Li2O含量的增加,纯铁在750℃熔融LiCl-Li2O中的腐蚀产物发生了由LiFe5O8向LiFeO2的转变,这与热力学计算得到的相稳定图一致,同时腐蚀减重随Li2O含量的升高而增大.Li2O含量是影响纯铁在熔融LiCl-Li2O中腐蚀行为的决定性因素.
Mixed molten salt LiCl- Li2O formed in the treatment process of spent fuel with lithium reduction technique will speed up the corrosion of the materials of reactive tank and delivery device. In order to find out the corrosion mechanism, the corrosion behavior of pure Fe in molten LiCl - Li2O with different Li2O concentrations at 750℃ was studied by immersion experiments. The phase structure of the corrosion production was analyzed with X-ray diffraction （XRD）. Electron probe microanalysis （EPMA） was used to study the morphology and the distribution of elements on the cross section. The experimental results showed that, with the increase of Li2O, the corrosion products of pure Fe in molten LiCl- Li2O translated from LiFe5O8 to LiFeO2, which is accordant with the thermodynamic phase stability diagram. At the same time, the weight loss was also increased with the increasing concentration of Li2O. It can be concluded that the concentration of Li2O is the crucial factor affecting the corrosion behavior of pure Fe in molten LiCl - Li2O.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2008年第5期728-731,共4页
Materials Science and Technology
基金
韩国原子能研究所合作项目(KAERI2400)
