摘要
Cr涂层锆合金包壳是提高轻水反应堆燃料组件抗高温氧化性能的重要方法。本工作旨在研究Cr涂层Zr-4合金在水蒸气环境中的高温氧化行为,采用多弧离子镀工艺制备Cr涂层Zr-4合金样品,在1000和1100℃水蒸气环境中开展高温氧化实验,采用高精度天平获得样品氧化增重,采用扫描电子显微镜(SEM)、能量色散谱仪(EDS)和X射线衍射仪(XRD)测试分析样品的表面与截面微观形貌、元素分布、物相及Cr-Zr扩散层厚度。结果显示,多弧离子镀制备的Cr涂层Zr-4合金样品表面存在大量尺寸不等的大颗粒,Cr涂层沿着(110)晶面择优生长。高温蒸气单位面积氧化增重与时间近似遵循抛物线规律,1100℃的蒸气氧化速率明显高于1000℃,相同温度下Cr涂层Zr-4合金的氧化速率低于无涂层Zr-4合金。高温蒸气氧化后,样品表面生成晶须状氧化物,且氧化物间存在大量微孔。在1100℃高温蒸气氧化3和4 h后,样品表面被氧化生成蠕虫状的团状物。样品截面呈层状结构,由外向内分别为Cr_(2)O_(3)层,Cr涂层,Cr-Zr扩散层,α-Zr(O)层(ZrO_(2)层)。但表面Cr_(2)O_(3)层的厚度并不是随着氧化时间的增加而同步增加的,而Cr-Zr扩散层的厚度随氧化温度和氧化时间的增加而增大,且与氧化时间基本呈线性关系。因此,采用多弧离子镀制备的Cr涂层Zr-4合金在1000和1100℃下表现出良好的抗高温蒸气氧化性能。
Cr-coated zirconium alloy cladding is an important method to improve the high temperature oxidation resistance of light water reactor fuel assembly.The high temperature oxidation behavior of Cr-coated Zr-4 alloys was studied in steam environment.The Cr-coated Zr-4 alloy samples were prepared by multi-arc ion plating process.High temperature oxidation experiments were carried out in 1000 and1100 ℃ steam environment.The oxidation mass gain of the samples was obtained by a high precision balance,and the surface and cross-section micro-morphologies,element distribution,as well as phase and thickness of the Cr-Zr diffusion layer were analyzed by scanning electron microscope(SEM),energy dispersive spectroscope(EDS) and X-ray diffractometer(XRD).The results show that there are a large number of droplets of different sizes on the surface of the Cr-coated Zr-4 alloy samples prepared by multi-arc ion plating,and the Cr coating grows preferentially along the(110) crystal plane.The oxidation mass gain per unit area and time approximately follows a parabolic law.The oxidation rate at 1100 ℃ is significantly higher than that at 1000 ℃.At the same temperature,the oxidation rate of the Cr-coated Zr-4 alloy is lower than that of the uncoated Zr-4 alloy.After high temperature steam oxidation,whisker-like oxides are formed on the surface of the samples,and there are a large number of micro-pores between the oxides.After high temperature steam oxidation at 1100 ℃ for 3 and 4 h,the surface of the samples is oxidized to form worm-like agglomerates.The cross section of the samples has a layered structure,consisting of Cr_(2)O_(3) layer,Cr coating,Cr-Zr diffusion layer,and α-Zr(O) layer(ZrO_(2) layer).However,the thickness of the surface Cr_(2)O_(3) layer does not increase synchronously with the increase in the oxidation time,while the thickness of the Cr-Zr diffusion layer increases with the increase in the oxidation temperature and oxidation time,which has a linear relationship with the oxidation time.Therefore,the Cr-coated
作者
刘世宏
肖魏魏
罗彪
黄景昊
邹树梁
刘义龙
任峥豪
Liu Shihong;Xiao Weiwei;Luo Biao;Huang Jinghao;Zou Shuliang;Liu Yilong;Ren Zhenghao(College of Mechanical Engineering,University of South China,Hengyang 421001,China;Hunan Provincial Key Laboratory of Emergency Safety Technology and Equipment for Nuclear Facilities,University of South China,Hengyang 421001,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2024年第7期1962-1969,共8页
Rare Metal Materials and Engineering
基金
湖南省自然科学基金(2022JJ40348)
衡阳市科技计划项目(202150063435)。
