Zr-Sn-Nb合金1000~1250℃蒸汽氧化行为  

Oxidation Behaviors of Zr-Sn-Nb Alloy in 1000~1250℃Steam

作　　者：张锋 张程煜[1] 赵琬倩 张瑶 陈乐[2] 李玫[1] 宋鹏程 Zhang Feng;Zhang Chengyu;Zhao Wanqian;Zhang Yao;Chen Le;Li Mei;Song Pengcheng(School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610041,China)

机构地区：[1]西北工业大学材料学院,陕西西安710072 [2]中国核动力研究设计院反应堆燃料及材料国家重点实验室,四川成都610041

出　　处：《稀有金属材料与工程》2021年第10期3677-3683,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51572224,11704360);火工品安全性可靠性技术重点实验室基金项目(WDYX19614260201)。

摘　　要：核反应堆包壳管在失水事故中会因剧烈的高温蒸汽氧化而破裂,从而引起核燃料泄露的严重后果。为此,本工作研究了核包壳Zr-Sn-Nb合金1000~1250℃蒸汽氧化行为。采用增重法计算了蒸汽氧化试样单位面积的质量变化,通过扫描电子显微镜观察了蒸汽氧化试样截面形貌并测量了氧稳定α相层(α-Zr(O))和氧化锆层(ZrO_(2))厚度,得到Zr-Sn-Nb合金氧化增重和α-Zr(O)、ZrO_(2)层生长动力学曲线。结果表明:1000℃蒸汽氧化时,α-Zr(O)层生长动力学曲线始终服从抛物线规律;氧化1500 s后,合金氧化增重和ZrO_(2)层生长动力学曲线由抛物线转变为直线规律,ZrO_(2)层内产生大量裂纹。1100~1250℃蒸汽氧化时,合金氧化增重和α-Zr(O)、ZrO_(2)层生长动力学曲线均服从抛物线规律,ZrO_(2)层结构始终保持完整。Zr-Sn-Nb合金的抗氧化性能优于Zr-4合金,其ZrO_(2)层和α-Zr(O)层生长速度慢于Zr-4合金。During loss of coolant accident,the oxidation can cause burst of the cladding tube in high temperature steam,which leads to the leakage of the nuclear fuel.In the present work,the oxidation behaviors of Zr-Sn-Nb alloy in 1000~1250℃steam were investigated.The mass gains per area were calculated by the mass gain method.The microscopic morphology,thickness of oxide layer of the alloy were measured by a scanning electron microscope.The oxidation kinetics of the alloy was characterized by mass gain and the thickness increase ofα-Zr(O)and ZrO_(2)layers.The results show that the parabolic mass gain curves and ZrO_(2)layer growth kinetics curves become to be linear in 1000℃steam for about 1500 s,whileα-Zr(O)growth kinetics always follow the parabolic law.Meanwhile,a large number of cracks form in the ZrO_(2)layers.The mass gain kinetics curves andα-Zr(O)and ZrO_(2)layers growth kinetics curves all follow the parabolic law in 1100~1250℃steam,and the ZrO_(2)layer is almost intact.The oxidation resistance of Zr-Sn-Nb alloy is higher than that of Zr-4 alloy.The growth rates of ZrO_(2)layer andα-Zr(O)layer are slower than that of Zr-4 alloy.

关 键 词：Zr-Sn-Nb合金 蒸汽氧化 α-Zr(O) ZrO_(2) 

分 类 号：TG146.414[一般工业技术—材料科学与工程] TG172.5[金属学及工艺—金属材料]