耐事故燃料包壳用FeCrAl合金的高温蠕变行为及变形机制  

High-temperature Creep Behavior and Deformation Mechanism of FeCrAl Alloy for Accident Tolerant Fuel Cladding

作　　者：崔健 白文秀 姚欢 武俊梅 巫英伟[4] 陈平[5] CUI Jian;BAI Wenxiu;YAO Huan;WU Junmei;WU Yingwei;CHEN Ping(Huineng Coal Power Group Co.,Ltd.,Ordos 017000,China;Ordos Institute of Technology,Ordos 017000,China;School of Aerospace,Xi’an Jiaotong University,Xi’an 710049,China;School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China;Nuclear Power Institute of China,Chengdu 610041,China)

机构地区：[1]汇能控股集团有限公司,内蒙古鄂尔多斯017000 [2]鄂尔多斯应用技术学院,内蒙古鄂尔多斯017000 [3]西安交通大学航天航空学院,陕西西安710049 [4]西安交通大学核科学与技术学院,陕西西安710049 [5]中国核动力研究设计院,四川成都610041

出　　处：《西北工程技术学报(中英文)》2025年第1期8-14,共7页Ningxia Engineering Technology

基　　金：国家重点研发计划项目(2019YFB1901003)。

摘　　要：FeCrAl作为一种高温耐腐蚀合金,是核反应堆耐事故燃料包壳的重要候选材料。采用蠕变试验和扫描电子显微镜技术,对FeCrAl合金开展了高温蠕变性能及蠕变前后材料微观结构变化的研究,探讨了该合金的高温蠕变主导机制。结果表明:当温度和应力较低时,蠕变过程中大晶粒会被诱导吞没小晶粒,蠕变后小角度晶界比例减少;但高温或高应力条件下位错在晶体内大量增殖,小角度晶界数量显著增多;在试验条件范围内,随着应力的升高,蠕变机制由晶界滑移转变为位错运动主导;随着温度的上升或者晶粒尺寸的减小,位错运动启动的临界应力有所降低,位错密度显著升高,该合金高温抗蠕变性能随之减弱。温度、应力和晶粒尺寸是影响合金高温蠕变行为的主要因素,蠕变前后材料织构无显著差异。高应力下蠕变机制以位错运动为主导,温度越高或者晶粒尺寸越小,位错运动开始的临界应力越小。As a high temperature corrosion-resistant alloy,FeCrAl is an important candidate for accident tolerant fuel cladding in nuclear reactors.The high-temperature creep properties of FeCrAl alloy and its microstructural changes before and after creep were investigated using creep tests and scanning electron microscopy(SEM).The dominant deformation mechanisms were explored.The results show that when the temperature and stress are low,large grains during the creep process engulf smaller grains,and the fraction of low-angle grain boundaries(GBs)decreases after creep.However,at high temperatures and high stresses,dislocation within the grains proliferate rapidly,and the number of low-angle GBs increases obviously.As the stress increases,the creep mechanism transitions from GB slip to dislocation motion within the present research scope.As temperature rises or grain size decreases,the critical stress for dislocation motion decreases,and the dislocation density increases considerably,leading to a gradual decrease in the high-temperature creep resistance of the alloy.Temperature,stress,and grain size play major roles in the creep process,with no significant changes in microstructure before and after creep.Under high stress conditions,the creep mechanism is dominated by dislocation motion.The higher temperature or the smaller the grain size,the smaller stress at which dislocations begin to move.

关 键 词：核燃料包壳 FeCrAl合金 微观组织 蠕变机制 

分 类 号：TL341[核科学技术—核技术及应用]