一体化快堆包壳用ODS合金的研制  

Preliminary Study on ODS Alloy for Integrated Fast Reactor

作　　者：李静[1] 李峻宏[2] 冯伟[2] 熊良银[1] 刘实[1] 刘一哲[2] 李依依 周培德[2] LI Jing;LI Junhong;FENG Wei;XIONG Liangyin;LIU Shi;LIU Yizhe;LI Yiyi;ZHOU Peide(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Department of Nuclear Engineering Design,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]中国原子能科学研究院核工程设计研究所,北京102413

出　　处：《原子能科学技术》2025年第S1期148-158,共11页Atomic Energy Science and Technology

基　　金：揭榜挂帅项目(2023-HGS-I-FWCG-0013);中核集团领创项目(CNNC-LCKY-2024-094);中核集团集中研发项目。

摘　　要：氧化物弥散强化(oxide dispersion strengthened,ODS)合金因为其优异的高温力学性能、耐辐照肿胀性能和耐腐蚀性能成为第4代裂变反应堆及一体化快堆包壳的优选结构材料,其杰出的综合性能与基体中弥散分布的、尺寸细小的纳米析出相密不可分。通过机械合金化和热等静压工艺,研制了两组12Cr-ODS FeCr合金。采用旋转锻造和冷轧工艺实现ODS合金棒材和包壳管材的制备,并开展纳米析出相分析、力学性能测试及热物理性能检测。结果表明,两组合金中的纳米氧化物主要为立方结构的Y_(2)Ti_(2)O_(7),尺寸细小且弥散分布;少量C元素的添加增加纳米析出相的颗粒尺寸。纳米析出相在合金中的弥散分布不影响材料体系的膨胀系数和热导率,但是影响材料的比热容,增加材料在高温条件下的热惯性。由于合金内纳米析出相的高密度析出及其对位错和晶界的强钉扎,ODS合金棒材表现出优异的抗高温蠕变性能,ODS合金管材表现出优异的高温拉伸性能。Due to the strong pinning to dislocations and grain boundaries as well as the available capturing of displaced atoms and helium bubbles,by oxide nanoparticles,oxide dispersion strengthened(ODS)alloys exhibit superior high-temperature mechanical properties,irradiation swelling resistance and corrosion resistance.ODS iron-based alloys have been considered as promising candidates for cladding tube and structural components of generationⅣfission reactor and integrated fast reactor.In the present study,two variants of 12Cr-ODS FeCr alloys,i.e.carbon-free NFACN-1 and carbon-added NFACN-2 alloy,were fabricated by mechanical alloying and subsequent hot isostatic pressing.Then the rods with a diameter of 12.0 mm were obtained by using rotary swaging technology,and the alloy tubes with a diameter of 9.0 mm and a wall thickness of 0.65 mm were manufactured by Pilger cold rolling processes.The change in distribution,size and composition of nanoscale precipitates along the fabrication was characterized by TEM,HRTEM and APT techniques,and its effect on mechanical properties and thermophysical properties was evaluated.The results show that the nanoscale precipitates in the two alloys are predominantly Y_(2)Ti_(2)O_(7) particles with cubic pyrochlore phase,and the composition of oxide nanoparticles has not changed in the thermomechanical processing for rods and tubes fabrication.Nevertheless,some nanoscale precipitates have been coarsened,in which size growth for the tube fabrication is higher slightly than that for the rod fabrication.And the coarsening of nanoscale precipitates is also facilitated by the addition of a small amount of C.With the aid of thermophysical properties measurement from room temperature to 1000℃,it is found that the instantaneous expansion coefficient and thermal conductivity of NFACN-1 and NFACN-2 alloys are less affected by the generation of nanoscale precipitates,compared to the non-ODS steel with similar components.However,an enhanced specific heat,especially in the temperature range of 400-800�

关 键 词：包壳材料 氧化物弥散强化合金 纳米析出相 高温力学性能 

分 类 号：TL351.1[核科学技术—核技术及应用] TG142.13[一般工业技术—材料科学与工程]