摘要
国际热核聚变实验堆计划是迄今为止全球规模最大、影响最深远的国际科研合作项目之一。核聚变堆包层模块需要选用高温性能相对优异、热导率高、热膨胀系数低、抗中子辐照肿胀的低活化铁素体/马氏体钢(reduced activation ferritic/martensitic steel,RAFM steel)。现有RAFM钢大多数是依据低活化元素选取原则在Cr-Mo系铁素体耐热钢种的基础上发展起来的,但存在热强性差、熔焊接头服役过程容易发生第IV类断裂等问题。本文首先概括了国内外RAFM钢的发展历程、合金化设计原理与组织设计思路、组织演变规律及调控方法,并对RAFM钢的固相连接(扩散连接与搅拌摩擦焊接)进展进行了总结,指出了高热稳定性的纳米级MX相对位错的钉扎作用是实现RAFM钢高温强化的重要因素,分析了RAFM钢冷却过程中板条马氏体非连续转变动力学成因,明确了形变热处理等组织调控技术对RAFM钢性能优化的作用机制,澄清了RAFM钢固相连接接头组织形成与演变规律,指明了高温服役过程中RAFM钢固相连接接头组织演变与断裂失效机制。
The International Thermonuclear Experimental Reactor(ITER)project is one of the world.s largest and most ambitious international scientific research collaboration projects to date.Reduced activation ferritic/martensitic steel(RAFM steel)has been selected as the candidate material for test blanket module in ITER due to its excellent mechanical properties at high temperature,high thermal conductivity,low thermal expansion coefficient,and intense neutron irradiation swelling resistance.According to the reduced activation element selection approach,RAFM steels were created using Cr-Mo ferritic heatresistance steels.However,RAFM steels have some disadvantages,including poor high-temperature endurance and type IV cracking in fusion-welded joints.The history of development,alloying principles,microstructural design principles,microstructure evolution and control,and solid-state joining technologies(diffusion bonding and friction stir welding)were discussed in this study.The pinning effect of nanoscale MX with excellent thermal stability on dislocations has been identified as a key factor in strengthening RAFM steel.In RAFM steel,the mechanism for a discontinuous martensitic transition during isochronal cooling has been elucidated.The microstructural formation,evolution,and failure of solid-state RAFM steel joints were shown,and its mechanical properties optimization due to thermo-mechanical treatment was realized.
作者
刘晨曦
毛春亮
崔雷
周晓胜
余黎明
刘永长
LIU Chenxi;MAO Chunliang;CUI Lei;ZHOU Xiaosheng;YU Liming;LIU Yongchang(State Key Laboratory of Hydraulic Engineering Simulation and Safety,School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第11期1521-1538,共18页
Acta Metallurgica Sinica
基金
国家自然科学基金项目Nos.52034004和51975404。
关键词
低活化铁素体/马氏体钢
强化机制
相变行为
组织演变
组织调控
扩散连接
搅拌摩擦焊
reduced activation ferritic/martensitic steel
strengthening mechanism
phase transformation behavior
microstructure evolution
microstructure control
diffusion bonding
friction stir welding
