基于小样品测试氧化物弥散强化HT9钢在650℃下的高温蠕变行为  

High-temperature Creep Behavior of Oxide Dispersion Strengthened HT9 Steel at 650℃Based on Small Sample Testing

作　　者：程硕 李世江 龚翱翔 赵磊 佟振峰 CHENG Shuo;LI Shijiang;GONG Aoxiang;ZHAO Lei;TONG Zhenfeng(School of Nuclear Science and Engineering,North China Electric Power University,Beijing 102206,China;State Grid Jibei Electric Power Co.,Ltd.Super High Voltage Branch,Beijing 102400,China)

机构地区：[1]华北电力大学核科学与工程学院,北京102206 [2]国网冀北电力有限公司超高压分公司,北京102400

出　　处：《原子能科学技术》2025年第2期436-443,共8页Atomic Energy Science and Technology

基　　金：国家重点研发计划(2022YFB3707605);国家自然科学基金(U1967212)。

摘　　要：氧化物弥散强化钢(ODS)由于其具有较好的高温性能和辐照性能,已成为先进核能系统候选材料。由于其采用粉末冶金的制备工艺,材料多为细晶或超细晶组织。这类细晶材料的高温蠕变行为机制较为复杂,晶粒尺度和弥散强化粒子对蠕变行为的影响缺乏深入认识。本文以氧化物弥散强化钢HT9-ODS和参比HT9钢为研究对象,选取典型的快中子反应堆服役温度650℃为实验温度,利用小尺寸样品进行了应力区间为80~180 MPa的蠕变试验。研究了HT9-ODS钢在高温下的蠕变行为,发现在应力高于100 MPa时,弥散颗粒通过钉扎位错使应力集中,高应力条件下的晶界滑动促进裂纹的萌生聚合,晶界滑动起主导作用;在应力降低到80 MPa时,晶界滑动作用下降,弥散颗粒阻碍位错运动,HT9-ODS钢蠕变寿命远长于参比HT9钢。One of the most popular materials for advanced nuclear energy systems is oxide dispersion strengthened(ODS)steel,which has been widely adopted as a candidate material for advanced nuclear energy systems due to its high-temperature mechanical properties and resistance to irradiation.Because of the powder metallurgy preparation process used in the preparation of ODS steels,the material is mostly of fine or ultra-fine crystalline organization.The mechanism of high-temperature creep behavior of this type of such fine-crystalline materials is more complex,and there are few researches on the mechanistic changes in the creep deformation process.In addition,there is a lack of in-depth understanding of the effects on the creep behavior of grain scale and diffusely reinforced particles.In this paper,the oxide dispersion strengthened steel HT9-ODS and the reference HT9 steel were taken as the objects of study,and they were prepared into small-sized samples for high-temperature creep experiments.The experimental temperature was selected as the typical fast neutron reactor service temperature of 650℃,and the stress interval was 80-180 MPa.The creep fracture morphology and microstructure of the samples were characterized and tested by using micro-scale characterization techniques.By comparing and analyzing the high-temperature creep strain curves of reference HT9 steel and oxide dispersion strengthened steel HT9-ODS,the creep behavior of HT9-ODS steel at high temperatures was investigated.The results show that when the stress is higher than 100 MPa,grain boundary sliding plays a dominant role in the creep deformation process,which promotes crack initiation and aggregation,and fracture occurs in a shorter time for both HT9-ODS steel and the reference HT9 steel.The pinning of dislocations by oxide dispersed particles leads to the concentration of stress at grain boundaries,which accelerates the fracture of HT9-ODS steel,making the creep life of HT9-ODS steel shorter than that of reference HT9 steel.As the stress is reduced to

关 键 词：HT9钢 HT9-ODS钢 氧化物弥散强化 蠕变 

分 类 号：TL341[核科学技术—核技术及应用]