高能重离子辐照的ODS铁素体钢脆化效应研究  

Embrittlement of an ODS Ferritic Steel Under High-energy Heavy-ion Irradiation

作　　者：刘娟[1,2] 张崇宏[1] 杨义涛[1] 宋银[1] 张丽卿[1] 缑洁[1] 咸永强 陈家超 Jinsung Jang 

机构地区：[1]中国科学院近代物理研究所,兰州730000 [2]中国科学院大学,北京100049 [3]Paul Scherrer Institute Villigen PSI,5232 Switzerland [4]韩国原子力研究所,韩国大田市305-353

出　　处：《原子核物理评论》2015年第3期347-352,共6页Nuclear Physics Review

基　　金：国家磁约束核聚变能发展研究专项(2011GB108003);国家重点基础研究发展计划(973计划)资助项目(2010CB832904)~~

摘　　要：与传统的铁素体钢相比,氧化物弥散强化(ODS)的铁素体钢具有更优的耐高温和抗辐照性能,近年来成为先进核能装置重要的候选结构材料。在HIRFL的扇聚焦型回旋加速器(SFC)材料辐照终端,对一种氧化物弥散强化(ODS)铁素体钢MA956进行了高能Ne离子辐照实验,旨在研究级联碰撞损伤和惰性气体原子注入条件下该材料力学性能的变化。利用辐照终端的能量衰减装置将SFC出口123.4 Me V的离子能量分解为介于38.5～121.0 Me V之间的30个入射能量值,并通过双面辐照在厚度60μm的样品中均匀产生了损伤。辐照剂量为9×1016ions/cm2,在样品中的平均位移损伤为0.7 dpa,注入的Ne原子浓度为350 appm。辐照期间样品温度保持在440℃附近。对辐照前后的样品分别在室温和500℃下进行了小冲杆试验(Small-punch Test),获得了辐照前后样品的加载位移曲线,由此得到该辐照条件下样品的延性损失为18%～26%。通过扫描电子显微镜观察了断口形貌和厚度变化,估算了样品的等效断裂应变和断裂韧性。结果表明,MA956钢经过高能Ne离子辐照后等延伸率减小,断裂韧性降低,样品发生了一定的脆化。透射电镜结果说明氧化物弥散相界面处微空洞的形成可能是导致脆化的原因。Oxide dispersion strengthened（ODS） ferritic steels have better high-temperature creep rupture strength and higher irradiation resistance than conventional ferritic steels, and show high prominence of application in advance nuclear reactors. Their stability under high-dose radiation conditions needs to be clarified. In the present study, a commercial ODS ferritic steel MA956 were irradiated with high20 Ne ions at a terminal chamber of the Sector-focused Cyclotron（SFC） at HIRFL（Heavy-ion Research Facility in Lanzhou）. With the energy gradient degrader of the irradiation chamber, the primary energy（123.4 Me V） of the Ne-ion was dispersed into30 different energies between 38.5 ～ 121.0 Me V, which resulted in a plateau distribution of lattice damage in the specimens. The specimens were irradiated from both sides so that the whole 60 μm thickness was nearly uniformly damaged. The specimen temperature was maintained around 440 ℃ during the irradiation. The irradiation dose is about 9 × 1016ions/cm2, corresponding to a damage level of 0.7 dpa and a Ne concentration of350 appm. The specimens before and after irradiation were tested with the Small-punch Test technique, at room temperature and 500 ℃, respectively. The fracture morphology was observed by scanning electron microscopy.The results show that MA956 underwent some loss of ductility and fracture toughness after the irradiation with high-energy20 Ne ions. It may be ascribed to the formation of nano-scale cavities at the oxides/matrix interfaces in the ODS steel specimens under irradiation.

关 键 词：ODS铁素体钢 高能重离子 辐照损伤 延伸率 断裂韧性 

分 类 号：O482.1[理学—固体物理] O774[理学—物理]