载能离子辐照的ODS铁素体钢硬化效应的研究

研究了氧化物弥散强化(ODS) 的3 种铁素体钢,包括: 19Cr-3.5Al ODS钢(MA956),16Cr-0.1TiODS和16Cr-0.1Zr ODS铁素体钢,在多能量的氦离子和MeV能量级的Bi、Xe 离子辐照条件下的硬化效应。获得了辐照硬化与原子离位损伤水平(dpa)、He 注入浓度的关系。结果表明,材料的硬度在低剂量范围会随着辐照剂量迅速增加,而在高剂量范围材料的硬度逐渐趋于饱和,可以用1/2 次的幂函数拟合辐照硬化与离位损伤水平之间的关系。不同入射离子——Bi离子和Xe离子都会引起ODS 钢的硬化,而氦离子还会在材料中聚集导致氦泡的形成,造成更加明显的硬化。实验证明,Ti 或Zr 掺杂的16Cr-ODS 铁素体钢较19Cr-3.5AlODS钢具有更强的抗辐照硬化能力,原因可归于其含有更高数密度的细小氧化物粒子——能够有效俘获点缺陷和氦原子,从而有效抑制晶粒内部和晶界出缺陷的长大。The present work investigates the irradiation hardening of ODS ferritic steels after multi-energy Heion implantation, or energetic Bi-ion and Xe-ion irradiation, to get an understanding of dependence of irradiationhardening on atomic displacement damage and gas accumulation. Three kinds of high-Cr ODS ferritic steels including the commercial MA956 (19Cr-3.5Al), the 16Cr-0.1Ti and the 16Cr-0.1Zr ODS ferritic steels were used.The results show that the hardness increases rapidly at the lower doses but tends to saturate at the higher dose.An 1/2-power law dependence on dpa value is obtained. Helium implantation contributes significantly to the irradiation hardening, possibly due to the impediment of the motion dislocations by helium bubbles. 16Cr-ODS (Ti or Zr added) ferritic which contains finer oxide particles in higher number density shows higher resistance to irradiation hardening than the MA056.     

高能重离子辐照的ODS铁素体钢脆化效应研究

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 MeV的离子能量分解为介于38.5~121.0 MeV之间的30 个入射能量值,并通过双面辐照在厚度60 μm的样品中均匀产生了损伤。辐照剂量为9x1016 ions/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-punchTest),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 high 20Ne 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 MeV) of the Ne-ion was dispersed into 30 different energies between 38.5~ 121.0 MeV, which resulted in a plateau distribution of lattice damage in the specimens. The specimens were irradiated from both sides so that the whole 60 m thickness was nearly uniformly damaged. The specimen temperature was maintained around 440 ℃ during the irradiation. The irradiation dose is about 9x1016 ions/cm2, corresponding to a damage level of 0.7 dpa and a Ne concentration of 350 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-energy 20Ne ions. It may be ascribed to the formation of nano-scale cavities at the oxides/matrix interfacesin the ODS steel specimens under irradiation .     

冷轧和退火对V-5Cr-5Ti合金组织结构和抗辐照硬化性能的影响

钒合金(V-5Cr-5Ti)是聚变堆第一壁以及包层的重要候选结构材料。不同加工工艺会对钒合金在聚变堆中的服役性能产生影响。本文利用兰州重离子研究装置(HIRFL)提供的337 MeV的高能Fe离子对不同程度冷轧(冷变形量分别为40%、60%和80%)以及冷轧后退火(1 273 K退火1 h)的V-5Cr-5Ti合金样品进行了辐照,研究了不同的冷轧和退火处理过程对材料抗辐照硬化性能的影响。电子背散射衍射技术(EBSD)测试结果显示,随着冷变形量的增加,样品中细小破碎晶粒比例增大,晶粒平均尺寸减小。退火处理后,细小破碎晶粒出现一定程度的长大,大晶粒几乎全部消失,晶粒尺寸分布更加均匀。维氏硬度结果表明随着冷变形量的增加,硬度随之增加,退火后硬度降低。辐照之后,材料硬度升高,出现了辐照硬化效应。在冷轧样品和退火样品中都观察到了辐照硬化效应随冷变形量的增加显著减弱的现象,这表明冷变形可以显著提高材料的抗辐照硬化能力。结合EBSD和硬度数据,对冷变形和退火处理引起钒合金抗辐照硬化性能变化的机理进行了讨论。讨论结果显示,冷轧使材料总的吸收尾闾增大,引起辐照硬化程度降低,退火处理使材料中晶界密度和位错密度降低,材料的总吸收尾闾降低,辐照硬化效应增加。     

反应堆压力容器钢A508-3辐照硬化的剂量率效应研究

针对不同剂量率对国产反应堆压力容器钢(Reactor Pressure Vessel,RPV)A508-3辐照硬化的影响,利用3.5 MeV的Fe离子在3种不同剂量率(0.1,0.5和1.0 dpa/h)下将样品辐照至4个不同剂量点(0.1,0.3,1.0和3.0 dpa),采用纳米压痕技术表征样品在不同辐照条件下的硬...     

The Effect of Microwave Irradiation on the Crystallization Behavior of PET/PEN Blends

The crystallization behavior of poly(ethylene terephthalate) (PET)/poly(ethylene‐ 2,6‐naphthalate) (PEN) blends before and after microwave irradiation for different time intervals has been investigated by means of wide angle X‐ray diffraction (WAXD) and differential scanning calorimetry (DSC) techniques. It was found that microwave irradiation could greatly affect the crystallization behavior of PET/PEN blends and significantly enhance their degree of crystallinity. For the PET/PEN (90/10) blends, the degree of crystallinity increased from 15 to 45%; for the PET/PEN (60/40) blends, the degree of crystallinity significantly increased, from 1 to 36%. However, with increasing irradiation time, the degree of crystallinity didn't continually increase. It reached a maximum at certain time point. The cold crystallization enthalpy △Hcc gradually decreased as microwave irradiation time increased and the melting enthalpy △Hm vis‐à‐vis the long time interval of such irradiation was decreased. In addition, the mechanism for microwave irradiation affecting the crystallization behavior of polymers is discussed.     

Effect of Magneto-Pulse Processing on the Microstructure and Magnetic Behavior of Amorphous Electrotechnical Steel

The effect of magneto-pulse processing on the microstructure and magnetic behavior of amorphous electrotechnical steel is studied. It is found that the directed ordering of Fe atoms helps to increase specific magnetization of saturation and the coefficient of the squareness of the hysteresis loop, and is related to ordering of the spin system.     

Effect of the Initial Temperature on the Penetration of Tungsten-Based Porous Alloy Strikers with a Hardening Filler into a Steel Obstacle

Technical Physics - We propose a series of experiments aimed at analysis of peculiarities and revealing general regularities in the penetrability of strikers made of a composite material based on...     

药型罩初始孔隙度对聚能射流行为的影响

 多孔材料药型罩由于其可压缩性,在压垮之前受炸药爆炸冲击压缩作用而使温度升高,为延迟射流的断裂时间提供了可能,估算了多孔材料药型罩压垮之前的冲击温升,并结合脉冲X光摄影研究了孔隙度对射流行为的影响。测试结果表明,一定的孔隙度范围内,射流的韧性随着孔隙度的增加而提高,射流直径随孔隙度的增加而变细。     

Effect of Heat Treatememt on Microstructure and Mechanical Properties of the Precipitation Hardening Elinvar Alloy

Russian Physics Journal - This study presents the experimental results of structural analysis of the phase composition, grain size, plasticity, and hardness of the elinvar Ni-span-C alloy 902 after...