H.M.Soliman
,
K.E.Mohamed
,
M.E.Abd El-Azim and F.H.Hammad(Metallurgy Dept.
,
Atomic Energy Authority
,
Cairo
,
Egypt)
材料科学技术（英文）
Low and medium carbon steels were aluminized by the pack aluminizing technique using halideactivated pure-Al and Fe-Al packs. The effect of mixture composition, aluminizing temperatureand time and C content of the steel substrate on the structure and thickness of the aluminidelayer, and on the oxidation resistance was investigated. The optimum oxidation resistance canbe achieved with a low carbon steel substrate when the intermetallic phases Fe3Al and FeAlform the surface of the aluminide layer. In this case, the Al concentration at the surface of thealuminide coating is at least ≥15 wt pct. Formation of high Al concentration phases (FeAl3 andFe2Al5) during aluminizing should be avoided as they tend to embrittle the aluminide layer andreduce its oxidation resistance.
关键词:
陆景彬
,
刘运祚
,
孙亮
,
杨东
,
梁国栋
,
王守宇
,
马英君
,
赵广义
,
李险峰
,
崔兴柱
,
李明非
,
霍俊德
,
曾国模
,
竺礼华
,
吴晓光
原子核物理评论
doi:10.3969/j.issn.1007-4627.2005.02.003
在稀土区奇奇核πh11/2(×)νi13/2转动带中, 系统地观测到随转动频率或角动量增加, B(M1)/B(E2)曲线表现出所谓parabola-like形状, 即在增加到某一转动频率或自旋后, B(M1)/B(E2)比值快速增强. 基于推转模型和粒子转子模型关于奇奇核二准粒子转动带磁偶极约化跃迁几率的描述, 对稀土区双奇核的这一行为进行了讨论. 指出该现象的发生与νi13/2准中子转动顺排特性密切相关. B(M1)/B(E2)比值在接近第二带交叉(即BC准中子对顺排)的较高频率处的增强效果, 可以理解为主要来源于带交叉引起的波函数中混合四准粒子成分的结果. 通过对B(M1)/B(E2)比值的增强效果发生在较低频率处的分析, 对稀土区奇奇核πh11/2(×)νi13/2带角动量耦合图像有了进一步认识.
关键词:
高自旋态
,
奇奇核
,
电磁跃迁特性
,
顺排
张阳
,
程文
,
王斌
,
王百亚
,
刘建超
宇航材料工艺
采用缠绕成型的方法制备了F-3A/E复合材料薄壁圆管,通过对比试验研究了树脂配方和增强纤维对管件轴压性能的影响,并对缠绕管件的轴压破坏模式进行研究.同时与F-12/E复合材料进行了对比分析.结果表明:(1)TH-1配方适合F-3A纤维制备复合材料;(2) F-3A/E复合材料缠绕管件轴压承载力比F-12/E复合材料管件的高16.5％～23.9％,且轴压性能具有良好的稳定性;(3) F-3A/E管件轴压破坏形式表现为脆性破坏,而F-12/E管件轴压则表现为韧性破坏模式.
关键词:
复合材料
,
缠绕成型
,
轴压
Zhenya Zhang
材料科学技术（英文）
This study investigated the microstructures and mechanical properties of ZK60 alloy prepared by a simplified rapid solidification powder metallurgy (RS P/M) processing system (S-RS P/M), which consists of warm press in dry air and hot extrusion. Microstructure characterizations showed that S-RS P/M alloy consisted of magnesium matrix and oxide stringers of ~1 μm in width. TEM (transmission electron microscopy) observations illustrated nano-size magnesia particles (10{30 nm) constituted oxide stringer in detail. Due to a relatively higher volume of nano-size magnesia particle produced during S-RS P/M process, 0.2% yield strength of S-RS P/M ZK60 alloy was found to be as high as 382 MPa, which is 10% higher than that of RS P/M alloy. The improvement in mechanical properties is mainly attributed to the combination effects of Orowan mechanism and coe±cient of thermal expansion (CTE) mismatch because of the approximately same average grain size.
关键词:
Microstructure
YANG Ying
,
YAN Qing-zhi
,
GE Chang-chun
钢铁研究学报(英文版)
Modified CNS-Ⅱ F/M steel was designed for in-core components of supercritical water cooled reactor. Study on the hot deformation behavior of modified CNS-Ⅱ F/M steel is of great importance for processing parameter planning and microstructure controlling during hot deformation. The hot deformation behavior of modified CNS-Ⅱ F/M steel was investigated through isothermal hot compression test at temperature ranging from 1223 to 1373 K and strain rate 001 to 10 s-1. The true stress-true strain data gained from compression tests were used to built constitutive equation of modified CNS-Ⅱ F/M steel. The influence of strain on the accuracy of constitutive analysis was incorporated, assuming strain has a influence on material constants. A 5th order polynominal equation with very good accuracy was used to represent the influence of strain on material constant. The flow stresses calculated from the constitutive equation were compared with test values in the whole experiment range and the absolute average error for the constitutive equation in predicting flow stress is 4728%. At last, the recrystallization behavior of modified CNS-Ⅱ F/M steel was investigated. The relationship of critical strain and peak strain with Zener-Hollomon parameter were given by an experimental equation.
关键词:
F/M steel
,
constitutive equation
,
dynamic recrystallization
舒武炳
,
刘朝阳
,
貟伦刚
,
蔡娟
,
宋家乐
高分子材料科学与工程
多官能度环氧树脂F-51与适量二乙醇胺反应,再与乙酸成盐得到一种水性环氧树脂,该树脂保留了较多的环氧基团,与胺类固化剂配合,可作为涂料或复合材料基体.此外,该改性树脂对其它环氧树脂有良好的乳化能力,用适量E-51环氧树脂与之混合,通过相转变法制备的水乳液稳定性好,固化膜综合性能良好,吸水率与溶剂型环氧体系相当.
关键词:
水性环氧树脂
,
相转变
,
反应型乳化剂
Electrochimica Acta
The mechanism of the oxygen reduction reaction (ORR) in a naturally aerated stagnant 0.5 M H(2)SO(4) Was studied using electrochemical methods. The cathodic polarization curve showed three different regions; electrochernical impedance spectroscopy (EIS) measurement was used accordingly. The EIS data were analyzed, and the mechanism for the ORR was proposed consequently. The three regions include a limiting current density region with the main transfer of 4e(-) controlled by diffusion (-0.50V < E < -0.40V), a combined kinetic-diffusion region (-0.40V<E-0.20V) with an additional 2e(-) transfer due to the adsorption of the anions, and a hump phenomenon region (-0.20V<E-0.05V), in which the chemical redox between the anodic intermediate Cu(I)(ads)* and the cathodic intermediate (HO(x))(ads)*, together with the electrochemical reaction, synergistically results in the acceleration of the ORR. Therefore, a coupled electrochemical/chemical process (the EC mechanism) in the hump phenomenon region was proposed, and a good agreement was found between the experimental and fitted results. The EC mechanism was confirmed by the deaerated experiments. (C) 2009 Elsevier Ltd. All rights reserved.
关键词:
Oxygen reduction;Hump phenomenon;Chemical redox;Copper;Electrochemical impedance spectroscopy;sulfuric-acid electrolyte;anodic-dissolution;sulfate-solutions;corrosion;behavior;adsorption;chloride;cu(111);alloy;model
沈朝
,
段振刚
,
孙耀
,
张乐福
,
徐雪莲
腐蚀与防护
采用慢应变速率试验(SSRT)研究了12C>F/M钢在25 MPa,550℃和650℃的超临界水(SCW)中的机械性能,以及在550℃的SCW中的应力腐蚀开裂(SCC)倾向.同时通过均匀腐蚀试验研究了12Cr-F/M钢在550℃/25MPa的SCW中的腐蚀性能.SSRT结果表明,12Cr-F/M钢在550℃/25 MPa时具有优良的机械性能,当温度升高到650 ℃时其机械强度下降明显,但延伸率基本不变.由断口SEM形貌可知,12Cr-F/M钢具有沿晶应力腐蚀开裂(IGSCC)倾向.均匀腐蚀结果表明,12CpF/M钢在550℃/25MPa的SCW中的腐蚀性能较差,其腐蚀增重呈现出抛物线生长规律,1 000 h后其腐蚀增重达741mg/dm2.同时发现其在600 h时表面氧化膜出现裂纹,1 000 h时后观察到氧化膜发生剥落,而氧化膜脱落主要是因为在降温过程中基体与氧化物间不一致的热膨胀系数造成的.
关键词:
腐蚀
,
应力腐蚀开裂
,
机械性能
,
超临界水
肖剑荣
,
徐慧
,
李幼真
,
刘雄飞
,
马松山
,
简献忠
中国有色金属学报
使用CF4和CH4为源气体,利用射频等离子体增强化学气相沉积法,制备了a-C:F:H薄膜样品.采用拉曼光谱仪、傅里叶变换红外光谱仪、X射线光电子能谱仪(XPS)对薄膜的结构进行了测试和分析.研究发现:该膜呈空间网状结构,膜内碳与氟、氢的结合主要以sp3形式存在,而sp2形式的含量相对较少;在薄膜内主要含有C-Fx(x=1,2,3)、C-C、C-H2、C-H3等以及不饱和C=C化学键;同时,薄膜中C-C-F键的含量比C-C-F2键的含量要高.在不同功率下沉积的薄膜,其化学键结构明显不同.
关键词:
a-C:F:H薄膜
,
等离子体增强化学气相沉积
,
低介电常数
,
化学键
YANG Ying
,
YAN Qing-zhi
,
MA Rong
,
GE Chang-chun
钢铁研究学报(英文版)
Ferritic/martensitic (F/M) steels have been recommended as one of the candidate materials for supercritical water cooled reactor (SCWR) in-core components use for its high thermal conductivity, low thermal expansion coefficient and inherently good dimensional stability under irradiation condition in comparison to austenitic steel. CNS-Ⅱ F/M steel which has good mechanical properties was one of the 9-12Cr F/M steels designed for SCWR in the previous work. In this study a modified CNS-Ⅱ F/M steel was used and it′s ultimate tensile strength was 925 MPa at room temperature and 483 MPa at 600 ℃ after optimizing heat treatment parameter. The ductile to brittle transition temperature of modified CNS-Ⅱ F/M steel is -55 ℃. Those are at the same level or even higher than that of CNS-Ⅱ and some commercial F/M steels nominated for SCWR in-core component use. The transmission electron microscope (TEM) results showed that the mechanical properties of the tempered martensite was closely related to the decomposition stage of the martensite.
关键词:
supercritical water reactor
,
ferritic/martensitic steel
,
cladding material
