材料期刊网

Transformation Behavior of Precipitates in a W-alloyed 10 wt pct Cr Steel for Ultra-supercritical Power Plants

Xiaoqiang Hu Namin Xiao Xinghong Luo Dianzhong Li

材料科学技术（英文）

Thermodynamic calculation, thermal analysis, and identification and observation of precipitates have been carried out on a W-alloyed 10 wt pct Cr steel by means of ThermoCalc program, differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron microscopy (TEM) with an energy dispersive X-ray spectrometer, respectively. Several critical phase transformation points were determined by combining experimental results with calculations. Two individually stable phases of Nb(C, N) and VN, instead of one single phase MX (X: C, N), M₂₃C₆ or Laves phases, were predicted in the calculated equilibrium phase diagram. An unstable elongated M₇C₃ with relatively higher Cr was detected unexpectedly in the normalized and tempered steel. Two kinds of spherical Nb(C, N) with different size were recognized as the primary and the secondary precipitates of Nb(C, N) which contain different V contents. It was observed that one kind of complex precipitate in a special V-wing shape was resulted from two plate-like VN adhering to coarse primary spherical Nb(C, N).

关键词: Heat resistant steel , 9-12%Cr steel , phase transformation , microstructure , MX precipitate

Transformation Behavior of Precipitates in a W-alloyed 10 wt pct Cr Steel for Ultra-supercritical Power Plants

Xiaoqiang Hu Namin Xiao Xinghong Luo Dianzhong Li

材料科学技术（英文）

Thermodynamic calculation, thermal analysis, and identification and observation of precipitates have been carried out on a W-alloyed 10 wt pct Cr steel by means of ThermoCalc program, differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron microscopy (TEM) with an energy dispersive X-ray spectrometer, respectively. Several critical phase transformation points were determined by combining experimental results with calculations. Two individually stable phases of Nb(C, N) and VN, instead of one single phase MX (X: C, N), M₂₃C₆ or Laves phases, were predicted in the calculated equilibrium phase diagram. An unstable elongated M₇C₃ with relatively higher Cr was detected unexpectedly in the normalized and tempered steel. Two kinds of spherical Nb(C, N) with different size were recognized as the primary and the secondary precipitates of Nb(C, N) which contain different V contents. It was observed that one kind of complex precipitate in a special V-wing shape was resulted from two plate-like VN adhering to coarse primary spherical Nb(C, N).

关键词: Heat resistant steel , 9-12%Cr steel , phase transformation , microstructure , MX precipitate

116HU聚酯亚胺无挥发浸渍树脂的性能及其在风电上的模拟结构试验

王君 , 邹家桂 , 陈政标 , 高建武 , 刘彦坤 , 张杰元 , 宋莎

绝缘材料

　　为解决苯乙烯和甲基苯乙烯在VPI浸渍树脂应用于风力发电机中的不足，采用不饱和聚酯亚胺、引发剂和无挥发活性稀释剂研制出116HU聚酯亚胺无挥发浸渍树脂，并对其各项性能进行了研究。结果表明：116HU聚酯亚胺无挥发浸渍树脂的常规性能满足风力发电机的要求，其耐热等级可达H级。用该树脂浸渍的风电模拟线棒具有优异的介电性能、耐湿热交变和高低温循环冲击性能及耐盐雾性能等，能满足风力发电机在极端环境运行的要求。

关键词: 聚酯亚胺 , 无挥发 , VPI , 风力发电机 , 耐湿热 , 耐盐雾

Li3N在KBH4和NH4Cl合成BN反应中的作用

张黛 , 范慧俐 , 徐晓伟 , 李永寿 , 李玉萍

人工晶体学报 doi:10.3969/j.issn.1000-985X.2003.01.015

采用氮气加压加温方法,以KBH4和NH4Cl为原料,通过在相同的温度、压力条件下,向反应体系中添加和不添加少量Li3N的对比实验,研究Li3N在KBH4和NH4Cl生成BN反应中的作用.反应产物中有无hBN和cBN生成是依据反应产物的X射线衍射图谱(XRD)和傅立叶变换红外光谱(FTIR)中有无hBN和cBN物相出现确认的.谢乐公式被用于估算生成的BN的粒径.结果表明,在650℃、7MPa的反应条件下,以KBH4和NH4Cl为原料没有生成BN的反应发生.但当在原料中加入Li3N后,反应产物中有大量hBN和少量cBN生成,其中hBN的平均颗粒尺寸约为14nm.分析确认,Li3N在上述由KBH4和NH4Cl合成hBN和cBN的反应中起催化作用.而且加入Li3N后,由KBH4和NH4Cl合成BN的反应压力和时间都明显低于Hu等人的相关报道结果.

关键词: 热气压法 , 合成 , 氮化硼 , 氮化锂 , 催化作用

ON SPINODAL BOUNDARIES OF Al-Li ALLOYS

WEI Yinghui , WANG Xiaotian (School of Materials Scince and Engineering , Xi'an Jiaotong University , Xi'an 710049 , China Manuscript received 10 Mareh , 1994)

金属学报(英文版)

The spinodal decomposition can occur in Al-Li alloys containing 5.8-14.2 at.% Li at room temperature. The modutated structure wavelength is approximately 3.1 nm for com mercial Al-LI alloys. The limit composition of the miscibility gap is 3.66 -16.06 at.%Li at 298 K. The highest temperature of the miscibility gap is 377 K.

关键词: : Al-Li alloy , null , null

大爆炸核合成相关的8Li(d, p)9Li反应截面测量

李志宏 , 柳卫平 , 白希祥 , 郭冰 , 连钢 , 颜胜权 , 王宝祥 , 陆昀 , 曾晟 , 苏俊

原子核物理评论 doi:10.3969/j.issn.1007-4627.2005.01.006

利用8Li次级束测量了质心系能量7.8 MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.

关键词: 8Li(d,p)9Li反应 , 角分布 , 天体物理S因子 , 渐近归一化系数

CRYSTAL STRUCTURE OF γ-Li_xFe_2O_3 WITH ELECTROCHEMICAL INSERTION OF Li

HUANG Jianshun CHEN Junming Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China Research Associate , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

Crystal structure of γ-Li_xFe_2O_3,inserted Li electrochemically,was studied by Moss- bauer spectroscopy together with X-ray diffraction,XPS and electrochemical method,On the insertion of Li at low current density,the crystal structure is keeping original spinel; while at higher current density or by thermal activation,owing to violent movement of Li~+ ions,part of crystal structure transforms into rock type similar to face-centered cubic structure of ferrous oxide.The transition channels during insertion of Li~+ ions and limitation of Li~+ ions inserted were discussed.

关键词: null , null , null

Al—Li合金的晶界断裂

姚大平 , 张匀 , 胡壮麒 , 李依依

材料研究学报

本文研究了两种晶粒组织的二元Al-Li 合金拉伸性能与断裂行为。结果表明Al-Li 合金力学性能与晶粒尺寸有关,其断裂行为决定于PFZ 内平面滑移或晶界沉淀相与滑移的交互作用。

关键词: Al—Li合金 , intergranular fracture , planar slip

Effect of Li(3)N additive on the hydrogen storage properties of Li-Mg-N-H system

Journal of Materials Research

The effect of Li(3)N additive on the Li-Mg-N-H system was examined with respect to the reversible dehydrogenation performance. Screening Study with varying Li(3)N additions (5, 10, 20, and 30 mol%) demonstrates that all are effective for improving the hydrogen desorption capacity. Optimally, incorporation of 10 mol% Li(3)N improves the practical capacity from 3.9 wt% to approximately 4.7 wt% hydrogen at 200 degrees C, which drives the dehydrogenation reaction toward completion. Moreover, the capacity enhancement persists well over 10 de-/rehydrogenation cycles. Systematic x-ray diffraction examinations indicate that Li(3)N additive transforms into LiNH(2) and LiH phases and remains during hydrogen cycling. Combined structure/property investigations suggest that the LiNH(2) "seeding" should be responsible for the capacity enhancement, which reduces the kinetic barrier associated with the nucleation of intermediate LiNH(2). In addition, the concurrent incorporation of LiH is effective for mitigating the ammonia release.

关键词: complex hydrides;improvement;mixtures;imides;amide;h-2

SUPERPLASTICITY OF A RAPIDLY SOLIDIFIED AI-Li ALLOY

MANG Weishi WANG Guozhi ZHANG Yongchang HU Zhuangqi SHI Changxu Institute of Metal Research , Academia Sinica , Shenyang , China Yongchang Associate Professor , Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

A rapidly solidified microcrystalline Al-Li-Cu-Mg-Zr alloy and its superplasicity have been investigated.An optimum tensile elongation of 585% was obtained at 540℃ and strain rate 1.67×10~(-2)s~(-1).The superplastic Al-Li alloy is manufaetured using thermomechanical pro- cessing:solution,overaging,warm rolling and recrystallization.Microstructural changes in thermomechanical processing and cavitation occurred during superplastic deformation have been observed.The superplastic failure of alloy may be caused mainly by nucleation and growth of cavities as well as the linkage around grains.

关键词: superplasticity , null , null , null