材料期刊网

THICKENING DYNAMICS OF TIN PARTICLES IN HAZ OF LOW CARBON STEEL

J.S.Gao , Q.A.Zhang , Y.C.Hong and G.Q.Yin East China University of Metallurgy , Ma’an Shan 243002 , China

金属学报(英文版)

AKinetic modelofthickening of TiNparticlesin heat- affected - zone( HAZ) of low car bonsteelhasbeen proposedinthispaper.Itisalsofoundthatthesolutionofsome TiNparti clesisrapid, andthethickening of TiNparticlesis mainlycontrolled by diffusion of Tiatomforwardinterfaceofinsoluble TiNparticles.

关键词: low carbon steel , null , null , null , null

Department of Metallurgy and Materials Engineering of Chongqing University

YAN Guangting Chongqing University , Sichuan , China.

材料科学技术（英文）

关键词:

Workability Studies in Forming of Sintered Fe-035C Powder Metallurgy Preform During Cold Upsetting

S Narayan , A Rajeshkannan

钢铁研究学报(英文版)

An experimental investigation on the workability behaviour of sintered Fe-035C steel preforms under cold upsetting, have been studied in order to understand the influence of aspect ratio and lubrication condition on the workability process. The above mentioned powder metallurgy sintered preform with constant initial theoretical density of 84% of different aspect ratios, namely, 04 and 06 respectively were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 min at 1200 ℃. Each sintered preform was cold upset under nil/no and graphite frictional constraint, respectively. Under the condition of triaxial stress densification state, axial stress, hoop stress, hydrostatic stress, effective stress and formability stress index against axial strain relationship was established and presented in this work. Further more, attained density was considered to establish formability stress index and various stress ratio parameters behaviour.

关键词: powder metallurgy , failure analysis , plastic behaviour , workability

Studies of the Local Structure and the g Factors of the Cu(2+) Site in Y(2)BaCuO(5)

Journal of Superconductivity and Novel Magnetism

The local structure and the g factors (g(x), g(y), and g(z)) of the Cu(2+) site in Y(2)BaCuO(5) are theoretically studied using the perturbation formulas of the g factors for a 3d(9) ion in orthorhombically elongated octahedra. The orthorhombic field parameters in these formulas are determined from the superposition model and the local geometry of the system. From the calculations, the oxygen octahedron is found to undergo the local elongation Delta Z (approximate to 0.05 angstrom) along c-axis and the relative bond length variation Delta X (approximate to 0.1 angstrom) along a- and b-axes, respectively. The calculated g factors based on the above local structure are in good agreement with the experimental data. The relationships between the anisotropies of the g factors and the low symmetrical (orthorhombic) distortions of the Cu(2+) site in Y(2)BaCuO(5) are discussed.

关键词: Crystal fields and spin Hamiltonians;Electron paramagnetic resonance;Cu(2+);Y(2)BaCuO(5);crystal

Q相-C2S-C4AF-C12A7系列水泥形成的研究

姜奉华 , 徐德龙

硅酸盐通报 doi:10.3969/j.issn.1001-1625.2004.06.006

通过研究Q相与C2S和Q相与C4AF的共存条件,构造Q相-C2S-C4AF水泥系统,对此系统水泥形成条件进行研究.研究表明:Q相与C2S和Q相与C4AF能够共存,可以组成Q相-C2S-C4AF-C12A7水泥系统.在Q相-C2S-C4AF-C12A7水泥系统中,Q相在1270℃开始生成,随着温度的升高,Q相的生成量逐渐增大;采用V2O5对β-C2S具有较好的稳定作用.随着C4AF量的增加,Q相的量也在增加,同时,烧成温度降低.

关键词: Q相 , Q相-C2S-C4AF水泥 , 形成条件 , 抗压强度

Q460C热处理挽救工艺

刘军刚

物理测试

Q460C钢板由于冶炼和轧制工艺不稳定,经常出现伸长率不合格的问题.论述了不同的热处理工艺对Q460C性能的影响.研究表明:Q460C经过正火后,强度明显降低.经过正火控冷后,强度、韧性均满足生产要求,提高了产品合格率.

关键词: Q460C , 热处理 , 力学性能

Q235(G)连铸坯角部横裂纹的影响因素及对策

何天科 , 谢永中

连铸 doi:10.3969/j.issn.1005-4006.2002.04.014

本文对Q235(G)连铸坯角部横裂纹的影响因素进行分析,指出在现有连铸工艺设备条件下,存在易产生角部横裂纹的因素.通过采取措施,铸坯角裂纹得到有效控制.

关键词:

Q460C连铸板坯的高温塑性

段双霞 , 孙建林 , 李志恩 , 富平原 , 雷爱民

钢铁研究学报

在Gleeble-1500热模拟机上测定了Q460C连铸坯的热塑性,深入分析了钢Q460C的高温脆化机理,确定了连铸坯的最佳矫直温度.结果表明,钢Q460C高温脆化受变形速率的影响较大,在第Ⅲ脆性区变形速率越低脆化越严重,实验用钢Q460C的低塑性区确定在660～985℃,连铸坯顶弯、矫直温度应高于985℃,有利于提高塑性,避免连铸坯表面裂纹的产生.

关键词: Q460C连铸板坯 , 热模拟 , 高温塑性

Q460C连铸板坯的高温塑性

段双霞 , 孙建林 , 李志恩 , 富平原 , 雷爱民

钢铁研究学报

在Gleeble1500热模拟机上测定了Q460C连铸坯的热塑性，深入分析了钢Q460C的高温脆化机理，确定了连铸坯的最佳矫直温度。结果表明，钢Q460C高温脆化受变形速率的影响较大，在第Ⅲ脆性区变形速率越低脆化越严重，实验用钢Q460C的低塑性区确定在660~985 ℃，连铸坯顶弯、矫直温度应高于985 ℃，有利于提高塑性，避免连铸坯表面裂纹的产生。

关键词: Q460C连铸板坯;热模拟;高温塑性

Theoretical explanation of the g factor for Cr4+ in Y2SiO5 crystal

Solid State Communications

The g factor of Cr4-- in Y2SiO5 crystal is calculated from a completed high-order perturbation formula, in which not only the conventional contribution to the g-shift Deltag(= g - g(c)) from the crystal-field mechanism, but also the contribution from the charge-transfer mechanism (which is neglected in the crystal-field theory) are considered. The calculated result shows good agreement with the observed value. It is found that the calculated Deltag due to the charge-transfer mechanism is opposite in sign and about 38% in magnitude, compared with that due to the crystal-field mechanism. So, in the studies of the g factor for a 3d(n) ion having high valence state in crystals, the contribution due to the charge-transfer mechanism should be taken into account. (C) 2004 Elsevier Ltd. All rights reserved.

关键词: insulators;points defects;crystal and ligand fields;electronic states;(localized);electron paramagnetic resonance;atomic screening constants;scf functions;cr4+-y2sio5;transition;pressure