材料期刊网

Slag for Decopperization and Sulphur Control in Molten Steel

WANG Jianjun , GUO Shangxing , ZHOU Li , LI Qiang

钢铁研究学报(英文版)

Decopperization in molten steel with FeSNa2S slag was investigated in the laboratory. It was found that with an increase in FeS content of the FeSNa2S slag, the decopperization ratio increased. The decopperization ratio could reach the maximum of 716% in hot metal. The decopperization ratio was closely related to the carbon content, and the higher the carbon content, the higher was the decopperization ratio. Sulphur addition was found in the process of decopperization, and the increase in sulphur content of molten steel was about 02%-042%. However, by adding 30%-50% of BaO to the FeSNa2S slag, the addition of sulfur content in molten steel could be reduced by about 50%. The finer slag system composition was FeS∶Na2S∶BaO=40∶20∶40.

关键词: molten steel;decopperization;FeS

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

Jian ZHANG/Langhong Lou

材料科学技术（英文）

关键词:

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

DL-EPR法评价2205双相不锈钢晶间腐蚀敏感性

徐菊良 , 邓博 , 孙涛 , 李劲 , 蒋益明

金属学报 doi:10.3724/SP.J.1037.2009.00598

利用Thermo-Calc软件并结合金相显微镜,定性研究了2205双相不锈钢在800℃下敏化不同时间后的微观组织演变过程.通过研究扫描速率、介质成分、介质温度和试样表面状态优化了双环电化学动电位再活化法(DL-EPR),并用该优化方法研究了2205双相不锈钢晶间腐蚀敏感性.结果表明:DL-EPR法能定量评价σ相对2205双相不锈钢晶间腐蚀敏感性的影响,随敏化时间延长,σ相含量增多,晶jian 腐蚀敏感性也随之增加.腐蚀形貌的观测验证了这一规律,

关键词: 2205双相不锈钢 , DL-EPR , 晶间腐蚀敏感性 , σ相

Effect of interstitial hydrogen on cohesive strength of Al grain boundary with Mg segregation

材料科学技术（英文）

The effect of interstitial hydrogen on the cohesion of the Al Sigma=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.

关键词: hydrogen;grain boundary;Al-Mg alloys;pseudopotentials;1st-principles

Effect of Interstitial Hydrogen on Cohesive Strength of Al Grain Boundary with Mg Segregation

Xiaoguang LIU , Xiaowei WANG

材料科学技术（英文）

The effect of interstitial hydrogen on the cohesion of the Al ∑=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.

关键词: Hydrogen , null , null

First-principles study on the effect of Mn and N on the cohesion of a gamma-iron grain boundary

Physical Review B

By use of the linear-combination-of-atomic-orbital (LCAO) method for a cluster model, we studied the electronic structure of gamma-from Sigma 11 [1 (1) over bar0](11 (3) over bar) grain boundary doping with N and Mn atoms. The effect of the segregation on the cohesion of the grain boundary is investigated based on the Rice-Wang thermodynamic model. It is found that N could not only largely enhance the cohesion of the grain boundary but also eliminate the detrimental effect of Mn. The cosegregation effect of Mn and N on the cohesion of the grain boundary depends on where they segregate. Nitrogen could be reliably used in alloyed steels as an efficient strengthening element.

关键词: electronic-structure;phosphorus segregation;stainless-steel;embrittlement;austenite;nitrogen;boron;impurities;fracture;metals

First-principle study of electronic properties of Ti3Si1-xAlxC2 solid solutions

Journal of Physics and Chemistry of Solids

The layered ternary ceramics Ti3SiC2 and Ti3AlC2 are isostructural and can form Ti3Si1-xAlxC2 solid solutions combining the advanced properties of both compounds [H.B. Zhang, Y.C. Zhou, Y.W. Bao, M.S. Li, Improving the oxidation resistance of Ti3SiC2 by forming a Ti3Si0.90Al0.1C2 solid solution, Acta Mater. 52 (2004) 3631-3637; E.D. Wu, J.Y. Wang, H.B. Zhang, Y.C. Zhou, K. Sun, Y.J. Xue, Neutron diffraction studies of Ti3Si0.9Al0.1C2 compound, Mater. Lett. 59 (2005) 2715-2719; J.Y. Wang, Y.C. Zhou, First-principles study of equilibrium properties and electronic structure of Ti3Si0.75Al0.25C2 solid solution, J. Phys.: Condens. Matter 15 (2003) 5959-5968; Y.C. Zhou, J.X. Chen, J.Y. Wang, Strengthening of Ti3AlC2 by incorporation of Si to form Ti3Al1-xSixC2 solid solutions, Acta. Mater. 54 (2006) 1317-1322]. In the present work, the solid solutions of Ti3Si1-xAlxC2 (x = 0, 0.25, 0.33, 0.5, 0.67, 0.75, 1) are investigated by first-principle calculations based on pseudo-potential plan-wave method within the density functional theory framework. The results show that as Al content increases in the solid solution, all the bonds have weakened to certain extents, which lead to an unstable structure both energetically and geometrically. The calculated results are compared and discussed with the reported data for the Ti3Si1-xAlxC2 solid solutions. (c) 2007 Elsevier Ltd. All rights reserved.

关键词: ceramics;ab initio calculations;electronic structure;electrical;conductivity;oxidation behavior;mechanical-properties;ti3sic2;temperature;ti3alc2;air;si

GH4169合金高温力学行为本构建模及参数识别

魏洪亮 , 杨晓光 , 于慧臣

材料工程 doi:10.3969/j.issn.1001-4381.2005.04.011

针对涡轮盘用GH4169合金开展了高温下单调拉伸、对称循环及非对称循环的实验工作,结果表明,该材料具有比较明显的循环软化和平均应力松弛特性.采用带Ohno/Wang修正的Chaboche粘塑性理论本构方程,对其表现出的复杂力学现象进行本构建模,介绍了Levenberg-Marquadt非线性优化算法,结合材料实验数据并通过该算法识别了本构方程参数,将本构方程通过用户子程序嵌入到有限元软件ABAQUS中,对GH4169合金的上述实验现象进行了数值模拟,计算曲线与实验曲线取得了较好的一致性.

关键词: 循环软化 , 平均应力松弛 , 本构方程 , 参数识别