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3.D Finite-Element Numerical Simulation of Centrifugal Induction Electrosalg Casting Solidification Process

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Journal of university of science and technology {3. 2001年第4期8卷 254-258页

作者： xichun chen, deguang zhou, jie fu,{3., university of science and technology beijing beijing 100083. China Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China

A 3.D finite-element numerical simulation model of temperature field for CIESC casting solidification process was developed with the aid of ANSYS software and a series of corresponding experiments were made. The results showed that the good agreement was obtained between the numerical simulation and the experiments. Based on the numerical simulation results, the characteristics of temperature distribution in the castings during CIESC solidification process were analyzed and summarized. According to the G/R-1/2 method and numerical simulation results, there is no any shrinkage defect in the CIESC casting and structure or casting is fine and compact.

关键词： 3.D finite-element numerical simulation ANSYS software solidification process centrifugal induction electroslag casting (CIESC) shrinkage defect

Study on Oxygen Content, Inclusions and Fatigue Properties of Bearing Steels Produced by Different Processes

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Journal of university of science and technology {3. 2001年第1期8卷 25-27页

作者： deguang zhou jie {3. xichun chen Jing Li metallurgy school, university of science and technology-beijing, beijing 100083. China Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China

The metallurgical properties and fatigue life of bearing steel processed by electric furnace (EAF), ladle refining (LF-VD), continous casting (CC) and electroslag remelting (ESR) have been investigated. The main results obtained are as follows: (1) Due to low oxygen content and dispersion inclusions in steel, the fatigue Life of LF-VD-IC or CC is three times as high as that of EAF steel; (2) The oxygen content in steel produced by CC process is about 9.0x10(-6), the carbon segregation (C/C(0)) is from 0.92 to 1.10 and the fatigue life of CC steel is equal to that of ladle refining ingot casting steel; (3. Although the amount of inclusion and oxygen in ESR steel is higher than that of LF-VD-IC or CC steel, the fatigue life of ESR steel is higher than that of the latter because of its fine and well dispersed inclusions.

关键词： bearing steel ladle refining continuous casting electroslag remelting oxygen content inclusion fatigue life

Precipitation Behavior of TiN in Bearing Steel

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Journal of Materials science & technology 2003年第2期19卷 184-186页

作者： deguang zhou, jie Ftf, {3. and Jing LIInstitute of Electric metallurgy, university of science and technology beijing, beijing 100083. China Inst. of Elec. Metall. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The precipitation behavior of titanium nitride (TIN) in bearing steel and effects of TiN inclusions on quality of the steel have been studied by thermodynamic calculation and experiment. The results show that with the increase of the content of Ti and [N], the properties of bearing steel decreased; adjusting the content of N and Ti could influence the precipitation occasion and condition of TiN in the steels. If Ti content is less than 3.x10-6 and nitrogen content is less than 53.10-6, the temperature of TiN precipitation is under the solidus temperature and the size '\s small so that they have little harmful and even beneficial effect on the properties owing to grain refinement.

关键词： Bearing steel Precipitation TiN

Characteristics and stability of oxide+carbonitride in H13.steel at 1250℃

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Journal of Iron and Steel Research International 2024年第1期31卷 134-142页

作者： Xiao-lin Sun Han-jie Guo Jing Guo Fei Wang Dong xu Gao-yang Song Shuai Wang school of Materials science and Engineering Hebei University of EngineeringHandan056038HebeiChina school of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China High Temperature Materials Research Institute Central Iron and Steel Research Institute Co.Ltd.Beijing100081China technology Innovation Center for High Quality Cold Heading Steel of Hebei Province Hebei University of EngineeringHandan056038HebeiChina

The morphology,size,quantity,and composition of complex oxide+carbonitride in H13.steel held at 1250℃for 5,10,and 15 h were *** results show that the ratio and number of complex carbonitrides with cores in H13.steel are gradually increased when holding at 1250℃compared with those in the original H13.steel,and the core size *** are one or more oxide cores in(Ti_(x),V_(1-x))(Cy,N_(1-y)),including xCaO·zAl_(2)O_(3.,xCaO·yMgO·zAl_(2)O_(3.,and CaO after holding at 1250℃,in addition to MgO·Al_(2)O_(3.and Al_(2)O_(3.in the original *** equilibrium temperature for(Ti_(x),V_(1-x))(Cy,N_(1-y))precipitation at the solidification front and decomposition in the solid state was theoretically analyzed,which was affected by the x value and the product of Ti and N contents in H13.***,the composition of(Ti_(x),V_(1-x))(Cy,N_(1-y))is influenced by the oxide *** is convinced that(Ti_(x),V_(1-x))(Cy,N_(1-y))with oxide cores has a higher stability,especially for oxides with a high Al_(2)O_(3.*** treatment at high temperature facilitates a more reasonable analysis of oxide+carbonitride,and the generation mechanism of oxide+carbonitride was discussed.

关键词： Complex carbonitride Decomposition Oxide core Characteristic Stability

A facile self-catalyzed CVD method to synthesize Fe3./N-doped carbon nanofibers as lithium storage anode with improved rate capability and cyclability

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Journal of Materials science & technology 2020年第9期44卷 229-236页

作者： Liang chen Zhi Li Gangyong Li Minjie zhou Binhong He jie Ouyang Wenyuan xu Wei Wang Zhaohui Hou school of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang414006China State Key Laboratory of Advanced metallurgy University of Science and Technology BeijingBeijing100083China

Uniform Fe3.C/N-doped carbon nanofibers were successfully synthesized through a facile self-catalyzed CVD method by using acetylene as carbon source and Fe3.4 as iron source and autocatalytic template for the reaction under moderate preparation conditions. The experimental and theoretical calculation results demonstrate that Fe3.C can improve the lithium storage performance of carbon nanofibers. Besides, the addition of PPy can not only control the growth rate of carbon fibers but also help to form uniform carbon fibers. As a result, the obtained Fe3.C/N-doped carbon nanofiber composites display favorable electrochemical performance as an anode for lithium-ion batteries, which including satisfactory rate performance of 402 m A h g-1 under 1.2 Ag-1, and good cycling stability of 502.3.m A h g-1 under 200 m Ag-1 over 400 cycles. The introduction of Fe3.C species and the uniform carbon fiber morphology are responsible for the long-cycling and high rate performance of materials.

关键词： Self-catalyzed CVD Fe3. N-doped carbon fibers Anode materials Lithium-ion batterie

Sintering kinetics involving grain growth and densification of Mg-PSZ nanopowders

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Journal of Iron and Steel Research International 2022年第7期29卷 1138-1144页

作者： Yi-ming She jie-fu Lang Di An Chao-wei Si xu-dong Luo Zhi-peng Xie jie-gang You school of Materials and metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina Institute of Advanced Structures Beijing Institute of TechnologyBeijing 100081China State Key Lab of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Sintering kinetics have been found to be effective in judging the evolution of *** using magnesium oxide-partially stabilized zirconia(Mg-PSZ)powder prepared by co-precipitation as raw materials,the evolution of densification and grain growth for Mg-PSZ ceramics were *** results indicated that the densification of samples was mainly controlled by grain boundary diffusion in intermediate sintering *** the sintering process,the grain growth mechanisms included normal grain growth,abnormal grain growth and solid solution drag-controlled grain ***,the apparent activation energy for grain growth of Mg-PSZ ceramics is lower than that of ZrO_(2)–Y_(2)O_(3.ceramics in the solid solution drag-controlled grain grow process,which will cause grain to grow *** sintering kinetics and microstructure of Mg-PSZ ceramics were studied,and the kinetic equation of grain growth at different temperatures was *** results show that the strength difference between Mg-PSZ and yttrium oxide-stabilized zirconia is closely related to the easy grain growth of Mg-PSZ ceramics.

关键词： Magnesium oxide-partially stabilized zirconia Sintering kinetics Grain growth mechanism Densification mechanism Sizing nozzle

Enhancement of magnetic properties and thermal stability of nanocrystalline (NdDyTb)_(12.3.(FeZrNbCu)_(81.7)B_(6.0) alloy with Co substitution

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International Journal of Minerals,metallurgy and Materials 2009年第6期16卷 696-700页

作者： Xiao-qian Bao Wei Li jie Zhu xue-xu Gao Shou-zeng {3. State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China College of Materials science and Engineering Yanshan University Qirdauangdao 066004 China

The major drawbacks of Nd-Fe-B magnets are relatively low Curie temperature and poor thermal stability. Ribbons with the near stoichiometric 2：14：1 composition of Nd10.8Dy0.75Tb0.75Fe79.7-xCoxZr0.8Nb0.8Cu0.4B6.0 （x=0, 3. 6, 9, 12, 15） were prepared by rapid quenching and subsequent heat treatment. The effect of Co element on the magnetic properties, thermal stability, and microstructure of the ribbons was systematically studied by vibrating sample magnetometer （VSM）, thermal magnetic analysis, atomic force microscopy （AFM）, and transmission electron microscopy （TEM）. It was found that Co substitution was significantly effective in improving the magnetic properties and the thermal stability of nanocrystalline ribbons. Although the intrinsic coercivity decreased from 13.8.7 kA/m for x=0 to 817.4 kA/m for x=15, the remanence polarization and maximum energy product increased from 0.83. T and 116.5 kJ/m^3.for the Co-free samples to 1.041 T and 155.1 kJ/m^3.for the 12at% Co-substituted samples, respectively. About 10 K increase in Curie temperature was observed for the 2：14：1 phase with 1at% Co substitution. The absolute values of temperature coefficients of induction and coercivity were significantly decreased with Co substitution, which may be attractive for high operational temperature applications. The microstructure of nanocrystalline ribbons was slightly refined with Co substitution.

关键词： nanocrystalline magnets Nd-Fe-B magnets Co substitution magnetic properties thermal stability microstructure

Crystallization behavior of blast furnace slag modified by adding iron ore tailing

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Journal of Iron and Steel Research International 2017年第6期24卷 601-607页

作者： Qian-qian Ren Yu-zhu Zhang Yue Long Shao-sheng chen Zong-shu zou jie Li chen-guang {3. school of metallurgy Northeastern University Shenyang 110819 Liaoning China State Key Laboratory of Advanced Steel Processes and Products Central Iron and Steel Research Institute Beijing 100081 China College of metallurgy and Energy North China University of Science and Technology Tangshan 063009 Hebei China

Blast furnace （BF） slag is a by-product of the ironmaking process and could be utilized to manufacture slag fiber by adding iron ore tailing. The crystallization behavior of the modified BF slag is significant to the fi- brosis process. To investigate the influence of basieity on the crystallization behavior, BF slag was modi- fied by adding iron ore tailing at room temperature and melted at 1 500 ℃. FactSage simulation, X-ray dif- fraction, scanning electron microscopy backscattered electron imaging coupled to an energy dispersive spectrometer, and hot thermocouple technique analysis were performed to explore the crystallization be- havior of the modified BF slag during the cooling process. It was found that the initial crystallization tem- perature increased with the increase in basicity. Melilite, anorthite, clinopyroxene, and wollastonite could be generated during the cooling process as basicity ranged from 0.7 to 0.9. Spinel could be found as one of the phases; however, wollastonite disappeared under a basicity of 1.0. The initial crystallization tempera- ture was controlled by the crystallization of melilite during the cooling process when the basicity of the modified BF slag ranged from 0. 7 to 1.0. Moreover, the cooling rate could also influence the crystalliza- tion of the modified BF slag.

关键词： Crystallization behaviorModified blast furnaceslagBasicityInitial crystallizationtemperatureIron ore tailing

Left-handed properties of a composite structure with metallic wires in a homogeneous Lorentz medium

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International Journal of Minerals,metallurgy and Materials 2012年第2期19卷 159-164页

作者： Yang Bai Fang xu Li-jie Qiao Key Laboratory of Environmental Fracture(Ministry of Education) University of Science and Technology BeijingBeijing 100083China

The electromagnetic properties of a composite structure with metallic wires in a Lorentz medium were studied. The results show that the electromagnetic properties of the medium host influence the plasma resonance of metallic wires and the left-handed character of the composite. The plasma frequency of metallic wires reduces with the rise of permittivity or permeability of the medium host. Also, the negative permeability of the medium can destroy the wires’ plasma resonance and prevent the realization of left-handed properties. The high loss of medium permittivity or permeability also inhibits the metallic plasma resonance. The negative influence of the media host on the left-handed properties of the composite structure can be effectively reduced by proper structure design, such as introducing a nonmagnetic medium in the host or using an anisotropic medium.

关键词： electromagnetic waves left-handed materials plasma resonance electromagnetic interaction