材料期刊网

Improvement of 3-D FEM Coupled Model on Strip Crown in Hot Rolling

WANG Tao , XIAO Hong , ZHAO Tie-yong , QI Xiang-dong

钢铁研究学报(英文版)

In order to simulate and analyze hot strip crown and flatness accurately and efficiently, the 3-D (three-dimensional) coupled model involved in RPFEM (rigid-plastic finite element method) is improved based on the analytical model of forecasting rolling force distribution. In the analytical model, variational method is employed to solve the lateral flow of metal and influential function method is employed to calculate roll deflection, the lateral distribution of rolling force can be obtained rapidly by iterative strategy. Then the 3-D coupled model uses the result as initial distribution of rolling force to calculate roll deflection and makes the initial on-load roll gap profile close to the final value, so as to reduce iterations and increase efficiency. Compared with previous algorithms, the improved model can reduce the iterations by about 50% and shorten the computing time by about 60% on the basis of the calculation accuracy.

关键词: rolling force , analytical model , RPFEM , coupled model , efficiency

Optimization of Pass Schedule in Hot Strip Rolling

QI Xiang-dong , WANG Tao , XIAO Hong

钢铁研究学报(英文版)

Rolling schedule not only determines the rolling process to be going smoothly, but also affects the shape accuracy and structure properties of finished strip. In order to gain good strip crown and flatness, the calculation formulas of the most suitable rolling force and bending force are deduced. By taking relatively equal load of rolling power and good shape as objective functions, the optimization mathematical models of finish rolling schedule are established. By contrast, the rolling schedules after optimization can improve the rolling mill working status and ensure the strip crown and flatness to be good. At the same time, the setting value of bending force is improved and this leaves more space for on-line shape control.

关键词: optimization , rolling schedule , rolling force , bending force , shape

原生QI成核中间相炭微球的结构

王成扬 , 姜卉 , 李鹏 , 郑嘉明

新型炭材料 doi:10.3969/j.issn.1007-8827.2000.04.003

以含有原生QI的煤沥青为原料,采用热缩聚方法制备出中间相炭微球.用扫描电子显微镜(SEM)观察了中间相炭微球的形貌和断面结构.经初步判断,在实验条件下原生QI成核煤沥青基中间相炭微球更倾向于"地球仪" 型结构.并对以QI为核形成中间相微球的过程进行了分析.

关键词: 原生喹啉不溶物 , 中间相炭微球 , 结构

煤沥青原料中QI含量对中间相有序生长的影响

黄爱华 , 金鸣林 , 李和兴 , 房永征

材料导报

试验是以2种含不同QI的煤沥青为原料,采用变径反应管进行热转化反应制备有序性中间相的研究.试验采用偏光显微镜和扫描电镜(SEM)观察了原料各反应阶段的微观结构,考察了QI对热转化过程中中间相有序生长的影响,分析了热转化过程中软化点及族组分的变化.结果表明:少量的喹啉不溶物含量不会阻碍中间相有序的发展.高QI(2.03%)原料易生成镶嵌结构的中间相体,高温处理后样品呈轴状、短纤维、层片松散的石墨化焦结构;含低QI(0.11%)的原料能生成较好的、大区域的中间相体,域结构的中间相体在外力导向和内部裂解气流的作用下容易生成有序的半焦,高温处理后呈大区域、片层紧密、有序性强的细纤维焦结构.同时研究发现,在热转化过程中可通过测定软化点(SP)和TI含量来确定中间相转化程度.软化点约低于250℃、TI为75%左右时为初始中间相区域体形成阶段、半焦生成的前期.

关键词: 煤沥青 , 热转化反应 , 喹啉不溶物 , 中间相

高软化点各向同性沥青和各向异性沥青中喹啉不溶物的结构研究

刘小红 , 王成扬 , 陈明鸣 , 于宝军

材料导报

以软化点相近的高软化点各向同性沥青和各向异性沥青为原料,经溶剂萃取分离出喹啉不溶物(QI),采用偏光显微镜、扫描电镜、元素组成分析、碘吸附测试和X射线衍射分析,对各向异性沥青的光学织构、QI的形貌及其微观结构进行了分析.结果表明,不同原料来源的各向异性沥青会表现出不同的光学各向异性.对高软化点沥青QI的分析表明,虽然母体沥青的软化点相近,但是具有不同光学各向性的沥青分离出的QI在形貌和微观结构上有较大的差异,各向异性沥青QI的分子交联度、芳香度和缩合度均比各向同性沥青QI小,但是平面分子结构更规整,有序度更高.同时发现,当沥青为各向同性时,母体沥青的分子有序度不如QI高,但当沥青为各向异性时,母体沥青的有序度却高于QI.

关键词: 各向同性 , 各向异性 , 高软化点 , 喹啉不溶物

Ab initio study of the intrinsic exchange bias at the SrRuO(3)/SrMnO(3) interface

Physical Review B

In a recent publication [S. Dong et al., Phys. Rev. Lett. 103, 127201 (2009)], two (related) mechanisms were proposed to understand the intrinsic exchange bias present in oxides heterostructures involving G-type antiferromagnetic perovskites. The first mechanism is driven by the Dzyaloshinskii-Moriya interaction, which is a spin-orbit coupling effect. The second is induced by the ferroelectric polarization, and it is only active in heterostructures involving multiferroics. Using the SrRuO(3)/SrMnO(3) superlattice as a model system, density-functional calculations are here performed to verify the two proposals. This proof-of-principle calculation provides convincing evidence that qualitatively supports both proposals.

关键词: thin-films;weak ferromagnetism;superlattices;anisotropy;bifeo3;srruo3;model

炭/炭复合材料用高性能浸渍剂沥青的研究

许斌 , 李铁虎

复合材料学报 doi:10.3321/j.issn:1000-3851.2003.02.013

根据原生QI杂质由微米级炭粒构成的特性,采用溶剂絮凝法对煤焦油进行了净化处理,以净化煤焦油为原料制备了低QI含量的高性能浸渍剂沥青,对比研究了高性能浸渍剂沥青的流变性能和渗透性能.结果证实:高性能浸渍剂沥青极大地改善了浸渍效果,并且使炭/炭复合材料的力学性能显著提高.

关键词: 炭/炭复合材料 , 浸渍剂沥青 , 原生QI杂质 , 粘度 , 渗透性 , 性能

中温煤沥青喹啉不溶物的脱除及炭化制备针状焦

唐闲逸 , 魏晓慧 , 许德平 , 张海永 , 贺欣 , 熊楚安 , 唐瀚滢

材料研究学报 doi:10.11901/1005.3093.2015.685

以中温煤沥青为原料,研究其在弹管反应器中的炭化以及“反溶剂法”脱出喹啉不溶物(QI)后的精制沥青的炭化效果.结果表明:含有较高QI的非精制沥青不能制备出较好的针状焦,但在500℃,0.2 MPa,10h的炭化条件下,能够得到相对较优热膨胀系数(CTE)的炭化结果;以煤油和洗油为混合溶剂,反溶剂法能够有效地脱除喹啉不溶物,在芳脂比0.4,沉降温度100℃,搅拌时间0.5 h,沉降时间4h,溶剂比1.8、2的条件下,QI含量分别降到0.0914％和0.0695％,将其在500℃、0.2 MPa、10h的条件下炭化,可制备出热膨胀系数(CTE)较低的针状焦.

关键词: 材料合成与加工工艺 , 中温煤沥青 , 反溶剂法 , 喹啉不溶物 , 炭化 , 针状焦

Sputtering Rates of Alloys in Glow Discharge

Jianshi REN and Gongshu ZHANG (Institute of Metal Research , Chinese Academy of Science , Shenyang , 110015 , China)Zhenshu WANG and Jinwei ZHAO (Shanghai University of Technology Shanghai , 200072 , China)

材料科学技术（英）

The sputtering rates of alloys were investigated under constant Ar pressure and voltage supplied.The alloys studied in this work range from binary intermetallic alloys to ternary and quaternary alloys. It is revealed that the sputtering rates of alloy targets under steady states are where q is the sputtering rates of alloys, Ci the weight percentage of i-th component in the alloy,and qi0 the sputtering rate of pure metal of i-th component.

关键词:

中间相炭微球的制备及结构研究

冀勇斌 , 李铁虎 , 艾艳玲 , 程有亮 , 方长青

功能材料

以煤沥青为原料,采用热聚合的方法,在不同的保温时间下制备出中间相炭微球,通过SEM、激光粒度分析和XRD等分析手段对其表面形貌、粒径分布和微晶结构进行了分析,研究了聚合时间对其球形度、表面QI、粒径分布、微晶结构的影响.结果表明:随着保温时间的延长,中间相炭微球的球形度均较好,表面的QI减少,表面变得比较光滑,粒径分布变得比较集中,微晶结构也较好,当进一步延长保温时间,粒径分布又变得比较分散,微晶结构也变差.

关键词: 中间相炭微球 , SEM , XRD , 粒径分布