材料期刊网

MODELING OF CONTROLLED THERMO-MECHANICAL PROCESSING OF TUBES FOR ENHANCED MANUFACTURING AND PERFORMANCE

D. Jin , E. D. Dominik , R. V. Kolarik II , J. E. Ives and E. B. Damm (The Timken Company , 1835 Dueber Avenue , S.W. , Canton , Ohio 44706-0932 , U.S.A.)

金属学报(英文版)

An integrated mathematical model to simulate seamless tube rolling processes has been developed at The Timken Company. The model is capable of simulating the thermal, deformation and microstructure evolution in the piercing, elongating and reducing/sizing and the austenite decomposition in the mill annealing and cooling operations. Finite difference schemes are employed to model cooling, reducing/sizing and stretch reducing, and finite-element schemes are employed to simulate piercing and elongating. The model predicts the thermal history, deformation, rolling load, torque, recrystallization and grain growth in hot tube rolling, austenite decomposition in cooling or annealing, and the final structure-properties. In this paper mathematical models which are employed to describe the thermal, deformation and microstructure evolution along with the modeling results are presented. The developed "tube rolling mill in the computer" provides a powerful tool for engineers for product and process development, process control, process optimization and quality control.

关键词: modeling , null , null , null , null

NK-HITEN610U2钢板及其焊接头抗H2S应力腐蚀开裂性能

郭志军 , 周建军 , 钟彦平 , 张玉福 , 吴学纲

材料保护

NK-HITEN610U2钢板已在我国用于液态烃球罐,由于液体烃中常含有水分和硫化氢,该材料在湿硫化氢环境中的耐蚀特性尚不明确.对采用回火焊道的焊接接头,经恒负荷拉伸、恒应变、焊接约束试板、氢诱导开裂、断裂韧性等试验和断口分析,对该钢板及其焊接接头在湿硫化氢环境中的抗H2S应力腐蚀开裂(SSC)性能进行了系统研究.发现其因母材中存在夹杂物偏析而对氢诱导裂纹(HIC)敏感,未经热处理的焊接接头,临界开裂应力指数Sc值小于10,材料在H2S介质中的临界应力强度因子KISCC值38 MPa·m-1/2,对SSC有一定的敏感性,认为用该材料在湿硫化氢环境中存在发生SSC的危险.据此,提出了球罐的检验和监控措施.

关键词: 球罐 , NK-HITEN610U2钢 , SSC , 焊接接头

U薄膜制备方法

吕学超 , 任大鹏 , 汪小琳

稀有金属材料与工程

探讨了U薄膜的制备方法.主要介绍了机械抛光、电解抛光、机械轧制、磁控溅射沉积、离子束辅助沉积和聚焦离子束方法等,涉及了精细U薄膜的制备要求.同时,简要介绍了防止U薄膜氧化的后处理手段.

关键词: U薄膜 , 制备方法 , U薄膜抗氧化处理

O2在U和U-Nb合金表面吸附的XPS研究

伏晓国 , 刘柯钊 , 汪小琳 , 柏朝茂 , 赵正平 , 蒋春丽

金属学报

采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa.s),而O2在金属Nb上的饱和吸附量仅约为10 L.

关键词: 合金 , null , null

O2在U和U-Nb合金表面吸附的XPS研究

伏晓国 , 刘柯钊 , 汪小琳 , 柏朝茂 , 赵正平 , 蒋春丽

金属学报 doi:10.3321/j.issn:0412-1961.2001.06.004

采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa@s),而O2在金属Nb上的饱和吸附量仅约为10 L.

关键词: O2 , U , U-Nb合金 , 表面吸附 , X射线光电子谱

STUDY OF PHASES IN U-10wt%Zr ALLOY BY NEUTRON DIFFRACTION

XIE Guoqiang , YANG Jijian , ZHANG Baisheng , LI Wendan(China Institute of Atomic Energy , Beijing) Manuscript received 13 December 1994

金属学报(英文版)

U—10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal structures.The collected diffraction data are processed using Rietveld' s profile technique (with program“ Fullprof ”). Four phases,α-U,δ, γand α—Zr, in the alloy at room temperature and the corresponding volume fractions as well their structural parameters are obtained from the data analysis, For the δ-phase, a partially ordered unusual hexagonal structure of the modified C32(AlB2) type is confirmed.

关键词: :U-10wt%Zr alloy , null , null

Detailed check of the LDA plus U and GGA plus U corrected method for defect calculations in wurtzite ZnO

Computer Physics Communications

Based on a detailed check of the LDA + U and GGA + U corrected methods, we found that the transition energy levels depend almost linearly on the effective U parameter. GGA + U seems to be better than LDA + U, with effective U parameter of about 5.0 eV. However, though the results between LDA and GGA are very different before correction, the corrected transition energy levels spread less than 0.3 eV. These more or less consistent results indicate the necessity and validity of LDA + U and GGA + U correction. (C) 2012 Elsevier B.V. All rights reserved.

关键词: Band-gap problems;LDA plus U and GGA plus U;ZnO;First-principles;augmented-wave method

U.S.Department of Energy Research in Intermetallic Alloys and Composites

Alan L. Dragoo (Division of Materials Sciences Office of Basic Energy Sciences U.S.Department of Energy Washington , D.C.20585) U.S.A.

金属学报(英文版)

关键词:

Huazhong University of Science and Technology(H.U.S.T)

材料科学技术（英文）

关键词:

U68CuCr与U75V钢轨的摩擦磨损行为对比

万永清 , 杨忠民 , 杨西荣 , 王慧敏 , 陈颖

钢铁 doi:10.13228/j.boyuan.issn0449-749x.20150410

通过在MM-200摩擦磨损试验机上轮对滚动摩擦模拟试验，研究U68CuCr、U75V两种钢轨分别与ER8车轮钢轮对滚动摩擦磨损行为。U68CuCr、U75V是相同强度级别，不同硬度的钢轨。结果表明：U68CuCr钢轨硬度略低于U75V钢轨的硬度，但U68CuCr钢轨试样及其ER8匹配车轮的试样的磨耗量显著小于U75V钢轨试样及其ER8匹配车轮试样的磨耗量。同时，U68CuCr钢轨的塑性变形层和白层都比U75V钢轨的厚。

关键词: 摩擦磨损 , 钢轨 , 磨耗量