材料期刊网

Finite Element Simulation of Hot Strip Continuous Rolling Process Coupling Microstructural Evolution

WANG Minting , ZANG Xinliang , LI Xuetong , DU Fengshan

钢铁研究学报(英文版)

Using the nonlinear rigidviscoplastic finite element method (FEM), a finite element simulation of the hot strip continuous rolling process was done, which completely integrates different phenomena such as the metallurgical behavior of the strip and the thermomechanics in the strip based on the physical metallurgical microstructural evolution law. By combining with the process parameters of certain 2 050 mm hot strip rolling, an actual rolling process of low carbon steel SS400 was simulated using the FEM model. Based on the simulation results, the distributions of the strain field, the temperature field, and the microstructure were presented. Meanwhile, the simulated rolling force, temperature, and microstructure are in good agreement with the measured results.

关键词: hot rolling;FEM;microstructure;coupling

Analysis of Metal Forming in TwoRoll Cross Wedge Rolling Process Using Finite Element Method

WANG Minting , LI Xuetong , DU Fengshan

钢铁研究学报(英文版)

A simulation model for tworoll cross wedge rolling (CWR) was presented by using threedimensional rigidplastic finite element method (FEM). The whole forming process of CWR, including knifing zone, guiding zone, stretching zone, and sizing zone, was simulated using the model in which dynamic adaptive remeshing technology for tetrahedral solid elements was used to fix element distortion. Based on the simulation results, the distributions of metal flow field, strain field, and damage field, and the geometry of the workpiece′s end were analyzed. These results could provide theoretical guidance for realizing net shaping and reasonable design of tools.

关键词: cross wedge rolling;finite element method;plastic forming;simulation

Coupling Thermomechanical and Microstructural FE Analysis in Plate Rolling Process

LI Xuetong , WANG Minting , DU Fengshan

钢铁研究学报(英文版)

Using threedimensional rigidviscoplastic finite element method (FEM), a coupling multivariable numerical simulation model for steel plate rolling has been established based on the physical metallurgy microstructural evolution rule and experiential equations. The effects of reduction, deformation temperature, and rolling speed on the deformation parameters and microstructure in plate rolling were investigated using the model. After a typical rolling process of steel plate 16Mn is simulated, the strain, temperature, and microstructure distributions are presented, as well as the ferrite grain transformation during the period of cooling. By comparing the calculated ferrite grain sizes with measured ones, the model is validated.

关键词: hot rolling;plate;FEM;microstructure;coupling

DU-Ti合金表面N+Ti+多层Ti/TiN复合膜的制备与耐蚀性

严东旭 , 刘天伟 , 龙重 , 白彬 , 张鹏程 , 黄河 , 郎定木 , 王晓红 , 朱建国

材料保护

采用单一的表面改性技术难以提高贫铀钛合金(Du-Ti)的耐蚀性能.采用等离子体浸没离子注入技术依次在Du-Ti合金表面注入N和Ti,再利用非平衡脉冲磁控溅射技术制备多层Ti/,TiN,研究了膜层的形貌、结构及耐蚀性能.结果表明:膜层厚约3μm,呈柱状结构,致密,但存在一些微缺陷,膜基结合紧密;膜层出现面心立方结构的TiN和密排六方的Ti,在DU-Ti合金界面形成了少量的UO2,没有铀的氮化物;膜层耐蚀性能较基体得到较大提高;微观缺陷是TiN层局部片状脱落的主要原因,外层TiN出现片状脱落后.注入层和内层Ti/TiN多层膜仍能有效保护基体.

关键词: 等离子体浸没离子注入 , 非平衡磁控溅射 , 复合膜 , DU-Ti合金 , 电化学腐蚀 , 耐蚀性

Du Pont推出全新应用的聚烯烃弹性体

合成材料老化与应用

关键词:

基于二氧化碳封存的超临界两相流动的数值研究

高诚 , 胥蕊娜 , 陈黎 , 姜培学

工程热物理学报

格子Boltzmann方法(LBM)在计算复杂结构物理模型时具有独特优势并在模拟两相流动过程中能够高效清晰捕捉相界面.本文介绍了基于Shan-Chen多相模型的格子Boltzmann方法的理论成果以及基于二氧化碳封存的超临界两相流的模拟研究.结果表明,Shan-Chen模型在模拟两相流时符合Laplace定律,且两相层流时的速度分布和相渗曲线均与理论值吻合.二氧化碳封存过程中,较大的注入速率在提高二氧化碳残余俘获量的同时会降低其化学俘获量.

关键词: 二氧化碳封存 , 超临界两相流 , Shan-Chen模型

水平轴风力机专用翼型性能评估方法

李星星 , 杨科 , 张磊 , 刘强

工程热物理学报

本文提出了风力机翼型完整的性能参数体系和相应的评估方法,并以此评估了CAS-W1翼型与DU翼型的性能特征.对翼型性能的评估侧重于失速特性、非设计点特性和翼型气动性能的稳定性.评估结果表明,相对于DU翼型,CAS-W1翼型系列设计点性能和非设计点性能较好,但是失速特性和性能稳定性需要优化.

关键词: 风力机专用翼型 , 气动性能评价 , 失速特性 , 稳定性参数

液晶显示用新型偏光片紫外光谱特性研究

欧阳艳东 , 黄翀 , 余云鹏 , 林舜辉

功能材料与器件学报 doi:10.3969/j.issn.1007-4252.2003.04.020

通过测量ITO玻璃及偏光片对各波段紫外光的光谱特性,分析比较一般偏光片和防紫外偏光片F1225DU的紫外透射光谱,从而说明新型偏光片的防紫外特性.F1225DU对紫外线有比较好的吸收,能挡住各种波长的紫外光,起防止紫外光破坏液晶显示器件的作用.

关键词: 偏光片 , 紫外光 , 液晶显示器 , 透射光谱

150t RH装置内钢液的流动和混合特性及吹气管直径的影响

蒋兴元 , 魏季和 , 温丽娟 , 李波

上海金属 doi:10.3969/j.issn.1001-7208.2007.02.008

在几何相似比为1∶4的水模型上研究了150t RH装置内钢液的流动和混合特性及吹气管直径的影响.模型的吹气管内径分别为0.10、0.15和0.2 cm.所得结果表明,该装置的环流量计算式为:Qlp＝0.0291Qg0.323Du0.65Dd0.84(t/min),式中Qg-提升气体流量, Nl/min;Du和Dd-上升管和下降管内径,cm.在给定的Qg、Du和Dd下,吹气管直径din的变化对液体的流态没有显著影响,环流量则略有改变,在(0.40～0.80)cm的范围内,Qlp＝0.0304Qg0.322Du0.651Dd0.839din0.07.在Du和Dd均为53 cm、din为0.60 cm的情况下,该装置内钢液的最大("饱和")环流量约为135.1 t/min,相应的Qg为2500 Nl/min.钢包内钢液的混合效果随Qg的增大迅速提高.增大din使混合时间τm(s)略有缩短,对应于0.10,0.15和0.20 cm的孔径,τm与搅拌功率密度ε(W/t)的关系分别为:τm ∞ε-0.497,τm ∞ε-0.493和Tm∞ε-0.476.

关键词: 150t RH装置 , 水模型 , 流动特性 , 混合特性 , 物理模拟 , 吹气管直径

钝尾缘翼型非定常气动特性及机理

张磊 , 杨科 , 徐建中 , 张明明 , 白井艳

工程热物理学报

钝尾缘翼型气动特性受到尾涡脱落的影响,在翼型DU 91-W2-250的基础上对称加厚得到了新钝尾缘翼氆DU91-W2-250_6,利用密网格进行了非定常气动特性的数值研究.在各个攻角下钝尾缘翼型气动特性都具有周期性的特点,具体的波动特征如波动幅值及周期等则受脱落涡的大小、脱落位置及尾迹宽度的影响,而升力系数波峰、波谷则分别出现在顺时针涡及逆时针涡脱落的时刻.

关键词: 翼型 , 钝尾缘 , 非定常