材料期刊网

Application of Adaptive Threading Technique to Hot Strip Mill

DING Jingguo , HU Xianlei , JIAO Jingmin , SHE Guangfu , LIU Xianghua

钢铁研究学报(英文版)

Thickness deviation of hot strip rolling needs to be strictly controlled in the computer system. An adaptive threading technique was researched, in which the measured data from threaded stands were used to predict thickness and material hardness errors, to modify the setup for the remaining unthreaded stands. After the adaptive threading model was used online on the hot strip mill of the Panzhihua Iron and Steel Group Co Ltd, the thickness deviation was decreased obviously. The hit rate of thickness control of different steel grades increases.

关键词: hot strip mill;adaptive threading;thickness deviation;stretch equation

THEREVERSSE TRANSFOR MATION OF THE STERSS INDUCEDεMIN FE 17MN 10CR 5SI 4NIALLOY

Q.S. Liu1 , 2 , 3) , L.C. Zhao3) , G.X. Dong2) and N.J. Gu1) 1) Heibei University of Technology , Tianjin 300130 , China 2) Tianjin Institute of Technology , Tianjin 300191 , China 3) Harbin University of Technology , Harbin 150001 , China

金属学报(英文版)

Theconstruction changinginthereversetransformation ofthestress induced εMin Fe 17 Mn 10 Cr 5 Si 4 Ni alloy is carefully inspected in transmission electron microscope, and then stress induced εM procedure of reverse transformation is analyzed. The behavior of reverse transformationisdissimilar when the organization of εMis different. The reversetransfor mation ofεM withtheshapeofsingle plateandstripisrelativelyeasy,anditsreversibilityincrystallographiciseasilytocarryout,fortheεM with multilayerstructure,thereversetrans formationtakes placein isolatedlayers, fortheεMthat grows well,thereversetransforma tion isrelatively difficult becauseofthe ductile harmonization between itsinternalorganiza tion structures.

关键词: stress induced εM , null , null

[C16min]Br修饰的多壁碳纳米管及其与低密度聚乙烯复合材料的制备及介电性能

徐佩 , 卢旭鑫 , 汪传斌 , 杨善中 , 孙晓红 , 丁运生

高分子材料科学与工程

为改善多壁碳纳米管(MWNT)在低密度聚乙烯(LDPE)中的分散性及复合材料的界面特性,采用溴化-1-十六烷基-3-甲基咪唑基离子液体([C16min]Br)对MWNT进行表面改性,并用Raman光谱对改性效果进行了表征.将经过修饰的碳纳米管(MIL)与LDPE熔融共混得到MIL/LDPE复合材料,采用场发射扫描电子显微镜(FESEM)和阻抗分析仪(LCR)对复合材料的结构与介电性能进行了分析.结果表明,相比与MWNT/LDPE(渗流阈值为5.2％,介电常数为82,介电损耗为0.93),MIL/LDPE(渗流阈值为9.1％,介电常数为169,介电损耗为0.51)介电常数增大,介电损耗降低.并且在低温时,MIL/LDPE介电常数随温度的变化甚小,显示出良好的温度-介电常数特性.

关键词: 咪唑基离子液体 , 碳纳米管 , 低密度聚乙烯 , 介电性能

住友金属用QSP工艺进行8m／min的高拉速试验

上海金属

关键词:

STUDY ON THE THREESTAGE CREEP OF THE DD3SINGLE CRYSTAL SUPERALLOY

Author X.A. Zhang1) , H.Q. Xia1) , Z.T. Wu1) , Y.F. Han1) , R. Shi2) and G.X. Hu2) \= 1) Mechanical Properties Laboratory , Beijing Institute of Aeronautical Materials , Beijing 100095 , China2) The State Education Commission Open Research Laboratory for High Temperature

金属学报(英文版)

Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, ChinaManuscript received 18 October 1998 The threestage creep behavior of DD3 single crystal superalloy had been studied. The results show that the creeprupture properties of DD3 single crystal satisfy the requirements for high performance turbine blade application. The influence of crystal orientation on the creeprupture property of DD3 single crystal was tested and discussed. An engineering criterion to evaluate the regimes of secondary and tertiary creep is proposed, and this method gives a reasonable result for practical applications. The fractography and TEM micrography of the tested specimens had been studied, and it is determined that the glidecontrolled creep is the basic creep mechanism of DD3 single crystal at intermediate temperature, but the thermally activated processes become dominant at higher temperature.

关键词: threestage creep curve , null , null , null

尼龙612的等温结晶动力学

王玉东 , 付鹏 , 李晓光 , 刘民英 , 赵清香

高分子材料科学与工程

用差示扫描量热(DSC)研究了尼龙612的等温结晶动力学.实验结果表明,在所研究的等温结晶温度范围内(184℃、186℃、188℃、190℃、192℃),尼龙612达到最大结晶速率时的时间、半结晶期和动力学结晶速率常数分别为:O.12min、0.19 min、0.22 min、0.29 min、0.59 min;0.15 min、0.22 min、0.24 min、0.33 min、0.64 min和22.03 min<'-1>、23.28min<'-1>、8.85 min<'-1>、5.15 min<'-1>、1.93 min<'-1>.等温结晶过程符合Avrmi方程,二次结晶现象不明显.在等温结晶过程中得到的Avrmi指数n在1.81～2.32之间,由理论分析可知,尼龙612等温结晶是一维生长和二维盘状生长.由Arrhenius方程求得尼龙612的等温结晶活化能ΔE=-209.5 kJ/mol.

关键词: 尼龙612 , 等温结晶动力学 , 结晶活化能

在不同时间下退火对非晶硅薄膜晶化的影响

靳瑞敏 , 陈兰莉 , 罗鹏辉 , 郭新峰 , 卢景霄

材料导报

用玻璃作衬底在不同温度下用PECVD法直接沉积非晶硅(a-Si∶H)薄膜,在400℃和500℃分别光退火5min、10min、20min、30min、40min、60min、120min,用拉曼光谱分析前后样品,发现随着晶化时间的延长晶化效果越好,500℃退火的薄膜比400℃的晶化效果好.

关键词: PECVD法 , 非晶硅薄膜 , 光退火晶化 , 拉曼光谱

冷却速度对T91相变速度和产物的影响

殷红旗 , 刘永长 , 宁保群 , 徐荣雷 , 张尧卿 , 韩雅静

材料科学与工程学报 doi:10.3969/j.issn.1673-2812.2007.01.030

本文研究了T91钢冷却过程中,不同冷却速度(10 k/min(200 k/min)对相变速度和产物的影响.研究表明不同的冷却速度生成的组织差别较大,在较低速冷却下(10 k/min和30 k/min)的组织为较多的先共析铁素体和板条马氏体,中速冷却(30 k/min和50 k/min)基本都为板条马氏体,在较高速冷却过程中(100 k/min和200 k/min)组织中除了板条马氏体还出现了片状马氏体,另外冷却速度还影响了相变开始点和相变速度.

关键词: T91 , 冷却速度 , 相变

红外光谱法对环氧沥青固化机理的研究

王治流 , 刘全伟 , 杨琥 , 程镕时

高分子材料科学与工程

利用Nicolet 170 SX傅里叶红外光谱仪对环氧沥青在固化温度(120 ℃)前及在恒定固化温度下固化5 min,15 min,35 min,75 min,240 min的基团变化作了跟踪研究,比较了羰基C=O和环氧基特征吸收峰的前后变化,提出了羧酸类化合物与环氧化合物反应的固化机理.

关键词: 红外光谱 , 环氧沥青 , 特征吸收峰 , 固化机理

K423A铸造高温合金的固溶处理

黄乾尧 , 师燕渝

钢铁研究学报

研究了固溶处理,特别是固溶处理时的冷却速度对K423A合金组织和性能的影响.固溶处理温度为1 190℃,冷却速度分别为4℃/min,10℃/min,20℃/min,40℃/min、76℃/min和空冷.结果表明,采用固溶处理工艺可基本消除该合金的枝晶凝固偏析,使γ颗粒析出均匀,从而改善塑韧性.随着固溶处理冷却速度的提高,γ颗粒得到细化.

关键词: 镍基铸造高温合金 , K423A , 固溶处理 , γ相 , 枝晶偏析