Effectiveness of a new automated control system for vacuum-arc remelting

At OAO Metallurgicheskii Zavod Elektrostal, a new automated control system for vacuum-arc remelting has been introduced at vacuum-arc furnace 8. The quality of the ingots obtained after vacuum-arc remelting with the new and old control systems in smelting shop 6 is compared, for EI435 alloy. In vacuumarc remelting, the quality of ingots from furnace 8 exceeds that for ingots from furnace 10. After treatment of the ingots in a 6300 press in forging and pressing shop 2 and in the 250/350 mill in rolling shop 3, metal savings of up to 83 kg per metric ton are noted for the products based on ingots from furnace 8.     

粉末冶金高强度锥齿轮成形模具结构

本文主要介绍在普通国产液压机的上-下二模架上压制高强度锥齿轮的模具结构。高强度锥齿轮由于其力学性能要求高，用粉末冶金方法生产时对压机要求较高，本厂通过将压制阴模放任浮动模板上的模具结构改进，利用同产压机浮动模板的移粉和上模后压功能，在普通国产液压机上，实现了产品的双向压制并且成形位置精确可控，满足通过进口机械压机才能达刊的密度均匀和控制精度高的成形效果，使零件的齿部密度与整体密度仅相差0．03g／cm^3左右。使刚安装在国产普通液压式粉未冶金成形压机上的该模具结构，可批量压制高强度的粉末冶金锥齿轮，使高强度粉术冶金锥齿轮成形可靠，结构简单，操作方便且成本低廉。     

定宽压力机(SP)同步控制原理及调试

针对鞍钢1780机组引进的日本IHI开发的定宽大侧压新技术,对其侧压模块运动轨迹的高精度控制进行分析,并对其同步控制及调试进行了说明.     

Production and application of Baosteel inorganic-lubricant-coated galvannealed automobile steel sheet

The inorganic-lubricant-coated galvannealed automobile steel sheet is a new product that improves the press formability of automobile body panels.In this paper,the production process,physical and chemical properties, press formability,and corrosion resistance of this new automobile steel sheet were discussed.Test results show that this inorganic solid-lubricant galvannealed automobile steel sheet has good surface friction characteristics and press formability.This product also meets the automobile industry's requirements for press formability,phosphate pro-perties,and corrosion resistance after coating.     

带式压滤机在转炉污泥脱水中的应用

通过对CPF2 0 0 0带式压滤机的运行试验和多年生产经验总结 ,对有关数据的测定、分析整理 ,得出带式压滤机对转炉污泥脱水的技术标准 ,对其它机型的带式压滤机处理转炉污泥具有推广使用价值。     

新型压滤机的改进设计

压滤机是镓、镁等稀有金属以及多品种氧化铝生产过程中过滤分离氢氧化铝的重要设备 ,深入分析对比了新旧两种压滤机在过滤氢氧化铝应用过程中的优缺点 ,充分肯定了新型板框式压滤机在生产过程中的优势。     

CONFORM铝连续挤压机主轴系统研究

本文分析了CONFORM连续挤压机主轴系统工作 时的受力情况，主轴受热伸长时在主轴系统产生很大的轴向力，对设备性能影响非常大。设计出一种新型联轴器联接主轴，此联轴器在受很小轴向力的作用时，允许被联接轴作轴向游动，基本消除了轴向力及春对设备性能的影响，此项设计改进已应用于LJ300连续挤压机，效果十分理想。     

预应力全方位压力矫直机研制

通过介绍全方位压力矫直机的研制过程,简述了中国重型机械研究院研制的新型压力矫直机的主要组成和结构特点。通过新的结构设计实现了四个方向同时进行矫直,改善了传统压力矫直机的工作效率,使用预应力机架保证了设备整体刚性,提高了设备长期使用的稳定性。     

交流伺服电机驱动机械压力机的发展

由于交流伺服驱动压力机目前尚不能胜任大吨位压力成形工艺的需要，因此，研制高容量、大扭矩、低转速交流伺服电机，提高大变负荷下交流伺服驱动系统的效率，开发新的传动机构以满足伺服控制和承载能力的需要是现阶段此项技术发展的关键所在。本文分析了机械压力机交流伺服电机驱动的背景，总结了交流伺服驱动压力机的特点及当前的发展现状。     

汽车薄钢板冲压级别分类的一种新方法

提出了一种新的汽车薄钢板冲压级别分类方法,将ＦＬＤ０作为 钢板冲压级别分类的出发点,按ＦＬＤ０的范围将钢板冲压级别分为６级。为了便于实际应用,找到ＦＬＤ０与ｎ、ｒ值及钢板厚度的关系,将钢板冲压级别用ｎ、ｒ值和钢板厚度三者表示。     

新型过滤机在工业领域的应用（续2）

论述新型自动厢式压滤机和带式真空过滤机的工作原理及其应用;介绍其他过滤机在工业领域的应用情况,并简述常用过滤介质的类别、物性与新型彗星式纤维滤料的特点和应用。     

Possibilities of a new cold upsetting method for increasing magnesium plastification

A new cold deformation method of cast magnesium is proposed. The method includes the implementation of the upsetting technique under lateral pressure. The billet is initially placed into a jacket made of ductile metal and then into a container. The billet is affected with a puncheon placed into the container with a gap. Under the press force, the jacket metal flows into the gap and forms the pressure. This results in an increase in the level of compressing stresses, which increases the ductility of magnesium. Deformation tests of cast magnesium samples showed that the relative reduction without destruction can be increased from 12?18 to 60–70%. Such an increase in ductility makes it possible to produce deformed magnesium billets without heating. A simplified removal procedure of the samples from jackets after the completion of deformation is foreseen. It is revealed that the process can be performed at average upsetting pressures of 820–830 MPa, which is acceptable for modern tool materials.     

带式压滤机脱水机理及结构的研究

带式压滤机是近年国外新发展起来的一种新型固液分离设备，本文对带式压滤机脱水机理及结构进行了深入的分析研究，并对其中一些问题提出了自己的看法。     

Detecting undetected HIV-1 variants in African children using degenerate polymerase chain reaction and sequence analyses

CONTEXT: Scientific journals issue press releases to disseminate scientific news about articles they publish. OBJECTIVE: To assess whether press releases about journal articles were associated with publication of subsequent newspaper stories. DESIGN: Retrospective content analysis of newspaper stories, journal press releases, and journal tables of contents. From December 1, 1996, to February 28, 1997, press releases and tables of contents were collected from BMJ, Nature, Science, and The Lancet, along with newspaper stories on scientific research published in The New York Times (United States), Le Figaro and Le Monde (France), El País and La Vanguardia (Spain), La Repubblica (Italy), and the International Herald Tribune. MAIN OUTCOME MEASUREMENTS: Number of newspaper stories that contained reference to articles appearing in the 4 scientific journals, number of newspaper stories that referred to journal articles described in press releases, and the order in which journal articles were mentioned in press releases. RESULTS: Of the 1060 newspaper stories analyzed, 142 referred to journal articles; of these, 119 (84%) referred to articles mentioned in press releases and 23 (16%) referred to journal articles not mentioned in press releases (comparison of proportions, P=.03). Articles described first or second were referenced in more newspapers than articles described later in the press release (P=.01 by chi2 analysis). CONCLUSIONS: Journal articles described in press releases, in particular those described first or second in the press release, are associated with the subsequent publication of newspaper stories on the same topic.     

加快调整产品结构步伐 培育新的经济增长点——对提高我省冶金工业质量和效益的思考

在分析我省冶金产品结构调整的必要性和紧迫性的基础上,阐述了如何抓住机遇调整产品结构,培育新的经济增长点的思路,并提出措施和建议。     

热连轧工艺中定宽压力机的性能特点

结合鞍钢新建１７８０ｍｍ热连轧带钢机组，介绍了当代热连轧带钢机组的最新设备之一－定宽压力机组的组成、作用儿技术特征。通过具体实例，论证了定宽压力机的设置，不仅提高了钢材的收得率，而且大大减少了板坯连铸机的浇铸宽度规格，从而提高了板坯连铸机的生产能力。     

Microstructural Evolution of the 55 Wt Pct Al-Zn Coating During Press Hardening

Press hardening is increasingly being used to produce ultra-high strength steel parts for passenger cars. Al-Si, Zn, and Zn-alloy coatings have been used to provide corrosion protection to press hardening steel grades. The use of coatings has drawbacks such as coating delamination or liquid metal-induced embrittlement. In the present work, the microstructural evolution of Al-Zn coating during press hardening was studied. The 55 wt pct Al-Zn coating can in principle provide both Al barrier protection and Zn cathodic protection to press hardened steel. During the heat treatment associated with the press hardening, the 55 wt pct Al-Zn alloy coating is converted to an intermetallic surface layer of Fe₂Al₅ and a FeAl intermetallic diffusion layer. The Zn is separated from both intermetallic compounds and accumulates at grain boundaries and at the surface. This Zn separation process is beneficial in terms of providing cathodic protection to Al-Zn coated press hardening steel.     

高压辊压机在耐火材料行业的应用

结合国外磨粉设备的生产技术和使用情况，山东镁矿开发了新型高压辊压机，它克服了国外同类设备存在的结构复杂、造价高、机械磨损严重、维修更换复杂等缺点。使用证明，与对辊破碎机和锤式破碎机闭路工艺相比，高压辊压机可以方便地调节物料，提高生产效率，节能降耗，可用做耐材行业的粉碎、研磨机械。     

关于用不同工艺制作的高密度铁基粉末冶金材料性能的研究

可能有几种方法可使铁基粉末冶金零件达到较高密度。二次压制/二次烧结可使密度大于7.3g/cm3,但受到成本与几何形状条件的限制。对一种新方法进行了评价,用这种方法可一次压制得到高使用性能材料,并将其和其他生产工艺进行了比较。比较是利用Ancorsteel 85HP与Distaloy 4800A基本材料进行的。对各种生坯与烧结件性能进行了评价,其中包括:生坯强度,横向断裂强度,拉伸性能及冲击值。数据清楚地证明,拥有专利的[1]ANCORDENSETM工艺(温压)提供的使用性能可与二次压制/二次烧结制作的相比拟。用一次压制达到了生坯密度值的无孔隙密度极限的98.5%。     

新型有机黏结剂HC用于制备冷压球团的研究

采用新型有机黏结剂(HC)代替膨润土制备冷压球团的方法,得到高冶金性能的入炉原料.随着HC和膨润土用量(质量分数,下同)的增加,铁矿球团和含碳球团生球的抗压强度均呈逐渐升高的趋势,当黏结剂用量为1.5％时,抗压强度分别为5264,2012 N/个;生球落下强度随着HC用量的增加而增加,但随着膨润土用量的增加变化趋势不明...