Steel-aluminum layered composite with a nanostructured intermediate layer

The results of an investigation into the influence of the degree of deformation on the structure of components of the layered steel-aluminum composite are presented. It is shown that the noticeable structural variations start from reduction ratio ? > 75%, or e > 1.54 in logarithmic units. The plastic deformation mechanism of a brittle intermetallic layer is described. It is shown that the viscoplastic intermediate layer of the steel-aluminum layered composite can be obtained by rolling when bringing the deformation ratio to 90%. As for the submicron structure, it can be obtained at ? > 95%, or e > 3.     

Development of high-activity 252Cf sources for neutron brachytherapy

The Gershenson Radiation Oncology Center of Wayne State University (WSU), Detroit, Michigan, is using 252Cf medical sources for neutron brachytherapy. These sources are based on a 20-year-old design containing < or = 30 micrograms 252Cf in the form of a cermet wire of Cf2O3 in a palladium matrix. The Radiochemical Engineering Development Center (REDC) of Oak Ridge National Laboratory has been asked to develop very compact, high-activity 252Cf neutron sources for use with remote afterloading equipment in order to reduce treatment times and dose to clinical personnel and to expedite treatment of brain and other tumors. To date, the REDC has demonstrated that 252Cf loadings can be greatly increased in cermet wires and with much smaller diameters. Equipment designed for hot cell fabrication of these wires is being tested. A parallel program is under way to relicense the existing source design for fabrication at the REDC.     

On the possibility of producing sap foil by powder boiling

Conclusions It was shown in the investigation that SAP foil can be produced by direct rolling of the powder (ASP-1 powder). The processes consist of cold compacting rolling of the powder, sintering, intermediate rolling, and cold rolling.During the experiments on rolling of powder ASP-1, the dependence of the strip thickness on the fill ratio for SAP was determined. The data obtained are very close to the results published by G. A. Vinogradov for pure aluminum.     

尖晶石基铝电解惰性阳极的研究进展

惰性阳极是铝电解行业比较关注且极富挑战性的课题。本文主要论述了惰性阳极的研究进展及国内外现状，重点阐述了氧化物阳极(SnO2基氧化物阳极及铁酸盐阳极)、金属陶瓷及氧化铈涂层等．并且只有惰性阳极 可润湿性阴极的新型电解槽同时使用才能达到人们所期望的降低能耗、消除污染、降低成本的目的。     

1215MS易切削钢盘条翘皮成因

针对连续4批1215MS盘条均存在翘皮缺陷的现象,首先调查了该4批盘条对应浇次连铸坯投轧盘条情况,排除了整个浇次钢坯均存在质量问题的可能。接着对化学元素、皮下气泡、炼钢工艺和轧制工艺等翘皮影响因素进行了排查,筛选出产生本次翘皮的重点嫌疑因素：轧制温度、钢坯表面质量、夹杂物。然后通过生产试验和实验室研究,确定了产生翘皮的主要因素,最后通过生产实践进行了验证。结果表明,本次1215MS易切削钢盘条翘皮与轧制温度、钢的洁净度相关,与钢坯针孔、振痕无明显相关性。适当提高轧制温度可避免产生盘条翘皮。     

Application of subgrain control to aluminum wire products

Substructure strengthening has been utilized by the wire industry to produce high strength, high conductivity, ductile aluminum wire suitable for electrical usage. This paper describes the choice of alloy additions and production methods necessary for producing and stabilizing a small subgrain structure. The interrelation between the various manufacturing steps, such as casting, rolling, and drawing, and the resulting microstructure which controls the electrical and mechanical properties is discussed. The necessity for strict control of the processing parameters established for various aluminum wire products is emphasized. This paper is based on a presentation made at a symposium on “Mechanical-Thermal Processing and Dislocation Substructure Strengthening”, held at the Annual Meeting in Las Vegas, Nevada, on February 23, 1976 under the sponsorship of the TMS/IMD Heat Treating Committee.     

Evaluation on some important force models for cold strip rolling

To improve the accuracy of rolling force prediction, some important force models were evaluated through applied computation for cold rolling of low carbon steel and aluminum alloy according to measured data on lab mill. The effects of model structure and three important variables ‐ flow stress, contact length and friction coefficient ‐ on the precision of computed force were quantitatively studied. Flow stress was measured with plane‐strain compression test, contact length was based on elastic flattening of work‐roll by Hitchcock, and friction‐coefficient was determined by rolling strain and numerical iteration. In steel rolling Bland & Ford integration model and Bryant & Osborn algebraic equation are better in accuracy than Ekelund and Parkins. In aluminum rolling all the models produce large deviations ΔF_R = 10–20% if flow stress, contact length and friction coefficient are determined with the same method as steel rolling. The elastic deformation of aluminum strip is now taken into account for its low elastic modulus. An effective method to determine plastic and elastic contact has been developed in this investigation. The accuracy of force computation is obviously improved for aluminum rolling.     

Effect of Ecap-Drawing on the Microstructure of a Bimetallic Wire

Metallurgist - The change of the microstructure of a bimetallic wire during one pass of ECAP-drawing at room temperature is considered. It is shown that both layers of the bimetallic wire deform...     

高速线材力能参数预报系统开发

在深入研究各种数学模型的基础上,建立了适合线材轧制的模型,利用VC++和VB联合开发了高速线材力能预报系统。为了提高软件的预报精度,建立了适合高速线材轧制的短时和长时自适应优化模型。在孔型设计时,利用该软件可以提高各机架轧制力、轧制力矩以及轧制功率的预报精度,为校核孔型设计和选择电机提供了指导和参考。通过仿真和软件在现场试用表明,优化后的模型比原模型具有更高的精度,并且在变钢种变规格轧制时误差波动较小。     

Inhibiting Brittle Intermetallic Layer in Magnesium/Aluminum Bimetallic Castings via In Situ Formation of Mg2Si Phase

Metallurgical and Materials Transactions B - A quasi-continuous Mg2Si layer is formed in situ at the magnesium/aluminum interface of bimetallic castings, by selecting a Si-containing aluminum alloy...     

固相轧结铜铝铜双金属复合材料工艺条件优化

借助实验结果，本文得到固相轧结铜铝铜双金属复合材料时的轧制功率，快慢辊侧轧制力矩之比以及产品了强度的回归表达式，在此基础上建立了多目标最优化模型，进而求得固相异步轧结铜铝铜双金属复合材料的最佳工艺条件。     

采用爆炸-轧制法制备钛/铝复合板

主要对制备1．5mm钛／铝复合薄板的爆炸一轧制工艺进行了实验研究。通过实验，确定了TA1和2A12这两种合金的爆炸焊接工艺参数。为了解决单张复合板在轧制过程中缠绕轧辊的问题，提出了两张爆炸焊接钛／铝复合板的对称轧制工艺，并且得到了成功的应用。对于轧制过程中复合板钛层表面出现的间歇性开裂现象，也进行了详细的分析。两种基体金属流动变形的不同步性以及铝对钛产生的不均匀牵引变形力是导致复合板钛层表面开裂的主要原因。     

提高轧机导卫辊寿命的研究

在分析棒、线材轧机使用的Gx铸造合金导卫轶失效形式的基础上，对不同热处理状态的GJH-2合金和Gx铸造合金，在不同温度下的高温磨损特性进行了对比试验，并将GJH-2合金制成导卫辊在轧机上进行了装机试验，试验结果表明，用GJH-2合金代替Gx铸造合金制作导卫辊可以大幅度提高导卫辊的使用寿命和经济效益，GJH-2合金导卫辊的使用寿命是Gx铸造合金辊的16.5倍。     

Highly efficient casting-rolling units for making wire rod and reinforcement bar

The Elektrostal’ Metallurgical Plant has operated the world’s first casting-rolling unit (CRU) since 1978, this unit having been designed and built in a collaborative effort with VNIIMETMASh and Moscow State Technical University. The unit was the first in the world to be able to commercially produce wire rod of special steels and alloys by directly (without the cutting of ingots) continuous casting and rolling. One of the most important innovations made here — a feature that determines the structure and specifics of operation of the unit — is the inclusion of a planetary section mill designed by VNIIMETMASh. The planetary mill realizes an elongation factor of up to 50 and takes the place of 18–20 conventional two-high stands. One of the most important characteristics of the unit is the reduced metal loss: this index is 5–8 times less than in the technology traditionally used to make wire rod.     

15架Y形连轧机轧制钛及钛合金线材的工艺研究

阐述了钛及钛合金的塑性变形特性,分析了Y型轧机的结构及孔型系统,提出用15架Y形连轧机轧制钛及钛合金线材。对连轧常数和连轧张力进行理论分析,通过试验研究确定了钛及钛合金线材连轧张力,从而为低成本、多品种的钛及钛合金线材的生产提出了新的思路,为满足航空航天等高科技领域对钛及钛合金线材的需求奠定了良好的基础。     

双金属复合轧制图解法配料的研究

本文研究了在20锡铝-钢双金属复合轧制过程中,影响钢层和20锡铝合金层厚度变化的因素,根据我厂多年的生产原始数据,通过画图分析,从而提出一个适合于双金属复合轧制的图解法配料方案。     

碳含量和控冷工艺对盘条ER70S-6性能及组织的影响

对3炉不同碳含量的焊接用钢盘条ER70S-6控冷工艺进行了研究，发现提高吐丝温度虽可以降低盘条的强度，但盘条中易出现混晶组织，碳含量小于0.08%可以使盘条的强度控制在较低水平。盘条拉拨试验结果表明，马氏体组织是引起脆断的重要原因，对盘条化学成分和冷却速度的控制是生产具有优良加工性能焊接用钢盘条的必要措施。     

Physicochemical aspects of technology of the Al2O3-Al layered cermet obtained using reaction sintering

Certain features of the technology of the Al₂O₃-Al layered cermet obtained by the reaction sintering (RS) in air of powdered billets that were fabricated by pressing the charge from the PAP-2 plateletshaped aluminum powder. The RS process was activated by the introduction of a dry residue of liquid glass (DRLG) into the charge (C = 3?C28%). According to the data of the X-ray phase analysis, the sintered material contains (vol %): Al (61?C82), ??-Al₂O₃ (8?C25), Na₂Si₂O₅ (2?C15), and Si (1?C14). Oxide phases and silicon are nanodimensional morphological objects (13?C100 ??m) in the layered aluminum host. The cermet density is 2.1?C2.45 g/cm³, tensile strength is 45?C90 MPa, and the ultimate bending strength is 320 MPa. The activation of RS by a small DRGL additive (3%) retains the layered cermet structure. It is leveled at a considerable increase in the RS time (up to 600 min) or C (up to 28%) because of recrystallization and involves plateletshaped aluminum particles in the chemical interaction.     

The spatial distribution of nucleation sites and its effect on recrystallization kinetics in commercial aluminum alloys

Particle distributions play a major role in the processing response of aluminum alloys. While large constituent particles play an important role in the nucleation of recrystallization, small particles may heavily restrict the growth of recrystallized grains. In the present investigation, a two-dimensional (2-D) tesselation procedure has been used to characterize the particle distribution in commercial aluminum alloys and its relevance to nucleation of recrystallization. This procedure enabled the quantification of the degree of particle clustering in samples rolled to different strain levels. A characteristic aspect seems to be a transition from a rather nonuniform spatial distribution at low rolling strains, toward a more or less random distribution at high strains. Nucleation kinetics has been found to be site saturated, indicating that all nucleation events effectively occur at the start of recrystallization. A simple model is proposed, which explains the development of the spatial particle distribution as a function of rolling strain.     

高速线材10道次精轧过程的有限元模拟

通过对钢厂高速线材热连轧过程的传热分析,借助ABAQUS软件建立了线材与轧辊的3维热机耦合模型,对42A钢(0.39%～0.46%C)从Φ16 mm精轧至Φ5.5 mm轧材的10道次精轧过程的温度场,应力-应变场和轧制力进行了模拟。得出精轧后轧件心部温度升高130℃,表面温度降低10℃,轧件降温主要是轧件的热辐射和水冷造成的。10道次轧制力的计算值与实测值的相对误差为1.88%～4.50%。