双辊薄带连铸取向硅钢的研究进展

利用薄带连铸技术生产取向硅钢具有独特的技术优势,国内外开展了大量的基础理论及工业化应用等研究工作,并形成了一些专利技术,但仍处于中试阶段。我国已在实验室条件下采用薄带连铸技术试制出取向硅钢原型钢,其中高磁感取向硅钢的磁感指标达到B8=1.94 T。薄带连铸生产取向硅钢的技术难点主要集中在凝固组织控制、抑制剂析出行为、高斯种子起源、冷加工塑性等方面。本文围绕薄带连铸技术制备取向硅钢的工艺要点和难点,概述了国内外薄带连铸取向硅钢的最新研究进展。最后,指出了薄带连铸取向硅钢的研究方向。     

一种 PLC 控制 L 型大板块包装机的设计

目的针对大板块包膜的特殊需求,设计一种由PLC控制的L型大板块自动包装机。方法通过分析大板块包膜背封、插角和点胶侧封动作的功能要求,采用Pro/E软件分别建立了取膜、背封、四角插封和点胶侧封等机构的三维模型,并对其关键的背封和四角插封机构进行了优化,完成了大板块自动化包装机的设计。结果该包装机能够对2种不同尺寸的大型板块进行完整包膜。结论采用四角插封方式,解决了大板块自动化包膜四角整齐包装的难题,提高了大板块包装机的工作效率和包膜效果。该机能够对不同尺寸的板块进行包膜,且更换组件更简便,具有广阔的应用前景。     

近终形连铸技术的现状及发展趋势

近终形连铸技术生产主要包括薄带及薄板坯连铸技术，是一项集冶金、材料、机械、自控等多学科交叉的重大高新技术。综述了薄主萍板坯连铸技术的国外新进展，分析了存在的问题及发展趋势，讨论了我国在该技术发展和应用上的现状及前景，提出若干建议。     

陶瓷金卤灯用封接材料膨胀系数的研究

为了制造性能良好的陶瓷金卤灯，保证陶瓷放电管和金属电极引线之间形成牢固的气密性封接是一个关键，和石英管不同，陶瓷管无法在加热软化后通过挤压与金属电极引线粘合在一起，为了完成放电管和电极的密封，必须采用合适的封接材料将它们封接起来，因此对陶瓷金卤灯的关键材料Al2O3-Dy2O3-SiO2系封接材料膨胀系数进行了研究。     

双座封系统导斜器的研制与应用

开窗是侧钻施工的基础，也是关键工序。本文介绍了一种具有机械和液压两种既相互独立又相辅相成、互相增效的座封系统导斜器，旨在提高开窗工序的成功率和可靠性。     

2006喷射成形国际会议简介(2)——喷射成形铝合金和喷射轧制技术

喷射轧制技术是将喷射成形与双辊铸造结合起来的一种薄带连铸技术.它是用高压气体将熔化金属雾化为液滴,然后定向地高速飞向轧辊的间隙,将半固态材料热变形为快速凝固的致密带材.     

特殊板壳式换热器封板的有限元模拟及强度研究

 对于板壳式换热器中的特殊开口封板,利用APDL语言（ANSYS parametric design language）实现全参数化驱动的三维有限元模型,通过三维有限元模拟,并对关键区域作路径分析,获得封板的应力分布规律．实验结果验证了数值模拟的有效性．经过分析,归纳出封板中的应力影响因素,提出工程关联式模型．以不开口区环板上的最大综合应力为研究对象,对封板进行参数化数值分析,并对数值模拟结果进行数据处理与拟合,得到封板强度计算工程算式．拟合公式所得数据与原模拟数据相比,平均绝对误差为0.238 MPa,平均相对误差为1.8%,这对于工程应用已经足够精确,可为新产品的工程应用提供参考．     

双辊薄钢带-铸辊界面热流特征的研究进展

综述了双辊薄钢带连铸过程中薄带-铸辊界面热流特征的研究进展.重点阐述了薄带-铸辊界面热流特征的研究方法及其所取得的成果,总结了界面平均热流系数的取值,并分析了界面热流与薄带凝固组织的关系.     

电站工程汽轮机汽封漏气分析及处理方案

在强调可持续发展的今天,如何提高能源的利用率,避免能量的损耗已经越来越受到各行各业的重视。在电站工程中,热力发电是一项非常重要的发电技术。在热力发电中,汽轮机汽封漏气是主要的能量损失形式。本文分析了汽轮机汽封漏气的具体情况,并且提出了减少汽封漏气的若干方案。     

SiO_2改性环氧树脂灌封材料

本文以SiO2作为增强材料,制备了SiO2/环氧树脂灌封材料,研究了不同的SiO2含量和热处理工艺条件对灌封材料性能的影响。实验发现,SiO2的加入对环氧树脂灌封材料的拉伸强度和体积电阻率有显著影响,SiO2含量为3%时环氧树脂灌封材料的拉伸强度达到最大值,并且其体积电阻率亦达到最大值;随着固化温度的提高,SiO2/环氧树脂灌封材料的体积电阻率不断减小,力学性能则先升后降,在固化温度为150℃时其力学性能最好。实验结果表明:SiO2含量为3%,固化温度为150℃时,SiO2/环氧树脂灌封材料的综合性能最好,其拉伸强度为1.6MPa,弹性模量为0.44GPa,体积电阻率为3.26×1013(Ω·cm)。     

Investigation on cracking mechanism of austenite stainless steel during in situ tension in transmission electron microscope

Twin-roll strip casting technology is a new one to produce austenite stainless steel strip directly. However, during this process, the cracking occurs usually on the surface of the steel strip. The technique of in situ tension in transmission electron microscope was used to observe and analyze the crack initiation and propagation in austenite stainless steel produced by twin-roll strip casting technology in this work. The results show that the crack initiates in dislocation free-zone firstly and then propagates along the direction vertical to the tensile force. The crack may propagate in continuous propagation way and discontinuous one respectively. When the shear stress on the close-packing face and the normal stress on the secondary close-packing face are at the same side of the tensile force, the cracks propagate continuously. However, when the shear stress on the close-packing face and the normal stress on the secondary close-packing face are in two sides, the cracks propagate discontinuously.     

Metallurgical investigation on fatigue failure of stainless steel chain in a continuous casting machine

Stainless steels strips (chains) are used for the connection of dam blocks in belt casting machines. Thermal cycling and repetitive stressing under complex loading conditions due to tension and bending are the most frequent function modes during production. Samples from fractured stainless steel strips used for the connection of dam blocks in a copper rod continuous casting line, were sent for failure investigation. Optical and scanning electron microscopy for structural and fractographic evaluation along with mechanical testing are used as the principal analytical techniques in the context of the present investigation. Failure analysis findings suggest strongly that the failure was caused by bending fatigue which assisted also by thermal cycling, initiated from the strip surface and followed by ductile final overload fracture. Final fracture occurred via ductile failure, when the remaining strip cross sectional area reaches a critical size, becoming unable to sustain the operating load. Review of the service history (operating conditions, e.g. process design, applied loads, thermal cycles), in combination to the examination of a potential substitution of the material to a more heat (and fatigue) resistant one are suggested as further fatigue damage preventive actions.     

Fundamental investigation of interfaces in particle reinforced steel sheets processed by thin strip casting

Along the steel industry history, the production of flat‐steel products has technologically evolved towards reducing slab thickness at the output of the continuous casting machine. This development has been related to the incessant requirement of providing a certain steel quality at lower costs. As a result of this procedure, the thin strip casting technology emerged in a commercial scale at the end of the nineties, with all the advantages of a near‐net‐shape manufacturing process. In particularly, the higher energy efficiency and reduced environmental impact turned it as a very promising and attractive technology for the steel industry. With the purpose of obtaining new types of steel sheets, characterized by improved mechanical and tribological properties, reinforced steel strips have been produced by introducing slight modifications to a twin‐roll caster. In this regard, a considerable enhancement of the mechanical properties has been achieved.     

Numerical analysis of the twin-roll casting of thin aluminium-steel clad strips

The production of thin aluminium-steel clad strips by means of twin-roll casting is one of the prospective trends in the development of sheet production. The main advantages of twin-roll casting are low specific energy and resource consumption. Besides this, the resulting compound has a high bonding strength owing to the presence of a continuous thin layer of intermetallic phases having an approximate thickness of 3 µm at the interface of the two metals. At the same time, the quality of the clad strip depends on the microstructure and properties of the aluminium layer formed directly from a melt. A deformation immediately following the solidification of the metal between the two rotated, internally water-cooled rolls has a substantial influence on this aluminium layer. Due to the complexity of observing the processes occurring in the melt pool, a numerical simulation became one of the main methods for their investigation. Simulation is widely used to describe the process of twin-roll casting of monomaterial strips, but so far it has not been used for to comprehensively analyse the process of twin-roll casting of clad strips. In the present paper, a two-dimentional finite-element simulation of the system “clad strip—water-cooled rolls” using the ANSYS software is proposed. A joint analysis is carried out of the heat transfer, viscous flow of aluminium melt, its solidification and deformation resulting in the temperature distribution in the cast metal as well as in the tool. The dependences of the deformation strain and outlet temperature of the clad strip on the main technological process parameters; obtained by numerical simulation, are shown.     

取向硅钢制备工艺及其发展趋势

取向硅钢作为一种重要的铁芯材料,在电力行业中有着广泛的应用.基于生产工艺及技术特点,取向硅钢的制备工艺可以分为传统厚板坯工艺、薄板坯连铸连轧工艺及双辊薄带连铸工艺.传统的厚板坯工艺是工业生产取向硅钢的主要方法,其按加热温度又可分为板坯高温加热、板坯中温加热以及板坯低温加热工艺,其中板坯低温加热工艺具有加热温度低、能耗少...     

AN EXPERIMENTAL STUDY OF THE STRIP CASTING PROCESS OF ALUMINUM ALLOY BY THE TWIN ROLL METHOD

Experimental studies on the twin roll casting process in order to produce thin aluminum alloy strips are presented in this paper. A new twin roll caster was developed as an effective experimental tool. The caster is equipped with a complete casting system incorporating a control and measuring system using multiple sensors and various actuators. The data acquisition system of the caster can measure various process parameters including meniscus, casting speed, and temperature as well as roll gap and pressure. With this system, aluminum alloy thin strips were manufactured and the process parameters such as strip temperature, casting velocity, and pressing force of roll were investigated. Furthermore, the crystallizability, microstructure, and mechanical properties of the strip are evaluated by X-ray diffractometer, scanning electron microscope, and tensile test. The results revealed the ability of the twin roll caster to produce directly the thin strip of aluminum alloy with improved mechanical strength.     

基于CAFE模拟双辊连铸纯铝凝固微观组织

鉴于双辊薄带连铸等轴晶区半固态铸轧组织对产品性能的重要性,基于热传输、流动传输、溶质传输等基本传输过程以及晶粒生长物理过程,建立了双辊连续铸轧纯铝凝固过程的宏观温度场、浓度场、微观组织及枝晶形貌演化的三维数学模型.采用CA-FE法对双辊连续铸轧纯铝在水冷钢辊连续铸轧中的凝固过程进行了模拟,采用光学显微镜研究了铸轧工艺参数对凝固组织的影响.数值模拟结果表明,所建立的数学模型能够合理描述晶粒沿任意角度生长的过程,温度场、溶质场和微观组织形貌的模拟计算结果合理.模拟结果与实验结果基本吻合,检验了模型的正确性.     

轻质核壳结构吸波材料的研究进展

随着现代科技的发展,电磁波辐射对人类的影响越来越大,在电子电路中释放的电磁波会破坏其他设备的性能并且损害人体健康,因此吸波材料的研究显得尤为重要。此外,具有优良电磁性能的复合吸波材料还可以用于制备飞行器隐身材料。这是因为高强度的微波吸收材料具有良好的介电损耗和磁性损耗,同时具有优越的阻抗匹配,而核壳结构的吸波材料是复合吸波材料中较为理想的材料。本文详细介绍了核壳结构吸波材料的合成方法,并根据核壳结构材料的分类及具体应用,阐述了近年来国内外核壳结构吸波材料的最新研究进展。     

连续铸钢前沿技术的工程化

论述了具有我国自主知识产权的高效连铸和薄板坯连铸工程化关键技术的特点；介绍了连续铸钢领域轻压下、液压非正弦振动、电磁连铸等前沿技术的开发现状；阐述了传统连铸技术超高效率、高品质化及近终形连铸、电磁连铸开发的研发方向。     

膜分离技术在垃圾渗滤液处理中的研究与应用

膜分离技术处理垃圾渗滤液在国外已经成熟,国内近年来也已经开始应用.系统地阐述了国内外膜分离技术在垃圾渗滤液中的研究与应用,分析了膜分离技术在垃圾渗滤液处理中的优势和不足,对膜分离技术在未来垃圾渗滤液处理中的发展前景进行了展望.