定宽机在2 250 mm热轧生产线的应用

随着连铸连轧技术的迅猛发展,定宽机因其具有生产效率高、宽度压下调整范围大等优势,逐渐替代了重型的立辊轧机而在热轧产线得到广泛应用;对定宽机的主要设备结构及工作过程原理进行了简要介绍,并结合定宽机在首钢京唐公司2 250 mm热轧线生产使用过程中遇到的问题,制定了优化解决方案,在实际生产中取得了较好效果。     

热连轧粗轧机AWC液压位置控制系统的建模研究

通过对采用三级电液伺服阀的1580热连轧粗轧机立辊液压压下系统的研究和分析,建立了立辊AWC液压系统的数学模型.用MATLAB语言对所建立的液压AWC数学模型进行了计算机仿真,并结合液压系统的动态因素对结果进行了分析,为深入研究粗轧宽度控制系统及指导在线调试提供了有益的参考.     

热轧带钢立辊调宽短行程控制模拟研究与应用

针对莱钢1500热连轧机组粗轧段立辊侧压调宽轧制的工艺特点,利用ANSYS/LS-DYNA建立了立辊-水平辊轧制的三维弹塑性有限元模型,研究了不同工况下的带钢轧后头尾端变形(失宽)规律,并据此建立了控制头尾端形状的短行程控制模型。通过比较可以看出,模型能够有效地减小头尾端失宽。这一成果已经应用于莱钢1500热连轧机宽度自动控制(AWC)系统中,并取得良好效果。     

短行程铝挤压机中伺服电机的控制技术

介绍了前上料短行程铝挤压机中的供锭方式、供锭机械手的控制系统工艺流程、硬件构成及程序设计。开发设计的Sinamics S120伺服驱动控制系统,实现了供锭机械手的伸缩定位控制。该伺服控制系统响应快,跟随性能好,具有很高的可靠性,为短行程挤压机的研发提供了技术保障。该伺服系统已应用于实际生产,完全满足工艺要求,生产效率和经济效益均得到不同程度的提高,对后续同类产品的设计起到了借鉴作用。     

基于改进PSO算法的热连轧粗轧短行程控制曲线优化

在对热连轧粗轧短行程控制原理和模型进行深入分析的基础上,采用一种新的进化寻优方法--粒子群优化方法(简称PSO算法),对短行程控制曲线进行优化.为了保证粒子群算法的全局最优性,在算法中采用带有变异算子的改进粒子群算法.经实验仿真证明,采用改进PSO算法优化后的短行程曲线,可以降低板坯头尾宽度偏差,减少头尾切损量,获得满意的效果,PSO算法是一种有效的短行程控制优化方法.     

模糊控制技术在铝电解槽控制的应用

在铝电解槽控制中，由于铝电解槽是一个具有多变量耦合、非线性、时变与大滞后特性的复杂工业过程系统，一些重要的工艺参数因检测技术的限制不能在线测定。难以建立精确的数学模型，而模糊控制技术能很好地适应电解槽这种工业炉窑的生产特性。本文结合铝电解生产的特点，提出“三阶段循环加料”策略。在此基础上采用了模糊控制技术，较好的解决了氧化铝浓度控制的问题。目前该技术巳成功地在各大型铝厂应用。     

热轧带钢宽度控制的改进措施

针对首钢京唐钢铁联合有限责任公司2250mm热轧生产线出现的管线钢头尾宽度偏窄、展宽轧制时宽度控制效果不好、立辊短行程参数维护繁琐效率低等问题,采取了将板坯上下表面温差控制在30℃以内、避免叩头板坯在定宽机处出现打滑、优化定宽机与立辊负荷分配、严格控制来料板坯宽度、开发新的立辊短行程维护工具等改进措施,取得了很好的效果。     

活套控制技术在棒材连轧机上的应用

分析了首钢棒材生产线活套系统的工作原理 ,提出了其在生产应用中的问题及相应的解决方法     

分体组合式导板在粗轧机上的应用

１概况我厂线一车间采用的原料尺寸为１２０ｍｍ×１２０ｍｍ方坯，长度为２５００～２９００ｍｍ。经２０道次的轧制，生产出１０ｍｍ盘圆。粗轧机组分为２组，第１机组为５２０ｍｍ×４四连轧机组，第２机组为４００ｍｍ×２三辊横列式机组。１９９２年４月对５２０ｍｍ轧机进行改造，５２０ｍｍ四连轧粗轧机组进口导卫采用了分体组合式导卫板。经过３年多的使用，取得了较好的经济效益。２　分体组合式进回导卫板的结构特点①该导卫装置在结构上采用了对称分体组合式，两扇导板既能分开（单独修磨）又能组合成一体。左右导板用螺栓联接，…     

磁粉离合器在轧机上的应用

本文主要介绍磁粉离合器、磁粉制动器的特性和它们在金属板带材轧机张力控制系统中的应用，并提供了轧机设计中制动器、离合器的选择依据。     

古代青铜文物保护研究现状及AMT的应用

介绍了古代青铜文物腐蚀的主要产物、青铜病的起因 及危害,概述了国内外青铜文物保护现状,在作者前期研究结果基础上,总结了2-氨基-5- 巯基-1,3,4-噻二唑(AMT)作为青铜文物缓蚀保护剂的缓蚀性能和保护机制,指出了AMT用于青 铜文物保护的优势和未来的研究方向.     

石英晶体微天平在金属腐蚀研究中的应用

简要介绍了石英晶体微天平(Quartz Crystal Microb alance，简称QCM)技术的基本原理，综述了QCM 在金属大气腐蚀、阳极溶解、钝化、局部腐 蚀以及缓蚀剂缓蚀行为和机理研究等方面的应用及其进展，讨论了QCM用于金属腐蚀研究的 优点和局限性.     

快堆包壳用ODS铁素体合金中Ti的强化作用

选用合理的机械合金化工艺,可使合金粉中的弥散相Ｙ２Ｏ３在机械合金化及随后的热固化过程中分解,并生成更加细小和稳定的复合氧化物Ｙ２Ｔｉ２Ｏ７,提高合金的蠕变强度,当合金中Ｔｉ含量大于２．０％,合金经８００℃,２４ｈ时效,将有Ｘ相析出,导致合金的蠕变强度明显降低。『     

焊接热影响区针状铁素体的形核长大及其对组织的细化作用

通过观察焊接热循环冷却过程中不同温度取样直接淬火后的微观组织,研究了焊接热影响区(HAZ)晶内针状铁素体(IAF)的形核长大过程,论证了针状铁素体分割原奥氏体晶粒及细化晶内组织的机理.Auger电子能谱(AES)证实,在TiOx-MnS型复合夹杂物边界附近存在贫Mn区,IAF易于在这类复合夹杂物上形核,单个复合夹杂物能...     

电磁铸造对2024铝合金力学性能和组织的影响

通过光学显微镜、差热分析仪和透射电子显微镜，对比分析了电磁铸造和连续铸造2024铝合金铸态及热处理态的显微组织和力学性能。电磁铸造铝锭的硬度较连续铸造铸锭提高1倍，疲劳性能提高2倍，差热分析曲线显示，电磁铸造试样具有比连续铸造高的热焓，说明其在加热过程中沉淀强化物析出较多。     

IGNITING SHS BY LASER AND ITS APPLICATION TO SELECTIVE LASER SINTERING OF METALLTC POWDER MATERIAL

How to directly fabricate metallic functional parts with selective laser sintering (SLS) process is a potential technique that scientists are researching. Existent problems during directly fabricating metal part by use of SIS are analyzed. For the sake of solving the problems, a new idea of adding self-propagating high-temperature synthesis (SHS) material into metallic powder material to form new type of SIS metallic powder material is put forward. This powder material can release controllable amount of heat during its interaction with the laser beam energy to reduce the requirement to laser power during directly sintering metallic part, to prolong the time of metallic liquid phase existing, and to improve the intensity and accuracy of SIS part. For this reason, SHS material‘s interaction with the CO2 laser beam energy is researched, which proves that CO2 laser beam energy may instantly ignite SHS reaction. On the basis of the above-mentioned researches, the effect of sintering the metal powder material mixing SHS material with CO2 laser is also researched,which shows: there is an optimal blending ratio of various material in the new metallic powder material. Under the optimal blending ratio and SIS process parameters, this new metallic powder material can indeed release amount of heat and SHS reaction may be controlled within the laser sintering. This research result makes it possible that the metallic part is directly sintered with small CO2 laser (less than 50W), which may greatly reduce the volume, cost and running expenditure of SIS machine, be propitious to application.     

IGNITING SHS BY LASER AND ITS APPLICATION TO SELECTIVE LASER SINTERING OF METALLIC POWDER MATERIAL

1.IntroductionSelective laser sintering (SLS) is one of typical rapid prototyping (RP) technology. SLS adopts the idea of a delamination manufacturing, which is not limited by complicated degree of part shape and not needs any frock & mould, to directly fabricate three dimension (3D) solid parts with powder materials. Theoretically, any powder materials, which can felt each other after they are heated, may be SLS materi-als. Range of SLS materials have covered with polymer powder, cerami…     

DIFFERENTIAL SCANNING CALORIMETRY AND X-RAY DIFFRACTION STUDIES ON AGING BEHAVIOR OF Zn-Al ALLOYS

1. IntroductionZinc-based Al alloys have been widely used in metallurgical, mechanical, mineral andother industry due to their excellent castability, wear and friction .esistancell]. The remarkable success has been gained in substituting for Al alloys as wear and friction alloy.However, one of the shortage for Zn-Al alloys is their poor structure stability, which meansthat the transformation would occur when working so that as-cast alloy would not be usedin harsh working condition. The suita…     

ON THE RELATIONSHIP BETWEEN THE EMBEDDED-ATOMMETHOD FUNCTION OF TITANIUM AND TEMPERATURE

1.IntroductionInthemid1980s,DawandBaskesdevelopedanewsemi-empiricalmethodfortotalenergycalculation,i.e.embedded-atommethod(EAM)[',2].Inadditiontopropertieswhichmethodsofthiskindalwayspossess,suchassimplicityforcalculationajscomparedwithahinitiomethod...     

EFFECT OF Mo AND Mo2C ON THE MICROSTRUCTURE AND PROPERTIES OF THE CERMETS BASED ON Ti（C,N）

Effect of Mo and Mo2 C on the microstructure and properties of Ti（C,N）-based cermets was investigated in this article. The results have indicated that the weight percentage of Mo from 5 to 10 can reduce Ti（C,N） grain diameter and thickness of the rim, and Ti（C,N） grain can be wetted by Ni-Cu-Mo liquid so as to get small contiguity of Ti（C,N） grain. In that way, the transverse rupture strength of Ti（C,N）-based cermets has reached 1800-1900 MPa; the fracture toughness has been due to 16-18 MPa.m1/2. But 15 wt pct Mo was not more effective on Ti（C,N）-based cermets, because the thickness of the rim becomes larger. In the circumstance of Mo2 C, 5 wt pct Mo2 C was good for microstructure and properties of Ti（C,N）-based cermets, but 11 wt pct Mo2C has resulted in larger contiguity of Ti（C,N） grain and big Ti（C,N） grain diameter so as to reduce transverse rupture strength and fracture toughness. So that, the effect of Mo on Ti（C,N）-based cermets is better than Mo2C.