钙处理钢用连铸中间包滑板的损毁原因与改进措施

介绍了宝钢连铸中间包铝碳锆滑板在浇铸钙处理钢过程中较易发生的异常情况,主要包括滑程的熔损、滑板问的渗钢以及镶锆环滑板的锆环破碎等.从滑板本身质量和实际操作可能存在的问题等方面分析了导致这些异常损毁的原因,并提出了优化滑板的材质体系及结构改进的措施.     

性能优良的Al2O3—C质滑板

目前,普遍使用碳结合Al_2O-C质砖作为SV系统的滑板 品用公司从1977年起开发碳结合Al_2O-C滑板。并且为改进滑板的性能,进行了滑板材质的改进 结果,钢包用的碳结合Al_2O_3-ZrO_2-C质滑板及高氧钢冶炼用的低温烧成的Al_2O-C质滑板均已被开发出来 本文概括介绍了这些改进后的滑板。     

挡渣滑板用锆板性能改进及应用

分析了某钢厂300 t转炉镶锆挡渣滑板的使用现状及内滑板锆板和锆管剥落的原因。通过造粒、控制稳定度改进锆板/锆管的性能，使其兼具良好的力学性能和抗热震性能；同时改进挡渣滑板的结构，将内滑板锆板与锆管做成一个整体部件以提高其抗机械破坏能力。改进后的挡渣滑板解决了原有锆板/锆管剥落问题，使用寿命可望提高到25次。     

我国高速动车组用浸金属炭滑板的服役工况及损伤特点的调研

受电弓滑板/接触网导线是高速铁路弓网中的关键耦合部件,其中纯炭滑板和浸金属炭滑板是高速动车组用受电弓滑板不可或缺的选材。基于优先保护接触网导线的原则,大幅度提高炭滑板的安全性和使用寿命已成为弓/网系统优化升级迫切需要解决的问题。滑板材料自身的组织结构及其服役工况直接影响弓/网系统的载流摩擦状态和载流效率。调研高速动车组用炭质滑板的服役工况及损伤规律可为动车组弓/网运行状态的评判、滑板材料的对应选材及组织结构优化提供科学依据。本文综述了高速动车组选用炭质滑板的发展历程,并以某干线高速动车组用浸金属炭滑板在服役后的表面状态及损伤情况为例,总结了浸金属炭滑板的损伤特点;重点论述了浸金属炭滑板的磨损面特征,纯炭滑板基体材料及其后续处理工艺之间的关联。提出宜以浸金属炭滑板的"服役性能-组织结构-制备工艺"全生命周期的联系为研究思路,实现纯炭滑板基体材料的力学和电学性能的双重优化,为旨在改善弓/网匹配的高速动车组受电弓滑板的选材提供依据。     

长寿命镁尖晶石滑板在英国钢铁公司TEESSIDE厂的应用

镁尖晶石滑板改进后可以适应苛刻的浇铸条件。本文剖析了工艺过程中各个环节对滑板性能的影响。据此对制造过程实行跟踪监测和过程统计控制，进而改进和了滑板的致密度和均一性。傅徨采取了表面修补和镶嵌修补的办法、降低了成本。     

电力机车受电弓炭滑板

本文叙述了电力机车对滑扳的要求、炭滑板所具有的优点与不足、以及改进炭滑板质量的措施。     

通过改善材质提高滑板寿命

日本住友金属工业公司鹿岛厂第一炼钢车间在对连铸机改造的同时，对钢包用滑板进行了改进。滑板采用小孔径，3块板改为2块板，并改进材质，同传统材料相比，滑板寿命提高了33％，成本降低了61％。     

滑板裂纹产生原因分析及改进措施

作为连铸技术关键设备的滑动水口在钢铁冶炼中起到越来越重要的作用。但是滑板的裂纹等问题一直在制约着滑板的连续使用,本文分析常见裂纹的产生及危害,以及减少裂纹的措施。改进后提高了滑板的使用寿命。     

日本滑板技术的最新发展

Ａｌ2 Ｏ3 -ＺｒＯ2 材质的滑板由于具有良好的抗剥落性而在日本获得了广泛的应用 ,其ＺｒＯ2 含量大约为 11%。但钢水中含有大量的游离氧 ,钢水中的ＦｅＯ和滑板中的Ａｌ2 Ｏ3 、ＺｒＯ2 反应生成低熔点的物质 ,从而使滑板的抗侵蚀性下降 ;另外 ,滑板在冷却过程中由于ＺｒＯ2 的膨胀增大了滑板内的裂纹 ,阻止了滑板寿命的提高。滑板中不含ＺｒＯ2 时可获得良好的抗侵蚀性 ,但 3%～6 %的ＺｒＯ2 可使滑板具有良好的抗剥落性。为获得长寿命的滑板 :(1)用Ｓｉａｌｏｎ结合代替原来的结合形式 ,提高滑板的高温强度 ,改进滑板表面的耐磨损性 ;(2…     

冶炼高氧钢用滑板的改进

本文介绍了日本轧钢厂在浇注高氧钢时，为防止滑板的腐蚀对浇注高氧钢用滑板材料进行了改进，为提高耐腐蚀性增加了ＭｇＯ含量，并用改进粒径配比的方法提高了高温抗折强度；此外，添加一种特殊的碳改进了耐热震性。     

Preparation and application of unfired Al2O3–Al–C slide plate materials in the presence of trace Zn

The unfired Al₂O₃–Al–C slide plates were prepared using tabular alumina aggregates and fines, Al powder and graphite powder as starting materials, and phenol formaldehyde resin as binder. The effects of trace Zn on properties and microstructure of samples at elevated temperatures were investigated. Post mortem investigations on the newly developed Al₂O₃–Al–C slide plates with trace Zn were carried out. The results showed that the properties of the unfired slide plate materials at low temperature (500–700 °C) were remarkably enhanced in presence of trace Zn, and the high temperature properties above 1000 °C of the slide plates with Zn were also greatly improved in comparison to the conventional ones. After used in 90 t ladles for 2 consecutive heats, the bore enlargement of the newly developed slide plates was less than 2 mm/heat, and roughening on the sliding surface was slight, showing good high temperature service performance. The improved properties were attributed to the high reactive Zn reacting with O₂ or CO to form ZnO ceramic phase and protected phenolic resin from oxidation at low temperature, and the vaporized Zn could promote non-oxide Al₄C₃ and AlN formation and growth at high temperature, creating strengthening and toughening effects.     

汽车左前开关控制面板的注射模设计

运用Pro/E软件设计了汽车内饰件左前开关控制面板注射模具.根据产品的结构,利用滑块参与分型,采用裙边曲面投影法实现不规则曲面的分型面设计,应用整体式斜导柱滑块侧抽芯机构代替了相互独立的侧型芯,提高了产品的精度,简化了模具结构,降低了制造成本.     

金属Al-Si结合Al2O3-C滑板的性能和使用

自主研制开发了节能型低碳金属Al-Si结合Al2O3-C滑板,其工艺特点是低温烧成,产品特性是低碳,与常用的Al2O3-C和Al2O3-ZrO2-C滑板相比,具有较高的热态强度,较好的抗热震性和抗氧化性。经大中型钢包的批量使用表明,其连续使用次数是高温烧成Al2O3-C滑板的两倍,与Al2O3-ZrO2-C滑板相当,用后滑板扩孔均匀,拉毛较少,裂纹微细。经残砖分析,认为金属Al-Si结合Al2O3-C滑板使用时的损毁过程可能是:表面工作层的非氧化物首先被氧化,导致结构疏松,强度降低,在铸孔处由高温钢水冲刷引起铸孔扩大,在滑动面处因机械摩擦造成滑动面拉毛。     

Structure and dynamics of polyrotaxane and slide-ring materials

Polyrotaxane (PR), in which cyclic molecules are threaded into a linear polymer chain, has generated great interest because the sliding and rotation of the cyclic molecules on the axial polymer chain lead to unique functional nanomaterials with novel dynamical properties. A typical example of the functional materials is a polyrotaxane network, called slide-ring (SR) material, prepared by cross-linking the cyclic molecules on different PRs. The cross-links composed of two cyclic molecules in a shape of figure-of-eight slide along the polymer chains and the sliding motion gives rise to remarkable physical properties of the SR materials. In order to understand the unique features of the functional materials including SR materials and develop novel applications of PR, it is necessary to reveal the physical properties of PR, especially the sliding motion of the cyclic molecules in PR. In this article, we review the static structure and molecular dynamics of PR based primarily on our recent studies. Furthermore, the difference between SR materials and usual chemical gels in deformation behavior is also described. The findings summarized in this review indicate the significance of the sliding motion of cyclic molecules characterizing PR and SR materials.     

电沉积纳米晶镍涂层的微结构与性能

采用电沉积法制备了纳米晶镍涂层，讨论了镀液中硼酸浓度对涂层晶粒尺寸的影响，并分别分析了显微硬度与平均晶粒尺寸、磨损体积及摩擦因数的关系。测试了微晶和纳米晶镍涂层的抗高温氧化性。结果表明：当硼酸在镀液中未达到饱和之前，镍的晶粒尺寸随硼酸浓度的增加而减小；当晶粒尺寸在8～20nm范围时，随着晶粒尺寸的减小，涂层的显微硬度增大，滑动摩擦因数和静摩擦因数均有所减小．耐磨性能提高，抗高温氧化性能增强。     

酚醛炭基C／C复合滑板材料的催化石墨化及其性能研究

通过溶剂分散法在酚醛树脂浸渍剂中引入催化剂,采用多次液相浸渍-炭化增密和催化石墨化处理的方法,制备出密度为1．60g·cm^-3左右、石墨化度大于77％的酚醛炭基C／C复合材料。对比考察了催化剂的引入和催化剂种类对酚醛炭基C／C复合材料石墨化度、电阻率、抗折强度和摩擦磨损性能的影响,探讨了酚醛炭基C／C复合材料用作受电弓滑板材料的可能性。结果表明：硼酸或二茂铁等催化剂的引入可显著提高酚醛炭基C／C复合材料的石墨化度,降低其电阻率和摩擦系数,改善其弯曲断裂韧性;添加硼酸催化剂的酚醛炭基C／C复合材料的导电性、抗折强度和摩擦磨损性能明显优于德国纯炭整体滑板材料,可望用作高速电力机车的受电弓滑板材料。     

惰气对水平管束沸腾传热增强机理及工业应用分析

试验研究了水平管束底部通入惰气时对其沸腾传热的影响,沸腾工质为水。试验结果表明,在中低热负荷下惰气对水平管束沸腾传热有一定的增强作用。其机理可解释为由惰气泡引起的对流传热的增强及沿管壁滑移的气泡下的薄层蒸发。其结果可应用于卧式再沸器沸腾传热的强化。     

滑板涂料的试制和使用

结合国外样品，选择适当成膜材料、基料等研制出低成本滑板涂料，在铜厂试用表明，该涂料具有快干、增强滑板润滑性、防止钢水粘附滑板的作用，提高了滑板的使用寿命。     

Model for the viscoelastic and viscoplastic responses of semicrystalline polymers

Constitutive equations are derived for the time‐dependent behavior of semicrystalline polymers at isothermal loading with small strains. A semicrystalline polymer at temperatures above the glass‐transition point for its amorphous phase is thought of as a network of macromolecules bridged by junctions (physical crosslinks, entanglements, and crystalline lamellae) that can slide with respect to their reference positions in the bulk material under straining. The network is assumed to be highly inhomogeneous, and it is modeled as an ensemble of mesoregions (MRs) with various strengths of interchain interaction. Two types of MRs are distinguished: passive, where these interactions prevent detachment of strands from junctions; and active, where active strands separate from junctions and dangling strands merge with the network at random times as they are thermally agitated. The viscoelastic response of a semicrystalline polymer reflects reformation of strands in active MRs, whereas its viscoplastic behavior is associated with sliding of junctions. Stress–strain relations for uniaxial deformation are developed by using the laws of thermodynamics. Adjustable parameters in the constitutive equations are found by fitting experimental data for isotactic polypropylene in a tensile test with a constant strain rate and in tensile relaxation tests at various strains. Fair agreement is demonstrated between the observations and the results of numerical simulation. It is revealed that the viscoplastic flow of junctions strongly affects the rearrangement process in active MRs, whose rate reaches a threshold value in the vicinity of the apparent yield point. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1438–1450, 2003     

边坡可靠性分析的非线性有限元正交设计算法

非线性有限元正交设计算法，是借助于回归分析，用正交多项式拟合各岩石力学特性参数与各单元滑移面及岩体整体滑动安全余量间的函数关系，以评判边坡工程的可靠性。该法较蒙特卡罗法精度高，能满足工程计算的精度要求，且方法简单、计算时间少，不需改变有限元法的有关方程和计算程序，易为人们接受。