模压成型高炉炭砖的研制及应用

为了提高国产高炉炭砖的质量,通过设计并引进模压成型设备、严格控制炭砖的模压成型工艺参数,研制了模压成型高炉炭砖.介绍了模压成型设备的特点,并从原料选择、颗粒级配与配方组成和模压成型参数3方面阐述了模压成型炭砖的工艺控制.研制的模压成型炭砖经检测,其性能指标已完全达到进口炭砖的水平,满足大型高炉的使用需求和寿命要求.     

高炉炉缸用热模压小炭砖的性能与使用

本文论述了我国高炉炭砖的现状,分析了炭砖破损的主要原因,介绍了热模压小炭砖的性能、特点及使用情况,并指出了改进我国炭砖质量的主要途径。     

高炉用高导热小块炭砖的特性

高炉用高导热小块炭砖的特性鞍钢修建公司唐兴智为了解决高炉炉衬的剧烈破损及炭砖的“环状断裂”和“异常侵蚀”问题，引进了美国ＵＣＡＲ公司生产的高导热热压小块炭砖技术，应用在鞍钢１０号高炉炉缸风口区、炉腹、炉腰及炉身下部。这次引进的ＮＭＤ热模压小块炭砖采用...     

沥青基炭复合材料新型制备工艺的特征研究

高温模压工艺是由模压成型工艺演绎而来的一种快速成型技术,但在制备沥青基炭复合材料时,该工艺明显存在着装备投资大、模压压力低和工艺实用性差的不足.为此,提出了一种新型的沥青基炭复合材料的制备工艺,即模压半炭化成型工艺(简称MSCT工艺) .为了验证MSCT工艺的突出优点,分别利用MSCT工艺和模压工艺制备了沥青基炭复合材料,并就其组织结构、体积密度和力学性能进行了研究.结果表明:MSCT工艺制备的沥青基炭复合材料的微观组织比模压工艺制备的要致密的多,从而使前者的体积密度( 1 .77g/cm3 )和抗压强度( 32 .5 MPa)分别比后者提高了2 8.3%和1 44 .4% .     

高温模压炭砖的研制

介绍了炼铁高炉用高温模压炭砖的研制概况。重点介绍了"抗铁水"炭砖研制情况,选用电煅煤和高温电煅煤为骨料,煤沥青作黏结剂在特制设备中快速压型烧结试制出高温模压炭砖。对原材料优化给出了炭砖的耐压强度、铁水溶蚀指数、透气度依赖于高温电煅煤含量的三个回归方程。还给出了3种炭砖的抗热震因子的结果。同时就远洋公司生产的高温模压炭砖质量指标与国内外优质炭砖进行了对比分析。     

文摘

高炉长寿用炭素耐火材料研究进展[刊,中]/卢正东,宋木森//武钢技术,2012,50(5):58～62对我国近年来高炉长寿用炭素耐火材料的研究与应用状况进行了综述,简要介绍了半石墨炭砖、石墨炭砖、微孔炭砖、超微孔炭砖、微孔模压炭砖及炭素捣打料的研究工作和发展现状,并明确了超微孔炭砖的发展目标。六电极连续式石墨化电炉的数值模拟[刊,中]/陈超,刘慧//工业炉,2012,34(5):1～3     

高性能机械用炭石墨材料制备工艺研究北大核心

通过实验研究了粉体颗粒粒径、成型方式、成型压力等制备工艺对机械用炭石墨材料性能的影响。结果表明,材料的抗折强度和抗压强度随着粉体颗粒粒径的减小而增大,模压成型方式是最适合于机械用炭石墨材料的成型方式,模压成型最佳的成型压力区间为220~250 MPa。     

炭材料热物理性能研究

炭材料宏观性能受微观组织多样性的影响表现出极强的多样性。实验制备几种模压炭材料，并对其热物理性能进行表征。结果表明，随着原材料中胶体石墨含量的增加，材料的电阻率下降，热导系数、热扩散率提高；材料的比热容、热导系数、线膨胀系数随温度升高而增大，热扩散率随温度升高而降低。研究结果还表明，用传统的石墨化度G参数表征多相炭材料石墨化度具有一定的局限性，而用G参数与衍射峰高相结合表征更能准确反映多相炭材料的石墨化特性。     

四种不同产地无烟煤性能研究

对四种国产无烟煤的化学成分、氧化率和岩相结果进行了分析，以及用此四种无烟煤在相同工艺条件下制成的微孔炭砖试样进行了试验研究。结果表明，阳泉煤制成的微孔炭砖性能优良，且阳泉煤变质程度最好，是生产微孔炭砖最为理想的原料；宁夏太西煤只要控制好煅烧质量，也是生产微孔炭砖的优质原料。     

新型高密度低气孔率电炉炭砖的开发与应用

分析了炉衬破损的原因，开发一种生产高密度低气孔率电炉炭砖的新工艺。结果表明，所得炭砖比普通炭砖有更高的体积密度、抗压强度，更低的气孔率，有利于提高炉衬的寿命。     

Investigations of the tribological properties of carbon fabric reinforced phenolic polymer composites filled with several nanoparticles

The carbon fabric composites filled with several nanoparticles were prepared by dip‐coating and hot press molding technique. The friction and wear behavior of the resulting composites were studied systematically using a block‐on‐ring arrangement. Experimental results showed that the optimal content of nanoparticles as fillers contributed to improve the tribological properties of the carbon fabric composites. Moreover, the friction and wear properties of the fabric composites were closely dependent with the sliding conditions. The differences in the transfer film formed on the counterpart surface during the friction process also accounted for the friction and wear behavior of carbon fabric composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Polyacrylonitrile‐based electrospun carbon paper for electrode applications

Polyacrylonitrile (PAN)‐based carbon paper with fiber diameters of 200–300 nm was developed through hot‐pressing, pre‐oxidation, and carbonization of electrospun fiber mats. Changes in morphology, crystallinity, and surface chemistry of the hot‐pressed carbon paper were investigated. More junctions between fibers were formed with increasing hot‐press time, which is attributed to melting and bonding of fibers. The bulk density increased to 0.5–0.6 g/cm³, which could help to improve the volume energy density for electrode applications. The conductivity of the carbon paper was found to be about 40 S/cm when the surface area was ～ 2 m²/g, and depends not only on the conductivity of the individual nanofibers but also on the contacts between the nanofibers. The performance of the electrospun carbon paper as an electrode for electrochemical reactions involving ferrocene molecules was affected by the preparation protocol: the higher surface area of the electrodes formed with shorter hot‐press times provided a higher current generated per unit mass than that obtained with electrodes prepared using longer hot‐press time, but electrodes prepared with longer hot‐press times exhibited higher electrical conductivity and faster electron transfer kinetics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

轮胎硫化设备及工艺研究进展

综述现阶段国内外轮胎硫化设备及工艺的研究进展。国内外轮胎硫化机的发展都经历了立式水压轮胎硫化罐、普通轮胎个体硫化机和轮胎定型硫化机3个阶段;液压式硫化机是现阶段轮胎硫化机的发展趋势,国外已全面推广,而国内机械式硫化机与液压式硫化机并存。硫化工艺则主要朝着高效节能的方向发展,加热方式已从蒸汽/过热水硫化过渡到氮气硫化,而硫化过程中摒弃胶囊的使用或采用刚性结构取代胶囊的作用也成为了研究热点。     

PPy/CS复合电极热压成型条件的优化

以壳聚糖（CS）和聚吡咯（PPy）制备的复合材料为活性基体,在不添加黏结剂的条件下,采用热压成型法制备复合电极。重点考察了不同导电剂对电极力学性能的影响,热压温度、成型压力、热压时间及不同种类活性炭对电极电化学性能的影响规律。结果表明：通过热压法不添加黏结剂能够获得性能优良的复合电极;以活性炭为导电剂的电极溶胀性和亲水性最好,且活性炭的比表面积越大电极的电化学性能越好;电极热压成型的最优条件为：热压温度150℃、成型压力10 MPa、热压时间20 min。     

High‐Energy Storage Performance of (Pb0.87Ba0.1La0.02)(Zr0.68Sn0.24Ti0.08)O3 Antiferroelectric Ceramics Fabricated by the Hot‐Press Sintering Method

(Pb_0.87Ba_0.1La_0.02)(Zr_0.68Sn_0.24Ti_0.08)O₃ (PBLZST) antiferroelectric (AFE) ceramics have been prepared by hot‐press sintering method and conventional solid‐state reaction process, and the dependence of microstructure and energy storage properties of the ceramics on sintering approaches has been studied. The results reveal that not only the microstructure, but also the electrical properties of the PBLZST AFE ceramics are significantly improved by using the hot‐press sintering method. Samples resulting from the hot‐press sintering process have high breakdown strength of 180 kV/cm which results from the increase of density. Coupled with large polarization, the hot‐pressed AFE ceramics are shown to have a high recoverable energy density of 3.2 J/cm³. The recoverable energy density of the hot‐pressed PBLZST AFE ceramics is 100% greater than the conventional sintered specimens with recoverable energy density of 1.6 J/cm³.     

Resin transfer molding of BMIs and polymides

Bismaleimdes (BMI) and experimental polyimides were resin transfer molded into carbon fiber fabrics using a custom-built injection mold placed within a vacuum hot press. This represents the first time that the latter type of materials has been resin transfer molded. This is a critical stage in developing materials and processing methods for future aerospace applications, such as the High Speed Civil Transport (HSCT).     

PE-b-PEO嵌段共聚物的合成及其芳烃/烷烃渗透汽化分离性能

采用阴离子聚合方法合成了具有不同环氧乙烷聚合度的聚丁二烯-b-聚环氧乙烷嵌段共聚物(PB-b-PEO嵌段共聚物),然后催化加氢得到聚乙烯-b-聚环氧乙烷嵌段共聚物(PE-b-PEO嵌段共聚物),使用凝胶渗透色谱仪(GPC)、核磁共振氢谱(1H-NMR)对共聚物进行了分析,结果表明所得聚合物具有预定的结构。通过熔融压片的方法制备PE-b-PEO嵌段共聚物均质膜,考察了PE-b-PEO嵌段共聚物分子链中聚环氧乙烷的聚合度对渗透汽化分离性能的影响。     

Thermal Stability of Low-SiC Fiber (Hi-Nicalon) Treated in a Hot Isostatic Press

The low-oxygen SiC fiber fabricated by the electron-beam irradiation curing method, Hi-Nicalon, was heated at 1773 to 2273 K in a hot isostatic press (800 MPa of argon) and was subsequently reheated at 1873 K at 1 atm (101 kPa) of argon. The hot isostatic press treatment delayed the onset of fiber deterioration to higher temperature. The fiber strength remained almost unchanged by subsequent reheating at 1873 K in 101 kPa of argon. The thermal stability of Hi-Nicalon, as a consequence of the permanent change in surface structure, can be greatly improved by treating in the hot isostatic press.     

多孔蜂窝红外陶瓷燃烧板用自动热压铸机的设计

热压铸工艺是一种成形中、小尺寸的结构复杂的陶瓷产品的良好方法。介绍了热压铸工艺的原理,分析了其工艺特点;同时还介绍了具有自动操作功能的热压铸工艺装置的设计,分析了其优良的性能及使用效果。     

Use of wet‐laid techniques to form flax‐polypropylene nonwovens as base substrates for eco‐friendly composites by using hot‐press molding

The wet‐laid process with flax (base) and polypropylene (binder) fibers has been used to obtain nonwovens for further processing by hot‐press molding. Mechanical characterization of nonwovens has revealed that slight anisotropy is obtained with the wet‐laid process as better tensile strength is obtained in the preferential deposition direction. The thermo‐bonding process provides good cohesion to nonwovens, which is critical for further handling/shaping by hot‐press molding. Flax:PP composites have been processed by stacking eight individual flax:PP nonwoven sheets and applying moderate temperature and pressure. As the amount of binder fiber is relatively low (<30 wt%) if compared with similar systems processed by extrusion and injection molding, it is possible to obtain eco‐friendly composites as the total content on natural fiber (flax) is higher than 70 wt%. Mechanical characterization of hot‐pressed flax:PP composites has revealed high dependency of tensile and flexural strength on the total amount of binder fiber as this component is responsible for flax fiber embedment which is a critical parameter to ensure good fiber–matrix interaction. Combination of wet‐laid techniques with hot‐press molding processes is interesting from both technical and environmental points of view as high natural fiber content composites with balanced properties can be obtained. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers