高可靠性梯度功能耐火材料

随着精炼和连铸技术的快速发展,要求连铸功能耐火材料透气元件、长水口、整体塞棒、浸入式水口具有高的可靠性和长寿命。与普通功能耐火材料相比,梯度功能耐火材料在材料组成及结构设计方面进行了优化,重点解决了产品的抗热震性和关键部位抗侵蚀性,从而使产品具有高安全可靠性和长使用寿命。     

日本钢铁工业用耐火材料的现状

介绍了日本钢铁工业用耐火材料，如炼铁、铁水预处理、转炉、盛钢桶、中间包和连铸用耐火材料。开发使用了各种优质、高效、环保型耐火材料，大幅度提高了使用寿命和降低了耐火材料单耗。如高炉主出铁沟耐火材料单耗降低了15％；炮泥单耗降低了12％；铁水预处理专用转炉的寿命达到了8000-13000炉次；转炉使用寿命稳定在8000-9000炉次；盛钢桶使用寿命提高到原来的4.5倍；中间包使用寿命最高达到2000次以上；连铸用长水口使用寿命达到了30次和40次。     

石墨在连铸耐火材料中的应用及展望

本文概要地介绍了石墨在连铸用各种耐火材料中,包括水平连铸机的结晶器、钢水罐和中间罐罐衬耐火砖、滑动水口砖、中间罐整体塞棒、长水口砖和浸入式水口砖生产中的应用情况;指出了连铸用耐火材料对石墨的化学成分及性能的要求;展望了九十年代石墨在连铸用耐火材料生产中的应用前景。     

连铸用耐火材料的现状及其今后发展趋向

为了满足连铸技术的迅速发展和连铸机台数的不断增加，本文介绍了国内外各种连铸用耐火材料，如钢包和中间包内衬材料、钢水过滤器、整体塞棒、滑动水口、长水口、浸入式水口、定径水口、分离环的材质、性能及其使用效果。今后，为了适应全连铸、多炉连铸和特殊连铸的需要，国内外将会进一步加大科研的力度，加强新品种的开发，加速产品的更新换代，提供优质、高效、多功能连铸用耐火材料，实现连铸用耐火材料与连铸技术的同步发展。     

连铸用功能耐火材料的现状及发展趋势

介绍了钢包底吹氩透气砖、滑动水口、连铸三大件和ZrO2质水口等连铸用功能耐火材料的现状及发展趋势,认为:现代连铸生产工艺对连铸用功能耐火材料长寿命和高适应性的要求越来越高,单一材质体系很难满足要求;根据产品不同部位的损毁方式和特点及浇铸钢种和冶炼工艺的不同,针对性地研发新材料将是连铸用功能耐火材料发展的现实要求;从材质发展的角度来看,连铸用功能耐火材料的材质向多样化、复合化发展将是必然的趋势.     

连铸用耐火材料的技术发展

介绍了连铸用钢包和中间包衬用耐火材料，整体塞棒、浸入式水口和长水口以及密封材料、保护渣等的最新发展     

连铸功能耐火材料制造的造粒工艺

主要介绍了制造炼钢连铸用浸入式水口、长水口及塞棒等功能耐火材料的造粒工艺,对比分析了欧洲技术、亚洲技术两大主要制造工艺的造粒技术特点、设备发展状况,并阐明了连铸三大件造粒技术工艺及设备的发展方向。     

含碳耐火材料用非纤维系隔热涂层材料的开发

开发出了以Al2O3-SiO2系空心材料为主原料的非纤维系隔热涂层材料。通过对浸入式水口和长水口的外表面涂敷不含纤维隔热材料和贴陶瓷纸的比较试验可知，这种隔热涂层材料不仅隔热效果好，而且还具有保护抗氧化剂的作用，能够有效延长连铸用耐火材料的使用寿命。     

钢铁工业用耐火材料的最新动向(3)

5·2 滑动水口用耐火材料 注钢用耐火材料,60年代以前是使用套筒塞棒,从1968年开始开发了滑动水口(SN),从钢包往中间包注钢水以及从中间包往结晶器中注钢水,并逐渐普及。此滑动水口是连铸用耐火材料的极大变革。 进而,耐火材料和金属件(SN装置)作为连成一体的商品,引起了极大的关心。 之后,SN用耐火材料,SN装置的开发也进展顺利,为连铸设备(图28、29)的发展做出了巨大贡献。     

长寿命定径水口的使用试验

定径水口是小方坯连铸用关键耐火材料之一,其品质的好坏直接影响连浇时间的长短.氧化锆定径水口抗冲刷、耐侵蚀、热震稳定性好,在我厂使用时其侵蚀速率为0.03～0.08 mm@H-1,年平均连浇时间达到了460min.1999年下半年,我厂方坯中间包开始采用镁质喷涂料取代硅质绝热板,中间包包衬的使用寿命明显提高,原有的普通氧化锆定径水口已不能满足使用要求.为此,研制开发了长寿命定径水口.     

Al2O3-C质整体塞棒在浇铸钙处理钢中的应用

分析了Al2O3-C质整体塞棒在钙处理钢浇铸过程中的侵蚀机制和其他一些重要影响因素,针对Al2O3-C质整体塞棒的特性,从炼钢的工艺改进、设备保障、优化过程控制和耐火材料材质优化等方面采取了相应措施,并提出了改进意见,使Al2O3-C质整体塞棒在钙处理钢的使用寿命不断提升,达到了比较满意的效果。     

铸钢用高通量复合水口的开发

随着铸钢工艺技术的发展,要求铸钢用水口在使用条件下具有安全可靠性和高的使用寿命。本实验通过研究不同材质铝碳、镁碳及尖晶石-碳的性能,成功地开发出高通量复合水口,它在大型钢包上使用后安全可靠、寿命高。     

Acoustic characterization and microstructure of high zirconia electrofused refractories

A new line of electrofused refractory materials with a very high content of zirconia (HZ) has been developed to satisfy the needs of new generation manufacturing glass furnaces. Such materials are subjected to severe operating conditions (temperature and corrosion) during their manufacturing and service life. These HZ materials required very high temperature casting and a suitable annealing process to prevent defects and cracks during manufacturing. Therefore, a research program has been launched to build numerical tools able to predict the thermo-mechanical behaviour of these materials during one of the most critical phases of manufacturing: the controlled cooling of the refractory blocks after melting and casting. The efficient development of such a tool requires the knowledge of thermo-mechanical properties of these materials with temperature, in conditions close to that occurring during processing.In the framework of this approach, the present paper deals with the characterization of elastic properties of two HZ materials, using two mechanical testing devices i.e. a pulse echography technique and a tensile test device. An innovative acoustic emission device is also used to help in identification of microdamage occurrence. The goal of this study is to investigate the microstructure organisation of materials at very fine scale (<100 μm) in order to correlate the obtained results with the macroscopic properties of the material. Characterisations are also performed at intermediate temperature to establish correlations with the manufacturing process.     

Towards prediction of local corrosion on alumina refractories driven by Marangoni convection

Refractory materials are used in the high-temperature melting of iron and steel, which are the basic materials in various metallurgical processes and other high-temperature industrial production and technology development methods. The Marangoni effect is a key factor in the direct premature destruction of refractory materials in use and exerts a significant impact on low-cost, high-quality steel production. In this study, the area of refractory/air/slag interface was expressed and observed. Based on the previous studies, the geometrical model of corrosion groove is modified by considering the erosion and dissolution of refractory oxides. The model is used to analyze the corrosion evolution caused by the Marangoni effect. The difference between the calculated results and the experimental results is compared, and the reliability of the geometrical and corrosion models is verified for predicting the Marangoni convection influence on the service life of refractory materials.     

对炭素回转窑燃烧室内部结构设计的改进

对贵州分公司0#炭素回转窑燃烧室的折流墙频繁垮塌进行分析,得出折流墙的材料和设计不合理是影响燃烧室使用寿命的主要原因,并对新设计的钢架与浇注相结合的“U”形折流墙进行了介绍。     

Multifunctional Refractory-lined Vessel: Ladle Aggregate

A ladle primarily is a container used to transport molten steel from the steelmaking unit to the casting facility.The essential requirements are heat resistant,insulative and strong enough to hold molten steel up to 300 t,with a structure of multilayered refractory lining in a steel shell vessel.When a ladle is assembled with three-phase graphite electrodes,a ladle furnace forms,starting steel refining process with/without the vacuum tank degasser and RH circulating degasser,in order to meet the growing demand on high purity and higher quality steel.The working lining is under aggressive conditions that comprise the chemical reaction with molten steel,the severe corrosion of liquid slag,the disaggregation through oxidation,and the strong stress due to the impacting of the melts and gases and the effects of thermomechanical behaviors.Magnesiacarbon brick is one of the major materials,being indispensable for the slagline of a ladle furnace.Alumina-magnesiacarbon brick has played an important role to substantially increase the service life in the metal zone,from the early lining materials of high alumina and doloma bricks.The permanent lining must assume sufficient responsibility to allow finishing the process of the engaged charge in case of a failure in the working lining.The insulation layer must be as thin as possible in order to maximize the ladle’s capacity,and reduce the shell temperature for saving energy.In this issue,several integrant refractories are reviewed or investigated in order to compile a lining overview,and to contribute a prolonged service life under aggressive working conditions of the ladle furnace.     

Service of refractories in the lining of a batch vacuum treatment unit in treatment of chromium steels

Conclusions The combination of batch vacuum treatment of steel with continuous casting makes more rigid the refractory service conditions in the vacuum treatment unit and reduces their life.The combination of domestic refractories used at Magnitogorsk is capable of providing sufficient refractory life of the vacuum treatment unit at Orsk-Khalikovo. This combination has been introduced into the Electric Melt Shop at Orsk-Khalilovo. It would be desirable to test PShPKh periclase-chromite parts in the vacuum treatment unit at Orsk-Khalilovo for the purpose of a further increase in the life of its lining.Translated from Ogneupory, No. 6, pp. 44–47, June, 1987.     

Service of zircon-containing nozzles for use in continuous steel casting plant

Summary During service in the casting of killed steel, zirconium containing nozzles took on a zonal structure. The least changed zone of the nozzles is scarcely distinguishable from the refractories before service. The working zones during service are saturated with oxides of iron, manganese, aluminum, silicon and titanium, and their amount is strictly related to the compositon and quantity of deoxidant.Highly refractory nozzles of ZrO₂ and made of a mixture of ZrO₂ and zircon, possessing a higher apparent porosity, acquire a larger working zone than nozzles made of zircon with clay additions.The dense working zone is more rapidly formed in nozzles made of zircon and clay. The oxides adsorbed in the pores of the refractory contribute to the tightening up of the aperture of the nozzles.Zircon nozzles with clay additions used at the Donets Steel Mill proved to have excellent wear resistance and the lowest tendency to closing up when casting low-carbon killed steels and can be recommended for permanent use in continuous steel casting plants.     

Behavior of ZrO2-C Refractories in Thin-strip Casting of Steel

Zirconia graphite refractory is used as a core-nozzle in the thin-strip casting of steel. Post-mortem analysis of used refractory was performed in an effort to establish the failure mechanism. Corrosion behavior was studied against molten steel with Mn O- SiO 2based liquid inclusions. Corrosion of these materials involves dissolution and oxidation of graphite in the matrix followed by penetration of liquid slag leading to degradation of ZrO 2particles. Thermodynamic equilibrium calculations were performed to study this corrosion mechanism.     

Development Tendency of the Refractories for Iron ＆ Steel Industry in China

This paper introduces the developing tendency of refractories for iron and steel industry combined with the new metallurgical techniques applied in iron and steel industry in China. Refractories for blast furnace long service life, smelting reduction iron-making process, secondary refining metallurgies and clean steel making, near net shape continuous casting are described respectively. To meet the requirement of iron and steel industry, the high quality, multi-functions and environment-friendly refractories with long service llfe will be focused and developed in the future. In addition, high grade refractories in China have great developing space and potential market.