Steelcasting and intermediate ladles for equipment for the continuous casting of steel

Conclusions The life of linings in large ladles depends on the grade of steel, the amount, chemical composition and consistency of the slag.The intermediate ladle made in the factory ensures reliable operation during the casting of metal by the continuous steel casting operation.Heating the intermediate ladle to 1100–1200°C by means of compact burners, working on coke gas, and new designs for cooled stoppers and stopper devices greatly reduces slab loss.In the process of evaluating the casting of transformer steel the loss due to nonmetallic inclusions was greatly reduced, but not completely eliminated.Further work must be done to explain the causes of the formation of slag inclusions and methods of handling the problem.     

加废钢条件下铁水包的异常侵蚀与用材问题探讨

对铁水包的异常侵蚀进行了调研,对铁水包用砖的性能、组成与结构进行分析.结果表明:1)铁水包包壁采用的铝碳化硅碳砖与包底用铝碳化硅碳砖不同,含较多的叶蜡石,Al2O3含量只有36.32％(w);体积密度、显气孔率、耐压强度均低于行业标准的要求;其抗氧化性差,使用过程中氧化形成多孔层,造成砖衬结构疏松,引起断砖、局部磨损及...     

Cast magnesia-spinel concrete linings for steelcasting ladles

Conclusions The magnesia-spinel concretes developed by the writers possess good mobility, thermal-shock resistance, volumetric stability, and low porosity. The concretes settle without additional compaction.A simple technology was developed for the production of cast concrete linings in steelcasting ladles. In transformer steel production the lining of 25-ton recasting ladles lasted six times longer than a chamotte brick lining and the specific consumption of refractories was four times lower; in 35-ton steelcasting ladles a lining of concrete MShG-15 lasted twice as long as a chamotte brick lining and the specific consumption of refractories was 1.3 times lower.An installation was devised for the production of cast concrete linings in steelcasting ladles.Translated from Ogneupory, No. 5, pp. 9–15, May, 1977.     

Siliceous refractories for iron ladles of the mixer type

Conclusions For the first time in the linings of iron-carrying ladles of the mixer type we have tested siliceous refractory products. They showed satisfactory resistance in all zones of the ladle in contact with metal, and especially in the zone where the iron jet hits the lining, which means that in contrast to ladles with mullite-silica linings we can carry out the complete campaign for the ladle without repairing this section.In the zones not contacting the iron, and in the central parts of the lining made of siliceous articles, they are less resistant than those made of mullite-silica.On the basis of these tests in mixer-type ladles we recommend the use of combined linings from siliceous and high-alumina articles.The annual savings from the use of siliceous linings is 67,000 rubles.Translated from Ogneupory, No. 2, pp. 21–24, February, 1982.     

Effect of Process Regimes on the Life of “Mayerton” Linings in 385-Ton Steel Teeming Ladles

The effect of performance factors on the life of linings of large ladles from periclase-carbon (the slag-line area) and alumopericlase-carbon (walls) refractories is considered. The studied performance factors are the changes in the properties of the refractories upon heating, the temperature regime of melting, the chemical interaction between the lining and the slag, the residence time of metal in the ladle, the causes of emergency situations, and the effect of external factors on the topography of the lining wear. Observations of 114 ladles have shown that the lining life is determined by three groups of factors. Preliminary estimates made by the authors lead them to expect that a correction of some acting conditions of operation and maintenance of the ladles will increase their life by 10 – 12% without changes in the quality of the refractories or the design of the lining.     

Use of unfired periclase-carbon refractories in parts of linings of 350-ton steel-teeming ladles

Workers of the Azovstal’Company have established the causes of the decrease in the endurance of slag-line areas of linings of 350-ton steel-teeming ladles. In 1995–1996 they conducted industrial tests and introduced a process for lining the slag areas of 350-ton teeming ladles with unfired periclase-carbon refractories. The mean service life of a lining of a 350-ton teeming ladle with a slag line made of periclase-carbon refractories amounts to 23 heats on the average without hot repairs of the slag line during the campaign. The wear of the periclase-carbon lining in the slag line is 3.6–4.3 mm per heat. The specific consumption of refractories and materials for a lining has been decreased by 0.6–0.8 kg per ton of converter steel. Such an operating capacity for the periclase-carbon refractories in slag lines is provided by the composition and structure of the refractories, which possess a high heat resistance and resist the effect of the molten metal and slag. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 2, pp. 37–39, February, 1998.     

Behavior of magnesia bricks in furnaces for the production of manganese alloys

Conclusions The application of dense magnesia bricks contributes to increased durability of the lining in metal manganese and manganese slag producing furnaces.The life of magnesia brick linings with an 11 to 13% porosity amounts to 45 days.The employment of large-size bricks hightens the resistance of the furnace bottom.Periclase-spinel brick proved unsuitable in the production of manganese slag.It is suggested that bricks with a porosity of 14 to 16% be tested for the purpose of determining optimal porosity.     

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.     

Results of a competition for the most resistant ladle brick

Conclusions The wear of the Chasov-Yar ladle brick was less than that of bricks made by the other factories; its average resistance for the five ladles was 13.3 melts.The average wear of the ladle brick made by the Zaporozh Plant exceeded the wear of the Chasov-Yar brick. The average resistance of this brick for the five ladles was 13.2 melts.The wear of the ladle brick made at the Belokamen Firebrick Plant is uniform, with only slight washing-out of the joints. The surface of the ladle after service was smooth and glazed.Examining all the materials tested during the competition the award panel awarded: first place in the compeitition to the Chasov-Yar Combine; second place to the Zaporozh Plant; third place to the Belokamen Plant.On the basis of material on the technology for the manufacture of ladle bricks used in the plants taking part in the competition, and also the service factors of the products during competitive testing, and on the basis of proposals from the All-Union, Ukraine and Vostok Institutes of Refractories for improving the quality of ladle brick, the award panel of the competition made the following recommendations for further improving the quality of ladle bricks:scientific-research institutes for refractories in collaboration with factory producers should carry out tests of fired ladle bricks made from chamotte and semiacid bodies, kaolinized and high-alumina raw materials and unfired products, and also should test linings made from rammed bodies in ladles of different capacities in different conditions of service;concerns should specialize in the manufacture of ladle bricks and install modern grinding, blending and pressing equipment;the assortment of bricks should be reexamined and the sizes of ladle bricks should be increased with the aim of reducing the number of joints in the structure;output of adequate supplies of high-grade special packaged mortars should be ensured.     

Mixtures of a base composition: Consumable lining of tundish ladles of continuous casting machines

Work on creating a refractory mixture of a base composition for consumable linings of tundish ladles of continuous casting machines is described. Various binders for mixtures deposited on the working lining of the tundish ladle by guniting have been tested. The endurance of a consumable lining based on periclase with an elevated content of CaO was 5 heats on a CCM of an electric steelmaking shop.Translated from Ogneupory, No. 4, pp. 28 – 30, April, 1996.     

Introduction of rammed linings for 250-ton steel-teeming ladles at Makeevka Metallurgical Combine

Conclusions In the open hearth shop of the Makeevka Metallurgical Combine the 250-ton steel-teeming ladles have been converted from a brick lining to a monolithic quartzite-clay rammed lining prepared with the use of a sand slinger using MKG-1 mixture according to Technical Specification 14-8-252-77 produced by the Krasnogorovka Refractory Plant. The use of monolithic linings of the ladle walls provided an increase in their average life from 9.06 to 15.6 heats.During service of the quartzite-clay rammed linings in teeming ladles partial degeneration of the quartz into cristobalite and full transformation of the fine crystalline binder into glassy occurs.The annual saving from the introduction of monolithic rammed linings of the 250-ton steel-teeming ladles of the Makeevka Metallurgical Combine was 2000,000 rubles.Translated from Ogneupory, No. 1, pp. 47–49, January, 1985.     

Increasing the life of steel ladle linings at the Cherepovets Metallurgical Factory

Conclusions A 4-stage lining was developed and introduced at the Cherepovets Metallurgical Factory for 300 ton steel ladles.As a result of introducing this lining and improving the quality of the brick the life of the ladle increased by 31% compared with that achieved in 1968.To ensure uniform resistance in the 4-stage lining over the height of the structure tests were made with a lining using semisilica brick based on Latnensk clay and Ovruch pyrophyllites in the upper and central belts of the structure. The use of the semisilica brick in place of the KShU-37 brick manufactured by the Borovich Refractories Combine increases the resistance of the lining in the ladles, and reduces the refractories consumption per ton of steel.Translated from Ogneupory, No. 4, pp. 22–25, April, 1971.     

改性石墨对镁碳砖性能的影响

为了提高钢包渣线镁碳砖的使用寿命,将0~1%质量分数的改性石墨引入到钢包渣线用镁碳砖中,研究了其加入量对镁碳砖体积密度、显气孔率、常温耐压强度、热膨胀率和抗渣性的影响,并采用偏光显微镜分析了试样的显微结构。结果表明:引入少量改性石墨对镁碳砖的致密度略有负面影响,但改性石墨在高温下产生的体积膨胀能弥补砖的基质收缩和砖与砖之间的缝隙,从而提高镁碳砖的抗渣性;当改性石墨加入质量分数为0.8%时,镁碳砖中骨料与基质的缝隙最小,抗渣性最好。     

矾土基高铝—尖晶石质钢包浇注料的研制和应用

以特级铝矾土、矾土基尖品石和烧结镁砂等为主要原料，采用超细粉凝聚结合，并对基质的化学矿物组成进行优化，开发出了矾土基高铝—尖晶石钢包浇注料。其烘烤特性良好，施工性能、物理性能及抗渣性比传统水玻璃结合的铝镁浇注料有显著提高。经在全国十多家钢厂的中小型钢包上使用，在绝大多数情况下其寿命比传统水玻璃结合的铝镁浇注料或铝镁炭发砖提高了１００％以上。     

Post-mortem analysis of MgO–Al2O3–C bricks containing bauxite used in steel ladle walls

A serious problem with integrated masonry linings ladle was that the ladle wall bricks were difficult to be partially replaced. Thus, the service life of the ladle was determined by the properties of ladle wall bricks. In this study, the new generation of MgO–Al₂O₃–C bricks with bauxite aggregates was tested in a ladle lining of an integrated steel ladle for 103 cycles, and the corroded microstructure of the used brick was investigated. A multilayered structure of bauxite aggregates could be observed in the used brick, which inhibited the slag penetration along the boundary of the magnesia aggregates and reduced the degree of the aggregates fall off from the used bricks. Besides, during the process of slag penetration, bauxite aggregates could melt into the slag, which increased the viscosity of the slag and weakened the penetration ability of the slag. The MgO–Al₂O₃–C bricks with bauxite addition could improve the service life of the ladle to a certain extent.     

Alumina-spinel castable for steel ladles: An overview

Alumina-spinel castable has excellent refractory properties, including high volume and thermal stability, good hot strength, and excellent resistance against corrosion, erosion, and thermal spalling. Excellent refractory properties have made it a preferred lining for steel ladles, reducing the erosion and corrosion of molten metal and slag and improving the ladle life and efficiency for decades. These castables are also significant for the replacement of chrome-bearing refractories that cause several health hazards. The current review paper covers preformed and in situ spinel containing alumina castables. It focuses on the importance of these castables in the sidewall and bottom portion of the steel ladle in detail, the effect of spinel and MgO content, and the factors affecting castable properties. The review also covers the final properties of castable and the application areas of alumina-spinel castable in steel ladle, purging plugs, and RH-degasser.     

不锈钢冶炼用铁水包Al2O3-SiC-C内衬砖的性能与侵蚀机理

铁水包内衬材料长期服役于间隔周期较长的高、低温交替环境,极易发生剥落与侵蚀损毁。为了探索影响铁水包内衬材料使用寿命的主要因素,对市面上四种铁水包Al₂O₃-SiC-C内衬砖的化学成分、物相组成、物理性能和微观结构进行了分析,并以高炉渣为侵蚀介质,重点研究了不锈钢冶炼用铁水包Al₂O₃-SiC-C内衬砖的侵蚀机理。结果表明:铁水包Al₂O₃-SiC-C内衬砖中Al₂O₃含量越高,高温下制品的液相量越低,越有利于提高耐火砖的高温力学性能;随着含碳量的增加,铁水包Al₂O₃-SiC-C内衬砖的抗渣性得到明显改善,但抗氧化性及高温抗折强度呈下降趋势;高炉渣中CaO、MgO向耐火砖中渗透,与耐火砖中的Al₂O₃、SiO₂发生反应形成高熔点的镁铝尖晶石及低熔点的钙长石等,生成的低熔相会加剧耐火砖的侵蚀。     

The Use of a Multiple-Purpose Lining of the Casting Ladle in an Integrated Steel-Processing Unit at the Oskol'skii Electrical Iron and Steel Works

A report is given on the production of periclase-carbon refractories using advanced technologies and raw periclase of different quality grade at the Semilukskii Refractory Plant Joint-Stock Company (SRP JSC). Refractories available from the SRP JSC were used at the Oskol'skii Electrical Iron and Steel Works JSC (OEISW JSC) to fabricate the multiple-purpose lining for casting ladles exploited in vacuum furnaces and integrated steel-processing units. The endurance of the lining for the walls and the slag zone of the casting ladle reaches 69 heats.     

Performance of a ceramic frit anti-oxidation coating on a MgO-C refractory brick

In steel production, ladles must be preheated to minimize the heat loss of the steel melt, prevent thermal shock of refractory bricks (MgO-C), and to maximize the lining life of ladle. Partial oxidation of MgO-C bricks begins in the graphite bond during the preheating. Oxidation of graphite bond also causes a decrease in performance of the bricks because of an increase in the brick porosity. In this article, coating on a MgO-C brick surface by a ceramic film to protect against carbon oxidation was studied. Coated and un-coated bricks were heated at 1200 °C, cooled to room temperature, then the brick properties investigated. The oxidization resistance properties of brick with coating were much better than those without coating, which should lead to longer refractory service life.     

Refractories for powerful blast furnaces abroad

Conclusions Abroad, the linings of the shafts of powerful blast furnaces are made from dense chamotte brick of high purity with the minimum content of iron oxides and other contaminating impurities. Impregnation of the fired chamotte brick with phosphates substantially increases the alkali resistance, and consequently the resistance of the blast furnace lining. The bosh and well are lined with carbon refractories. Speedy mechanized laying of the wells is done with large blocks up to 6.4 m long, and with cross sectional measurements of up to 0.8-0.6 m. In particularly severe service conditions in the absence of a protective skin layer in the lower part of the shaft and shoulders successful use is being made of carbon linings using electrographitic and semigraphitic products.Effective cooling systems with high thermal conductivity carbon refractories reduces the temperature, which substantially retards the wear of the working layers in the lining.Translated from Ogneupory, No. 7, pp. 56–59, July, 1973.