Growth of the production of rails from continuous-cast semifinished products of electrical steel

Since 2001, the Novokuznetsk Metallurgical Combine has produced 3.0 million tons of R65 railroad rails of continuous-cast steel made in electric furnaces. The combine has significantly improved all the most important quality indices of the steel during this period, and the service life of the rails has increased from 0.5·10⁹ to (0.8–1)·10⁹ tons gross. The combine has mastered the production of rails with superior cold resistance and rails suited of use in high-speed rail systems. It is beginning production of rails with a bainitic structure and rails made of hypereutectoid steels. All these results have been obtained through the construction of new production facilities and modernization of the combine’s existing equipment. Plans for future rail production include extensive reconstruction of the heat-treatment section of the rail-beam shop and reconstruction of the machine-tool bay, the latter involving replacement of part of the equipment. Arc steelmaking furnace No. 1 and two continuous casters will be rebuilt in the electric steelmaking shop. The ultimate goal is to increase the durability and reliability of the rails so as to put them on par with the best rails in the world.     

Modern small-capacity unit for the vacuum-oxygen refining of steel

A vacuum-oxygen refining unit has been installed in the pouring and furnace bays of electric steelmaking shop No. 2 at the Zlatoust Metallurgical Plant. The shop specializes in the production and casting of stainless, chromium-nickel, and complex-alloyed steels, alloyed high-speed and tool steels, and nickel alloys. The unit can be used to perform both vacuum degassing and vacuum oxygen refining.     

Efficient Reconstruction of an Open-Hearth Shop in Stages

A plan is described for step-by-step reconstruction of the open-hearth shop at the Ural Railcar Factory. The plan includes the introduction of out-of-furnace treatment of the steel in a ladle-furnace unit, replacement of the open-hearth furnaces by two 30-ton arc steelmaking furnaces, and the introduction of a chamber-type vacuum-degassing unit.     

Features of a technology for making steel in 180-ton arc furnaces in the electric steelmaking shop at the Magnitogorsk Metallurgical Combine

This article presents the main specifications of arc furnaces that have been installed in the electric steelmaking shop at the Magnitogorsk Metallurgical Combine. One feature of these furnaces is that they can be operated with the use of liquid pig iron. Here’ the amount of pig iron in the charge can be as high as 40%. The use of liquid pig (up to 30%) shortens the refining operation in the furnace.     

Using the DVS system for the bottom-blowing of steel in the electric steelmaking shop at the Moldavian Metallurgical Plant

Use of the injection equipment in the DVS system on electric steelmaking furnaces at the Moldavian Metallurgical Plant has shown that, other conditions being equal (consumption of oxygen and natural gas, composition of the charge materials), it is more effective than the DPP system for the bottom injection of inert gases into steelmaking baths. The system injects the energy carriers directly into the liquid metal. The results obtained from one DVS injection unit turned out to be better than those obtained from the simultaneous operation of three DPP units.     

Reaching the Design Capacity of a Continuous Section Caster

A new growth strategy has been devised for the West Siberian Metallurgical Combine. The cornerstone of the plan is the reconstruction of the combine's steelmaking facilities, which will involve a complete changeover to continuous casting. Oxygen-converter shop No. 2 is the first shop to be rebuilt. In October 2002, the shop added a continuous section caster with a nominal capacity of 1.2–1.4 million tons of continuous-cast semifinished products a year. The caster reached this level of output in September 2003 (11 months after startup). The design parameters of the caster were attained thanks to a combination of technological, technical, and organizational factors: development and optimization of new technologies for steelmaking, out-of-furnace treatment of the steel, and continuous casting; optimization of the steelmaking-casting schedule; modernization of the caster's equipment. The addition of a “ladle-furnace” unit and reconstruction of the main components of the caster will boost its capacity beyond the original limit, which will in turn allow the combine to make competitive, high-quality products and react quickly to changes in the market.     

Russian electrometallurgy: Achievements,problems, prospects

The changes in the Russian metallurgy, in particular, electric furnace steelmaking, having occurred in the recent years are analyzed. The main increase in the steelmaking output is due to putting into operation of new electric furnaces in new miniworks and enterprises equipped earlier with open-hearth furnaces. Reaching the rated capacity of a furnace in Russia substantially lags behind foreign enterprises. Only 30–35% of the Russian market of corrosion-resistant steel are provided by Russian metal.     

Effectiveness of using oxygen-gas burners in modern arc steelmaking furnaces

Oxygen-gas burners have become a standard component of modern electric-arc steelmaking furnaces worldwide as a means of increasing productivity and reducing electric power consumption. The use of such burners in these furnaces is expedient from both an economic and an energy standpoint. On the average, the use of 1 m³ of natural gas to heat the scrap in the furnace charge saves 0.6–0.8 m³ of natural gas for the refining operation. The amount of heat obtained from the combustion of natural gas can be increased significantly by equipping arc steelmaking furnaces with high-capacity rotary oxygen-gas burners that allow changes to be made to the direction of the flame.     

直流（DC）电弧炉技术的发展动态

大电流可控硅整流电源的发展和炉底电极这一难题的解决促使直流（ＤＣ）电弧炉的迅速发展，近几年大部分新建电弧炉为ＤＣ炉并将一些已有的交流（ＡＣ）电弧炉改成ＤＣ电弧冶炼。     

Microcontroller-based system for controlling annealing in bell-type furnaces

Improving the quality of cold-rolled steel while lowering the cost to make it is presently impossible without resort to modern methods of monitoring the operations involved in the manufacturing process. Such monitoring can be done without the purchase of expensive new equipment. The use of Siemens equipment to automate the single-stack stands of 12 bell-type furnaces in one cold-rolling shop has alleviated overheating of the outer turns of the coils while cutting the consumption of fuel gas 12–13%. The automation has had no effect on the heat-treatment regimes that are used. __________ Translated from Metallurg, No. 3, pp. 58–60, March, 2006.     

Increasing the output and the energy efficiency of electric arc furnaces with shaft heating of metal scrap

It is proposed to equip the electric arc furnaces with shaft heating of scrap that operate with continuous scrap melting in a liquid metal with powerful gas-oxygen burner units. When scrap is heated to 800°C at a gas flow rate of 15.5 m³/t and a bath is blown by oxygen at the slag-metal boundary, fuel-arc steelmaking units can successfully compete with the best modern electric arc furnaces in capacity and have ecological advantages.     

Metal losses during steelmaking in arc furnaces and methods for their decreasing

The structure of metal losses in steelmaking in ultrahigh-power arc steel-melting furnaces is estimated and refined using reported data and the results of our investigations. Methods for decreasing the iron losses in electric furnace steelmaking by performing organization and technological measures in arc-furnace plants and methods for utilizing the slags, dusts, and slimes of electric furnace steelmaking are considered. The pyrometallurgical utilization of the slags and dusts with the maximum iron recovery from them is shown to be promising.     

中国电炉炼钢降本增效关键点分析

分析了中国电炉炼钢的产量、装备、重点消耗指标现状情况,总结了中国电炉钢占比低于世界平均水平、电炉大型化取得一定成绩、电炉废钢单耗降低趋势出现扭转等特点,并从多角度提出电炉炼钢降本增效的关键环节,即电价改革、炉料结构优化、炉型选择、工艺节能、绿色化和智能化、管理创新与标准化体系建设等。同时提出电炉炼钢迎来发展机遇期,建议继续加大技术研发和应用力度,多方共同努力实现电炉炼钢可持续发展。     

Origin of Nonmetallic Inclusions and Ways of Alleviating Their Contamination of Steel

The use of a new technology that involves inoculating tube steel during casting can save money by eliminating the need for vacuum degassing (production cost $25/ton) and treating the steel on a ladle-furnace unit (production cost $15.70/ton). The cost of such treatment is ∼$4–5/ton. Inoculation of the steel during casting does not require complex equipment and can easily be done in any steelmaking shop. Rolling of the inoculated steel results in a larger yield of useable tubes, and the finished rolled product has better mechanical characteristics and greater corrosion resistance than steel made by the usual technology.__________Translated from Metallurg, No. 4, pp. 73–77, April, 2005.     

电弧炉炼钢技术的发展趋势

电弧炉炼钢在环保、投资以及效率方面优势明显,为了重点推行该节能环保型炼钢工艺流程,近年来电弧炉炼钢技术得到快速发展。综述了国内外电弧炉高效化冶炼技术、绿色化生产技术和智能化控制技术的发展现状,其中绿色化和智能化是电弧炉炼钢技术的未来发展趋势。集操作、工艺、质量、成本以及环保于一体,进一步提升电弧炉炼钢技术的绿色化和全流程监测与控制的智能化,是推动整个钢铁行业向智能化和绿色化转型升级的重要举措。     

直接还原铁作为废钢替代品在电弧炉中的应用

为了满足用户对优质钢和纯净钢的要求,直接还原铁作为废钢的替代品用于电弧炉炼钢应是一种可行的选择。概述了直接还原铁的特点,指出高比例使用DRI可以得到N、Cu、Cr、Ni、As、Sn等含量低的钢,直接还原铁可认为是一种较好的电弧炉炼钢原料。     

Modern steelmaking technologies

Based on our experimental results, we propose the following low-cost technologies in the field of steelmaking for implementation: the use of briquettes, which are alternative to solid cast iron and scrap metal and contain scale and carbon-containing wastes, in the charges of electric furnaces and converters; microalloying of metal by nitride phases; modification of steel in a ladle by SiCa + Ba master alloys; and the application of daisy-chain blowing of the metal in a ladle (small-bubble conditions). The efficiency of these technologies for melting in electric furnaces and secondary metallurgy is supported. It is shown that electromagnetic mixing of metal in combination with the optimum conditions of soft reduction of a slab should be used in continuous casting to form an internal structure in a slab at the level of the first class on the Mannesmann scale.     

Role of prereduced pellets in the slag foaming in modern EAFs

The problems of electric arc furnace slags are considered, and the role of prereduced pellets in the slag foaming in electric arc furnaces is studied. The optimum rate of loading of prereduced pellets into a furnace that ensures effective steelmaking slag foaming is determined as a function of the degree of pellet prereduction.     

Scrap metal: The problem of its shortage and efficient use

The most important element of manufacturing processes that employ new metallurgical technologies is improving the quality of the scrap metal used in the given process. Introducing modern scrap-processing equipment is especially important in this regard. At the same time, it is also necessary to use the latest technological advances in order to reduce the oxidation loss of iron during refining in arc steelmaking furnaces.     

Theoretical and experimental studies of the composition and reducibility of the dust from arc steel-melting furnaces

The chemical and mineralogical composition of the dust from electric gas-cleaning filters of the steelmaking furnaces at the Moldavian metallurgical works is studied. The conditions of effective removal of zinc and lead from the ASF gas-cleaning dust are determined.