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Results of computational experiments on studying multiphase flow and interphase interaction in the volume of an industrial 50-ton tundish of a continuous caster, including when blowing with argon through bottom blowing blocks, are presented. A mathematical model has been developed that makes it possible to predict the dynamics of melt mixing at a given casting speed. The pattern of influence of the layout of the ladle’s working space on the area of “stagnant zones” in the ladle volume has been found.

The influence of the electromagnetic mixing (EMM) of liquid metal in the mold of the continuous casting machine on its thermal work, the formation of the structure and properties of cast billets are investigated. The influence of the current and frequency of EMM on the mechanical properties, macro-and microstructure of round and square sorted billets was established.

Mold breakout is one of the significant problems in a continuous casting machine (caster). It represents one of the key areas within the steel production facilities of a steel plant. A breakout event on a caster will always cause safety hazards, high repair costs, loss of production, and shutdown of the caster for a short while. In this paper, a logic-judgment-based mold breakout prediction system has been developed for a continuous casting machine. This system developed new algorithms to detect the different sticker behaviors. With more algorithms running, each algorithm is more specialized in the other behaviors of stickers. This new logic-based breakout prediction system (BOPS) not only detects sticker breakouts but also detects breakouts that takes place due to variations in casting speed, mold level fluctuation, and taper/mold problems. This system also finds the exact location of the breakout in the mold and reduces the number of false alarms. The task of the system is to recognize a sticker and prevent a breakout. Moreover, the breakout prediction system uses an online thermal map of the mold for process visualization and assisting breakout prediction. This is done by alerting the operating staff or automatically reducing the cast speed according to the location of alarmed thermocouples, the type of steel, the tundish temperature, and the size of the cold slab width. By applying the proposed model in an actual steel plant, field application results show that it could timely detect all 13 breakouts with a detection ratio of 100%, and the frequency of false alarms was less than 0.056% times/heat. It has the additional advantage of not needing a lot of learning data, as most neural networks do. Thus, this new logical BOPS system should not only detect the sticker breakouts but also detect breakouts taking place due to variations in casting speed and mold level fluctuation.

Improvement of macrostructure indicators of slabs during continuous casting of steel on a thin-slab machine of the sheet-rolling shop of Vyksa Steel Works JSC was achieved by introducing the latest programs into the automation system for the soft reduction process.

Increase in efficiency of a continuous casting machine is directly related to reduction of a shutdown period to repair and to eliminate accident consequences. One of the most widespread and severe accidents on the machine is the strand shell breakout under a mold. This article presents results of development and operation of the intelligent system for prediction of liquid metal breakouts under the mold of slab continuous casting machines. The most significant scientific results of the study are: mathematical model of copper mold wall temperatures values distributed on the mold perimeter, diagnostic criteria for strand shell sticking in the mold, and techniques and algorithms of strand shell sticking in the mold. Applying the listed results at development of continuous casting machine automation systems allow to reduce the number of accidents on continuous casting process, what is very important for the steel industry.

The paper presents the results of the study aimed at solving the problem of rational distribution of electric drives of pulling rollers along the technological line of a continuous casting machine and selecting a minimum number of pulling rollers in different areas of the secondary cooling zone. The research includes construction and ranking the criteria for distribution of drive rollers along the production line of the continuous casting machine; development of methods and algorithms for calculating the required distribution of load moments on pulling rollers and distribution of electric drives of pulling rollers along the secondary cooling zone in three modes of the electric drive operation of the pulling-straightening device: containment of the dummy bar in the preparatory casting mode of the continuous casting machine; pulling the dummy bar with the head of the ingot at the initial stage of pouring the metal; withdrawal of the ingot in the working mode of casting. Theoretical studies were carried out with the use of analytical and numerical methods for solving algebraic equations, methods of structural modeling. Experimental studies were carried out in the conditions of a large metallurgical enterprize with subsequent processing of the obtained data by statistical methods. The technical and economic analysis of the options of the electric drive execution of the pulling-straightening device showed that due to a significant reduction in the number of electric drives of pulling rollers, the payback period of replacement of a group scheme of power supply of electric motors to an individual one in new continuous casting machines decreases from 5.8 to 7.8 years with the traditional distribution of pulling rollers along the secondary cooling zone to 2.8–3 years with their rational distribution, calculated by the developed methods. The results of the work were used in the design of a slab machine for continuous casting of curvilinear strands intended for casting wide slabs up to 2.5 m. According to the proposed method, the number of electric drives pulling the rollers was reduced to 56.

Statement of the problem: stabilization of the rate of strand withdrawal out of the mould and the secondary cooling zone after change operations of a tundish or a submerged nozzle is one of the attempts to increase the productivity of a continuous casting machine and the quality of a casting strand. The aim of this work is to study the causes of oscillation occurrence in the rate of strand withdrawal and the development of the electric drive control system of the secondary cooling zone providing the increased machine productivity via stabilization of the rate at preserving the required quality of the internal structure of cast strands. Experimental studies were based on the analysis of the changes in load currents of withdrawal roll motors, the total current of the electric drive of the secondary cooling zone of continuous casting machines, macro template laboratory data on the main internal defects detected in strands with the use of methods of statistical data processing. The result: the method proposed for stabilization of the rate of strand withdrawal by means of compensating the harmonic component of the total moment of resistance of strand withdrawal by the reduced amplitude of oscillations of the strand withdrawal rate more than three times allows improving the quality of the macrostructure of cast strands with the increased strand withdrawal rate by 5 %. The results of mathematical modeling and experimental studies can be used in the design of automated electric drives of the secondary cooling zone of continuous casting machines of curved type.

The expanded use of continuous-cast billet in the production of structural-steel bar is considered. The quality of 135 × 135 mm continuous-cast billet produced on a standard continuous-casting machine and the bar derived from it is evaluated. At more recently built plants, the production of quality bar from continuous- cast billet requires total extension of the order of 6–7. On the basis of the analysis developed in the present work, it is possible to determine the maximum critical bar cross section such that the required properties are ensured.

Route maps for the production cycle of operation and repair of continuous casting machine slab rolls in the Azovstal’ and Il’ich Metallurgical Combines (Mariupol’) are presented. It is shown that the complete roll operating cycle in horizontal, curvilinear, and radial sections of the secondary cooling zone as their diameter changes as a result of wear, grinding, and surfacing, makes it possible to increase roll running time, to reduce purchasing expenditure, technical servicing, and restoration. It is established that an increase in secondary cooling zone roll life with diameter 380–270 mm with unchanged composition of the basic and surfacing metal is provided by surfacing technology with formation of a corrosion-resistant surface layer of individually deposited welds with a gap between adjacent welds.

VNIIMETMASh completes modernization of an existing section continuous steel casting machine for the metallurgical plant of Baku Steel Company (Azerbaijan). The work makes it possible in CBCM-2 with base radius R = 6 m to produce round pipe billets 130, 170, 190, and 220 mm in diameter, and also square billets 130 ×130 mm in cross section.