Requirements on the systems controlling the electrical conditions of superpowerful arc furnaces in steel smelting are outlined. The basic principles for electrical optimization at different phases of smelting are considered. An improved mathematical model is proposed for analysis of the arc furnace's electrical char acteristics and the dynamics of the automatic control system governing electrode motion. A diagnostic system capable of identifying the phase of smelting on the basis of the harmonics of the arc currents shortens the fur nace's working cycle and reduces the power consumption.

The article is concerned with the advanced automatic control system of electrode positioning at electric arc steel making furnaces and ladle furnaces. Analysis of structure of modern electrode positioning control systems’ nonlinear controllers for electric arc furnaces and ladle furnaces is considered. Disadvantages of these systems were analyzed. A control system with a conventional structure from well-established foreign suppliers was compared with the advanced automatic control system of electrode positioning.

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It is known that the working rate of industrial equipment is determined by the working capacity of the ceramic components used in the design. Thus, the production of equipment for the isothermal deformation of titanium alloys depends on the capacity of the ceramic backing tiles to withstand high heating rates to temperatures of 1000-1100~ It is known that the magnitude of the temperature coefficient of linear expansion ~ in its physical essentials is the primary cause of thermal stresses, especially during frequent heating of the articles in operation. Thus, low values of ~ in quartz ceramic ensure that it has a high thermal-shock resistance.It is useful to know the behavior of ceramics with different ~ values in conditions of heating with high rates of thermal loading, for example when testing on a gasdynamic rig in a current of high-temperature gas. Such a method was used to assess material based on magnesia-spinel ceramic [i].In the present article we present the results of determining the resistance to frequent hearings of materials having a dense structure and which are based on high-alumina ceramics containing 3%* fluxes (B203, SiO 2, CaO) [2]; quartz ceramic [3]; fusion-cast corundum Kor-93 prepared from the melt [4]; mullite chamotte (63% Al=Os) and its mixture with 9 and 13%electrocorundum; high-temperature chamotte (83% A1203) [5,6]; mixtures of corundum and zircon containing 74.2% of A1203, 17.7% ZrSiO~, 5.8% MgO, 2.3% silicone resin K-9 [7][ aluminum titanate % [8]; mixtures of corundum with aluminum titanate (50:50) with an addition of 9% Si02 on 100% [9]. *Here and subsequently, mass parts are stated. %Specimens of aluminum titanate provided by V. V. Kolomeitsev.