The purpose of the work is to determine rational schemes for their production by analyzing the technological and design parameters of a number of broadband mills that roll hot-rolled strips less than 2,0 mm thick. It is shown that at present there is a constant increase in the production of extremely thin hot-rolled strips (0,8-1,5 mm thick), which can be used instead of more expensive (by $ 20-30 per ton) cold-rolled strips. The development of the production of hot-rolled strips of such a thickness is limited by a number of problems, in particular, the low temperature of the end of rolling (760-820 °C), which leads to a significant decrease in the ductility of the rolled stock; limiting the rolling filling speed, which does not allow increasing the temperature of the end of rolling the complexity of controlling the cross-sectional profile and flatness of the strips. Using mathematical modeling, it was found that the strip thickness and rolling speed have the greatest influence on the temperature of the end of rolling. The thickness and temperature of the rolls at the entrance to the finishing group of stands have a lesser effect. A decrease in the number of stands in the finishing group increases the temperature of the end of rolling at a constant thickness of the rolls, but when the thickness of the rolls changes in accordance with the number of stands, the effect is significantly reduced. The most favorable technological parameters for the production of extra-thin hot-rolled strips are provided by casting and rolling units, which are characterized, in comparison with broad-strip mills, as a rule, by a greater thickness and temperature of the rolls (or continuously cast slabs) and a smaller number of stands. An increase in the thickness of billets (slabs) requires an increase in the permissible values of the energy-power parameters of rolling, as well as the use of special solutions that will ensure minimal heat loss by the rolls before entering the finishing group of stands. Calculations show that, based on the reliable maximum refueling speed of hotrolled strips (10-11.5 m / s) achieved in the industry, the minimum thickness of strips with high plastic characteristics is: for broad-strip mills - 1.9-2.0 mm; for casting and rolling units, depending on their type - 1.3-1.6 mm.
The purpose of the work is to develop a computer system for calculating and optimizing the hot rolling modes of the headquarters, forecasting and increasing the residual life of rolling mill equipment. It is shown that in recent years there has been a steady increase in the production of hot-rolled staffs of high-strength steels and especially thin staffs. Mastering the production of such strips leads to an increase in the load on the equipment of rolling mills. The result is increased wear of equipment elements and their premature failure. The Institute of Ferrous Metallurgy of the National Academy of Sciences of Ukraine has developed a computer system for online monitoring of the residual resource of the wide strip hot rolling mill. The main functions of the computer system are: adaptation of models of power parameters of the rolling process; verification of models according to the actual assortment; calculations of power parameters according to adapted models; optimization of rolling modes to ensure the allowable values of power parameters of rolling and the target temperature of completion of rolling, the maximum productivity of the mill; calculations of the number of load cycles of elements in the equipment of the mill; estimation of the residual resource of the equipment taking into account its initial values. The following schematization methods were chosen for the design of the residual resource forecasting system: for dynamic loads - the method of allocation of complete cycles, for static loads - the method of extremes. All objects of the drive line which are diagnosed are divided into three classes: details which can be both separately, and as a part of knots or units; units that can be both separately and as part of units; units consisting of parts and assemblies. The calculation of the residual resource is performed only for details. The residual life of the node or unit is determined by the part that is part of it and has the smallest residual life. The developed computer system was tested on one of the existing hot strip mills. To do this, the transfer of source data contained in industrial databases to the developed computer system for monitoring the residual resource was established. The test showed a fairly high reliability of forecasting the power parameters of the rolling headquarters and the assessment of the residual life of the equipment and the drive line of the rolls of the working stands.
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