Mathematical models of stand deformation for ACS TP for plate rolling mills

Abstract

One of the most important indicators of the plate mill operation is the accuracy of implementation of the specified geometric dimensions of rolled products. To a large extent, this indicator depends on the accuracy of predicting rolling parameters using mathematical models. The mathematical model of the stand deformation, along with the rolling force model, is the most important in controlling the geometric dimensions of rolled products on thick-plate mills: thickness, width, profile and flatness of the sheet. The paper discusses the well-known methods of calculating the deformation of the stand elements, it is shown that they give significantly different results and are suitable only for a qualitative assessment of the deformation of the stand, and those of them that have sufficient accuracy are cumbersome and unsuitable for implementation in control computer used in the automation of rolling processes in real time. From the above, it follows that the most correct method for obtaining a model of stand deformation suitable for use in ACS TP is experimental. The paper considers the stand deformation model developed by the authors, obtained by conducting “active” experiments with minimal disruption of the technological process. The experimental technique provides for the redistribution of reductions between passes during rolling of various billets in the entire range of widths rolled on the mill. Another method for determining the deformation characteristics of the stand, developed by the authors, is considered and makes it possible to determine these characteristics in the process of automatic rolling control without redistributing reductions between passes. The mathematical models of the stand deformation described in the paper, developed by the authors, were used in a number of automated control systems for rolling modes on the rolling mill.