Research And Application Of Width Control Mathematical Model For Hot Strip Roughing Rolling Process

Width control is an important component part of the roughing rolling control process and its controlling precision has become one of the significant indicators of strip steel production quality. Good width control accuracy not only can reduce the cutting loss rate of head and tail and the edge of the rolling piece, improving the yield, but also can create convenient conditions for the subsequent manufacturing procedure. The width control of the hot rolling strip steel products mainly accomplished in the roughing area according to the current equipment layout of the hot rolling production line, so only with accurately strip width control mathematical model established in the roughing area can we get width control accurately and effectively control the exit width of finishing mill. So under the background of one domestic 1580mm hot rolling strip steel engineering project, the width control mathematical model in the process of roughing rolling was studied in order to improve the width control precision of this production line. In this paper, the main research contents are as follows:(1) Based on a large number of domestic and overseas related articles about width control of roughing rolling, the development history of hot rolling mill and roughing rolling control technology, especially the width control technology in the process of hot roughing rolling were reviewed and analyzed in order to lay a theoretical foundation to the research of width control technology.(2) Based on the equipment layout and process flows of one domestic 1580mm hot rolling strip steel production line, with width control mathematical model of roughing rolling as the core, relevant mathematical models used in the process of width setting of this production line were analyzed and elaborated so as to lay a foundation for subsequent width model development.(3) Based on the influence factors to the width control model, the width spread in the process of finishing was considered and the width setting model was optimized. Self learning model to the width spread in the roughing passes and self learning model to the finishing exit width were researched and developed, thus, setting accuracy of stable period of width control mathematical model has been greatly improved.(4) In the view of the width loss exiting at the slab head and tail, the cause of this phenominon was analyzed. Based on the review and analysis of the existing curve of short stroke control and its control effect, combining the production practice of this line, the cubic polynomial curve of short stroke control to the strip head and tail was carried out and the short stroke control form in the non-stable period was optimized and the width control precision of.strip head and tail was improved.(5) The statistical results showed that the developed width control mathematical model had high precision and satisfied the requirements to the width setting precision and product width control accuracy.