Management of geometric parameters of sheets on rolling mills.

Abstract

The main task of rolling production is to provide rolled products of sufficient quality. Among the primary parameters of metal sheets to be rolled there are their flatness and section. Managing the section and flatness of the strip is a complex problem, and for its solution, there are used not only the tools for automatic control and technical parameters adjustment but also various implementing bodies with which rolling mills are equipped. Nowadays, hydraulic pressure devices are widely used in sheet-rolling mills as elements of fast-acting systems of automatic strip thickness adjustment (SAST), as well as systems of section and flatness control. Systems of shaped rolls with their axial deflection in opposite directions are also applied. Using in the sheet-rolling mills the above-mentioned special bodies and systems of control of section and flatness of sheet to be rolled provides the compliance of these parameters with the specified requirements. The paper investigates the factors influencing section and flatness of sheets, as well as the described special bodies and systems of control of sheet section and flatness regarding the automated systems of managing technological processes of sheet-rolling mills. In SAST, on heavy-plate mills (HPM) and broadband mills for hot rolling, the principle of maintaining the constancy of the inter-roll gap is used as the main one. SAST can be built based on the principles of relative or absolute adjustment of the strip width described in the paper. The search for a universal enough method of influencing the inter-roll gap shape has led to the creation of a system of shaped rolls with their axial deflection in opposite directions (continuously adjustable rolling section). Such a system provides a symmetrical change in the section of the inter-roll gap, which is easily adjusted to any rolling apps.