Modeling the Thermal Regime of a Cold-Rolling Mill with Allowance for Differences in the Cooling Conditions for the Top and Bottom Rolls

Abstract

A mathematical model is constructed to describe the thermal regime in cold rolling. The model links the perturbing and control variables together in a single algorithm based on a system of heat-balance equations solved in sucesssion for all of the stands of a continuous mill. Design parameters of the mill, parameters of the rolling regime, and thermophysical constants are used as the initial data. Heat-transfer coefficients that characterize conductive and convective heat exchange during the rolling operation are among those constants. Some numerical values for these quantities are given in the article, while other values are refined for each specific mill as part of the model's adaptation to the given situation. The reliability of the model was checked on a five-stand 1700 mill by measuring the temperature of strip at the inlet of the first stand and the outlet of the fifth and final stand. The temperatures of the work rolls in all of the stands were also measured immediately after roll changes. Testing of the proposed model showed that it can be used to improve the thermal regime and cooling systems of continuous cold-rolling mills.