Mathematical Models for Set-up Control System in H-beam Universal Rolling

Abstract

It is well known that universal rolling of H-beam shows complicated behaviors of metal flow between web and flange, multiplication of roll separating force and complex distribution of temperature in comparison with flat rolling.
Because of these complex rolling characteristics, there is a limit of dimensional accuracy in manual control by operators. An automatic roll gap control system is necessary to obtain high productivity and high dimensional accuracy of H-beam.
Authors developed the mathematical models for this control system of universal rolling as following procedure.
(1) Rolling temperature model
The distribution of temperature in the cross section of H-beam is computed by the finite difference method. Then the simplified mathematical model has been developed to predict the mean temperature of both web and flange during rolling based on these results of the computation.
(2) Roll separating force model and flange width spread model
Lead model rolling experiments have been performed in various rolling conditions of reduction ratio, thickness and flange width. From these works, the models to predict the flange width spread and roll separating force have been obtained as the function of the rolling conditions which are mainly the geometrical size of H-beam.
Due to application of these models to set up control, high dimensional accuracy of H-beam has been obtained.