GB1305314A - - Google Patents

Abstract

1305314 Programmed process control CENTRE NATIONAL DE RECHERCHES METALLURGIQUES 19 April 1971 [13 Feb 1970] 21476/71 Heading G3N A process for the predetermination of the datum values of a rolling mill finishing train is controlled by a computer wherein are imposed data including the required thickness at the exit of the last frame of the mill, the required temperature at the exit and the required temperature at the coiler, the nature of the steel and the diameters of the working rolls. At the exit of a roughing pass train the width, temperature and thickness of the strip are measured and by means of mathematical models the speed of the strip at the exit from the mill and its profile is determined. The process comprises the following operations: (a) determining the instantaneous values of the rolls, allowing for their wear and thermal condition; (b) determining the force to be applied to the last roll stand; (c) determining the necessary thickness of the strip at the entrance to the last roll stand; (d) selecting on the basis of the strip characteristics, the optimum distribution of power between the roll stands and distributing the total absorbed power accordingly; (e) checking that the power for each stand does not exceed a given maximum; (f) determining consecutively the strip thickness between the roll stands, the corresponding strip speeds, the roll peripheral speeds and the roll driving motor speeds; (g) calculating the forces exerted in the roll stands and checking against a given maximum; (h) checking whether the force distribution renders it possible to produce a plane strip and if not modifying the force distribution; (i) determining the datum values of the train, clamping screws, and forces at gauge control devices; (j) selecting datum values for loop tensioners; (k) feeding all said datum values to corresponding servomechanisms.