Temperature control in hot strip mill
AssigneeGeneral Electric Company
InventorsDonald J. Fapiano, Michael A. Smith
Life of this patent
Estimating the term…
Abstract
A method for controlling the temperature of a workpiece in a hot strip mill includes calculating temperature changes of the strip at each mill stand location by determining changes in workpiece deformation resistance and correlating the changes in deformation resistance to changes in temperature. Error corrections are made for changes in rolling speed. The calculated temperature change at each mill stand is used to control water sprays positioned adjacent the mill stands. A temperature sensor is placed downstream of the last mill stand to act as a check on the desired delivery temperature of the workpiece. Temperature discrepancies from the temperature sensor are fed upstream to modify temperature corrections.
Claims17
In a hot strip rolling mill including at least one mill stand having opposed work rolls where a metal workpiece is reduced in thickness by passing the workpiece between said opposed work rolls, said mill stand having means to sense the force applied to the workpiece and at least one controllable water spray means positioned adjacent thereto, a method for controlling the temperature of the workpiece during the rolling process, comprising the steps of:
- (a) sensing the force applied to the workpiece at said mill stand during a plurality of successive time intervals;
- (b) determining the reduction in workpiece thickness at said mill stand during each of said intervals;
- (c) developing the deformation resistance of said workpiece, during each of said intervals, from the ratio of the force applied to the workpiece to the reduction in workpiece thickness;
- (d) determining an apparent temperature change in the workpiece, if any, as a function of the differences between the initial and each successively developed deformation resistance;
- and,
- (e) controlling the application of a water spray from said spray means onto said workpiece as a function of said apparent temperature change to thereby control the temperature of said workpiece.
In a hot strip rolling mill having at least two mill stands each having opposed work rolls where a metal workpiece is reduced in thickness by passing the workpiece between said opposed work rolls, each stand including means to hold the workpiece thickness delivered therefrom at a predetermined value and means to sense the force applied to the workpiece, said mill including at least one controllable water spray means positioned between two adjacent stands, a method of controlling the temperature of the workpiece during the rolling process comprising the steps of:
- (a) sensing the force applied to the workpiece at each mill stand during a plurality of successive time intervals;
- (b) determining an apparent temperature change in the workpiece as a function of the differences between the initial and each successively sensed force;
- and,
- (c) controlling the application of a water spray from said spray means onto said workpiece as a function of said apparent temperature change to thereby control the temperature of said workpiece.
Dependencies are inferred from the claim text.