Continuous Casting and Rolling Installation For Producing a Steel Strip

Abstract

In order to produce a steel strip ( 1 ), a continuous casting and rolling installation comprises a liquid steel storage device ( 2 ), a liquid steel charging device ( 3 ), a vertically operating casting device ( 5 ) with a revolving mold ( 6 ), a reduction device ( 7 ) with a plurality of roll pairs ( 8 ), a diverting device ( 9 ) for diverting the cast steel strip ( 1 ) into a horizontal position, a horizontally operating rolling mill ( 10 ) and a winding device ( 11 ), which are controlled via individual technological control loops ( 2 ′ to 11 ′). In order to adjust the technological control loops ( 2 ′ to 11 ′) in an integrated manner, it also comprises a control system ( 12 ) which connects the installation parts ( 2 to 11 ) or components with regard to control, operates on the basis of mathematical models ( 17 ), and coordinates the individual installation parts ( 2 to 11 ) with regard to the interaction thereof, while taking into consideration the effects of the control steps of an installation part ( 2 to 11 ) upon installation parts ( 2 to 11 ) following in the direction of mass flow. The control system ( 12 ) contains a material model ( 17 ), by means of which a thermal behavior of the steel or steel strip ( 1 ) from the steel storage device ( 2 ) to the winding device ( 11 ) can be modeled using path tracking. The technological control loops ( 2 ′ to 11 ′) are controlled at the correct times according to the modeled thermal behavior of the steel or steel strip ( 1 ).

1 .- 19 . (canceled) 
   
   
       20 . A continuous casting and rolling installation for producing a steel strip, comprising the following components:
 a liquid steel storage device;   a liquid steel charging device;   a vertically operating casting device with a revolving mold;   a diverting device for diverting a cast steel strip into a horizontal position;   a horizontally operating rolling mill;   a winding device, wherein the components are controlled by a plurality of technological control loops, each control loop assigned to one of the components;   a control system for adjusting the technological control loops in an integrated manner, wherein the control system connects the liquid steel storage device, the liquid steel charging device, the casting device, the diverting device, the rolling mill, and the winding device, wherein the control system operates on the basis of mathematical models, and wherein the control system coordinates an interaction between the components, wherein the coordination of the interaction takes into consideration effects of a control step applied to one of the components on a component arranged downstream of the one component relative to a mass flow direction; and   a reduction device arranged between the mold and the diverting device, wherein the reduction device has a plurality of roll pairs, and wherein the reduction device is controlled by one of the technological control loops which is also controlled by the control system, wherein   the control system contains a material model for modeling a thermal behavior of the steel or steel strip on a transportation path from the steel storage device to the winding device using path tracking, and wherein   the technological control loops are controlled using the modeled thermal behavior of the steel or steel strip according to a correct control timing.   
   
   
       21 . The continuous casting and rolling installation according to  claim 20 , wherein the steel strip cast by means of the mold has a casting thickness of between 40 and 100 mm upon exit from the mold. 
   
   
       22 . The continuous casting and rolling installation according to  claim 20 , wherein
 the steel strip can be reduced in the reduction device to a rolling mill input thickness of between 10 and 40 mm.   
   
   
       23 . The continuous casting and rolling installation according to  claim 22 , wherein
 the steel strip can be reduced in the reduction device to a rolling mill input thickness of between 15 and 35 mm.   
   
   
       24 . The continuous casting and rolling installation according to  claim 21 , wherein the steel strip can be reduced in the reduction device by at least 25% in relation to the casting thickness. 
   
   
       25 . The continuous casting and rolling installation according to  claim 20 , wherein
 the reduction device comprises an upper part in which the steel strip is re-formed and a lower part in which the steel strip retains its form.   
   
   
       26 . The continuous casting and rolling installation according to  claim 20 , wherein the installation can be controlled by the control system such that the steel strip does not solidify completely until it is in the reduction device. 
   
   
       27 . The continuous casting and rolling installation according to  claim 25 , wherein the steel strip does not solidify completely until it is in the lower part. 
   
   
       28 . The continuous casting and rolling installation according to  claim 20 , wherein
 the steel strip has a final thickness of between 0.3 and 6.0 mm at which it is wound up by the winding device.   
   
   
       29 . The continuous casting and rolling installation according to  claim 20 , wherein
 the steel strip is reduced in the reduction device to a rolling mill input thickness which is determined according to a final thickness at which the steel strip is wound up by the winding device.   
   
   
       30 . The continuous casting and rolling installation according to  claim 20 , further comprising a cooling stretch arranged between the rolling mill and the winding device, wherein the cooling stretch is controlled by a technological control loop controlled by the control system. 
   
   
       31 . The continuous casting and rolling installation according to  claim 20 , further comprising a descaler arranged upstream of the rolling mill, wherein the descaler is controlled by a technological control loop controlled by the control system. 
   
   
       32 . The continuous casting and rolling installation according to  claim 20 , further comprising an intermediate winder and an equalizing furnace both arranged between the diverting device and the rolling mill, wherein the intermediate winder and the equalizing furnace are controlled by a technological control loop controlled by the control system. 
   
   
       33 . The continuous casting and rolling installation according to  claim 20 , wherein phase changes in the steel or steel strip are modeled within the framework of the material model. 
   
   
       34 . The continuous casting and rolling installation according to  claim 33 , wherein phase changes comprise phase changes from liquid to solid or from austenite to ferrite. 
   
   
       35 . The continuous casting and rolling installation according to  claim 20 , wherein structural characteristics of the steel strip are modeled within the framework of the material model. 
   
   
       36 . The continuous casting and rolling installation according to  claim 20 , wherein
 the melting temperature of the steel is measured and fed into the material model as an initial parameter.   
   
   
       37 . The continuous casting and rolling installation according to  claim 20 , wherein
 downstream of the mold, downstream of the reduction device, within the rolling mill and/or downstream of the rolling mill, within and/or downstream of the cooling stretch an actual temperature of the steel strip is recorded and used for adapting the material model.   
   
   
       38 . The continuous casting and rolling installation according to  claim 20 , wherein the components of the installation comprise locally active devices for influencing the temperature of the steel or of the steel strip, and wherein the locally active devices are regulated via the technological control loops assigned to the components in accordance with guidance by the control system. 
   
   
       39 . The continuous casting and rolling installation according to  claim 20 , wherein
 the control system determines at least one reference variable for influencing the temperature of the steel and/or steel strip, wherein the influencing is effective across all the components, and wherein the control system controls the components concerned according to this reference variable.   
   
   
       40 . The continuous casting and rolling installation according to  claim 20 , wherein
 the thermal behavior of the steel or steel strip is also calculated in real time in the material model, and wherein deviations in components arranged upstream are deliberately corrected in components arranged downstream.