EP2906369A1

EP2906369A1 - Width-altering system for strip-shaped rolled material

Info

Publication number: EP2906369A1
Application number: EP13765985.0A
Authority: EP
Inventors: Ansgar GRÜSS; Andreas Jungbauer; Robert Linsbod; Rainer Burger
Original assignee: Primetals Technologies Germany GmbH
Current assignee: Primetals Technologies Germany GmbH
Priority date: 2012-10-09
Filing date: 2013-09-17
Publication date: 2015-08-19
Anticipated expiration: 2033-09-17
Also published as: US20150258592A1; RU2015117467A; KR102131182B1; CN104837574B; CN104837574A; EP2906369B1; RU2643002C2; KR20150065862A; US9764367B2; IN2015DN02529A; WO2014056681A1; DE102012218353A1

Abstract

The invention relates to a method for altering the width of a strip-shaped rolled material (5), in particular before hot rolling, during hot rolling or after hot rolling the rolled material in a hot rolling mill. The problem addressed by the invention is to specify a method for altering width, by means of which the length of a rolled out transition piece lying outside the width tolerances can be reduced. Scrap losses are supposed be reduced thereby. This problem is solved in that the crown of at least one working roll and/or at least one backing roll of a stand (7) is set as a function of a width error e = B_setp-B between a setpoint width B_setp and the width B of the rolled material (5), wherein the crown is increased when e > 0 and the crown is reduced when e < 0. AA R_crown BB B_setp

Description

description

Width control of a strip-shaped rolling stock Technical field

The present invention relates to a method for

Width control of a strip-shaped rolling stock,

in particular before hot rolling, during hot rolling or after hot rolling of the rolled stock in a hot rolling mill.

During hot rolling, a metallic rolling stock, for example a strip-shaped rolling stock made of steel or aluminum, is plastically deformed warm in a rolling nip of a roll stand.

Specifically, the invention relates to a method for

Width control of a strip-shaped rolling stock, wherein the rolling stock, a first aggregate and a second aggregate

passes through uncut, having the following

Process steps:

- Production of the rolling stock with a first width Bi, wherein the rolling stock from the first unit with a width B = Bi emerges and the emerging rolling below

Maintaining a train <J = <J _Norma i transported in the transport direction to the second unit;

- Production of a transition piece of the rolling stock, wherein the rolling stock from the first aggregate with the width B with Bi -SB <B ₂ emerges;

- Production of the rolling stock with a second width B ₂ , wherein the rolling stock from the first aggregate with the width B = B ₂ exits. Moreover, the invention relates to a method for

passes uncut and the rolling stock is rolled in a rolling stand in the first unit and / or in the second unit, comprising the following steps:

- Production of the rolling stock with a first width B _lr wherein the rolling stock from the first unit with a width B = Β emerges and the exiting rolling to the second

Aggregate is transported;

- Production of the rolling stock with a second width B ₂ , wherein the rolling stock from the first aggregate with the width B = B ₂ exits.

State of the art

From the prior art, it is known, the width of a continuously produced slab strand in a

Continuous casting machine by moving at least one narrow side wall to change in the mold. Furthermore, it is known to couple a continuous casting machine inline with a hot ^¬ rolling mill, so that the hot rolling mill can directly hot rolls an uncut or cut slab strand produced in the continuous casting machine. Such a coupling of a casting machine to a hot rolling mill is called a cast-roll compound plant (also known as Thin Slab Casting and Rolling Plant, or TSCR for short); the

uncut, direct coupled mode of operation of the cast-roll composite plant becomes endless operation (engl., endless

Operation). An example of a casting rolling mill Compound system that can be operated very well endless is the Arvedi ESP (Endless Strip Production) system.

Furthermore, it is known to produce a rolling stock with a different width with a cast-rolling composite plant. Typically, the width of the slab strand is changed in the mold, whereby a tapered or widening slab piece (also called transition piece or wedge-shaped transition piece) with a certain length (depending on the casting speed and the travel speed of

Narrow side wall) is produced. The slab with the transition piece is then in the rolling mill of

Rolled composite system, which in any case a slowly tapered or slowly wider rolled strip is produced.

Because the slowly changing band in the

Generally, the width tolerances can not comply, is disadvantageous in that the band with the rolled out

Transition piece can not be sold directly. Thus, it is desired to keep the length of the transition piece as short as possible. This can be done either by the

Cut out the transition piece from the slab or out of the rolled strip, which in any case

considerable application losses occur. Furthermore, the transition piece can be trimmed or trimmed, whereby the Ausbringverluste can be reduced slightly. A very fast adjustment of the narrow side walls in the mold is also eliminated, since this can easily lead to breakthroughs in the thin strand shell of the slab strand.

How the application losses further reduced and the

Operational safety can be maintained at a high level, is not apparent from the prior art. Summary of the invention

The object of the invention is to overcome the disadvantages of the prior art and to provide a method for influencing the width of a strip-shaped rolling stock, with which the length of a rolled transition piece, which is outside the width tolerances, can be reduced. This should reduce the Ausbringverluste.

This task is performed by a procedure for

Dissolved width control of a strip-shaped rolling stock, wherein the rolling stock a first aggregate and a second

Run through unit uncut, having the following

Steps:

Maintaining a move <? = a _Normal transported in the transport direction to the second unit;

- Production of the rolling stock with a second width B ₂ , wherein the rolling stock from the first aggregate with the width B = B ₂ exits;

the solution takes place in that the train σ is set to the rolling stock between the first unit and the second unit in response to a width error e = B _Soll -B between a desired width B _So n and the width B of the rolling stock, the train σ is increased at e <0 to σ> σ _Νοηηα1 . _{According to the} invention, a width error e between a desired width B _So ii and the width B of the rolling stock is determined and the tension σ is set to the rolling stock between the first and the second aggregate as a function of the width error e. In this case, the train σ is increased at a negative width error e to <5><5 _normal , whereby the width of the rolling stock

Exit from the second unit is reduced. This principle is based on the realization that when rolling a belt, there is usually not only an increase in length (the so-called elongation) but also a width increase (the so-called spread). However, when the tape is under tension, the increase in width becomes less or even negative. It should be noted that the mentioned principle is by no means limited to rolling mills, but rather is applicable to any directly coupled aggregates. It is only important that the train can be adjusted to the rolling stock between the two units.

The increase of the tension σ can e.g. by increasing the drive torque of the second unit (with the second unit following the first unit in the transport direction). Alternatively or additionally, the

Drive torque of the first unit can be reduced. This can e.g. done by the drive motors in a rolling stand or a pair of drive rollers.

To increase the width of the rolling stock, it is advantageous if the train σ with a positive width error e on (7 <(7 _Norma is reduced Here, _-. Absolute terms - the train σ even assume negative values, which means that the normal stress in the transport direction is a compressive stress. The reduction of the train σ can for example be done by reducing the drive torque of the second unit. Alternatively or additionally, the drive torque of the first unit can be increased. This can be done by the

Drive motors in a rolling stand or a pair of drive rollers done. Thus, in the method according to the invention, it is also possible to compensate for positive width errors at least partially, preferably completely. It should be noted that although the width of a band can also be influenced by the use of loop lifters between two rolling stands, this is excluded for positive latitude errors due to the system.

The first and second unit may, for example, be a caster and a roughing train, a roughing and finish rolling line, or generally also the area between two driving rollers, but in order to be able to impress a tension to the belt between the driving rollers, at least the drive torque of a drive roller should be adjustable independently. Of course, it is also possible that the two units are two consecutive rolling mills on one and the same rolling mill.

The adjustment of the train σ as a function of the width error e can be either controlled or regulated, i. under

Consideration of the measured width B _If the rolling stock is on exit or after leaving the second unit. At the controlled setting is advantageous that the actual width of the rolling stock or the rolled product after rolling of the rolling stock of further influences (such as the temperature of the hot strip) into account. It is particularly advantageous if the setting of the train σ (which also has a negative sign and thus can be a pressure) taking into account a mathematical

Constriction model for the rolling stock is done. This model advantageously takes into account the deformation resistance as a function of the degree of deformation, forming speed and temperature as well as the current structural condition, the creep behavior dependent on the current rolling stock condition, the chemical composition of the rolling stock, the temperature of the rolling stock and optionally a temperature-dependent elastic modulus of the rolling stock.

It is particularly useful if the first or the second unit is a rolling mill and the rolling stock is rolled in the rolling stand. In this case, the train can be easily adjusted to the rolling stock via increased or decreased rolling moments, without the need for additional equipment expense would be necessary. The object of the invention is also by a

Method for influencing the width of a band-shaped

Walzguts solved, wherein the rolling stock passes through a first unit and a second unit uncut and the rolling stock is rolled in a rolling stand in the first unit and / or in the second unit, comprising the following

Process steps:

Production of the rolling stock with a first width Bi, wherein the rolling stock exits from the first aggregate with a width B = Bi and the outgoing rolling stock to the second

Aggregate is transported;

- Production of a transition piece of the rolling stock, wherein the rolling stock from the first aggregate with the width B with Bi -SB <B ₂ emerges; - Production of the rolling stock with a second width B ₂ , wherein the rolling stock from the first aggregate with the width B = B ₂ exits;

the solution is achieved in that the crown of at least one working and / or at least one support roller of the

Roll stand is set in response to a width error e = B _SoU -B between a desired width B _So n and the width B of the rolling stock, wherein at e> 0 increases the crown and e <0, the crown is reduced.

In a rolling stand as a first and / or second unit, the crowning of a working or support roller of the rolling stand in response to the width error e, in addition or alternatively to influence the train of the rolling stock

can be adjusted, wherein at e> 0 increases the crown of the roller and at e <0, the crown of the roller is reduced. The term "crowning" is to be understood here as meaning the central crowning, whereby, when the crowning is increased, the thickness of the rolling stock in a central region is reduced, so that the expansion of the rolling stock during rolling is increased. On the other hand, in the case of a negative latitude error e, the central crown is reduced, so that the spread during rolling is reduced. The

Adjustment of the crown of a roll may e.g. above

Roll bending reactors or also via a thermal

Influencing (for example zone-dependent cooling) of the roller. Is at a thermal influence a

Increasing the crowning desired, the cooling of the edge regions of the roller is increased more than the central areas. As a result, the central area of the roller expands more than the edge areas, whereby the crown is increased. On the other side is the crown reduced when the cooling in the central region of the roller is increased more than in the edge regions.

In order not to change the geometry of the rolling stock too much by adjusting the crowning for width control, it is advantageous if both units have a roll stand, and a change in the crowning of a roll takes place mainly in the first aggregate. This ensures that the rolled product after rolling in the second unit has a desired geometry.

Also, the adjustment of the crown as a function of the width of the error e can be carried out either controlled or regulated, ie taking into account the measured width _B of the rolled material, for example, at the exit from the second unit or later at an additional location.

In particular, when setting the crown, it is very advantageous, the transport time of the rolling stock of the first

Aggregate or from a measuring device for detecting the actual width B _is to be considered to the rolling stand. As a result, the width in the transition piece in the rolling mill of the second

Aggregates corrected in the correct time. The consideration of the transport time can also be used when setting the train for width control.

Since normally only bands with a certain width can be sold, it is advantageous if the desired width B _So ii is a jump function H (t) from Bi to B ₂ or from B ₂ to Bi. Alternatively, the desired width B _So n may also be a ramp function R (t) from Bi to B ₂ or from B ₂ to Bi. Of course, other functions are possible. In general, it is expedient if the first unit is a mold of a casting machine, for example a Bogenstrangg- ießmaschine or a two-roll casting machine, or a rolling mill, for example, a rolling stand of a roughing mill.

In particular, during hot rolling in a hot rolling mill, it is expedient, the rolling stock from the first unit on a

Roller table to transport the second unit. The

However, the invention is by no means limited thereto but works e.g. also for freely suspended loops between two aggregates.

Brief description of the drawings

Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, reference being made to the following figures, which show the following:

1 and 8 each show a schematic representation of part of a cast-rolled composite plant for carrying out the width-influencing of a strip-shaped rolling stock between a continuous casting machine and a roughing mill

Figures 2 and 5 each show a representation of the width B _KO kiii _e of the rolling material in the mold, the width B _Treibro ii _e at the drive roller and the target width B _So n at the position of the drive roller over time to the embodiment of Figure 1

FIG. 3 and FIG. 6 each show a representation of the width error e over time at the position of the drive roller for FIG

Embodiment of FIG. 1 4a shows a control scheme for carrying out the method according to the invention

4b, 7 and 10 each show a control scheme for carrying out the method according to the invention

9 shows a representation of different widths over time for the embodiment according to FIG. 8, description of the embodiments

1 shows a part of a casting-rolling composite plant with a continuous-arc machine 1 for continuous

Pouring molten steel into thin slabs and one

subsequent, in-line, rolling mill. Of the

Walzstraße was only a rolling mill 7 of the roughing mill shown; on the presentation of the other parts of the system has been omitted. In the mold 8, liquid steel is continuously cast into a thin slab strand, initially the width of the strand B = Bi = 1800 mm and its thickness is 90 mm. The casting speed 11 is 5 m / min; the metallurgical length of the continuous casting machine 1 from the mold 8 to the two driving rollers 10 is 15 m. Subsequent to the mold 8 of the thin slab strand is supported in the strand guide 9, guided and further cooled, the strand in the last third of the arcuate

Strand guide 9 solidifies. The strand guide 9 is indicated by two strand guide rollers. The solidified thin slab strand exits via the drive rollers 10 from the continuous casting machine 1 and represents the rolling stock 5. The pair of drive rollers 10 forms the first unit 2. The rolling stock 5 is in the transport direction 6 from the first unit 2 uncut on the roller table 3 to the second unit 4 out, wherein the second unit 4 by a rolling stand. 7 the roughing line is formed. Rolled product 5 rolled in the rolling stand is also referred to as rolled product 12.

If now another width of the rolled product 12 is desired, the two narrow side plates of the mold 8 are moved transversely to the casting direction. For example, the two narrow side plates are moved from B ₂ = 1800 mm to B ₂ = 1850 mm during the uninterrupted operation of the cast-rolling composite system at a travel speed of 50 mm / min. By this movement is formed after the mold 8 in a width-changing, wedge-shaped thin slab strand (also called transition piece) in the strand guide 9 from. The width B _KO kiiie of the thin slab strand upon exit from the ingot mold 8 and at the outlet of the rolling material 5 from the first unit 2 _Tre B i _bro n _e are represented by solid lines in Fig. 2 Due to the length of the continuous casting machine, the head of the transition piece emerges from the first unit 2 with a delay of 3 minutes from the mold 8. For width adjustment in the mold it is noted that in the production of thin slabs usually the

Narrow sides of the mold at the beginning of the transition piece slowly inclined, then the inclined plates

procedure, and finally the inclined plates are returned to their original inclination. This has the advantage that the strand is better supported by the mold walls. The widths B _KO kiiie and B _Tre i _bro n _e in this procedure are shown in phantom in FIG. Furthermore, the desired width B _So n of the rolling stock 5 is shown in Figure 2, wherein the desired width mathematically as

B _target = 1800 + 50.H (240) can be written, the

Heaviside hop function H (t) at 240 s from zero to one jumps. For example, the jump function is known from http: // mathworld. tungsten. com / HeavisideStepFunction. html.

The principle of the invention is based on the fact that, depending on the width error e with e = B _SoU -B the train on the rolling stock 5 between the first unit 2 (specifically, the pair of

Driving rollers 10) and the second unit 4 (the rolling stand 7 of the roughing mill) is changed, with a negative e of the train σ is increased to the rolling stock 5 in the transport direction 6. Thus, the rolling stock 5 is constricted by the train, whereby the width of the rolling stock 5 and the rolled product 12 is reduced.

The width error e is shown in FIG. On the

Representation of the width error e for in Fig. 2

dash-dotted widths was waived.

A control scheme for implementing the method according to the invention is shown in FIG. 4a. Specifically, the

Width error e determined by the difference between the target value for the width B _So n and the width B, wherein B is determined by the width of the thin slab strand at the output of the mold 8, taking into account a dead time of 3 min by the deadtime member 13. The width error is then amplified by an amplifier member 14 and held by the limiting member 15 within allowable minimum and maximum limits. The result σ _3ο ιι is fed to a train regulator R _a for the mill stand 7, which sets the train σ on the rolling stock 5 accordingly. The manipulated variable u is applied to the controlled system G, wherein the

Controlled system G as output an actual width B _is the

Rolled product 12 at the exit from the second unit 4 supplies. The essential difference between the control scheme in Figure 4a and the control scheme in Figure 4b is that the actual width B _{actual of} the rolled product 12 immediately after exiting the second unit 4 through the

Width measuring device 16 is measured (see Figure 1) and the control loop is returned, so that the accuracy of the width control can be significantly increased. Of course, it would also be possible to choose another function for the desired width B _So n, for example as in FIG. 5. Such a choice leads to positive and negative values for the same width B, however

Width error e, so that the control according to FIG. 4 a or the control according to FIG. 4 b upsets the rolling stock 5 with positive values of e. The compression of the width of the rolling stock 5 is increased.

In any case, the actual width B _{actual of} the rolled product 12 is kept closer to the desired width B _So n by the inventive method, so that the width tolerances can be better met.

In addition to influencing the tension σ for influencing the width of the rolling stock 5, it is also possible for the

Crown of a working and / or a backup roll of

Roll stand 7 as a function of the width error e

adjust. For this purpose, e.g. the control scheme of Figure 7 is used. The difference from the scheme according to FIG. 4b is that the width error e additionally belongs to a controller

R _ß aiii _gk is supplied to the solution of the crowning influenced s ^¬ a working and / or backing roll of the roll stand 7, which affects the crowning of the roller over the control value U2. Thus, the controlled system G by two manipulated variables ui, U2 influenced, wherein the controlled variable _is the width B of the rolling material 5 (after the second specifically the aggregate 4

Rolling stand 7). The manipulated variable ui corresponds to the

Manipulated variable u from FIG. 4b. As can be seen in FIG. 1, the actual width B _actual can be measured by the width measuring device 16 at the output of the second unit 4 and supplied to the control loop.

1 shows a part of a casting-rolling composite plant with a continuous casting machine 1, a first unit 2 in the form of a pair of drive rollers 10, a second unit 4 in the form of a rolling mill 7 and in addition a third unit 17 in Form of a further roll stand 7. To achieve higher pull-out or holding forces, the first unit 2 could of course also include several drive rollers 10. The second unit 4 together with the third unit 17 forms the roughing of the cast-rolling composite system. In Fig 8, the rolling stock 5 of the

Drive rollers 10 discharged from the continuous casting machine 1 with a thickness of 90mm, then rolled in the second unit 4 to a thickness of 50mm, and finally reduced in the third unit 17 to a thickness of 30mm. The width of the strand after the mold 8 B _KO kiiie _? the width of the strand in the drive roller 10 B _Treibro ii _e , the target width B _So n and the width of the strand after exiting the second unit 4 - once without B _Ag g _rega t 2 and once when using the

B _is method according to the invention - are shown in FIG. The actual width of the rolling stock 5 or of the rolled product 12 is in turn measured immediately after the second unit 4 by the width measuring device 16. From Figure 9 it can be seen that the actual width _B of the roll product 12 through the application of substantially longer remains within the tolerance width, so that the Ausbringverluste be reduced. The control scheme for FIGS. 8 and 9 is shown in FIG. In contrast to the control scheme of Figure 4b of the

Width error e = B _So nB _{Is used} to control a first train σι between the first 2 and the second unit 4 and for controlling a second train 02 between the second 4 and the third unit 17, wherein the resulting manipulated variables ui, U2 with each other on the G ^{controlled system} G ^¬ act. Optionally, both the gain factors Ki and K _{2 of} the gain members 14, the boundaries of the limiting members 15 and the controller R _a for the first

Branch for influencing the train σι and for the second branch to influence the train 02 are chosen differently.

Although the invention in detail by the preferred

Thus, the invention is not limited by the examples disclosed and other variations can be deduced therefrom by those skilled in the art without departing from the scope of the present invention

To leave invention.

LIST OF REFERENCE NUMBERS

1 continuous casting machine

2 first unit

3 roller table

4 second unit

5 rolling stock

6 transport direction

7 rolling stand

8 mold

9 strand guide

10 drive roller

11 casting speed

12 rolled product

13 deadtime member

14 amplifier link

15 limiting member

16 width measuring device

17 third unit

B width

Is actual width

Bsoii target width

Width of the strand when leaving the mold

BTroller Width of the rolled stock at the exit from the first

Unit 2 unit

Bi first width

B ₂ second width

e width error

G controlled system

R controller

Ra train regulator

σ train

t time u, ul, u2 manipulated variable

Claims

claims

1. A method for influencing the width of a strip-shaped rolling stock (5), wherein the rolling stock (5) passes through a first unit (2) and a second unit (4) uncut and the rolling stock (5) in a roll stand (7) in the first unit (2 ) and / or rolled in the second unit (4), comprising the following method steps:

- Production of the rolling stock (5) with a first width Bi, wherein the rolling stock (5) from the first unit (2) with a width B = Bi emerges and the emerging rolling stock (5) to the second unit (4) is transported;

- Production of a transition piece of the rolling stock (5), wherein the rolling stock (5) from the first unit (2) with the width B exits with Bi <B <B ₂ ;

- Production of the rolling stock (5) with a second width B ₂ , wherein the rolling stock (5) from the first unit (2) with the width B = B ₂ emerges;

characterized in that the crown of at least one working and / or at least one support roller of the roll stand (7) is adjusted in dependence on a width error e = B _SoU - B between a desired width B _So n and the width B of the rolling stock (5) , where e> 0 increases the crown and e <0 reduces the crown.

2. The method according to claim 1, characterized in that the adjustment of the crowning in dependence of

Width error e controlled.

3. The method according to any one of claims 1 to 2, characterized in that the adjustment of the crown in

Depending on the width error e is regulated, the Width B, measured width _B of the rolling stock (5) at the exit of the second unit (4) or thereafter.

4. The method according to any one of claims 1 to 3, characterized in that the adjustment of the crowning the

Transport time of the rolling stock from the first unit (2) to

Roll stand (7) considered.

5. The method according to any one of the preceding claims, characterized in that the desired width B _target either a

Jump function H (t) or a ramp function R (t) from Bi to B ₂ or from B ₂ to Bi.

A method according to any one of the preceding claims, characterized in that the first unit (2) is a mold of a casting machine, e.g. a continuous sheet casting machine (1) or a two-roll casting machine.

A method according to any one of claims 1 to 6, characterized in that the first unit (2) is a rolling stand (7), e.g. a roll stand (7) of a roughing mill.

8. The method according to any one of the preceding claims, characterized in that the rolling stock (5) from the first unit (2) on a roller table (3) to the second unit (4) is transported.

9. The method according to any one of the preceding claims, wherein the from the first unit (2) emerging rolling stock (5) while maintaining a train <J = a _normal in the transport direction (6) to the second unit (4) is transported, characterized in that the train σ on the rolling stock (5) between the first unit (2) and the second unit (4) in Dependence of the width error e = B _setpoint -B is set, whereby the tension σ is increased at e <0 to (7 X7 _Norma!

10. The method according to claim 9, characterized in that the train σ is reduced at e> 0 to CT <cr _Norma i.

11. The method according to any one of claims 9 to 10, characterized

characterized in that the setting of the train σ in

Dependence of the width error e controlled takes place.

12. The method according to any one of claims 9 to 10, characterized in that the adjustment of the train σ in

Depending on the width error e is regulated, wherein the width B is a measured width B _is the rolling stock (5) at the exit from the second unit (4).

13. The method according to any one of claims 9 to 12, characterized in that the adjustment of the train σ under

Taking into account a mathematical constriction model for the rolling stock under tension σ.