DE10301762A1 - Rolling steels and non-ferrous metals, takes additional factor into account to represent change in strength of rolled material, when calculating a given rolling force - Google Patents

Abstract

Calculation of the given rolling force (FW.V/E) includes consideration of a factor (kV/E), representing increase or loss in strength of the rolled material (1).

Description

The invention relates to a method for rolling rolled goods, especially steel and non-ferrous materials, in which the rolling stock is rolled in at least one rolling stand, the rolling stand being one Control and / or regulating device a rolling force is specified and wherein the rolling force is a function of the deformation resistance, the Width of the rolling stock, the radius of the rolls of the roll stand and the decrease in the thickness of the rolling stock in the roll stand.

When thermomechanically rolling steel and non-ferrous materials, it is necessary to use a control and / or control device for the rolling stands used Specify rolling force, which is known as a function of Resistance to deformation, width of the rolling stock, radius of the rolls and the Thickness reduction of the rolling stock in the roll stand results.

Solutions are known in the prior art who try material dependent Events in Rolled stock when determining the target rolling force and the thickness control in the rolling stand to consider.

In the DE 36 37 043 A1 describes a method for predetermined compliance with narrow thickness tolerances when rolling rolled material in hot strip mills by means of a process computer. In this solution, a successively acting influence of the process computer for specifying operating point parameters for the thickness control is disclosed. Material class, acceptance, temperature and rolling speed are taken into account when calculating the rolling force.

WO 93/11886 A1 discloses a Rolling plan calculation method for setting the target rolling force and predetermined roll gap of a roll stand. Thereby, framework-specific and / or material-specific rolling force adjustment elements are taken into account.

WO 99/02282 A1 describes a Process for controlling or presetting the roll stand depending at least one of the sizes rolling force, Rolling moment and advance, in which the modeling of the influences by means of information processing based on neural networks or by means of an inverted rolling model by recalculating the material hardness in the pass using a regression model. To train the neural Network or to use an inverted rolling model, however only rolling results are available. An application of this procedure on materials that have not yet been rolled or on systems with others Parameters are therefore not immediately possible.

With thermomechanical rolling, and / or softening process takes place in the rolled material. This to lead usually to higher and above that the rolling stock fluctuating rolling forces. No concepts are described in the cited prior art, with which the hardening and / or softening processes in the target rolling force calculation and be taken into account in the thickness control in the roll stand. Hence comes it with the previously known solutions for impairment plant safety, process stability and, in particular, absolute and relative thickness errors over the length of the rolling stock.

In the article “New Trends in Hot Flat Rolling Technologies and Pass Schedule Optimization "by N. Wehage et al., MPT International, No. 4/1998, pages 60 to 71 for consideration of hardening and softening processes in the target rolling force calculation a material and temperature dependent correction factor for the Resistance to deformation specified. However, this only takes into account indirectly Consolidation and softening processes, because important influencing factors such as The degree of forming, the forming speed, the gap ratio and the transformation temperature are not considered become. The proposed correction is also only effective in the calculation of the target rolling force, but not with the thickness control.

Overall, the said reveals State of the art no ways like the hardening and / or softening processes in thermomechanical rolling of steel and non-ferrous materials as part of the target rolling force calculation and the thickness control are, so that these effects are sufficiently taken into account can.

The invention is therefore the object to propose a process of the type mentioned at the outset, with an increase absolute thickness accuracy, plant safety and process stability in thermomechanical rolling of steel and non-ferrous materials taking into account hardening and / or softening processes can be ensured.

The solution to this problem by Invention is characterized in that the calculation of the predetermined Rolling force continues by taking into account a factor takes place that the solidification and / or softening of the rolling stock indicates or maps.

It is preferably provided here that the determination of the rolling force F _{W / VE is based} on the relationship F W / VE = k W * B * (R W ·(H 0 - H 1 )) 1.2 · k V / E results in
k _W deformation resistance,
b width
R _W roll radius,
h ₀ thickness before the stitch h ₁ thickness after the stitch
k _{V / E} hardening / softening factor
is. The factor k _{V / E} is particularly preferred for the hardening and / or softening of the rolling stock depending on at least one of the process parameters
Forming temperature T _W ,
Degree of deformation phi,
Total degree of deformation of the finish rolling phase Sum (phi),
Forming speed phip,
pressed length of roll gap I _d ,
average thickness of the rolling stock in the roll gap h _m ,
target final rolling temperature T _End ,
Temperature of the A _R3 point T _AR3 ,
_Time since the start of the _{finish rolling phase} t _FWPh
determined. Here, the factor k _{V / E} for the hardening and / or softening of the rolling stock can be derived from the relationship k V / E = b 0 + b 1 * T W + b 2 Exp (Sum (phi)) + b 3 · In (phip) + b 4 · (I d /H m ) + b 5 * T End / T AR3 + b 6 · t FWPh result, where b ₀ to b _{6 are} predetermined constants (regression coefficients).

The calculation of the roll stand adjustment is advantageously carried out on the basis of the gage meter equation known per se, wherein a module is taken into account which indicates or depicts the hardening and / or softening of the rolling stock. The determination of this module C _{M, V / E} can be derived from the relationship C M, V / E = dF W, V / E / dh 1 result in
dF _{W, V / E} change in rolling force
ie ₁ change in the outlet thickness
is. The gauge meter equation used can result from the relationship ds AGC = (1 + C M, V / E / C G dh) 1 = (1 + C M, V / E / C G ) (DF W, V / E / C G + s - s should ) result, where d
s _AGC change of nip setting
ie ₁ change in the outlet thickness
C _{M, V / E} consolidation / softening module
C _G scaffolding module
ie ₁ change in the outlet thickness
dF _{W, V / E} Change in rolling force during hardening / softening
s adjustment of the roll gap
s _{should be the} target position of the roll gap
is.

The control and / or regulation of the Roll gap of the roll stand can be done with the inclusion of process parameters that during and / or be determined after a stitch. In particular, the process parameters can measured rolling force that required Rolling time and / or the required Be break time. Finally it can be provided that before performing a subsequent stitch the control and / or regulation of the roll gap of the roll stand due to the determined data of the previous stitch takes place.

In the drawing, an embodiment of the Invention shown.

Show it:

1 schematically the course of the rolling force over the employment or outlet thickness of the rolling stock in a rolling stand,

2 schematically the structure of a roll stand with a control and / or regulating device and

3 schematically the working concept of the control and / or regulating device for adjusting the roll gap in the roll stand.

In 1 the course of the rolling force F _W is shown schematically over the employment or outlet thickness s / h in a rolling stand. The functional curves shown correspond to the known gaugemeter equation, in which the roll stand expansion and the compensation for bending, oil film behavior of the plain bearing, roll eccentricity and tapping points are taken into account. The position of the electromechanical and / or the hydraulic adjustment in the roll stand is determined by means of the gage meter equation and the calculated nominal rolling force to ensure the desired outlet thickness of the rolling stock. The stand expansion curve for the current rolling conditions is with the reference number 11 Mistake.

2 shows schematically the structure of a roll stand 2 with a control and / or regulating device 3 , The figure shows the connection and communication of the process, process computer and device for thickness control. In the mill stand 2 becomes the rolling stock 1 rolled, which is moved in the production flow direction R. The double arrow below the roll stand 2 symbolizes the rolling direction, which can be reversing.

The control and / or regulating device 3 assigns a process computer 4 on that with a device for thickness control 5 is in operative connection. The device for thickness control 5 gives a determined position of employment 6 an electromechanical and / or hydraulic adjusting device 7 with the one in the roll stand 2 a desired roll gap is set. The device for thickness control 5 are measured values 8th for the thickness of the rolling stock 1 as well as 9 and 10 for the temperature of the rolling stock in front of and behind the roll stand 2 fed.

In the process computer 4 the pass schedule calculation and the rolling force adaptation are stored. process computer 4 and device for thickness control 5 are connected, whereby from the process computer 4 from the device for thickness control 5 the Setpoints for the starting position, pass schedule, set rolling force and the module C _{M, V / E} are supplied. From the device to the thickness control 5 the actual values for the roll gap, the rolling force, the rolling time, the reversing time, the thickness, the temperature and the gauge meter thickness are again sent to the process computer 4 fed.

In 2 the roller adjustment is intended as an electromechanical / hydraulic adjustment; but it can also be carried out only as a hydraulic adjustment.

During the roll pass, the actual rolling force values are measured, filtered and averaged, and with the associated actual setting values of the electromechanical and / or hydraulic setting, the process computer 4 and the device for thickness control 5 to hand over.

After the roll pass, the roll time and the pause times actually required for reversing and cooling before the pass are also given to the process computer 4 to hand over.

The device for thickness control 5 determines during the roll pass calculated actual thickness values from the transferred process data on the basis of the conventional gage meter equation known per se, which is expanded by the module C _{M, V / E} for the hardening and / or softening of the material, whereby the changes in Microstructure in the rolling stock 1 can be taken into account in different temperature ranges. The gauge gauge equation, which has been expanded to this extent, is used for the control processes of the roll gap, which is described in 3 is shown schematically. In the mill stand 2 data is recorded and sent to the outlined control loop, whereby the bending, the oil film bearing, the roller eccentricity and the tapping can be compensated. The control loop is also provided with measured values or stored reference values for the rolling force and for the thickness of the rolling stock 1 fed. In the 3 Otherwise, the nomenclature used corresponds to that 1 ,

During the break, the roll force adaptation is determined as part of the process computer 4 from the transferred, averaged actual rolling force value and the actual thickness of the rolling stock calculated back using the extended gauge metal calibration 1 a recalculated target rolling force, again taking into account the hardening and / or softening factor k _{V / E} and then an adaptation factor for the target rolling force of the subsequent pass.

In the pause between the passes, the pass schedule computer then determines the target position of the electromechanical and / or hydraulic adjustment for the following pass, taking into account the hardening and / or softening factor k _{V / E} when determining the target rolling force, after which the thickness control with the newly transferred conventional operating point parameters and additionally with the module C _{M, V / E} for the hardening and / or softening of the material to take into account the changes in the microstructure in different temperature ranges after tapping.

• a) Vor dem Anstechen in der Fertigwalzphase wird vom Stichplanrechner als Bestandteil des Prozessrechners die Soll-Anstellposition der elektromechanischen und/oder der hydraulischen Anstellung unter Berücksichtigung des Ver- und/oder Entfestigungsfaktors k_V/E bei der Sollwalzkraftbestimmung vorgegeben.
• b) Vor dem Beginn eines jeweiligen Stiches werden der Dickenregelung vom Prozessrechner die herkömmlichen Arbeitspunktparameter zur Berücksichtigung in der Gaugemetergleichung bei der Ausregelung von Walzkraftänderungen und zusätzlich der Modul C_M,V/E zur Berücksichtigung der Ver- und/oder Entfestigung im Material übergeben, der ein gewichtetes Abbild der Gefügestrukturänderungen des Werkstoffs in unterschiedlichen Temperaturbereichen in Form des in die Korrektur der Anstellungsposition eingeflossenen Ver- und/oder Entfestigungsfaktors k_V/E ist.
• c) Während des Walzstiches werden die Walzkraft-Istwerte gemessen, gefiltert und gemittelt sowie mit den zugehörigen Ist-Anstellwerten der elektromechanischen und/oder der hydraulischen Anstellung dem Prozessrechner und der Dickenregelung übergeben.
• d) Nach dem Walzstich werden zusätzlich die Walzzeit und die vor dem Stich für Reversieren und Abkühlung tatsächlich benötigte Pausenzeit dem Prozessrechner übergeben.
• e) Während des Walzstiches ermittelt die Dickenregelung aus den übergebenen Werten die Dicken-Istwerte und verwendet die um den Modul C_M,V/E für die Ver- und/oder Entfestigung des Materials erweiterte Gaugemetergleichung zur Berücksichtigung der Änderungen der Gefügestruktur in unterschiedlichen Temperaturbereichen für die Regelvorgänge.
• f) In der Pausenzeit ermittelt die Walzkraftadaption als Bestandteil des Prozessrechners aus dem übergebenen, gemittelten Walzkraft-Istwert und der über die erweiterte Gaugemetergleichung zurückgerechneten Ist-Dicke eine rückgerechnete Soll-Walzkraft, wiederum unter Berücksichtigung des Ver- und/oder Entfestigungsfaktors k_V/E und anschließend einen Adaptionsfaktor für die Soll-Walzkraft des nachfolgenden Stiches.
• g) In der Pausenzeit zwischen den Stichen ermittelt der Stichplanrechner danach die Soll-Anstellposition der elektromechanischen und/oder der hydraulischen Anstellung für den darauffolgenden Stich unter Berücksichtigung des Ver- und/oder Entfestigungsfaktors k_V/E bei der Soll- Walzkraftbestimmung, wonach die Dickenregelung mit den neu übergebenen herkömmlichen Arbeitspunktparametern und zusätzlich mit dem Modul C_M,V/E der Ver- und/oder Entfestigung des Materials zur Berücksichtigung der Änderungen der Gefügestruktur in unterschiedlichen Temperaturbereichen nach Anstich startet.

Using the explained method, the following process sequence in particular has proven itself, whereby the absolute thickness accuracy, the plant safety and the process stability in thermomechanical rolling are increased and hardening and / or softening processes in the rolling stock can be taken into account:

• a) Before the piercing in the finishing rolling phase, the target plan position of the electromechanical and / or hydraulic adjustment is specified by the pass schedule computer as part of the process computer, taking into account the hardening and / or softening factor k _{V / E} when determining the target rolling force.
• b) Before the start of each stitch, the process computer transfers the conventional operating point parameters to be taken into account in the gaugemeter equation for the compensation of rolling force changes and additionally the module C _{M, V / E} to take into account the hardening and / or softening in the material is a weighted image of the structural changes in the material in different temperature ranges in the form of the hardening and / or softening factor k _{V / E that} has been incorporated into the correction of the position of employment.
• c) During the roll pass, the actual rolling force values are measured, filtered and averaged and transferred to the process computer and the thickness control with the associated actual setting values of the electromechanical and / or hydraulic setting.
• d) After the roll pass, the rolling time and the pause time actually required for reversing and cooling before the pass are also transferred to the process computer.
• e) During the roll pass, the thickness control determines the actual thickness values from the transferred values and uses the gage meter equation expanded by the module C _{M, V / E} for the consolidation and / or softening of the material to take into account the changes in the microstructure in different temperature ranges for the control processes.
• f) During the break, the rolling force adaptation, as part of the process computer, determines a recalculated target rolling force from the transferred, averaged actual rolling force value and the actual thickness recalculated using the extended gauge meter equation, again taking into account the hardening and / or softening factor k _{V / E} and then an adaptation factor for the target rolling force of the subsequent pass.
• g) In the pause between the stitches, the stitch schedule computer then determines the target position of the electromechanical and / or hydraulic adjustment for the following stitch, taking into account the displacement and / or Softening factor k _{V / E} in the target rolling force determination, after which the thickness control with the newly transferred conventional operating point parameters and additionally with the module C _{M, V / E} the hardening and / or softening of the material to take into account changes in the microstructure in different temperature ranges Parting starts.

1

rolling

2

rolling mill

3

Tax- and / or control device

4

process computer

5

Facility for thickness control

6

setting position

7

positioning device

G

reading for the Roll thickness

G

reading for the Rolled material temperature

10

reading for the Rolled material temperature

11

mill stretch for the current rolling conditions

12

compensations for bending, oil film storage,

Roller eccentricity, tapping

F _{W, V / E}

rolling force

k _W

forming resistance

b

width of the rolling stock

R _W

radius the rolls of the roll stand

k _{V / E}

factor

.delta.h

thickness reduction of the rolling stock

h ₀

thickness before the stitch

h ₁

thickness after the stitch

t _FWPh

time since the start of the finish rolling phase

b ₀

regression coefficient

b ₁

regression coefficient

b ₂

regression coefficient

b ₃

regression coefficient

b ₄

regression coefficient

b ₅

regression coefficient

b ₆

regression coefficient

s

employment

C _{M / VE}

Encryption / Entfestigungsmodul

DF _{w / VE}

modification the rolling force

ie ₁

modification the outlet thickness

dS _AGC

modification the roll gap setting

C _G

stand modulus

S _should

is to position of the roll gap

T _W

forming temperature

phi

deformation

PhIP

strain

Sum (phi)

Summenumformgrad the finish rolling phase

id

pressed length of the nip

T _END

sought final rolling

T _AR3

Temperature of the A _RS point

F _W

rolling force

s / h

employment or outlet thickness of the rolling stock

R

Production flow direction

Claims (10)

Rolling method ( 1 ), in particular steel and non-ferrous materials, in which the rolling stock ( 1 ) in at least one roll stand ( 2 ) is rolled, the roll stand ( 2 ) from a control and / or regulating device ( 3 ) a rolling force (F _{W, V / E} ) is specified and the rolling force (F _{W, V / E} ) is a function of the forming resistance (k _W ), the width (b) of the rolling stock ( 1 ), the radius (R _W ) of the rolls of the roll stand ( 2 ) and the decrease in thickness (Δh) of the rolling stock ( 1 ) in the roll stand ( 2 ), characterized in that the calculation of the predetermined rolling force (F _{W, V / E} ) continues to be carried out by taking into account a factor (k _{V / E} ) which stabilizes and / or softens the rolling stock ( 1 ) indicates or maps. A method according to claim 1, characterized in that the determination of the rolling force (F _{W, V / E} ) from the relationship F W / VE = k W * B * (R W ·(H 0 - H 1 )) 1.2 · k V / E where k _{W is} the forming resistance, b is the width of the rolling stock ( 1 ), R _{W is} the radius of the rolls of the roll stand ( 2 ), h ₀ the thickness before the pass, h ₁ the thickness after the pass and k _{V / E} the factor for the hardening and / or softening of the rolled stock ( 1 ) is. A method according to claim 1 or 2, characterized in that the factor (k _{V / E} ) for the hardening and / or softening of the rolling stock ( 1 ) is determined depending on at least one of the process parameters forming temperature (T _W ), degree of forming (phi), total degree of forming of the finish rolling phase (Sum (phi)), forming speed (phip), pressed length of the roll gap (I _d ), average thickness (h _m ) of the rolling stock ( 1 ) in the roll gap, target final rolling temperature (T _End ), temperature of the ARS point (T _AR3 ) and time since the start of the _{finish rolling phase} (t _FWPh ). A method according to claim 3, characterized in that the factor (k _{V / E} ) for the hardening and / or softening of the rolling stock ( 1 ) from the relationship k V / E = b 0 + b 1 * T W + b 2 Exp (Sum (phi)) + b 3 · In (phip) + b 4 · (I d /H m ) + b 5 * T End / T AR3 + b 6 · t FWPh results, where b ₀ to b _{6 are} predetermined constants. Method according to one of claims 1 to 4, characterized in that the calculation of the pitch (s) of the roll stand ( 2 ) on the basis of the known gage meter equation, taking into account a module (C _{M, V / E} ) which consolidates and / or softens the rolling stock ( 1 ) indicates or maps. A method according to claim 5, characterized in that the determination of the module (C _{M, V / E} ) from the relationship C M, V / E = dF W, V / E / dh 1 results, where dF _{W, V / E is} the change in rolling force and ie _{1 is} the change in outlet thickness. Method according to claim 5 or 6, characterized in that the gage meter equation used is derived from the relationship ds ACC = (1 + C M, V / E / C G dh) 1 = (1 + C M, V / E / C G ) (DF W, V / E / C G + s - S Should ) where the _{AGC is} the change in the roll gap setting, C _{M, V / E} the strengthening / softening module, C _G the stand module comprising the change in the rolling force in relation to the change in the outlet thickness without taking into account the hardening and / or softening of the rolling stock ( 1 ), ie ₁ the change in the outlet thickness, dF _{W, V / E} the change in the rolling force taking into account the hardening and / or softening of the rolling stock ( 1 ), s which _is the pitch of the roll gap and S _is the target pitch of the roll gap. Method according to one of claims 1 to 7, characterized in that the control and / or regulation of the roll gap of the roll stand ( 2 ) taking into account process parameters that are determined before, during and / or after a stitch. A method according to claim 8, characterized in that the process parameters the measured rolling force, the required rolling time and / or the required Is break time. Method according to Claim 8 or 9, characterized in that, before a subsequent pass is carried out, the control and / or regulation of the roll gap of the roll stand ( 2 ) based on the determined data from the previous stitch.