The medium thin slab continuous casting and rolling plate shape integrated control method
Technical field
The invention belongs to the hot-strip production technical field, particularly a kind of medium thin slab continuous casting and rolling plate shape integrated control method is applicable to the plate shape control that hot-strip is rolling.
Background technology
The factor that influences hot-strip production board shape is extremely complicated, therefore, the difficulty of plate shape control is very big, coverage is very wide, finishing mill roll shape optimal design and matching technique had both been comprised, technological parameters such as the original roll forming precision of finishing mill also comprise between the finishing mill working roll cooling uniformity, frame kinetic parameters such as side water spray angle, pressure between cooling water distribution consistency degree, finishing stand; Existing finish rolling setting control model, plate shape setting control model, plate shape dynamic control model have coiling temperature control model and band steel shape wave control technology again.Though done a large amount of fruitful work the experts and scholars of countries in the world in recent ten years, to have developed control technologys such as PC, CVC, HC, PFC and carried out plate shape and set control, plate shape control problem really solves." iron and steel " magazine the 2nd phase of calendar year 2001 " control of plate shape and hot-strip free regulation rolling " literary composition points out " to be plate shape control problem in the free regulation rolling question essence.For realize free regulation rolling need the amount of reducing wear, the homogenising wearing and tearing distribute or and develop special plate shape control technology." problem just proposed here." Northeastern University's journal " (natural science edition) 2002 the 7th phases deliver " Hot Strip shape (PFC) control system one literary composition is set 2050mm hot-rolling mill plate shape and has been carried out off-line simulation, has set the basis for improving belt plate shape." but and unresolved practical problem.U.S. Pat 5927117, Japan Patent JP2001179320 etc. has proposed some board-shape control methods, and all there is following several respects deficiency in all these technology:
1, be difficult to realize the Comprehensive Control that flatness, convexity and limit are fallen;
2, belt plate shape and THICKNESS CONTROL fail to accomplish to be coupled fully, do not eliminate interference to each other;
3, the plate deformationization of band steel in laminar flow cooling, air cooling and coiling process is failed to quantize to and is realized automatically in the control model its compensation control after the finish rolling.
Summary of the invention
The purpose of this invention is to provide a kind of plate shape integrated control method that is applicable to the medium thin slab continuous casting and rolling production line, combine with plate shape control model by mm finishing mill unit working roll and support roller roll design, the control of work roll bending power and working roll string roller position, realization realizes free regulation rolling to effective control of strip profile, band steel flatness, strip edge portion shape, by the thick decoupling zero control of plate shape application of model, make belt plate shape and thickness of slab in control, accomplish to be coupled fully, eliminate interference.
Comprise according to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention
1) adopt new roll technology,, process shape of working roll curve and support roller roll shape curve with numerically control grinder by mm finishing mill unit shape of working roll and the design of support roller roll forming,
2) carry out work roll bending power and working roll string roller position calculation by second computer, control system is carried out the design and the adjusting of bending roller force and string roller position according to result of calculation, realizes the effective control to strip profile, flatness, limit portion shape,
3) described work roll bending power is calculated and is comprised:
A) determine the target convexity of all size band steel according to rolling product, the target flatness, and the flatness detection signal carried out temperature and tension compensating,
B) according to the rolled piece width, each frame draught pressure, shape of working roll, support roller roll forming, roll thermal deformation, roll wear are out of shape, calculate each frame work roll bending power of rolling every band steel,
C) regulate the feed-forward regulation value that obtains work roll bending power by each frame drafts,
D) detect the feedback regulation value that the convexity deviation that obtains obtains upstream frame F1-F3 work roll bending power by the convexity instrument,
E) obtain the flatness deviation by the detection of flatness instrument, calculate the work roll bending force feedback regulated value of downstream frame F4-F6 thus,
4) working roll string roller position calculation: forecast inhomogeneous roll wear distortion according to rolling scaduled unit, calculate each frame working roll string roll position setting value of every block of band steel,
5) described plate shape control model comprises and presets control model, dynamic control model, strip flatness and gauge decoupling zero control model.
According to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, preset the control model and comprise:
1) the string roller presets the control model, according to supplied materials situation and string roller strategy, calculating is set in the string roller position of the working roll of each frame, improves the uneven wear of roll roll surface, realizes free regulation rolling,
2) Bending Force Preset Based control model, set in each frame roll-force and working roll string roller position, under the fixed prerequisite of roll forming, the work roll bending power of each frame is set calculating, improving the strip shape quality of band steel toe portion, and lay the foundation for the FEEDBACK CONTROL of plate shape.
According to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, the string roller preset model in the plate shape control model comprises conventional string roller strategy and special string roller strategy.
According to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, conventional string roller strategy is as follows:
1) as the string roller interval SFT that sets
INT=1 o'clock, when promptly whenever rolling roller of a steel string,
A) during rolling i piece steel, the string roller amount SFT of top working roll
TOP(i) equal the i.e. string roller amount SFT of working roll during (i-1) piece of rolling lastblock
TOPPromptly (i-1) adds that the string roller step-length SFT of setting is
SFT
TOP(i)=SFT
TOP(i-1)+STEP
B) the string roller amount SFT of bottom working roll during rolling i piece steel
BTM(i) equal top working roll string roller amount SFT this moment
TOP(i) negative value, promptly
SFT
BTM(i)=-SFT
TOP(i),
C) the string roller amount of top working roll adds that the absolute value of the string roller step-length of setting surpasses the string roller extreme position SFT that sets when rolling i piece steel
LMT,
That is: | SFT
TOP(i)+STEP|>SFT
LMTThe time, the negative value of getting string roller amount step-length is for setting string roller step-length, that is:
STEP=-STEP,
2) wait until at interval in 2 when the string roller of setting, i.e. SFT
INT=2, when promptly whenever rolling 2 steel string rollers one time,
A) when rolling i piece steel, the string roller amount SFT of top working roll
TOPThe string roller amount SFT of working roll when (i) equaling rolling lastblock steel
TOP(i-1) add the string roller step-length STEP of setting, that is:
SFT
TOP(i)=SFT
TOP(i-1)+STEP
B) when rolling next piece steel is i+1 piece steel, the string roller amount SFT of top working roll
TOPThe string roller amount SFT of top working roll when (i+1) equaling rolling i piece steel
TOP(i), that is:
SFT
TOP(i+1)=SFT
TOP(i)
C) when rolling i, i+1 piece steel, the string roller amount SFT of bottom working roll
BTM(i), SFT
BTM(i+1) equal top working roll string roller amount SFT at that time respectively
TOP(i), SFT
TOP(i+1) negative value, that is:
SFT
BTM(i)=-SFT
TOP(i)
SFT
BTM(i+1)=-SFT
TOP(i+1)
D) during rolling (i+1) piece steel, the string roller amount SFT of top working roll
TOP(i+1) and the absolute value of the string roller step-length STEP sum of setting greater than the string roller extreme position SFT that sets
LMT, that is:
|SFT
TOP(i+1)+STEP|>SFT
LMT
The time, get the negative value of setting string roller amount and be string roller step-length, that is:
STEP=-STEP
3) the string roller when setting equals 3, SFT at interval
LMI=3, when promptly whenever rolling 3 steel string rollers 1 time,
A) when rolling i piece steel, the string roller amount SFT of top working roll
TOP(i) equal rolling last 1 i.e. string roller amount SFT of top working roll during i-1 piece steel
TOP(i-1) add the string roller step-length STEP of setting, that is:
SFT
TOP(i)=SFT
TOP(i-1)+STEP,
When b) rolling back 2 blocks of steel are i+1 piece steel and i+2 piece steel, the string roller amount SFT of top working roll
TOP(i+1) and SFT
TOPThe string roller amount SFT of top working roll when (i+2) being equal to rolling i piece steel
TOP(i), that is:
SFT
TOP(i+1)=SFT
TOP(i)
SFT
TOP(i+2)=SFT
TOP(i)
C) when rolling i, i+1, i+2 piece steel, the string roller amount of bottom working roll equals the negative value of top working roll string roller amount respectively, that is:
SFT
BTM(i)=-SFT
TOP(i)
SFT
BTM(i+1)=-SFT
TOP(i+1)
SFT
BTM(i+2)=-SFT
TOP(i+2)
D) the string roller amount SFT of top working roll when rolling i+2 piece steel
TOP(i+2) add that the string roller step-length STEP sum of setting is greater than the extreme position SFT that sets the string roller
LMT, that is:
| SFT
TOP(i+2)+STEP|>SFT
LMTThe time, get the negative value of setting string roller amount and be string roller step-length, i.e. STEP=-STEP, the rest may be inferred.
According to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, special string roller strategy is to having the working roll of special roll shape curve, take all factors into consideration the plate shape control of working roller abrasion and band steel, working roll string roller position when optimize calculating rolling every block of band steel, to realize the control of special objective, rolling etc. as the ultra-thin material of free regulation rolling.
Medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, the Bending Force Preset Based control model computing formula in its plate shape control model is:
BF=K
RBRF+K
WC
W+K
bC
b+K
inC
in+K
outC
out
The default definite value BF of promptly curved power equals roll-force influence coefficient K
RBMultiply by the influence coefficient K that roll-force RF adds top working roll equivalence roller
WMultiply by the equivalent roll forming of the comprehensive roll forming of working roll (initial roll forming, hot-rolling shape, wearing and tearing roll forming sum), the influence coefficient Kb that adds support roller equivalence roll forming multiply by the equivalent roll forming of the comprehensive roll forming of support roller (initial roll forming, hot-rolling shape, wearing and tearing roll forming sum), and the influence coefficient Kin that adds the supplied materials convexity multiply by supplied materials convexity C
In, add the influence coefficient K of target convexity
OutMultiply by target convexity C
OutSum, and rolling influence coefficient K
RBEqual mill rolling force lateral stiffness COEFFICIENT K
RBWith mill roll bending power lateral stiffness COEFFICIENT K
BFThe negative value of ratio, that is:
K
RB-K
BF/K
RF。
Related COEFFICIENT K in the model
RF, K
BF, K
W, K
B, K
IN, K
OUTIt is all relevant with factors such as work roll diameter, support roller diameter, axially twitch amount of working roll, working rolls,
According to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, described dynamic control model is:
1) bending roller force FEEDFORWARD CONTROL model is followed according to the fluctuation of roll-force and to be carried out feed-forward regulation control work roll bending power, and the account form of bending roller force feed-forward regulation increment is:
ΔBF=(-K
BF/K
RF)·ΔRF
Be that bending roller force variation delta BF equals mill roll bending power lateral stiffness COEFFICIENT K
BFBy mill rolling force lateral stiffness COEFFICIENT K
RFThe merchant that milling train removes gained is multiplied by the negative value that roll-force variation delta RF obtains again,
2) bending roller force feedback control model is calculated a certain F4-F6 frame or one and with upper spider work roll bending power the plate shape flatness deviation that detects is carried out the adjusting increment of FEEDBACK CONTROL, and its computing formula is:
ΔBF=K
BFF(FLAT
T-FLAT
M)
The feedback regulation amount Δ BF that is bending roller force equals the influence coefficient K of bending roller force to flatness
BFFMultiply by smoothness objectives value FLAT
TWith flatness measured value FLAT
MPoor, for the F1-F3 frame then with convexity feedback, smoothness objectives value FLAT
T=OI.
The purpose of bending roller force FEEDFORWARD CONTROL guarantees to reach strip profile desired value and flatness desired value.
To such an extent as to when the bending roller force FEEDFORWARD CONTROL regulated quantity of too big this frame of a certain frame roll-force fluctuation reaches capacity, can regulate the bending roller force of adjacent frame according to certain strategy.
When flatness fluctuates too big, when to such an extent as to the feedback regulation amount of last frame reaches capacity, can regulate the bending roller force of previous or several frames according to certain strategy, when the adjusting because of bending roller force causes reaching the target convexity, can adjust the bending roller force of several frames before the mm finishing mill unit or the sharing of load of whole unit according to certain strategy.
According to medium thin slab continuous casting and rolling plate shape integrated control method of the present invention, the string roller step-length STEP=30mm~150mm of described setting, the big value SFT of string roller amount that sets
LMT=± 150mm~± 250mm.
In production practices, can coordinate by roll-force between finish rolling setting model and the plate shape setting model and bending roller force, realize the coupling of band steel head plate shape and thickness setting; Coordinate to realize band steel total length plate shape and thickness dynamic coupling region controlling by roll-force and bending roller force that thickness is controlled between AGC and the plate shape dynamic model automatically.
The roll forming technology that is adopted among the present invention comprises working roller technology and support roller roll shape technology.
Description of drawings
Fig. 1 is plate shape complex control system figure of the present invention.
Fig. 2 is strip flatness and gauge decoupling zero control principle figure.
The specific embodiment
As shown in Figure 1, medium thin slab continuous casting and rolling plate shape integrated control method of the present invention is characterised in that:
1) adopts new roll technology, by mm finishing mill unit shape of working roll and the design of support roller roll forming, process shape of working roll curve and support roller roll shape curve with numerically control grinder, for roll surface length is 1500mm~2600mm, diameter is its roll forming of working roll of 500mm~1100mm, being that the interior diameter difference of roll surface is 0~0.60mm, is that 1200mm~2300mm diameter is its roll forming of support roller of 1200mm~1600mm for roll surface length, and promptly roll surface interior diameter difference is 0mm~1.00mm.
2) carry out work roll bending power and working roll string roller position calculation by second computer, control system is carried out the design and the adjusting of bending roller force and string roller position according to result of calculation, effective control that realization is opened shape to strip profile, flatness, limit portion, smoothness objectives are OIU
3) described work roll bending power is calculated and is comprised:
A) determine the target convexity of all size band steel according to rolling product, the target flatness, and the flatness detection signal carried out temperature and tension compensating,
B) according to the rolled piece width, each frame draught pressure, shape of working roll, support roller roll forming, roll thermal deformation, roll wear are out of shape, calculate each frame work roll bending power of rolling every band steel,
C) regulate the feed-forward regulation value that obtains work roll bending power by each frame drafts,
D) detect the feedback regulation value that the convexity deviation that obtains obtains upstream frame F1-F3 work roll bending power by the convexity instrument,
E) obtain the work roll bending force feedback regulated value that the flatness deviation obtains downstream frame F4-F6 by the detection of flatness instrument,
4) working roll string roller position calculation: forecast inhomogeneous roll wear distortion according to rolling scaduled unit, calculate each frame working roll string roll position setting value of every block of band steel,
5) described plate shape control model comprises and presets control model, dynamic control model, strip flatness and gauge decoupling zero control model.
As shown in Figure 1, described plate shape preset control model comprise:
1) the string roller presets the control model, according to supplied materials situation and string roller strategy, calculating is set in the string roller position of the working roll of each frame, improves the uneven wear of roll roll surface, realizes free regulation rolling,
2) Bending Force Preset Based control model, set in each frame roll-force and working roll string roller position, under the fixed prerequisite of roll forming, the work roll bending power of each frame is set calculating, with the strip shape quality of improvement band steel toe portion, and be the anti-plumbous control dynasty basis of plate shape.
String roller shown in Figure 1 presets control, comprising: the string roller preset model in the described plate shape control model comprises conventional string roller strategy and special string roller strategy.
Described conventional string roller strategy is as follows:
1) as the string roller interval SFT that sets
INT=1 o'clock, when promptly whenever rolling roller of a steel string,
A) during rolling i piece steel, the string roller amount SFT of top working roll
TOP(i) equal the i.e. string roller amount SFT of working roll during (i-1) piece of rolling lastblock
TOP(i-1) add the string roller step-length STEP of setting, that is:
SFT
TOP(i)=SFT
TOP(i-1)+STEP
B) the string roller amount SFT of bottom working roll during rolling i piece steel
BTM(i) equal top working roll string roller amount SFT this moment
TOP(i) negative value is promptly:
SFT
BTM(i)=-SFT
TOP(i),
C) the string roller amount of top working roll adds that the absolute value of the string roller step-length of setting surpasses the string roller extreme position SFT that sets when rolling i piece steel
LMT,
That is: | SFT
TOP(i)+STEP|>SFT
LMTThe time, get string roller amount step-length and be negative setting string roller step-length, that is:
STEP=-STEP,
2) wait until in 2 SFT at interval when the string roller of setting
INT=2, when promptly whenever rolling 2 steel string rollers one time,
A) when rolling i piece steel, the string roller amount SFT of top working roll
TOPThe string roller amount SFT of working roll when (i) equaling rolling lastblock steel
TOP(i-1) the string roller step-length STEP that adds setting is promptly:
SFT
TOP(i)=SFT
TOP(i-1)+STEP
B) the string roller amount SFT of top working roll when rolling next piece steel is i+1 piece steel
TOPThe string roller amount SFT of top working roll when (i+1) equaling rolling i piece steel
TOP(i), that is:
SFT
TOP(i+1)=SFT
TOP(i)
C) when rolling i, i+1 piece steel, the string roller amount SFT of bottom working roll
BTM(i), SFT
BTM(i+1) equal top working roll string roller amount SFT at that time respectively
TOP(i), SFT
TOP(i+1) negative value, that is:
SFT
BTM(i)=-SFT
TOP(i)
SFT
BTM(i+1)=-SFT
TOP(i+1)
D) the string roller amount SFT of top working roll during rolling (i+1) piece steel
TOP(i+1) and the absolute value of the string roller step-length STEP sum of setting greater than the string roller extreme position SFT that sets
LMT, that is:
| SFT
TOP(i+1)+STEP|>SFT
LMTThe time, get the negative value of setting string roller amount and be string roller step-length, that is:
STEP=-STEP
3) the string roller when setting equals 3, SFT at interval
INT=3, when promptly whenever rolling 3 steel string rollers 1 time,
A) when rolling i piece steel, the string roller amount SFT of top working roll
TOP(i) equal rolling last 1 i.e. string roller amount SFT of top working roll during i-1 piece steel
TOP(i-1) go up the string roller step-length STEP that sets, that is:
SFT
TOP(i)=SFT
TOP(i-1)+STEP,
The string roller amount SFT of top working roll when b) rolling back 2 blocks of steel are i+1 piece steel and during i+2 piece steel
TOP(i+1) and SFT
TOPThe string roller amount SFT of top working roll when (i+2) being equal to rolling i piece steel
TOP(i), that is:
SFT
TOP(i+1)=SFT
TOP(i)
SFT
TOP(i+2)=SFT
TOP(i)
C) when rolling i, i+1, i+2 piece steel, the string roller amount of bottom working roll equals the negative value of top working roll string roller amount respectively, that is:
SFT
BTM(i)=-SFT
TOP(i)
SFT
BTM(i+1)=-SFT
TOP(i+1)
SFT
BTM(i+2)=-SFT
TOP(i+2)
D) the string roller amount SFT of top working roll when rolling i+2 piece steel
TOP(i+2) add that the string roller step-length STEP of setting is greater than the extreme position SFT that sets the string roller
LMT, that is:
| SFT
TOP(i+2)+STEP|>SFT
LMTThe time, get the negative value of setting string roller amount and be string roller step-length, i.e. STEP=-STEP, the rest may be inferred.
Described special string roller strategy is to having the working roll of special roll shape curve, take all factors into consideration the plate shape control of working roller abrasion and band steel, working roll string roller position when optimize calculating rolling every block of band steel, to realize the control of special objective, for foregoing roller parameter, working roll string roller maximum SFTLMT=± 200mm.
As shown in Figure 1, dynamic control model comprises:
1) bending roller force FEEDFORWARD CONTROL model is followed according to the fluctuation of roll-force and to be carried out feed-forward regulation control work roll bending power, and the account form of bending roller force feed-forward regulation increment is:
Δ BF=(K
BF/ K
RF) Δ RF is that bending roller force variation delta BF equals mill roll bending power lateral stiffness COEFFICIENT K
BFBy mill rolling force lateral stiffness COEFFICIENT K
RFThe merchant that milling train removes gained is multiplied by the negative value that roll-force variation delta RF obtains again,
2) bending roller force feedback control model is calculated a certain F4-F6 frame or one and with upper spider work roll bending power the plate shape flatness deviation that detects is carried out the adjusting increment of FEEDBACK CONTROL, and its computing formula is:
ΔBF=K
BFF(FLAT
T-FLAT
M)
The feedback regulation amount Δ BF that is bending roller force equals the influence coefficient K of bending roller force to flatness
BFFMultiply by smoothness objectives value FLAT
TWith flatness measured value FLAT
MDifference for the F1-F3 frame then with convexity feedback, smoothness objectives value FLAT
T=OI.
The bending roller force FEEDBACK CONTROL will be considered the control action of laminar flow cooling to plate shape.
For rolling thickness is 110mm~180mm, the string roller step-length STEP=30mm~100mm of described each coefficient value of the 1780mm milling train of slab for setting, and the big value SFTLMT=of the string roller amount ± 150mm that sets~± 250mm.
Described each coefficient value is respectively:
Target convexity: 20~60 μ m
Roll-force influence coefficient K
RB: 0.235~0.024
Mill rolling force lateral stiffness COEFFICIENT K
RF: 9430~19370t/mm
Mill roll bending power lateral stiffness COEFFICIENT K
BF: 470~2200t/mm
The influence coefficient K of working roll equivalence roll forming
w:-290~-730t/mm
The influence coefficient K of support roller equivalence roll forming
b:-140~-360t/mm
The influence coefficient K of supplied materials convexity
In: 170~440t/mm
The influence coefficient K of target convexity
Out:-2200~-470t/mm
Bending roller force is to the influence coefficient K of flatness
BFF: 0.3~3.3t/I
Mill rolling force longitudinal rigidity coefficient M
RF: 480~700t/mm
Mill roll bending power longitudinal rigidity coefficient M
BF: 570~890t/mm
As shown in Figure 2, the strip flatness and gauge Decoupled Model is, described strip flatness and gauge decoupling zero control model is when the bending roller force of some or several frames changes, roll-force to its corresponding frame is adjusted control accordingly, perhaps when the roll-force of some or several frames changes, work roll bending power to its corresponding frame is adjusted control accordingly, and the computing formula of this model is: the relation between bending roller force variable quantity and roll-force variable quantity and roll-force change:
Δ RF=((M
RF+ M
BF)/M
BF)/(2 Δ BF) be that roll-force variation delta RF equals mill rolling force longitudinal rigidity coefficient M
RFAdd mill roll bending power longitudinal rigidity coefficient M
BFBy mill rolling force longitudinal rigidity coefficient M
BFRemove the merchant who obtains and multiply by 2 times bending roller force variation delta BF.
Adopt method of the present invention, on certain the 110mm~180mm of iron company slab continuous casting rolling system production line, test, can guarantee that strip profile control reaches ± the accounting for more than 90% of 0.018mm, band steel flatness reaches accounting for more than 90% of 30I, surpass 70Km ± 10Km with width belt steel rolling length, strip width changes from narrow to wide can reach 300mm, and strip edge portion shape (the irregular amount of strip edge portion thickness in 0~100mm scope) can be effectively controlled.