CN106903166B - A kind of method of aluminum alloy plate materials asymmetrical rolling warpage forecast and optimization - Google Patents
A kind of method of aluminum alloy plate materials asymmetrical rolling warpage forecast and optimization Download PDFInfo
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- 239000002184 metal Substances 0.000 claims description 10
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- 238000005452 bending Methods 0.000 claims description 3
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- 238000004458 analytical method Methods 0.000 abstract description 3
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- 238000012545 processing Methods 0.000 abstract description 3
- 238000012800 visualization Methods 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 238000005098 hot rolling Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 229910018569 Al—Zn—Mg—Cu Inorganic materials 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 230000005483 Hooke's law Effects 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
- B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
- B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
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- G06F30/20—Design optimisation, verification or simulation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B2003/001—Aluminium or its alloys
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Abstract
The invention belongs to metal material processing fields, a kind of method of warpage forecast and optimization during aluminum alloy plate materials asymmetrical rolling, the significant decrease of asymmetrical rolling bow warping can be achieved or completely eliminate, and without carrying out special transformation to existing milling train, rolling parameter (such as plate thickness, rolling pass drafts, friction speed ratio) only need to be adjusted, bow warping degree during asymmetrical rolling can be controlled and provides warpage.Advantages of the present invention: it is based on analogue simulation asymmetrical rolling process, and practical rolling experiment is combined to carry out analysis of the aluminum alloy plate materials asymmetrical rolling without warpage technique, it would know that the warp direction of asymmetrical rolling plate under actual working conditions, asymmetrical rolling plate operating status is determined in advance, provides visualization scheme for actual process adjustment；Being obtained in advance based on analogue simulation makes the asynchronous rolling technological parameter (such as reduction in pass) for rolling zero warpage of plate, can significantly improve template quality, avoid transformation rolling equipment or install additional to force straightener.
Description
Technical field
The invention discloses a kind of methods of warpage forecast and optimization during aluminum alloy plate materials asymmetrical rolling, it can be achieved that different
It walks the significant decrease of rolled plate warpage or completely eliminates, belong to metal material processing field.
Background technique
High-performance aluminium alloy (such as Al-Zn-Mg-Cu system) cut deal is with its excellent specific strength, corrosion resistance, toughness and resists tired
Labor performance and the manufacture for being widely used in fuselage ring, bulkhead etc., become vital Aircraft Structure Materials.Traditional hot rolling technology
Be prepare the main manufacturing process of such tough Aluminum Alloy Plate of height at present, but using the technique production cut deal during it is general
Store-through eventually leads to plate thickness direction tissue and mechanical heterogeneity along the non-uniform problem of plate thickness Direction distortion,
Seriously affect and limit service life and the extensive use of such sheet alloy.
Asymmetrical rolling can be realized as a kind of advanced forced plasticity deforming technique by the transformation to synchronous rolling mill,
Main rolling mode has with diameter friction speed asymmetrical rolling (upper and lower roll roller diameter is identical, and revolving speed is different) and the synchronized asymmetrical rolling of reducing
(upper and lower roll roller diameter is different, and revolving speed is identical).During asymmetrical rolling, since asymmetry of the upper and lower roll to deformation of rolled wire is led
It causes to generate violent additional shear strain inside rolled piece, so as to improve the uniformity of stocking through-thickness deformation, facilitates plate
The raising of material comprehensive performance.Improving the sides such as metal and alloy materials structural homogenity, raising performance based on Differential speed rolling technology
The advantage in face, the technology are widely used in the rolling research and production of the metals such as aluminium/magnesium and alloy, and obtain good result.Hair
Bright patent (CN101524707A, CN105603341A), which discloses, obtains tiny crystal grain, formability and intensity using asymmetrical rolling
The metal rolled technique significantly improved；Patent of invention (such as CN201210590806.1, CN200410021496.7,
CN200510046810.1) orientation silicon steel performance is improved using Differential speed rolling technology；Patent of invention
(CN201010524366.0) material surface nanosizing is realized using Differential speed rolling technology.However, due in the operation of rolling with
The asymmetry of upper and lower roll contact metal or alloy deformation cause asymmetrical rolling plate occur upwarping or under curved phenomenon, cause plate
Material is difficult to continuously bite, and reduces rolling efficiency, and serious warpage even will cause plate and stick roller, milling equipment damage and be produced into
This increase etc..Currently, the application study of Differential speed rolling technology still concentrates on thin plate band, reason is batching for coiling machine application
Tension significantly suppresses the warpage of thin plate band, thus relative warpage issues and is not affected by too many concern.However middle thickness
For plate when asymmetrical rolling is processed, there is no coiling machines to provide tension for roll two sides, therefore how to improve or optimize asymmetrical rolling
Warpage issues caused by the plate shape of medium-thick plate, reduction/elimination asymmetrical rolling just seem especially prominent and important.It is asked for this
Topic is generally realized by transformation milling equipment, installs horizontal hydraulic pressure bending system additional such as on milling train or on rolling line
It installs additional and forces straightening equipment, invest huge and be difficult to realize update in a short time.For asymmetrical rolling cut deal warpage issues,
Patent of invention CN104624664A proposes by adjusting the method for height of rolling line and up/down working roll biting speed to 400mm
Slab roughing Head ski -up phenomenon is controlled, and patent of invention (CN03114584.1, CN200520079602.7) discloses one
Kind is solved the warpage during asymmetrical rolling using the lead-in angle variset of design and is asked by the guide plate height of adjusting milling train
Topic.However, the mill table system in actual production line is long and all fixed, the method that foregoing invention patent provides is realizing plate
There are difficulty in terms of the continuous rolling of asymmetrical rolling.
The invention patent is different to solve to control the asynchronous plate shape for rolling plate by the method that direct-on-line adjusts rolling parameter
The warpage issues of rolled plate are walked, while can guarantee plate thickness Direction distortion and structural homogenity, avoids and milling train is advised greatly
Brought technology and cost problem is transformed in mould.
Summary of the invention
The present invention is intended to provide it is a kind of can Fast Prediction asymmetrical rolling aluminum alloy plate materials warpage method, while providing one kind
The method that can obviously improve or solve the problems, such as such bow warping.The present invention is not necessarily to carry out special transformation to existing milling train, only needs
It adjusts rolling parameter (such as plate thickness, rolling pass drafts, friction speed ratio), plate is stuck up during can controlling asymmetrical rolling
Qu Chengdu and the solution for providing warpage issues.
The technical scheme is that forecast and the optimization method of a kind of metal or alloy plate asymmetrical rolling warpage, packet
Include following steps:
Step 1: the two dimensional plane strain model of asymmetrical rolling sheet alloy is established using simulation analysis software and was rolled
The geometrical model of journey；Definition Model material properties (including specific heat capacity, thermal coefficient, elasticity modulus, thermal expansion coefficient, Poisson's ratio,
Density etc. (simulation software can transfer the functional value under corresponding conditions using automatic interpolation mode))；Grid division is (due to plate shape
Shape rule, can be used the automatic partition functionality of software, grid is four-node quadrilateral element)；The heat exchange of course of hot rolling is set
The boundary conditions such as (being converted into the efficiency of heat including plastic work done, frictional work is converted into hot efficiency), friction；Set rolling parameter simultaneously
Carry out simulation calculation；Inputting different asymmetrical rolling working conditions, (such as rolling temperature, friction speed ratio, drafts and plate are initially thick
Degree), export asymmetrical rolling plate plate shape.
Step 2: asymmetrical rolling bow warping curvature ρ under different simulation operating conditions is calculated, obtains rolling under a certain rolling temperature
Plate original depth, reduction in pass, up-down rollers friction speed than with the relationship of rolling slab warping curvature, which is joined by different operating conditions
Two-dimensional curve under the space X-Y that numerical value is established with corresponding curvature value determines.
Step 3: calculating asynchronous when rolling slab warping curvature close to zero, rolls plate thickness, reduction in pass, friction speed ratio and faces
Dividing value establishes the asynchronous plate that rolls without the critical operating condition relationship of warpage, the critical operating condition value mentioned in the step can according to the following steps into
Row determines:
(1) according to the two-dimensional curve of different the duty parameter values and curvature value established in step 2, the curve and X-axis are found
The intersection point of (i.e. axis where rolling parameter), the corresponding parameter value of the intersection point can be determined as the reference point of critical parameters.
(2) it using the reference point as object, floats up and down 5%, simulating, verifying is carried out, finally with reference point attachment ± 5%
Value of the range incurvature closest to zero is critical parameters value.
Step 4: the asymmetrical rolling established according to step 3 is tested using experimental mill, is repaired without the critical operating condition of warpage
Positive simulation as a result, simultaneously finally establish match with milling train without the critical rolling parameter of warpage.
In the present invention, asymmetrical rolling system two dimensional model is established using simulation analysis software described in step 1 specifically:
(1) two dimensional plane strain model is based primarily upon the elastic-plastic constitutive relation of metal or alloy material, i.e. resistance of deformation
Existence function relationship between (trus stress) and strain (true strain), rate of deformation and deformation temperature:
Wherein, elastic stage still follows Hooke's law, and plastic period need to meet Von-Mises yield criterion, and
Aluminium alloy plasticity relationship can use Zener-Hollomon relationshipIt indicates, wherein σ is trus stress
(MPa), ε is true strain,For rate of deformation (s-1), T is deformation temperature (K), and Δ H is deformation activation energy, and R is gas constant.
Above-mentioned relation dependent constant can be obtained by the true stress-true strain curve under different temperatures, and in conditions such as temperature, rates of deformation
The relationship is fixed when determining, can be obtained by thermomechanical simulated experiment, and in practical rolling simulation calculating process, is adjusted
With related data of metal or alloy material under the conditions of different distortion, such as stress, strain value.
(2) it establishes asymmetrical rolling roll and rolls slab geomitry model, wherein the implementation of asymmetrical rolling is upper in the present invention
Bottom roll roller diameter is identical and roller speed is different；Roll is reduced to ideal epistemology model, and rolling sheets material is elastic-plastic model；Roll plate with
The determination of roll, the convection transfer rate for rolling plate and air facilitates the influence for accurately describing temperature in the operation of rolling.
(3) difference for rolling plate Yu top and bottom rolls friction is had ignored in the operation of rolling, using Coulomb friction law, according to experiment
The anti-practical rolling friction coefficient of release is 0.35.The value corresponds to the coefficient of friction between aluminium alloy and roll, other metals or conjunction
Golden plate material can be known from document with the coefficient of friction of roll or be determined by simulating and testing the method combined.
(4) working condition during analogue simulation is rolled specifically: upper and lower roller diameter is all Φ=400mm；Upper roller roller speed
For VOn=1m/s, lower roll roller speed are set as VUnder=1.1m/s, 1.2m/s, 1.3m/s, corresponding friction speed ratio DSR be respectively 1.1,1.2,
1.3；Plate original depth H < 50mm.Plate temperature, which is rolled, during rolling simulation is set as practical rolling temperature, such as the invention patent
It is set as 400 DEG C for 7050 aluminium alloys.
The calculation method of buckling (ρ) is carried out according to the parameter and following formula marked in Fig. 1 in step 2 of the present invention
It calculates:
In Fig. 1, r is the bending radius after bow warping, and L is the distance between two points selected in arc of curvature, and c is selected arc of curvature
It rises.
Step 4 selects thick 7050 aluminum alloy plate materials of 40mm, rolls plate to this before the rolling and carries out 400 DEG C of -3 hours air
Furnace isothermal holding, so that it is uniform to temperature to roll plate thickness；The unlubricated processing of roll in the operation of rolling calculates prediction gained using simulation
The reduction in pass of no warped boar shape carries out experiment rolling.
Technique provided by the invention has the advantage that compared with traditional straightening schemes
1. this method is based on analogue simulation asymmetrical rolling process, and it is asynchronous to combine practical rolling experiment to carry out aluminum alloy plate materials
The analysis without warpage technique is rolled, the warp direction of asymmetrical rolling plate under actual working conditions is would know that, determines in advance asynchronous
Rolled plate operating status provides visualization scheme for actual process adjustment；
2. this method can directly adjust asynchronous rolling process parameter, such as according to actually rolling plate thickness and used friction speed
Than being obtained in advance based on analogue simulation makes the asynchronous rolling technological parameter (such as reduction in pass) for rolling zero warpage of plate, can obviously mention
High template quality avoids transformation rolling equipment or installs additional to force straightener.
Detailed description of the invention
The asynchronous computation model for rolling slab warping curvature of Fig. 1 present invention and parameter.
Asymmetrical rolling process roll and the simulation model figure of plate is rolled in Fig. 2 present invention.
During Fig. 3 analogue simulation H=30mm plate asymmetrical rolling (friction speed ratio DSR=1.2), bow warping degree is with road
The secondary increased variation tendency of drafts.
Show that different-thickness plate obtains under the conditions of different friction speed ratios without warped boar by simulation calculation in Fig. 4 present invention
The critical reduction in pass of shape.
Fig. 5 using analogue simulation obtained critical reduction without warpage asynchronous rolling process and rolling experiment value comparison
Schematic diagram.
Fig. 6 simulation calculate obtain friction speed ratio be 1.2, when roller radius is 600mm it is maximum initially roll plate thickness with it is critical thick
Spend relationship (solid line is linear fit in figure, dotted line is nonlinear fitting) (R between drafts2To be linearly or nonlinearly fitted phase
Relationship number).
Specific embodiment
The present invention will be further described for citing with reference to the accompanying drawing.
As Figure 1-Figure 2, a kind of method of aluminum alloy plate materials asymmetrical rolling warpage forecast and optimization of the present invention, this method
Specifically includes the following steps:
Step 1. establishes the two dimensional plane strain model of asymmetrical rolling metal or alloy plate using simulation calculation software, should
Model front guide roll and is defined as plastoelastic rolled piece composition by being defined as topping roll and bottom roll of the rigid -plastic with diameter, wherein
The rotational angular velocity of topping roll and bottom roll can be separately adjustable to realize asymmetrical rolling function, and Definition Model material properties divide
Grid, be arranged asymmetrical rolling during heat exchange, friction boundary condition；
Asymmetrical rolling difference working condition is included that top and bottom rolls rotating ratio, difference roll plate original depth, per pass by step 2.
The built two dimensional plane strain model of secondary difference drafts input step 1 simultaneously carries out simulation calculation, output asymmetrical rolling template, and according to
This template calculates the buckling ρ of asymmetrical rolling plates obtained by different operating condition Imitatings, establish initial plate thickness, reduction in pass,
Up-down rollers friction speed obtains relation curve than the relationship between buckling；
Step 3. finds the curve and X-axis according to the relation curve between step 2 curvature established and rolling parameter
The corresponding plate thickness of intersection point, reduction in pass and friction speed ratio, this value are the corresponding asymmetrical rolling plate of each rolling parameter without sticking up
Bent critical working condition；
Step 4 calculates the obtained critical working condition of asymmetrical rolling according to step 3, in the enterprising row metal of milling train or sheet alloy
Asymmetrical rolling experiment, the analog result of step 1- step 3 is handled according to the following conditions according to experimental result:
Condition one: plate template is rolled in the upturned vertical height of straightened condition or plate head not when rolling gained is asynchronous
When greater than lower a time milling train opening degree, the warpage degree of asymmetrical rolling plate can meet continuous asymmetrical rolling requirement, at this time may be used
Analog result is not modified；
Condition two: when the asynchronous upturned vertical height in wrench portion of rolling of rolling gained is greater than lower a time milling train opening degree
Or be bent downwardly when the transfer roller for rolling plate and milling train being caused to collide, no warpage need to be obtained to analogue simulation according to concrete outcome
Critical rolling operating condition is accordingly corrected；
Step 5. is obtained using step 4 by the modified and critical working condition of the close asymmetrical rolling of actual conditions
Realize metal or alloy plate without warpage asymmetrical rolling, so that the warpage during solving such sheet alloy asymmetrical rolling is asked
Topic.
Definition Model material properties in the step 1 include specific heat capacity, thermal coefficient, elasticity modulus, thermal expansion coefficient,
Poisson's ratio and density.
The calculation formula of buckling ρ in the step 2 is that formula is as follows:
In formula, L is the distance between two points selected in arc of curvature, and c is that selected arc of curvature is risen.
Initial plate thickness, reduction in pass, up-down rollers friction speed are established in the step 2 than the relationship between buckling
It establishes that the rolling operating condition simulate calculating according to the Simulation Calculation of step 1 foundation and obtains specific curvature value, and with
Curvature value is Y-axis, rolling parameter is that X-axis establishes curve.
In step 3, the reduction in pass range for obtaining critical operating condition is 5-55%, and friction speed ratio is 1.0-1.7.
Modification method in the step 4 are as follows:
(1) when obtaining the critical working condition of no warpage using analogue simulation and carrying out rolling experiment, if milling train exit is rolled
Plate bends towards upper roller side, that is, rolls plate and upwarp, then explanation reaches and actually faces needed for no warped state under the rolling working condition
Boundary's reduction in pass is greater than analogue simulation value, can be resolved at this time by following two mode:
1.1 continue growing reduction in pass and when milling train is still able to satisfy plate nature bite condition, can not change it is initial
Under conditions of plate thickness and friction speed ratio, step 1- step 3 is repeated by increasing reduction in pass, rolls plate up to acquisition is straight, it is every heavy
The amplification of multiple primary reduction in pass is no more than 5%.
1.2 continue growing reduction in pass and when milling train is not able to satisfy plate nature bite condition, increase reduction in pass
Method will hinder rolling continuity, at this time can under conditions of initial plate thickness and constant reduction in pass, by reduce it is different
Speed ratio simultaneously repeats step 1- step 3, until acquisition is straight to roll plate, the range of decrease for the friction speed ratio being often repeated once is 5-10%.
(2) when obtaining the critical working condition of no warpage using analogue simulation and being rolled, if milling train exit to roll plate curved
It to lower roll side, that is, rolls and is detained under plate, then explanation is under the rolling working condition, the critical road of reality needed for reaching no warped state
Secondary drafts is less than analogue simulation value, can repeat step 1- step 3 by way of reducing reduction in pass at this time, until obtaining
Straight to roll plate, the range of decrease for the reduction in pass being often repeated once is no more than 5%.
In steps of 5, it is needed in the practical operation of rolling according to rolling nature bite condition, i.e. α < arctan μ, wherein α is to roll
Nip angle processed, μ are coefficient of friction, and the relationship between initial plate thickness and critical reduction matches to determine with practical rolling power
Roll initial plate thickness, only initial plate thickness, which is less than or equal to this, could obtain the rolled plate of no warpage when can roll initial plate thickness.
Embodiment 1:
It is soft first with Finite Element Simulation Analysis for the warpage issues for improving or solving asymmetrical rolling Aluminum Alloy Plate material
Part establishes asymmetrical rolling two dimensional plane strain model (as shown in Figure 2), specifically includes the following steps:
The foundation of step 1. geometry and material model: top and bottom rolls are reduced to ideal rigid plastic model in model, up and down
Roller roller diameter is all 400mm, and upper roller revolving speed is 1m/s, and lower roll revolving speed is 1.2m/s, and corresponding friction speed ratio is 1.2；Define simulation process
In roll the material property parameter of plate, such as the specific heat of material, thermal coefficient, Poisson's ratio (in the present embodiment under condition of different temperatures
It is derived from document for the correlation performance parameters of 7050 aluminium alloys [Dong Yuehui waits the finite element of aluminium alloy thick plate quenched residual stress
Simulation and its influence aviation journal to machining deformation, 2004,4:429-432.])；The load-deformation curve of plate passes through heat
Compression experiment obtains.Rolled plate grid division having a size of 2mm × 2mm, grid sum according to the original depth of simulation plate and
Variation (as initially with a thickness of 30mm when, plate thickness direction is divided into 15 layers), simulate plate length be 200mm.
Step 2. roll and the foundation for rolling plate transmission of heat by contact model: rule of thumb plate is rolled in formula acquisition and the radiation of air is changed
Hot coefficient is 6.8w/m2DEG C, the contact heat transfer coefficient for rolling plate and roll is 55Kw/m2·K；Due to work of deformation in the operation of rolling
And roll is set as 95% with rolling plate friction and be converted into the conversion ratio of heat.
Step 3. friction model: Coulomb friction law (τ=μ p) is used in the operation of rolling, i.e. shearing friction stress (τ)
It is proportional to and rolls normal pressure (p) suffered by plate, coefficient of friction (μ) is according to document [Duan X, et al.Prediction of
temperature evolution by FEM during multi-pass hot flat rolling of aluminum
Alloys.Model.Sim.Mater.Sci.Eng., 2001,9:525-538.] and rolling experiment is counter pushes to adopt with 0.35.
The material property parameter and thermal parameter of two-dimensional finite element model each section are assigned respectively.
Change reduction in pass by adjusting roll gap size, carry out simulation calculation,
The plate shape effect picture of asymmetrical rolling plate is exported, mode calculates the buckling value of plate at this time according to Fig. 1
ρ.Fig. 3 show 7050 aluminum alloy plate materials that original depth is 30mm after friction speed is than the asymmetrical rolling for 1.2, and plate shape is with rolling
The increased situation of change of reduction in pass.When drafts is 30%, the asynchronous plate that rolls increases drafts to slow roll curving
It is asynchronous to roll that plate plate shape is generally flat, and the buckling calculated at this time is almost 0 when to 40%, so when reduction in pass
To make plate without the critical reduction in pass of warpage under the conditions of the asymmetrical rolling；Drafts is continued growing to 45%, rolls slab warping
Direction changes, that is, bends towards quick roll side.
Roller speed is 1.1m/s under adjusting, and corresponding friction speed ratio is 1.1, repeats step (1)-(6), and calculating is asynchronous to roll slab warping
Curvature.
Roller speed is 1.3m/s under adjusting, and corresponding friction speed ratio is 1.3, repeats step (1)-(6), and calculating is asynchronous to roll slab warping
Curvature.
Under the conditions of friction speed ratio is 1.1~1.3, selects to roll plate original depth respectively as 10~40mm, repeat step (1)-
(6), calculating is asynchronous rolls slab warping curvature.
The asymmetrical rolling plate shape obtained according to analogue simulation in above-mentioned steps calculates under the conditions of each asynchronous rolling process
The buckling of plate, and the critical reduction in pass of the corresponding no warpage asynchronous rolling process of each working condition is found,
Different initial plate thickness, different friction speed ratios and the critical reduction in pass of asymmetrical rolling (corresponding no warpage) are established based on these data
Between variation relation figure, as shown in Figure 4.As seen from the figure, with friction speed than increasing, 7050 aluminum alloy plate materials of a certain original depth
Corresponding critical reduction dramatically increases；Initial plate thickness is bigger simultaneously, and corresponding critical reduction is also bigger.
Embodiment 2:
7050 aluminum alloy plate materials for being 40mm using original depth, are obtained different without warpage using analogue simulation in the present invention
Step rolling mill practice carries out experiment rolling, and experiment rolling parameter is identical as the set parameter of simulation.After obtaining experiment rolled plate
The buckling of institute's rolled plate is measured, measured value is as shown in Figure 5.Compared with simulation results, actual measurement critical reduction with
Simulation results coincide substantially, show that the above method can accurately, reliably forecast that 7050 aluminium close under different asymmetrical rolling operating conditions
The warping phenomenon of golden cut deal.
Table 1 furthermore presents thick 7050 aluminum alloy plate materials of 40mm under the conditions of friction speed ratio is 1.2, asynchronous through different passages
The simulation calculated result and experimental result of plate thickness and critical reduction in pass after rolling, the two are coincide fine.By the table it is found that
During multi-pass asymmetrical rolling, there is corresponding face for different-thickness plate after the critical reduction in pass of use per pass
Boundary's reduction in pass can ensure that the asynchronous plate shape for rolling plate is straight.
Embodiment 3:
Above-described embodiment proof can realize that asymmetrical rolling is manufactured without warpage plate using critical reduction in pass method, however real
Due to the limitation of mill milling ability in the production of border, not every original depth can pass through above-mentioned critical reduction in pass method
To realize warpage optimization.Therefore, it is obtained according to milling equipment condition common in existing industrial production using critical passage pressure
It is necessary that the maximum that lower amount method is able to achieve warpage optimization, which can roll initial plate thickness,.According to rolling bite condition, i.e. nip angle
It needs to meet relationship between (α) and coefficient of friction (μ): α < arctan μ；And nip angle and roller radius R, reduction in pass (Δ
H) there are relationships between: cos α=1- (Δ h/2R).It would know that the maximum reduction Δ of a certain rolling equipment according to the two relationships
hmaxWith maximum nip angle αmaxBetween there are relationships: Δ hmax=2R (1-cos αmax).Using coefficient of friction 0.35 given above and
Work roll radius 600mm is calculated it is found that the maximum reduction Δ h that milling train is able to achievemax=67.4mm.
Can be calculated according to above-mentioned critical reduction and buckling value simulation calculating process and obtain friction speed ratio is 1.2, roll
There are relationships as shown in Figure 6 between initial plate thickness and critical reduction when radius 600mm.When the initial plate that thickness is H obtains nothing
The critical reduction in pass of warpage is less than Δ hmaxIt, then can be by increasing reduction in pass (critical reduction in pass) come real when/H
Otherwise the existing asynchronous plate that rolls cannot without warpage.It is seen that the rolling condition is realized without maximum corresponding to warpage plate
Initial plate thickness further carries out simulation discovery, 130mm to 130mm, 140mm and 150mm heavy-gauge sheeting between 130-150mm
Critical reduction in pass can be used to realize asymmetrical rolling without warpage in heavy-gauge sheeting, and 140mm and 150mm heavy-gauge sheeting then will appear
Phenomenon is stuck up, it cannot be guaranteed that obtaining straight template.Certainly, by reducing friction speed ratio, critical reduction in pass can also be used and realize nothing
The initial plate thickness of warpage asymmetrical rolling can also increase.
As it can be seen that can predict Aluminum Alloy Plate not synchronous and asynchronous well using Finite Element Method provided by the invention
Roll the warpage degree of plate and corresponding plate shape under operating condition.Meanwhile asymmetrical rolling aluminium is effectively solved the present invention provides a kind of
The method of alloy cut deal warpage issues, i.e. adjusting asymmetrical rolling reduction in pass to critical value, thus can get slide plate type,
Greatly contribute to the serialization of Aluminum Alloy Plate material asynchronous rolling process.
Asymmetrical rolling sheet alloy warpage forecast provided by the invention and optimization solution are the reality of Differential speed rolling technology
Border application provides reliable, effective Technical Reference and operation instruction
Obviously, examples detailed above is only illustration method practicability example, and not to embodiment and rolling stock
Restriction.For those of ordinary skill in the art, other different forms can be also made on the basis of the above description
Variation or variation.There is no necessity and possibility to exhaust all the enbodiments, and thus amplifies out apparent
Variation or change still locate
Among the protection scope of the invention.
1 finite element modelling result of table and rolling measured result comparison
Claims (5)
1. a kind of method of aluminum alloy plate materials asymmetrical rolling warpage forecast and optimization, which is characterized in that this method specifically include with
Lower step:
Step 1. establishes the two dimensional plane strain model of asymmetrical rolling metal or alloy plate, the mould using simulation calculation software
Type front guide roll and is defined as plastoelastic rolled piece composition by being defined as topping roll and bottom roll of the rigid -plastic with diameter, wherein on
The rotational angular velocity of roll and bottom roll can be separately adjustable to realize asymmetrical rolling function, and Definition Model material properties divide net
Lattice, be arranged asymmetrical rolling during heat exchange, friction boundary condition；
Asymmetrical rolling difference working condition is included that top and bottom rolls rotating ratio, difference roll plate original depth, per pass not by step 2.
With the built two dimensional plane strain model of drafts input step 1 and simulation calculation is carried out, exports asymmetrical rolling template, and plate accordingly
Type calculates the buckling of asymmetrical rolling plate obtained by different operating condition Imitatingsr, establish initial plate thickness, reduction in pass, up and down
Roller friction speed obtains relation curve than the relationship between buckling；
The calculation formula of buckling is as follows:
In formula,LFor in arc of curvature select distance between two points,cIt is risen for selected arc of curvature；
Step 3. finds the friendship of the curve and X-axis according to the relation curve between step 2 curvature established and rolling parameter
The corresponding plate thickness of point, reduction in pass and friction speed ratio, this value are the corresponding asymmetrical rolling plate of each rolling parameter without warpage
Critical working condition；
Step 4. calculates the obtained critical working condition of asymmetrical rolling according to step 3, in the enterprising row metal of milling train or sheet alloy
Asymmetrical rolling experiment, is handled the analog result of step 1- step 3 according to the following conditions according to experimental result:
Condition one: it rolls plate template when rolling gained is asynchronous and is not more than in the upturned vertical height of straightened condition or plate head
When lower a time milling train opening degree, the warpage degree of asymmetrical rolling plate can meet continuous asymmetrical rolling requirement, at this time can not be right
Analog result is modified；
Condition two: when rolling gained it is asynchronous roll the upturned vertical height in wrench portion greater than lower a time milling train opening degree or to
When lower bending causes the transfer roller for rolling plate and milling train to collide, it is critical no warpage need to be obtained to analogue simulation according to concrete outcome
Rolling operating condition is accordingly corrected；
Modification method in the step 4 are as follows:
(1) when obtaining the critical working condition of no warpage using analogue simulation and carrying out rolling experiment, if milling train exit to roll plate curved
It to upper roller side, that is, rolls plate and upwarps, then explanation is under the rolling working condition, the critical road of reality needed for reaching no warped state
Secondary drafts is greater than analogue simulation value, can be resolved at this time by following two mode:
1.1 continue growing reduction in pass and when milling train is still able to satisfy plate nature bite condition, can not change initial plate thickness
Under conditions of friction speed ratio, step 1.1-1.3 is repeated by increasing reduction in pass, until acquisition is straight to roll plate, every repetition one
The amplification of secondary reduction in pass is no more than 5%；
1.2 continue growing reduction in pass and when milling train is not able to satisfy plate nature bite condition, increase the side of reduction in pass
Method will hinder the continuity of rolling, at this time can be under conditions of initial plate thickness and constant reduction in pass, by reducing friction speed ratio
And step 1.1-1.3 is repeated, until acquisition is straight to roll plate, the range of decrease for the friction speed ratio being often repeated once is 5-10%；
(2) when obtaining the critical working condition of no warpage using analogue simulation and being rolled, if the plate that rolls in milling train exit is bent towards down
Roller side is rolled and is detained under plate, then explanation is under the rolling working condition, the critical passage pressure of reality needed for reaching no warped state
Lower amount is less than analogue simulation value, can repeat step 1.1-1.3 by way of reducing reduction in pass at this time, until obtaining straight
Plate is rolled, the range of decrease for the reduction in pass being often repeated once is no more than 5%；
Step 5. is obtained using step 4 can be real by the modified critical working condition of the asymmetrical rolling close with actual conditions
Cash category or sheet alloy without warpage asymmetrical rolling, so that the warpage during solving such sheet alloy asymmetrical rolling is asked
Topic.
2. the method according to claim 1, wherein the Definition Model material properties in the step 1 include than
Thermal capacitance, thermal coefficient, elasticity modulus, thermal expansion coefficient, Poisson's ratio and density.
3. the method according to claim 1, wherein established in the step 2 initial plate thickness, reduction in pass,
Up-down rollers friction speed establishes the Simulation Calculation according to step 1 foundation to the rolling work than the relationship between buckling
Condition carries out simulation and calculates the specific curvature value of acquisition, and is that X-axis establishes curve using curvature value as Y-axis, rolling parameter.
4. the method according to claim 1, wherein in step 3, obtaining the reduction in pass model of critical operating condition
It encloses for 5-55%, friction speed ratio is 1.0-1.7.
5. the method according to claim 1, wherein in steps of 5, being needed in the practical operation of rolling according to rolling certainly
Right bite condition, i.e.,α<Arctan μ, whereinαFor rolling nip angle,μFor coefficient of friction, initial plate thickness and critical reduction it
Between relationship roll initial plate thickness with what practical rolling power matched to determine, only initial plate thickness is less than or equal at the beginning of this can roll
The rolled plate of no warpage could be obtained when beginning plate thickness.
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Effective date of registration: 20201125 Address after: 100083 Haidian District, Xueyuan Road, No. 30, Patentee after: University OF SCIENCE AND TECHNOLOGY BEIJING Patentee after: Aluminum Corporation of China Ltd. Address before: 100083 Haidian District, Xueyuan Road, No. 30, Patentee before: University OF SCIENCE AND TECHNOLOGY BEIJING |