CN109311081A - The method for producing plate ingot casting by vertical casting aluminium alloy - Google Patents
The method for producing plate ingot casting by vertical casting aluminium alloy Download PDFInfo
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- CN109311081A CN109311081A CN201780033894.6A CN201780033894A CN109311081A CN 109311081 A CN109311081 A CN 109311081A CN 201780033894 A CN201780033894 A CN 201780033894A CN 109311081 A CN109311081 A CN 109311081A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
- B22D11/122—Accessories for subsequent treating or working cast stock in situ using magnetic fields
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
- B22D11/003—Aluminium alloys
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/114—Treating the molten metal by using agitating or vibrating means
- B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
- B22D11/041—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for vertical casting
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Abstract
The present invention is a kind of method for casting metal alloy, especially aluminium alloy in the ingot mold extended along longitudinal axis, and the horizontal cross-section of the ingot mold is parallelepiped.During casting, traveling alternating magnetic field is applied to liquid phase alloy, and the magnetic field has the amplitude peak propagated along propagation axis.Under the influence of magnetic field, Lorentz force is applied to liquid phase alloy, so that the Lorentz force of maximum intensity is propagated along the propagation axis.It according to the method for the present invention include the maximum intensity for the Lorentz force that modulation is propagated along the propagation axis.This modulation is obtained by determining one or more parameters of Lorentz force as the time changes, and one or more of parameters are referred to as force parameter.The invention further relates to the ingot castings obtained by the method.The invention enables can be substantially reduced to cause the non-uniform so-called interval gross segregation of the alloying element spatial distribution in ingot casting.Therefore, the ingot casting of acquisition is more evenly.
Description
Technical field
Technical field of the invention is to produce ingot casting after casting liquid aluminium alloy.
Background technique
During vertical casting, in order to form ingot casting, the solidification of metal or metal alloy is showed by so-called gross segregation
As influencing.In metal cooling period, convection current is formed, generates circulation whirlpool (vortex de recirculation), when circulation is revolved
When the service life in whirlpool and the characteristic duration of solidification order magnitude range having the same, the reason of circulation whirlpool is gross segregation.This
A little phenomenons lead to the Local enrichment or local depletion of chemical substance in the ingot casting of solidification.These gross segregations are ingot casting ingredients
The reason of heterogeneity.
Gross segregation well-known to those skilled in the art is as caused by the dilution of eutectic alloy element along the vertical of ingot casting
Negative center gross segregation to central axis.In works " the Direct-Chill Casting of of John Wiley et al.
These gross segregations have been described in light alloys " (Wiley Publishing Company, in September, 2013, the 158-172 pages).
The main mechanism of the cause of center gross segregation described in this works is:
Thermosolutal convection and these convection current in the collecting tank as caused by temperature gradient and concentration gradient (marais)
Flowing penetrates into mushy zone；
Crystal grain was transported to cold-zone under the action of gravity, Archimedes buoyancy principle and nature or forced convertion；
Flowing in mushy zone caused by volume contraction when passing through solidification, can be by metallostatic pressure come auxiliary
It helps；
Liquid is caused to flow in mushy zone by mechanically deform；
May as coming down in torrents, injecting or discharge caused by gas, mixing, vibration etc., penetrated into cold-zone and mushy zone
In and change the forced flow in convective motion direction.
This is a continuous gross segregation, which indicates gross segregation in the entire height or a part height of ingot casting
On the fact that recur, in other words, it is substantial uniform along casting axis.
Interval gross segregation phenomenon describe in the literature it is less, and interval gross segregation phenomenon show as it is macro in negative center
It sees and forms V-arrangement band on every side of segregation.These V-arrangement bands by eutectic and Peritectic Alloy element alternately be enriched with it is poor
Change.When the element of segregation absorbs X-ray in the mode different from the atom for the metal for being constituted ingot casting, pass through the longitudinal direction to ingot casting
Section --- usually at the half-breadth in plane L/TC --- carries out X-ray radiophotography and is observed that these bands.Its other party
Method can check this phenomenon, such as the longitudinal sections of anodic oxidation using echography or are observed with the naked eye, this be by
The difference of optical reflectance between aluminium alloy enrichment of element area or stripping section.In general, interval gross segregation is in caliper zones
Most significant on the T/2.5 of domain, region T/2 corresponds to the central axis of ingot casting.According to specialized vocabulary well known by persons skilled in the art,
Term T/n (wherein n is integer) indicates the region for being located at the T/n distance at the edge of ingot casting, and wherein T indicates the thickness of ingot casting.
After starting casting, one forms beveled forward portion, cyclical intermission gross segregation between solid area and fluid zone
Just occur very early.They can be observed under all situations of the aluminium alloy cast aluminium alloy gold of loading, and casting is usually pressed
It is greater than the format of 300mm according to thickness, this thickness threshold value itself depends on casting speed.
Publication " the Banded segregation patterns in DC cast of R.C Dorward et al.
AlZnMgCu alloy ingots and their effect on plate properties " (Aluminum, 1996,
Volume 72, the 4th phase, the 251-259 pages) describe the band that interval segregation is formed in alloy 7000.According to these authors, this
Phenomenon is due to being vibrated by the convection current of collecting tank related with vortex emission mechanism (that is, liquid phase of metal) come periodic triggers
Crystal grain avalanche.This article specifies that interval gross segregation can be the mechanical property of the plate obtained by original cast product
The reason of (such as toughness) changes.Therefore, it finds and the casting method of these interval gross segregations is inhibited to be advantageous.
Reduction has been described or inhibits continuous gross segregation, such as center gross segregation.In particular, having been described that out
In the purpose of stirring or actuating flowing, applying a magnetic field allows to limit the appearance of continuous gross segregation.Document US5375647 is retouched
The method for example for reducing the center gross segregation occurred during casting metal alloy cast ingot is stated.The method is included in cold
But the stabilizing magnetic field that application is generated by least one by the coil of direct current during.
Document FR2530510 describes the method for electromagnetic casting, and wherein stabilizing magnetic field and variable frequency magnetic field act on simultaneously,
To generate two radial vibrations simultaneously in the metal of ot-yet-hardened and limit stirring.
" the Effect of low-frequency magnetic field on of B.Zhang et al.
Macrosegregation of continuous casting aluminum alloys " (material flash report 57 (2003)
1707-1711 pages) variable magnetic field of low frequency (10 between 100Hz) has been applied to the 200mm made of alloy AA7075
Steel billet, and observed the beneficial effect of reduction center gross segregation, primarily with respect to the frequency of 30Hz.
EP2682201 describes a kind of use and is symmetrically installed relative to another longitudinally asymmetric plane about ingot mold
Two inductors carry out electromagnetic agitation method.These inductors generate two electromagnetic fields of different frequency, described two electricity
It is propagated along with longitudinal axis according to opposite direction in magnetic field.At least one of described inductor generates being total in liquid metal
The magnetic field of vibration frequency.
WO2014/155357 is related to being intended to shift the method and apparatus of molten metal, and electromagnetic inductor includes at least two pairs
Electromagnetic pole and the first magnetic is generated between the second pole in the pole and different a pair of of electromagnetic poles in first pair of electromagnetic pole
Field component, and the second magnetic-field component is generated between two poles in one or more pairs of electromagnetic poles, the second magnetic-field component is thus
One or more vortex are generated in the molten metal.
Inventor thinks that method as described above can not efficiently reduce the appearance of interval gross segregation.Inventor proposes
It can limit to form the method that such gross segregation even is eliminated them, preferably to control the product generated by casting
Mechanical property.
Summary of the invention
An object of the invention is a kind of for the cast aluminium alloy gold ingot casting in general rectangular ingot mold
Method the described method comprises the following steps:
Prepare aluminium alloy；
Along the longitudinal axis of flowing in the ingot mold cast aluminium alloy gold, during casting, by with solidification
The cooling alloy of the trickling (ruissellement) of the coolant liquid of metal contact；
During casting, applying amplitude according to frequency periodicity changing magnetic field, the magnetic field is by being arranged in the ingot casting
At least one magnetic field generator around mold generates, so as in process of setting in the difference of the liquid portion of the alloy
Place applies Lorentz force；
The magnetic field applied is the magnetic field traveling (glissant) propagated along propagation axis, so that the magnetic field is most
It is significantly propagated along the propagation axis, while limiting propagation wavelength, the traveling magnetic field causes the Lorentz of maximum intensity
Power is propagated along the propagation axis；
The method is characterized in that, determines that the magnetic parameter of the Lorentz force value of maximum intensity is interior in predetermined time interval
Be it is variable, to obtain the Lorentz to the maximum intensity propagated along the propagation axis in the time interval
The modulation of power, the magnetic parameter are referred to as force parameter, and the parameter is:
The amplitude peak in the magnetic field；
And/or the frequency in the magnetic field；
And/or the propagation wavelength in the magnetic field.
The method may include any following characteristics being used alone or in combination:
The section of the ingot mold defines thickness and length in a horizontal plane, and the thickness is less than or equal to described
Length, the thickness are greater than 300mm and are preferably at least 400mm；
The frequency in the magnetic field is less than 5Hz or 2Hz or 1Hz；
Time interval of the Lorentz force for the maximum intensity propagated along the propagation axis between 20 seconds to 10 minutes
It is interior at least 30N.m-3Variation；
The magnetic field makes during the time interval, the absolute value of the variable density of maximum Lorentz force be greater than or
Equal to 0.05N.m-3.s-1；
The propagation axis of the amplitude peak in the magnetic field is in the plane for being parallel to casting direction；
During casting, the variation of the force parameter be periodically, the period between 20 seconds to 20 minutes, or at 1 point
Clock is between 15 minutes, or between 2 minutes to 10 minutes；
During casting, the Lorentz force of the maximum intensity is not equal to zero；
During casting, the variation of the force parameter is obtained by the periodic interruptions in the traveling magnetic field；
In the time interval, at least one point of the liquid portion of the alloy, dimensionless Hartmann
(Hartmann) at least 3 times of number variation, or even 5 times of variation；
The aluminium alloy is selected from the alloy of 2XXX, 6XXX or 7XXX series, and the thickness is at least 400mm or 450mm.
According to an embodiment, the generator is electromagnetic inductor, and referred to as faradic electric current flowing passes through
Each electromagnetic inductor.The method includes during the time interval:
Change the faradic intensity；
And/or change the faradic frequency；
And/or change the distance between electromagnetic inductor and the ingot mold.
According to this embodiment, the method may include change the faradic intensity or frequency for flowing through inductor
Rate, then the described method includes:
It is defined on and generates the faradic strong of resonance wave on the Free Surface of the aluminium alloy flowed in the ingot mold
The preliminary step of at least one critical value of degree and frequency；
The variation range of the faradic intensity or frequency is determined according to the critical value predetermined.
The method may include the multiple critical values for defining the faradic intensity and frequency, represent to define
The resonance curve for generating the intensity of the resonance of the Free Surface and the critical value of frequency, the method includes by the resonance
Curve determines the variation range of the faradic intensity or frequency in the range of defining.
Preferably, the method includes changing the faradic frequency for flowing through inductor.
According to an embodiment, at least one generator is permanent magnet, which comprises
Change the distance between the permanent magnet and the ingot mold；
And/or the rotation speed of the rotation permanent magnet and the change magnet；
And/or two permanent magnets of rotation.
Another object of the present invention is the aluminium alloy obtained by the method as described in above and in the following description
Ingot casting.
The ingot casting can be shown, and a kind of 0.5% element is greater than for the weight content of the alloy, or for institute
The summation of two kind element of the single content greater than 0.5% of alloy is stated, decentralized standard is less than 3.3, and preferably less than 3, more favorably
Ground is less than 2.5, and still more advantageously less than 2 and more preferably less than 1.5, the decentralized standard is defined according to following expression formula:
ε=Δ CZA/ΔCZR(6)
ΔCZA=max (CZA)–min(CZA)(4),
ΔCZR=max (CZR)–min(CZR)(5),
Wherein:
-max(CZA) and min (CZA) it is illustrated respectively in being considered of measuring in the analysis area with interval gross segregation
The maximum concentration and Cmin of the summation of element or the two kinds of elements considered, the analysis area is for example in T/2.3 and T/3.3
Between；
-max(CZR) and min (CZR) be illustrated respectively in and be considered being influenced by interval gross segregation being examined in small reference area
The maximum concentration and Cmin of the summation of the element of worry or the two kinds of elements considered, the reference area is for example in T/6 and T/
Between 12；
The concentration is at least one distribution curve established at the half-breadth in fore-and-aft plane L/TC and on the direction TC
(profil) it is measured on, the distribution curve represents the interval gross segregation on the direction TC.
The ingot casting can have less than 0.01, preferably less than 0.007 and even more preferably less than 0.005 spectral intensity mark
Standard, the spectral intensity standard pass through following calculating:
Determine that the single weight content of element of the weight content greater than 0.5% or alloy that represent alloy is greater than 0.5%
The amplitude peak of Fourier (Fourier) transformation of the distribution curve of the interval gross segregation of the summation of two elements, described point
Cloth curve is established on the direction TC, and the amplitude peak is 8 to space periodic (p é riode) range between 25mm
Interior determination；
Pass through the nominal concentration C of the element0Or the summation normalization of the nominal concentration of two by being considered kinds of elements
(normaliser) amplitude peak.
Other advantages and features will become more apparent upon from the explanation below to specific embodiment of the invention, these explanations
It is provided and is shown in the attached drawing being listed below with non-limiting embodiment.
Detailed description of the invention
Figure 1A to Fig. 1 E instantiates the embodiment according to the prior art and apparatus and method according to the invention.Figure 1A is shown
The main component of equipment, and Figure 1B and Fig. 1 C respectively represents the room and time of the amplitude in traveling magnetic field according to prior art
Distribution.Fig. 1 D and Fig. 1 E respectively represent the room and time of the amplitude in the unstable traveling magnetic field of embodiment according to the present invention
Distribution.
Fig. 2 represents the so-called resonance curve of the Free Surface of collecting tank, and the resonance curve represents faradic intensity
With the so-called critical value of frequency, occur the resonance of the Free Surface of collecting tank at the critical value, it is real by the critical value
Apply electromagnetic agitation process.
Fig. 3 is by implementing the existing skill of representative according to the first embodiment (so-called embodiment 1) for representing the prior art
The radiophotography of the longitudinal sections for the product that the first embodiment of the method for art obtains.
Fig. 4 shows the concentration point of the Zn of the horizontal line and analysis area and reference area along longitudinal sections shown in Fig. 3
The embodiment of cloth curve.
Fig. 5 A is shown with the digital processing of successful execution on each distribution curve of the resolution ratio acquisition of 0.1mm.Fig. 5 B
Show the distribution curve obtained by the processing executed.
Fig. 6 A and Fig. 6 B show the feature distribution curve of the product by implementing to obtain according to the method for embodiment 1.Figure
6A shows the concentration profile of multiple horizontal Zn along longitudinal sections shown in Fig. 3.Fig. 6 B is shown by executing
The obtained distribution curve of digital processing.
Fig. 7 shows the Fourier transformation of distribution curve shown in Fig. 6 B.
Fig. 8 shows the collection obtained by the method for implementing second embodiment according to the present invention (so-called embodiment 2)
The so-called resonance curve of the Free Surface of liquid bath.
Fig. 9, Figure 10 A, Figure 10 B and Figure 11 are shown through the product implementing to be obtained according to the method for this second embodiment
Feature.Fig. 9 is the radiophotography of the longitudinal sections of the product.Figure 10 A shows multiple water along longitudinal sections shown in Fig. 9
The concentration profile of the Zn of horizontal line.Figure 10 B is shown to be obtained by the digital processing executed on the distribution curve that is shown in FIG. 9
Distribution curve.Figure 11 shows the Fourier transformation of these multiple distribution curves.
Specific embodiment
Unless otherwise stated, all instructions of the chemical component about alloy are represented as based on alloy total weight
Weight percent.Expression formula 1.4Cu means the copper content indicated with weight % multiplied by 1.4.The title of alloy meets this field
The regulation of Aluminum Association known to technical staff.
Figure 1A shows the embodiment of casting method well known in the prior art.In this embodiment, aluminium alloy 1 is by opening
Mouth 2i is flow in ingot mold 2.Ingot mold 2 extends along longitudinal axis Z.Ingot mold is defined by peripheral shell, described
Section of the peripheral shell in horizontal plane XY is parallelepiped.Cooling fluid 3, such as water, against the wall stream of the product of solidification
It is dynamic.The method is referred to as semicontinuous direct cooling casting (Direct-Chill Casting).False bottom 4 can translate
(translater) so as to leaving during casting opening 2i.Ingot mold 2 is parallel to first level axis X and prolongs along thickness e
It stretches and is parallel to the second horizontal axis Y, extend perpendicular to X-axis line along length l.Thickness e is greater than 300mm.Beyond this
The thickness of sample occurs interval gross segregation 11 with obvious way.
Under the action of cooling, solid area 1s is formed in cooling housing adjacent, solid area 1s surrounds fluid zone 1l, by
Term " collecting tank (marais) " indicates.Interface between fluid zone 1l and solid area 1s is front 10, with the solidification of alloy
Occur, front 10 is advanced towards the center of ingot mold.At the end of cooling, parallelepiped ingot casting, also referred to as art are formed
Language " product ".
The alloy is the aluminium alloy of 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX or 8XXX series.Alloying element
Mass fraction be greater than 1%, even greater than 3% or even 5% alloy especially suitable for according to the method for the present invention, this be because
Higher for the mass fraction of these alloying elements, interval gross segregation is more obvious.Present invention is particularly beneficial for 2XXX, 5XXX,
The alloy product of 6XXX or 7XXX, thickness is at least equal to 400mm or even 450mm.
Magnetic field generator 5 is shown, the magnetic field B of the fluid zone 1l for being applied to alloy can be generated.This generation
Device can be permanent magnet or electromagnetic inductor, and electromagnetic inductor generates magnetic field when flowing through electric current (so-called induced current).
The magnetic field B for being applied to fluid zone 1l is with amplitude B0With the alternating field of frequency f.The effect in the magnetic field is to apply
Collecting tank is stirred under the action of the Lorentz force on metal liquid area 1l.In fact, applying magnetic field B causes to be formed in the alloy
There is Lorentz force F and makes F ∝ J × B in the electric current J generated in the fluid zone affected by magnetic fields of alloy, wherein × indicate arrow
Integrating is measured, ∝ indicates proportionate relationship.This Lorentz force has with the oscillating component of the frequency of twice field frequency f.
Due to the thickness of ingot mold, select frequency f to allow enough magnetic field B to penetrate into collecting tank, to obtain
Obtain effective stirring of liquid.Product thickness increases, and frequency f is even lower.In the case where the thickness of aluminium alloy is greater than 300mm,
Frequency is even more preferably less than 5Hz, or even more advantageously less than 2Hz or 1Hz.
Generator 5 can generate traveling magnetic field.Term " traveling magnetic field " indicates alternating magnetic field, amplitude B0It is not constant
, and in minimum value and amplitude peakBetween change, amplitude peakIt is propagated along propagation axis Δ, it is more excellent
Selection of land is straight propagation axis.Term " amplitude " means the maximum value that periodical magnitude (grandeur) has.It is highly preferred that
Propagation axis belongs to the plane for being parallel to casting direction.
The distance lambda for separating two maximum values of magnetic field amplitude is the wavelength in traveling magnetic field.Figure 1B is indicated at moment t (solid line)
With the amplitude B in the magnetic field advanced along propagation axis moment t+ Δ t (dotted line)0Distribution embodiment.In propagation axis, show
Coordinate r corresponding with the position of point of collecting tank is gone out.Fig. 1 C shows the time-evolution for the alternating magnetic field advanced at this point.
Due to maximum amplitude valuePropagation, the amplitude in the magnetic field at the point is in minimum valueWithBetween change,Not as the time changes.
Traveling magnetic field generator 5 around multiple electromagnetic inductors of peripheral shell arrangement by constituting.In the coordinate of collecting tank
Lorentz force at point r includes oscillating component, is modulated with frequency 2f, which is twice of field frequency.Vibrate long-range navigation
The hereby amplitude F of the density of power0It can be indicated according to following formula:
Wherein σ indicates conductivity.
It can be by the travel speed V in magnetic fieldGIt is defined as VG=f λ (2), in this case, expression formula (1) can be indicated such as
Under:
Therefore, the amplitude of the Lorentz force at the point r of collecting tank depends on the amplitude in the magnetic field applied at this point
Square.By the modulation to its amplitude, the application in traveling magnetic field is translated at the point of collecting tank.Therefore, at the point of collecting tank
The amplitude in magnetic field as the time function in minimum radiusAnd amplitude peakBetween change.This is equally applicable to
Lorentz force density, at the point r of collecting tank, when the amplitude in magnetic field is in the point maximum, lorentz force density has maximum value.
By being placed in its own in the reference XYZ connecting with ingot mold 2, the maximum value of the amplitude in magnetic field is propagated along propagation axisAlso result in the Lorentz force F that maximum intensity is propagated along propagation axis Δmax.The power propagated along propagation axis
Combination establishes liquid along the movement of the axis, forms electromagnetism pump element.
It was found by the inventors that passing through the amplitude peak F for being modulated at the Lorentz force propagated in collecting tank at any timemax,
Gross segregation of having a rest decaying, or even disappear, especially on ingot casting of the thickness greater than 300mm.
This time modulation can be by controlling the parameter in the amplitude of equation (1) and (3) middle lorentz force density explained
Variation obtain, the parameter is referred to as magnetic force parameter, such as:
The maximum amplitude value in magnetic field
The frequency f in magnetic field；
The wavelength X in traveling magnetic field.
It, can be by changing when traveling magnetic field is generated by the multiple electromagnetic inductors being arranged in around the ingot mold
Pole-changing spacing, the i.e. phase difference between the induced current flowed in each inductor, to obtain the time of lorentz force density
Modulation.This change can change the wavelength X in traveling magnetic field, i.e., between two maximum values propagated along propagation axis away from
From.The faradic frequency flowed in inductor can be variable, this changes the frequency f in magnetic field.It is faradic
Amplitude is also possible to variable, this changes the maximum amplitude value in magnetic fieldFig. 1 D shows an embodiment, wherein
The maximum amplitude value in magnetic fieldWavelength X with traveling magnetic field is with temporally variable.Therefore, it shows in collecting tank
Spatial distribution B of the amplitude in moment t0(the spatial distribution B of t (solid line) and amplitude in moment t+ Δ t0(t+ Δ t) (dotted line).?
During time interval Δ t, amplitude peak?(t) and(change between t+ Δ t).Similarly, wavelength X
λ (t+ Δ t) is changed into from λ (t).In Fig. 1 E for the time-evolution that the alternating magnetic field for showing traveling is located on one point, show
One embodiment, wherein for frequency f and constant wavelength X, the maximum amplitude value in magnetic fieldWith time change.
Therefore, in the embodiment of Fig. 1 D and Fig. 1 E, the maximum amplitude value of the Lorentz force propagated in collecting tank in t and
In value F between t+ Δ tmax(t) and Fmax(change between t+ Δ t).
The significant duration is reached in the time-modulation for implementing force parameter during casting, what is more preferably larger than cast continues
The 50% of time or even 80%.The time-modulation can for example apply at least 30 minutes, even at least 1 hour.
Particularly, traveling magnetic field B can be generated by two inductors being arranged on the same face of ingot casting.Preferably,
Inductor is arranged in face of the larger face of ingot casting, i.e., has a face of maximum longitudinal cross-section in the two of ingot casting face.Induction
Device can be superposed on one another to generate so-called longitudinal phase shift, or is arranged side by side to generate so-called horizontal phase shift.It retouches below
In the embodiment stated, the equipment described in application WO2014/155357 is used, and more precisely, according to reference to figure
19 and Figure 20 A description configuration, wherein along longitudinal axis Z orient three inductors be arranged to towards each of ingot casting compared with
Big face.
Traveling magnetic field can also be generated by the one or more permanent magnets for being arranged in ingot mold periphery, and be configured to
It is moved relative to ingot mold.For example, traveling magnetic field can be generated by rotation permanent magnet.
Traveling magnetic field parameter, the either variation of its amplitude, its frequency or its wavelength can apply in collecting tank
Revocable Lorentz force.Them are even made to disappear it was found by the inventors that this can make the appearance of interval gross segregation decay.
These conditions may will affect the circulation of spontaneous generation in collecting tank and mitigate its consequence.
Preferably, in collecting tank, the pace of change of the maximal density of Lorentz force is greater than 0.05N.m-3.s-1, and it is more excellent
Selection of land is greater than 0.1N.m-3.s-1, and more preferably larger than 0.2N.m-3.s-1.In one embodiment, in long-range navigation during casting
Hereby the maximum pace of change of the maximal density of power is at least 1N.m-3.s-1, and more preferably at least 2N.m-3.s-1。
It is highly preferred that being sent out in the time interval of characteristic duration for being less than or equal to the circulation generated by free convection
The variation of raw one or more force parameter.These duration change according to the thickness and casting speed of ingot casting.In view of thickness e
In 300mm between 700mm and casting speed is between 30mm/ minutes to 80mm/ minutes, the characteristic duration of circulation is held
20 seconds (thickness of 300mm, 30mm/ minutes casting speeds) to 10 minutes continuous (thickness of 700mm, 80mm/ minutes casting speed
Degree).Therefore, force parameter changes in the time interval Δ t determined according to these characteristic durations.Term " variation " means
At least 10% significant changes of the force parameter considered, and preferably force parameter at least 20% or even 30%.
The variation of force parameter can be periodically, when the time cycle of variation can be about the feature lasts of circulation
Between, i.e., according to the size of casting and velocity conditions between 20 seconds to 10 minutes.Preferably, in collecting tank, variation when
Between during the period, the maximal density of Lorentz force changes at least 30N.m-3, advantageously at least 40N.m-3, preferably at least 50N.m-3, even more preferably at least 60N.m-3。
During casting, the variation of force parameter is also possible to dullness, such as according between the beginning and end of casting
Increasing function or decreasing function, the value of force parameter continuously or gradually incrementally change.
Advantageously, during casting, the Lorentz force of maximum intensity is not equal to zero.In general, it is in inductor or coil
Electric current be equal to zero when be equal to zero.Therefore, advantageously, the variation of force parameter is obtained by the periodic interruptions of traveling field
's.
Advantageously, during casting, the Lorentz force of maximum intensity is greater than 80N/m3, preferably more than 100N/m3, more excellent
Selection of land is greater than 120N/m3, even more preferably greater than 140N/m3.Inventor has found really, in embodiment 5 (Figure 20 a-d)
It shows, when power is too weak, the inhibition to interval gross segregation is not optimal.Inhibition as interval gross segregation is modified
The minimum value of starting point depend on the position and alloy of all casting parameters, especially stirring means, inductor relative to plate
Ingredient.
According to an embodiment, changed respectively by changing the faradic frequency flowed in inductor and amplitude
The frequency f and/or amplitude peak in magnetic fieldFor this purpose, the method may include defining operation ranges (that is, induced current
Frequency and/or intensity variation range) preliminary step.This preliminary step includes one or more of determining frequency/intensity pair
A value, referred to as critical value, in the Free Surface 1 of collecting tanksupPlace generates resonance, which leads to the Free Surface 1supOccur
Significant oscillation, the significant oscillation are as shown in Figure 1A.These significant oscillations are usually observed with the naked eye.Term " significant oscillation " meaning
For example along the amplitude of the oscillation of longitudinal axis Z be greater than or equal to 5mm.For example, power frequency is fixed and faradic
Intensity increases, until observing significant oscillation.
In view of the different critical value of frequency (or intensity), can be determined by testing with the Free Surface in collecting tank
Observe the difference of resonance to the resonance curve R in (frequency/intensity) corresponding frequency/strength plane at face.Use the song
Line R determines the variation range of intensity and/or frequency, to prevent or limit the resonance for the Free Surface for collecting tank occur.It is practical
On, resonance curve defines stable region and casting may become dangerous in range of instability.But modulate faradic frequency
Rate or intensity, to modulate the frequency f or amplitude peak in traveling magnetic fieldAllow to for example periodically temporarily close
Resonance curve R, while stilling remain in stable region.This can maximize the intensity of Lorentz force, to stir collecting tank, together
When still remain in acceptable security configuration.In fact, mixing effect is especially important near resonance curve.
Such resonance curve R depends on casting condition, the i.e. size, casting speed of ingot mold, the magnetic field of application
Configuration, the configuration in the magnetic field of the application depend on magnetic field generator, that is, depend on inductor or one depending on using or
Multiple permanent magnets.Resonance curve R is shown in Fig. 2, which is by being according to 45mm/ minutes casting speed cast thickness
What the ingot casting of 525mm × 1650mm obtained, apply magnetic field by three inductors to execute magnetic stirring, the three inductor cloth
It sets before the larger face of each of ingot casting and 90 ° of phase shift to form levels electromagnetic pump element, as described above.It also shows
The curve graph of the percentage (referred to as nominal force) of the intensity of Lorentz force is represented, 100% corresponds to when frequency is equal to 0.2Hz
When available faradic maximum intensity in a device.The intensity corresponds to resonate in 0.2Hz frequency.Preferably, feel
The intensity and frequency for answering electric current are positioned at some percentage by resonance curve and the intensity for representing nominal Lorentz force --- for example
The 10% of the intensity --- the space defined of curve in.
Preferably, the method includes changing the faradic frequency for flowing through inductor.Inventors have found that changing
Frequency is advantageous, this is because the variation in the infiltration of generated field can make force gradient in the thickness and depth of liquid well
On more effectively change.In addition, power electronic equipment makes the variation of frequency be faster than the variation of intensity；This is unstable pressureWeaker period provide additional freedom degree.In fact, by fluid dynamic characteristic time and solidification
Characteristic time decoupling is advantageous to avoid interval gross segregation.
Another example of curve is shown in FIG. 8, and will discuss in conjunction with the embodiments later.Fig. 2 and Fig. 8 show reality
It tests determining resonance curve R and represents the curve of Lorentz force, the intensity of the Lorentz force is equal to predetermined nominal
The 10% of Lorentz force.
The variation of one or more force parameters especially can permit alternating periods, during the period, dimensionless Hart
Graceful several Ha are low (usually less than 1) and height (typically larger than 3 or even 5) respectively.Dimensionless Harmann number Ha is that one kind is usually used in magnetic
The number in fluid dynamics field.It represents magnetic viscosity and the ratio between the viscosity of the charged liquid flowed in magnetic field.It should
Number is bigger, and the contribution of Lorentz force is bigger.Preferably, dimensionless Harmann number Ha is replaced with a ratio, and the ratio is extremely
Between few 3 or at least 5 low value and high level.Such configuration is preferably as it can be in the kinetic energy pair applied by magnetic field
The period of the free convection of resistant to liquids metal and the prevailing period alternating of free convection.
In conjunction with as described in example given below, compared with the method for the prior art, by according to the method for the present invention
The product of acquisition has limited interval gross segregation, even imperceptible.In the following embodiments, existed by analysis
The horizontal distribution curve (along axis TC) of the radiophotography carried out at half-breadth in fore-and-aft plane L/TC carries out the table of product
Sign calibrates these distribution curves to obtain the spatial distribution that Zn or Cu type is overlapped gold element.It is enriched with the absorbability of these heavy elements
Stronger area is shown as dim spot on the negative film for carrying out radiophotography, so that bright spot be presented on the radiophotography of display.It uses
The radiophotography of Al-Zn alloy exemplifies in Fig. 4 to obtain the implementation of the concentration profile of Zn.
Term L, TL and TC well known by persons skilled in the art correspond respectively to ingot casting along longitudinal axis size, claimed
For the axis and referred to as " strigula " axis along which of " long horizontal line (travers) ".
Addedly or alternatively, chemical analysis can be carried out along horizontal distribution curve, to quantify the chemical element
Along the spatial distribution of axis TC.Interval gross segregation is characterized in that the quality of alloying element is most significant in intermittent gross segregation
Area in maximum deviation (i.e. near T/2.5), the alloying element is Zn here.
In order to quantify interval gross segregation, as shown in Figure 5A, with spatial resolution 0.1mm concentration for the treatment of distribution curve, institute
Stating concentration profile is obtained by radiophotography or any other method.The distribution obtained with the resolution ratio of 0.1mm
Curve is original distribution curve, is labeled as distribution curve A.Sliding average more than 2mm can overcome microsegregation, obtained
Smooth distribution curve is marked as distribution curve B.Another of original distribution curve is more than that the sliding average of 50mm allows to
Overcome interval gross segregation, and obtain continuous gross segregation, distribution curve obtained is referred to as distribution curve C.By being distributed
Curve B subtracts distribution curve C to obtain the corrected distribution curve for corresponding to interval gross segregation, corrected distribution curve
It is marked as distribution curve D.Such distribution curve is shown in figure 5B.As in figure 5B as it can be seen that corrected distribution is bent
Line main representative interval gross segregation, and not by or hardly the continuous gross segregation of acceptor center and microsegregation are influenced.In this way
Corrected distribution curve can characterize interval gross segregation.
It is then possible to calculate the analysis area Z between T/2.3 and T/3.3AIn maximum concentration it is poor, this maximum difference
It can be indicated according to following equation:
ΔCZA=max (CZA)–min(CZA)(4)
Wherein max (CZA) and min (CZA) it is illustrated respectively in the element considered measured between T/2.3 and T/3.3 most
Big concentration and Cmin.
The element considered is the element that weight content is greater than or equal to 0.5% in alloy.Preferably, it can be alloy
Essential element, term " essential element " corresponds to the definition that provides of Aluminum Association.
Maximum difference Δ CZAThe nominal concentration C of the element considered can be passed through0Normalization.Product according to the present invention is excellent
Selection of land has less than 10%, and even more preferably less than 8%, even less than 6% this normalized rate value.However, Δ CZA
Absolute value may be by the property of product thickness, the element considered, especially its distribution coefficient and/or its concentration influence.Cause
This, is especially useful that characterization by the product obtained according to the method for the present invention, calculates reference area Z as referenceRMaximum
Difference, reference area ZRLess sensitive to the interval gross segregation between T/6 and T/12, this maximum difference can be with following
Equation indicate:
ΔCZR=max (CZR)–min(CZR)(5)
Wherein max (CZR) and min (CZR) it is illustrated respectively in the maximum of the element considered measured between T/6 and T/12
Concentration and Cmin.
Therefore, decentralized standard ε is obtained, decentralized standard ε can assess the interval gross segregation of considered element:
ε=Δ CZA/ΔCZR(6)
In order to overcome the localized variation of ingredient, it is advantageous that determine Δ CZAWith Δ CZR, to calculate at least five concentration distribution
The average value of curve, the concentration profile separate at least 10mm.
ε is lower, and interval gross segregation is not significant.Have by the product obtained according to the method for the present invention less than 3.3,
Preferably less than 3, more advantageously less than 2.5, or even more advantageously less than 2 and more preferably less than 1.5 decentralized standard ε.
According to nomenclature well known by persons skilled in the art, T/n indicates the distance along horizontal axis relative to ingot casting edge,
T/2 corresponds to the center of ingot casting.
It will by the nominal composition that the Fourier transform of the original distribution curve to ingredient analyze and pass through element
It is also useful that it, which is normalized,.This analysis can identify the space periodic of characterization interval gross segregation.Interval gross segregation
Period is 8 between 25mm.When interval gross segregation is very big, then observed within the scope of 8 to the space periodic between 25mm
The amplitude peak of Fourier component.The dimensionless standard ζ of spectral intensity has been determined, has corresponded to the pass the nominal of considered element
Concentration C0Amplitude peak of the normalized Fourier component within the scope of 8 to the space periodic between 25mm.Through the invention
The product that method obtains preferably has less than 0.01, preferably less than 0.007, and preferably less than 0.005 standard ζ.
Decentralized standard ε and spectral intensity standard ζ is advantageously applied to the essential element of considered alloy, for 7xxx's
Alloy is usually Zn, and the alloy for 2xxx is usually Cu.These standards can also be applied to the summation of two kinds of elements, such as
Zn+Cu in certain alloys of 7xxx is total and/or the alloy of 6xxx in Mg+Si summation.These standards can also be applied to close
The summation of two kind element of the single content greater than 0.5% of element of the weight content of gold more than or equal to 0.5% or alloy.
In the case where considering the summation of two kinds of elements, for normalizing maximum difference Δ CZAAnd/or Fourier transform
Value corresponds to the summation of the nominal concentration of considered element.
It can be used in casting or after forging by the ingot casting of the rectangular section obtained according to the method for the present invention,
Optionally can be after reinforced alloys solution heat treatment, quenching and aging to structure.Advantageously, by according to the method for the present invention
The ingot casting of the rectangular section of acquisition is rolled and/or forges.
Embodiment 1
The casting of AA7035 alloy is carried out in the case where no electromagnetic agitation.The ingredient of casting alloy includes nominal concentration
For the Zn of 5.6% weight, nominal concentration is the Mg of 1.3% weight.The specification of ingot casting is 1650mm × 525mm.This embodiment generation
It is presented with technology.The fining agent AlTiB 5:1 for being 1Kg/t with concentration carries out crystal grain refinement.Casting speed is 35mm/ minutes.Fig. 3
Radiophotography of the ingot casting in plane L/TC at half-breadth is shown, negative center gross segregation can be clearly identified on radiophotography
With interval gross segregation.Fig. 6 A shows Zn content along the different level original distribution curve of axis TC and by by Fig. 3
The sliding average of derivation is more than the smooth distribution curve B that 2mm is obtained.Radiophotography can quantify the member for causing to be contrasted with aluminium
Element is Zn in this case.This annotates the embodiment 2 being applied below to.Observe that negative center gross segregation exists with clearing
It is maximum at T/2, interval gross segregation is observed between T/2.3 and T/3.3.Fig. 6 B is shown in each smooth distribution curve
(distribution curve B) is subtracted represent the basic distribution curve (distribution curve C) of continuous gross segregation after obtain along axis TC
Zn content corrected different distributions curve (distribution curve D).
For Δ CZA, the maximum different value of Zn content is 0.75% weight, and for Δ CZRFor 0.19% weight, thus
The normalized maximum different value of analysis area and reference area is respectively 13.3% and 3.5%.The dispersion mark defined by equation (6)
Quasi- value ε is 3.9.The Fourier transform of each distribution curve is calculated, and in the nominal composition normalizing of 5.6% weight by Zn
It is illustrated in Fig. 7 after changing.Abscissa is represented 0 to the space periodic between 30mm.Observe correspond to be distributed in 8 to
The prominent peak value of difference between 25mm and specifically in 10mm to the different spaces period between 25mm.For be distributed song
Line, with the nominal concentration C for passing through Zn0It is normalized strong to the corresponding spectrum of the Fourier component amplitude peak between 25mm 8
The quasi- ζ of scale is at least 0.01.
Embodiment 2
In a second embodiment, the casting of AA7035 alloy is carried out under electromagnetic agitation.The ingredient of casting alloy includes mark
Concentration be referred to as 5.6% weight Zn and nominal concentration be 1.3% weight Mg.The specification of ingot casting is 1650mm × 525mm.With dense
The fining agent AlTiB5:1 that degree is 1Kg/t carries out crystal grain refinement.Casting speed is 35mm/ minutes.By in each face of ingot casting
Opposite (the plane YZ corresponding to coordinate system shown in Figure 1A) setting of L/TL has flowed through alternating current, along longitudinal axis
Three inductors of Z orientation obtain electromagnetic agitation, and the alternating current has the frequency of 0.25Hz, and three inductors are relative to that
60 ° of this phase shift and it is spaced 0.6m, to form electromagnetism pump element.The distance between inductor and ingot casting are 172mm.The electricity
Every one side of magnetic pump element orients in opposite direction.Inductor generates traveling magnetic field on the horizontal level, and axis of travel is parallel
In direction TL, wavelength X is 3.6m.By the nominal value of the electric current in modification inductor, the long-range navigation incuded in liquid collecting tank
Hereby the maximum intensity of power is with 2N.m-3.s-1Pace of change from about 180N/m3Change to 240N/m3.Corresponding to these cast bars
The resonance curve of part is shown in fig. 8.Faradic Strength Changes are represented by double-head arrow in this figure.
Fig. 9 shows radiophotography of the ingot casting in plane L/TC, and the negative center at T/2 can be identified on radiophotography
Gross segregation.Figure 10 A is shown along the different level original distribution curve (distribution curve A) of the Zn content of axis TC and smooth
Distribution curve (distribution curve B).Negative center gross segregation is distinguished, it is maximum at T/2.Figure 10 B, which is shown, is subtracting correspondence
The Zn content along axis TC of the corrected distribution curve type obtained after the distribution curve of continuous gross segregation
Different level distribution curve (distribution curve D).
For Δ CZA, the maximum different value of Zn content is 0.24% weight, for Δ CZRFor 0.28% weight, analysis area
Normalized maximum different value with reference area is respectively 4.3% and 5%.Such as the decentralized standard value ε defined by equation (6)
Interval gross segregation in analysis area between 0.9:T/2.3 and T/3.3 is removed.Calculate the Fourier of each distribution curve
Transformation, and be illustrated in Figure 11 after through the normalization of the nominal composition of 5.6% weight of Zn.Abscissa is represented 0
To the space periodic between 30mm.No longer observe prominent peak value.For all distribution curves, with the nominal concentration C for passing through Zn0
Normalized 8 to the corresponding spectral intensity standard ζ of Fourier component amplitude peak between 25mm is at least 0.05.
Embodiment 3
In this embodiment, the casting of AA7050 alloy is carried out in the case where no electromagnetic agitation.The ingredient of alloy is
The Cu of the Zn of 6.3% weight, the Mg of 2.2% weight and 2.1% weight.The specification of ingot casting is 1650 × 525mm.Use fining agent
AlTiC 3:0.15 carries out crystal grain refinement, and addition ratio is 1Kg/ tons.Casting speed is 45mm/ minutes.It constitutes embodiment 4
With reference to.
Figure 12 shows radiophotography of the ingot casting in plane L/TC, can identify on radiophotography in negative at T/2
Heart gross segregation.Figure 13 a shows the summation of two kinds of elements Zn and Cu along axis TC by the radiophotography derivation of Figure 12
Smooth level distribution curve (distribution curve B).In fact, radiophotography can only quantify the member for causing to be contrasted with aluminium
Element is Zn and Cu in this case.This annotates the embodiment 4 and 5 being applied below to.Figure 13 b, which is shown, is subtracting correspondence
The Zn+Cu concentration along axis TC of the corrected distribution curve type obtained after the distribution curve of continuous gross segregation
Different level distribution curve (distribution curve D).For Δ CZA, the maximum different value of Zn+Cu summation is 0.81% weight, for
ΔCZRFor 0.19% weight.Such as the decentralized standard value ε defined by equation (6) is 4.4.Figure 14 is shown by Zn and Cu
8.3% weight nominal composition summation normalization after each distribution curve Fourier transform.Abscissa represent 0 to
Space periodic between 30mm.It is normalized 8 to the Fourier between 25mm with the summation of the nominal composition by Zn and Cu
The corresponding spectral intensity standard ζ of component amplitude peak is greater than 0.01 for one in distribution curve or for all distribution curve
Greater than 0.007.
Embodiment 4
In this embodiment, the casting of AA7050 alloy is carried out.The ingredient of alloy is the Zn of 6.3% weight, 2.2% weight
Mg and 2.1% weight Cu.The section of ingot casting is 1650 × 525mm.It is thin that crystal grain is carried out using fining agent AlTiC 3:0.15
Change, addition ratio is 1Kg/ tons.Casting speed is 45mm/ minutes.(correspond to figure by the opposite of each face L/TL in ingot casting
The plane YZ of coordinate system shown in 1A) setting flows through alternating current, obtains electricity along three coils of axis Z orientation
Magnetic stirring, alternating current is in intermediate coil relative to 90 ° of electric current phase shift in end coil.The wavelength of traveling field is 2.4m.By
This electromagnetism pump element obtained is mirrored into arrangement relative to each face L/TL of ingot casting, and direction of travel is parallel to long crossline direction,
The traveling of generation dissipates from the half-breadth of ingot casting.It is obtained by applying the cyclically-varying for the frequency of alternating current for flowing through coil
Unstable pressure, as Figure 15 frequency and intensity map in double-head arrow shown in.Therefore, by 0.450 between 0.600Hz
The maximal density of Lorentz force that generates of frequency variation in the period of 3 minutes in from about 110N/m3Change to 150N/m3, this
Correspond approximately to 0.22N/m3The pace of change of/s.
Figure 16 shows radiophotography of the ingot casting in plane L/TC, can identify on radiophotography in negative at T/2
Heart gross segregation.Interval gross segregation is greatly attenuated relative to reference to (Figure 12), as shown in Figure 17 a and 17b.
Figure 17 a shows the smooth water of the element summation of the Zn+Cu along axis TC derived from the radiophotography of Figure 16
Flat distribution curve (distribution curve B).Figure 17 b, which is shown, to be obtained after subtracting the distribution curve corresponding to continuous gross segregation
Different level distribution curve (the distribution of the summation of two kinds of elements Zn and Cu along axis TC of corrected distribution curve type
Curve D).For Δ CZA, the maximum different value of Zn+Cu content is 0.30%, for Δ CZRIt is 0.14%.Such as pass through equation
(6) the decentralized standard value ε defined is 2.2.Therefore, in the summation normalization of the nominal composition of 8.3% weight by Zn and Cu
Later, the interval gross segregation in analysis area is reduced and is illustrated in Figure 18.Abscissa is represented 0 between 30mm
Space periodic.For all distribution curves, with the summation of the nominal composition by Zn and Cu it is normalized 8 between 25mm
The corresponding spectral intensity standard ζ of Fourier component amplitude peak is less than 0.005.
Embodiment 5
In this embodiment, the casting of AA7050 alloy is carried out.The ingredient of alloy is the Zn of 6.3% weight, 2.2% weight
Mg and 2.1% weight Cu, the content of other elements is both less than 0.5% weight.The section of ingot casting is 1650 × 525mm.
Crystal grain refinement is carried out using fining agent AlTiC 3:0.15, addition ratio is 1Kg/ tons.Casting speed is 45mm/ minutes.Pass through
There are alternating current, edge in opposite (the plane YZ corresponding to coordinate system shown in Figure 1A) the setting circulation of each face L/TL of ingot casting
Three coils of axis Z orientation obtain electromagnetic agitation, alternating current in intermediate coil relative to the electricity in end coil
90 ° of phase shift of stream.The wavelength of traveling field is 2.4m.Thus obtained electromagnetism pump element is mirrored into relative to each face L/TL of ingot casting
Arrangement, direction of travel are parallel to long crossline direction, and the traveling of generation dissipates from the half-breadth of ingot casting.
Apply zero-based variation by intensity to the alternating current for flowing through coil, obtains unstable strong
System, as Figure 19 frequency and intensity map in arrow shown in.Therefore, the maximum unit body of the Lorentz force generated by Strength Changes
The intensity of product power is in 4 minutes usually from 0N/m3Change to 140N/m3, this corresponds to 0.58N/m3The pace of change of/s.With
Afterwards, the intensity of the maximum unit body force of Lorentz force is in 5 minutes from 140N/m3Change to 360N/m3, this corresponds to
0.73N/m3The pace of change of/s.
(intensity is from 0N/m in 4 minutes by Figure 20 a for result obtained3Change to 140N/m3) and Figure 21 a (at 5 minutes
Internal force is from 140N/m3Change to 360N/m3) shown in the longitudinal sections of continuous two radiophotographies each other illustrate.
Figure 20 b shows the flat of the summation of the essential element Zn+Cu along axis TC derived from the radiophotography of Figure 20 a
Slip level distribution curve (distribution curve B).Figure 20 c is shown to be obtained after subtracting the distribution curve corresponding to continuous gross segregation
Different level distribution curve (the distribution of the summation of the element Zn+Cu along axis TC of the corrected distribution curve type obtained
Curve D).For Δ CZA, the maximum different value of the content of Zn+Cu is 0.70% weight, for Δ CZRIt is 0.22%.Such as by
The decentralized standard value ε that equation (6) defines is 3.2.Figure 20 d is shown in the nominal composition by 8.3% weight of Zn and Cu
The Fourier transformation of each distribution curve after summation normalization.Abscissa is represented 0 to the space periodic between 30mm.For
All distribution curves, with the summation by the nominal composition of Zn and Cu it is normalized 8 to the Fourier component between 25mm most
Significantly corresponding spectral intensity standard ζ is less than 0.01.It is noted, however, that the value that spectral intensity standard ζ is shown is greater than 0.005.
Figure 21 b shows the flat of the summation of the essential element Zn+Cu along axis TC derived from the radiophotography of Figure 21 a
Slip level distribution curve (distribution curve B).Figure 21 c is shown to be obtained after subtracting the distribution curve corresponding to continuous gross segregation
The different level distribution curve of the summation of the essential element Zn+Cu along axis TC of the corrected distribution curve type obtained
(distribution curve D).For Δ CZA, the maximum different value of the content of Zn+Cu is 0.37% weight, for Δ CZRIt is 0.15%.Example
It is such as 2.4 by the decentralized standard value ε that equation (6) defines.Figure 21 d show by 8.3% weight of Zn and Cu it is nominal at
The Fourier transformation of each distribution curve after the summation normalization divided.Abscissa is represented 0 to the space week between 30mm
Phase.It is normalized 8 to the Fourier between 25mm with the summation of the nominal composition by Zn and Cu for all distribution curves
The corresponding spectral intensity standard ζ of component amplitude peak is less than 0.005.
Therefore it observes, if power is greater than 140N/m3, then the inhibition of interval gross segregation is improved.In fact, working as power
When too weak, observe that the decentralized standard value ε of spectral intensity ζ is greater than preferred value of the invention.Therefore, it has been recognised by the inventors that by periodicity
Interval gross segregation cannot advantageously be inhibited by interrupting the unstable pressure that traveling field generates.
Claims (16)
1. the method includes following steps for the method for the cast aluminium alloy gold ingot casting in general rectangular ingot mold
It is rapid:
Prepare aluminium alloy；
Along the longitudinal axis of casting, cast aluminium alloy gold during casting passes through the metal with solidification in the ingot mold
The cooling alloy of the trickling of the coolant liquid of contact；
During casting, apply amplitude (B0) according to the periodically variable magnetic field of frequency (f), the magnetic field is by being arranged in the casting
Ingot mould tool around at least one magnetic field generator generate, so as in process of setting in the difference of the liquid portion of the alloy
Apply Lorentz force (F) at point；
The magnetic field applied is the traveling magnetic field propagated along propagation axis, so that the amplitude peak in the magnetic field
It is propagated along the propagation axis, while limiting and propagating wavelength (λ), the traveling magnetic field causes the Lorentz force of maximum intensity
(Fmax) propagated along the propagation axis；
The method is characterized in that, determines the Lorentz force (F of maximum intensitymax) magnetic parameter (Δ in predetermined time interval
T) in be it is variable, to obtain the Lip river to the maximum intensity propagated along the propagation axis in the time interval
Lun Zili (Fmax) modulation, the magnetic parameter is referred to as force parameter, and the parameter is:
The amplitude peak in the magnetic field
And/or the frequency (f) in the magnetic field；
And/or the propagation wavelength (λ) in the magnetic field.
2. according to the method described in claim 1, wherein the section of the ingot mold define in a horizontal plane thickness (e) and
Length (l), the thickness are less than or equal to the length, and the thickness is greater than 300mm and is preferably at least 400mm.
3. method according to any of the preceding claims, wherein the frequency in the magnetic field be less than 5Hz or 2Hz or
1Hz。
4. method according to any of the preceding claims, wherein the maximum intensity propagated along the propagation axis
Lorentz force (Fmax) in time interval between 20 seconds to 10 minutes at least 30N.m-3Variation.
5. method according to any of the preceding claims, wherein the magnetic field makes in the time interval (Δ t)
The absolute value of period, the variable density of maximum Lorentz force are greater than or equal to 0.05N.m-3.s-1。
6. method according to any of the preceding claims, wherein the propagation axis of the amplitude peak in the magnetic field is flat
Row is in the plane of casting direction.
7. method according to any of the preceding claims, wherein the variation of the force parameter is week during casting
Phase property, the period between 20 seconds to 20 minutes, or between 1 minute to 15 minutes, or between 2 minutes to 10 minutes.
8. method according to any of the preceding claims is referred to as felt wherein the generator is electromagnetic inductor
Answer the electric current flowing of electric current by each electromagnetic inductor, the method includes during the time interval:
Change the faradic intensity；
And/or change the faradic frequency；
And/or change the distance between electromagnetic inductor and the ingot mold.
9. according to the method described in claim 8, including the faradic intensity or frequency that change flows through inductor, institute
The method of stating includes:
It is defined on the Free Surface (1 of the aluminium alloy flowed in the ingot moldsup) on generate resonance wave it is faradic
The preliminary step of at least one of intensity and frequency critical value；
The variation range of the faradic intensity or frequency is determined according to the critical value predetermined.
10. according to the method described in claim 9, including defining the faradic intensity during the preliminary step
It is bent to define the resonance of intensity value and frequency values for the resonance for representing the generation Free Surface with multiple critical values of frequency
Line (R), the method includes the faradic intensity or frequency are determined in the range of being defined by the resonance curve
Variation range.
11. method according to any one of claims 1-7, wherein at least one generator is permanent magnet, the method
Include:
Change the distance between the permanent magnet and the ingot mold；
And/or the rotation permanent magnet, and change the rotation speed of the magnet；
And/or two permanent magnets of rotation.
12. method according to any of the preceding claims, wherein the aluminium alloy be selected from 2XXX, 5XXXX, 6XXX or
The alloy of 7XXX series and the wherein thickness are at least 400mm or 450mm.
13. method according to any of the preceding claims, wherein in the time interval (in Δ t), in the conjunction
At at least one point of the liquid portion of gold, dimensionless Harmann number changes at least 3 times, or even 5 times of variation.
14. aluminium alloy cast ingot is obtained by method described in any one of claims 1 to 13.
15. aluminium alloy cast ingot according to claim 14, which is shown, and the weight of the alloy is contained
Amount is greater than a kind of 0.5% element, or the summation of two kinds of elements for the single weight content of the alloy greater than 0.5%,
Decentralized standard is less than 3.3, and preferably less than 3, more advantageously less than 2.5, still more advantageously less than 2 and more preferably less than 1.5,
The decentralized standard is defined according to following expression formula:
ε=Δ CZA/ΔCZR(6)
ΔCZA=max (CZA)–min(CZA)(4),
ΔCZR=max (CZR)–min(CZR)(5),
Wherein:
-max(CZA) and min (CZA) it is illustrated respectively in the member considered measured in the analysis area with interval gross segregation (ZA)
The maximum concentration and Cmin of element or the summation of two kinds of elements considered, the analysis area for example T/2.3 and T/3.3 it
Between；
-max(CZR) and min (CZR) be illustrated respectively in and be considered being influenced to measure in small reference area (ZR) by interval gross segregation
The maximum concentration and Cmin of the summation of the element considered or the two kinds of elements considered, the reference area is for example in T/6
Between T/12；
The concentration is surveyed at least one distribution curve established at the half-breadth in fore-and-aft plane L/TC and on the direction TC
Amount, the distribution curve represents the interval gross segregation of the considered element on the direction TC.
16. the spectral intensity standard (ζ) of aluminium alloy cast ingot according to claim 14 or 15, the aluminium alloy cast ingot is less than
0.01, preferably less than 0.007 and even more preferably less than 0.005, the spectral intensity standard passes through following calculating:
Determine two elements that the single content of element of the weight content greater than 0.5% or alloy that represent alloy is greater than 0.5%
Summation interval gross segregation distribution curve Fourier transformation amplitude peak, the distribution curve is in the direction
It is established on TC, the amplitude peak determines within the scope of 8 to the spatial period between 25mm；
Pass through the nominal concentration C of the element0Or described in the summation normalization of the nominal concentration of two by being considered kinds of elements
Amplitude peak.
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| FR1654834A FR3051698B1 (en) | 2016-05-30 | 2016-05-30 | METHOD OF MANUFACTURING LAMINATION INGOTS BY VERTICAL CASTING OF AN ALUMINUM ALLOY |
| FR1654834 | 2016-05-30 | ||
| PCT/FR2017/051195 WO2017207886A1 (en) | 2016-05-30 | 2017-05-17 | Method for producing sheet ingots by vertical casting of an aluminium alloy |
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| US3842895A (en) * | 1972-01-10 | 1974-10-22 | Massachusetts Inst Technology | Metal alloy casting process to reduce microsegregation and macrosegregation in casting |
| EP0100289A2 (en) * | 1982-07-23 | 1984-02-08 | Cegedur Societe De Transformation De L'aluminium Pechiney | Process for the electromagnetical casting of metals using at least one magnetical field differing from another bordering magnetical field |
| JPS61253153A (en) * | 1985-05-02 | 1986-11-11 | Kobe Steel Ltd | Production of hot workable phosphor-bronze |
| CN1059484A (en) * | 1990-06-13 | 1992-03-18 | 艾尔坎国际有限公司 | The apparatus and method of direct-chill casting ingot |
| CN1329526A (en) * | 1998-12-01 | 2002-01-02 | Abb股份有限公司 | A method and device for continuous casting of metals |
| CN1425519A (en) * | 2002-10-25 | 2003-06-25 | 东北大学 | Aluminium alloy low frequency electromagnetic oscillation semicontinuous casting crystal grain fining method and device |
| WO2009018810A1 (en) * | 2007-08-03 | 2009-02-12 | Forschungszentrum Dresden - Rossendorf E.V. | Method and device for the electromagnetic stirring of electrically conductive fluids |
| WO2009096791A1 (en) * | 2008-02-01 | 2009-08-06 | Stichting Netherlands Institute For Metals Research | Method and apparatus for control of macrosegregation during solidification of a metallic alloy |
| EP2682201A1 (en) * | 2011-03-03 | 2014-01-08 | Federal'Noe Gosudarstvennoe Avtonomnoe Obrazovatel 'Noe Uchrethdenie Vysshego Professional'Nogo Obrazovanija"Sibirskij Federal'NYJ Universitet" | Method and apparatus for the continuous casting of aluminium alloys |
| CN103600045A (en) * | 2013-11-18 | 2014-02-26 | 上海大学 | Continuous steel casting process and device with function of electromagnetic excitation compound mechanical stirring |
| WO2014155357A1 (en) * | 2013-03-28 | 2014-10-02 | Evgeny Pavlov | Method and apparatus for moving molten metal |
| CN105057622A (en) * | 2015-08-21 | 2015-11-18 | 中南大学 | Method and device for restraining macrosegregation of cast aluminum alloy cast ingots in direct chill (DC) casting |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5246060A (en) | 1991-11-13 | 1993-09-21 | Aluminum Company Of America | Process for ingot casting employing a magnetic field for reducing macrosegregation and associated apparatus and ingot |
-
2016
- 2016-05-30 FR FR1654834A patent/FR3051698B1/en active Active
-
2017
- 2017-05-17 US US16/096,780 patent/US20210220905A1/en not_active Abandoned
- 2017-05-17 RU RU2018145016A patent/RU2018145016A/en not_active Application Discontinuation
- 2017-05-17 CA CA3024166A patent/CA3024166A1/en not_active Abandoned
- 2017-05-17 CN CN201780033894.6A patent/CN109311081A/en active Pending
- 2017-05-17 ES ES17731208T patent/ES2858125T3/en active Active
- 2017-05-17 EP EP17731208.9A patent/EP3463716B1/en active Active
- 2017-05-17 WO PCT/FR2017/051195 patent/WO2017207886A1/en unknown
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3842895A (en) * | 1972-01-10 | 1974-10-22 | Massachusetts Inst Technology | Metal alloy casting process to reduce microsegregation and macrosegregation in casting |
| EP0100289A2 (en) * | 1982-07-23 | 1984-02-08 | Cegedur Societe De Transformation De L'aluminium Pechiney | Process for the electromagnetical casting of metals using at least one magnetical field differing from another bordering magnetical field |
| JPS61253153A (en) * | 1985-05-02 | 1986-11-11 | Kobe Steel Ltd | Production of hot workable phosphor-bronze |
| CN1059484A (en) * | 1990-06-13 | 1992-03-18 | 艾尔坎国际有限公司 | The apparatus and method of direct-chill casting ingot |
| CN1329526A (en) * | 1998-12-01 | 2002-01-02 | Abb股份有限公司 | A method and device for continuous casting of metals |
| CN1425519A (en) * | 2002-10-25 | 2003-06-25 | 东北大学 | Aluminium alloy low frequency electromagnetic oscillation semicontinuous casting crystal grain fining method and device |
| WO2009018810A1 (en) * | 2007-08-03 | 2009-02-12 | Forschungszentrum Dresden - Rossendorf E.V. | Method and device for the electromagnetic stirring of electrically conductive fluids |
| WO2009096791A1 (en) * | 2008-02-01 | 2009-08-06 | Stichting Netherlands Institute For Metals Research | Method and apparatus for control of macrosegregation during solidification of a metallic alloy |
| EP2682201A1 (en) * | 2011-03-03 | 2014-01-08 | Federal'Noe Gosudarstvennoe Avtonomnoe Obrazovatel 'Noe Uchrethdenie Vysshego Professional'Nogo Obrazovanija"Sibirskij Federal'NYJ Universitet" | Method and apparatus for the continuous casting of aluminium alloys |
| WO2014155357A1 (en) * | 2013-03-28 | 2014-10-02 | Evgeny Pavlov | Method and apparatus for moving molten metal |
| CN103600045A (en) * | 2013-11-18 | 2014-02-26 | 上海大学 | Continuous steel casting process and device with function of electromagnetic excitation compound mechanical stirring |
| CN105057622A (en) * | 2015-08-21 | 2015-11-18 | 中南大学 | Method and device for restraining macrosegregation of cast aluminum alloy cast ingots in direct chill (DC) casting |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2017207886A1 (en) | 2017-12-07 |
| EP3463716A1 (en) | 2019-04-10 |
| ES2858125T3 (en) | 2021-09-29 |
| RU2018145016A (en) | 2020-07-09 |
| FR3051698A1 (en) | 2017-12-01 |
| FR3051698B1 (en) | 2020-12-25 |
| US20210220905A1 (en) | 2021-07-22 |
| CA3024166A1 (en) | 2017-12-07 |
| EP3463716B1 (en) | 2021-02-17 |
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