CN100345647C - Continuous casting method for steel - Google Patents
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- CN100345647C CN100345647C CNB2004800095773A CN200480009577A CN100345647C CN 100345647 C CN100345647 C CN 100345647C CN B2004800095773 A CNB2004800095773 A CN B2004800095773A CN 200480009577 A CN200480009577 A CN 200480009577A CN 100345647 C CN100345647 C CN 100345647C
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Abstract
At least three electromagnets are disposed along the longitudinal direction of a mold. While the electromagnets generate a vibrating magnetic field, peak positions of the vibrating magnetic field is shifted in the longitudinal direction of the mold.
Description
Technical field
The present invention relates to the continuous casing of steel, particularly relate to not, improve the continuous casing of the steel of the MOLTEN STEEL FLOW in the casting mold by applying magnetic field from providing the mouth of a river of molten steel to be blown into inactive gas with casting mold (below be called casting mold) to continuous casting.
Background technology
In recent years based on automotive sheet, strong request improves the quality of steel part, develops into from the slab stage and just requires the good high-quality slab of degree of purity.As the method for making such high-quality slab, open the spy and to have delivered in the flat 11-100611 communique by the field trash fusing point that is contained in the molten steel is reduced, prevent to be used for providing the obstruction of the submersed nozzle of molten steel to casting mold, be not blown into argon inactive gas such as (Ar), the no gas foundry engieering that molten steel is cast continuously from the mouth of a river.
Like this, when not being blown into inactive gas and casting continuously,,, can improve the characteristic on surface so compare with the situation that is blown into gas owing on the casting billet surface that obtains, do not capture bubble.Have because of the liquid steel temperature in the casting mold reduces, cause solidifying of crystallizer protecting residue (mold flux) in the part, it is rolled in the molten steel, becomes the problem of the reason of internal flaw.Require the characteristic on surface further to improve in addition.
And in the defective of slab, have cause because of field trash and bubble with invar water in the defective that causes of component segregation, molten steel flow in the casting mold has been carried out a lot of research and invention owing to them substantial connection is arranged all the time.One of them is the method with the MOLTEN STEEL FLOW in the magnetic field control casting mold.
For example (A) is as the method for stack D.C. magnetic field on the shifting magnetic field, the spy open delivered in the flat 10-305353 communique will clip the long limit of casting mold and the pole configuration of relative two sections at the back side on the long limit of casting mold, (a) form the direct current magnetostatic field and exchange the magnetic field that the shifting magnetic field superposes being configured on the magnetic pole of downside, or (b) form the direct current magnetostatic field and exchange the magnetic field that the shifting magnetic field superposes being configured on the magnetic pole of upside, on being configured in the magnetic pole of downside, apply the method for MOLTEN STEEL FLOW in the control casting mold of direct current magnetostatic field.
Delivered in No. 3067916 communique of this external special permission by suitable Linear Driving is flow through with DC current with alternating current and braking and a plurality of electric windings has been set, the device of the MOLTEN STEEL FLOW in the control casting mold.
This external spy opens to have delivered in the flat 5-154623 communique phase place is departed from the method that flows in the control casting mold of 120 interchange shifting magnetic fields of spending and the stack of direct current magnetostatic field respectively.
Open to have delivered in the flat 6-190520 communique the spy and utilize the magnet that is arranged on above the submersed nozzle tap hole, act on the whole width after making the stack of magnetostatic field and high frequency magnetic field, utilize the magnet that is arranged on the tap hole below simultaneously, make the casting method of the steel of magnetostatic field effect.
(B) as the method that makes the combination of top D.C. magnetic field and shifting magnetic field, bottom, open the position of having delivered in the clear 61-193755 communique the spy and apply magnetostatic field surrounding the steel flow thigh that flows out from submersed nozzle, flow velocity is reduced, more electromagnetic mixing apparatus is being set, the electromagnetic agitation method that stirs in the horizontal direction than magnetostatic field simultaneously by the position in downstream.
(C) as the method that makes the combination of shifting magnetic field, top and bottom D.C. magnetic field, open the spy and to have delivered in the flat 6-226409 communique by the pole core center being arranged on from the liquid level to the flow export magnet between (more than downward 50 degree), make the shifting magnetic field effect, simultaneously by pole core being arranged on the casting method that makes the magnetostatic field effect than submersed nozzle by the magnet of bottom.
This external spy opens to have delivered in the flat 9-262651 communique and by top electromagnetic agitation magnet is being set than submersed nozzle lower end, than submersed nozzle lower end the magnet that can apply shifting magnetic field and magnetostatic field is being set by the bottom, different according to steel grade and casting speed are used the casting method of magnetostatic field and shifting magnetic field flexibly.
Open to have delivered in the 2000-271710 communique the spy and in submersed nozzle, be blown into Ar gas and during cast steel, making magnetic flux density is that the above magnetostatic field of 0.1 tesla acts on the steel flow thigh after coming out from submersed nozzle, use the electromagnetic mixing apparatus continuous stirring at an upper portion thereof, or make the periodically variable method of mixing direction.
Open to have delivered in the clear 61-140355 communique the spy and have the magnetostatic field that disposes so that the steel flow thigh that provides in the one side direction casting mold of the long limit of casting mold to be provided, dispose the shifting magnetic field generating apparatus up, the upper surface that makes molten steel is from the casting mold of horizontal cross-section mediad minor face one side flow and the structure of casting mold top.
Open to have delivered in the clear 63-119959 communique the spy and be provided with the electromagnetic mixing apparatus that in molten steel, produces bottom horizontal flow sheet on mold top, be provided with in the mold bottom and be used to make the electromagnetic brake that slows down from the stream thigh of the outflow of submersed nozzle, the technology of the stream thigh that control is flowed out from submersed nozzle.
The liquid steel level of having delivered in casting mold in No. 2856960 communique of special permission uses magnetostatic field, uses the linear pattern mouth of a river as the continuous casting mouth, uses the magnetic field of advancing flowing out oral area, the control technology of the MOLTEN STEEL FLOW in the casting mold of magnetostatic field is used in its underpart.
(D) as the method that applies D.C. magnetic field separately, the spy open delivered in the flat 3-258442 communique be oppositely arranged in the long limit of casting mold one side, with the electromagnetic brake of the almost identical electromagnet effect magnetostatic field of length with long limit.
The spy open delivered in the flat 8-19841 communique from casting mold width central authorities to than casting mold minor face assigned position in the inner part near both ends, will magnetic pole bent to casting mold top one lateral bending or that tilt be arranged on the width central part than submersed nozzle tap hole by under the position, by making the effect of D.C. magnetic field or low-frequency ac magnetic field, the method for the MOLTEN STEEL FLOW in the control casting mold.
In international publication WO95/26243 communique, delivered whole width and will have substantially uniformly that the D.C. magnetic field of magnetic flux distribution is applied on the casting mold thickness direction along casting mold, control the stream thigh that flows out from submersed nozzle, thereby the meniscus flow velocity is controlled at the technology of 0.20～0.40m/s.
Open to have delivered in the flat 2-284750 communique the spy and make the uniform magnetostatic field of casting mold thickness direction act on the whole width of strand, act on the upper and lower of submersed nozzle tap hole, effectively the steel flow thigh is applied brake force, make the uniform technology that flows.
(E) as the method that applies D.C. magnetic field or shifting magnetic field, open the spy and to have delivered in the flat 9-262650 communique by DC current being flow through be located at a plurality of windings of the bottom of submersed nozzle tap hole, apply magnetostatic field, or by flowing through alternating current, apply the shifting magnetic field, control the casting method of MOLTEN STEEL FLOW.
Delivered among this external " material and technology " vol.3 (1990) p256 by making the interchange shifting magnetic field act on the stream thigh that flows out from submersed nozzle, made the steel flow thigh braking (so-called EMLS) of outflow or quicken the technology of (so-called EMLA).
(F) as the method that only applies the shifting magnetic field, open when having delivered the MOLTEN STEEL FLOW of utilizing in the electromagnetic induction control casting mold in the flat 8-19840 communique the spy, molten steel is applied the technology of the static AC magnetic field of frequency 1～15Hz.
In " iron and steel " 66 (1980) p797, delivered in slab caster, utilized electromagnetic agitation to obtain along the technology (so-called M-EMS) of the molten steel rotating flow thigh of the horizontal direction of mould wall.
The technology with these (A)～(F) has following problem: can be involved in crystallizer protecting residue (mold power), maybe can not prevent to capture the field trash of shifting to the freezing interface, can not fully improve slab surface quality.Therefore studied the technology in the magnetic field (below be called oscillating magnetic field) of the direction periodic inversion of Lorentz force.
(G) as the method that only applies oscillating magnetic field, in No. 2917223 communique of special permission, delivered the low-frequency ac stationary magnetic field that does not move in time is provided, by in the time will solidifying, excite the low frequency electromagnetic vibration at once, make the ingotism of the column of solidifying the front cataclasm, swim in the melt metal, the method that is conceived to make the solidified structure miniaturization and reduces center segregation, but the effect that reduces the casting billet surface defective is very little.
Summary of the invention
Strong request in recent years improves surface quality and reduces cost, and wishes further to improve the surface and the inner quality of strand, and the MOLTEN STEEL FLOW of controlling effectively in the casting mold becomes very necessary.
The present invention is the invention of carrying out in order to solve existing issue; its objective is the continuous casing that a kind of steel is provided; not when submersed nozzle is blown into inactive gas and casts continuously; can suppress to be involved in crystallizer protecting residue; the internal soundness of strand is improved; can suppress simultaneously field trash and bubble to the capture of solidifying core, improve cc billet surface quality.
In order to reach this purpose, limit the velocity flow profile of the not solidified molten steel in the casting mold in the present invention.Just by near thickness (short side direction of the casting mold just) central authorities of strand, molten steel flow speed being reduced; suppress being involved in of crystallizer protecting residue; near freezing interface near the wall of casting mold; molten steel flow speed is increased; obtain the clean effect of field trash and bubble, suppress to the capture of solidifying core.
Be not blown into inactive gas and when casting from the submersed nozzle that molten steel is provided to casting mold in the present invention, use electromagnetic agitation to make liquid steel temperature homogenising in the casting mold.Therefore be defined in the distribution of molten steel flow speed of minor face (thickness of the strand just) direction of casting mold.Just near the thickness central authorities of steel billet, molten steel flow speed is reduced, suppress being involved in of crystallizer protecting residue, make molten steel carry out local flowing, prevent to capture bubble and field trash, reduce the blemish of strand near the freezing interface of the wall of casting mold.
As its method, be necessary to try every possible means applying on the method for AC magnetic field, carry out the result of model experiment and analog computation, obtain to draw a conclusion.
Open shown in the flat 6-190520 communique as the spy, the long-pending skin effect of utilization electric current in the magnetic field of the thickness direction of strand, make Lorentz force concentrate on the surface of freezing interface or molten steel, only can't effectively Lorentz force only be concentrated on the freezing interface with this, make Lorentz force concentrate on the freezing interface, must control the magnetic line of force and distribute.
As its method, at the electromagnet that width (the long limit of casting mold just) the direction configuration phase of strand is alternately reversed, it alternately is effective making it.Thickness direction at strand makes under the situation of magnetic field vibration, owing to electromagnetic force can not be concentrated on the casting mold wall, just electromagnetic force can not be concentrated on the freezing interface, so be necessary to make the magnetic field vibration at the width of casting mold.Wherein must reverse, so phase place must differ more than 130 ° owing to the current phase of switching on to the electromagnet that replaces is actual.
On the other hand, the structure of winding as shown in Figure 1, the width that the winding that flows through alternating current (hereinafter referred to as exchanging winding) is wound at strand has on the interdigitated electrode structure iron core of three above magnetic poles, and, can make the magnetic field vibration of width by in fact adjacent current phase is reversed.In Fig. 1, the 10th, casting mold, the 12nd, submersed nozzle, the 14th, molten steel (oblique line partly is a low-speed region).If the underfrequency of alternating current can not excite fully and flow at this moment, as too high, then not servo-actuated of molten steel is that 1Hz is to 8Hz in electromagnetic field so be fit to scope.
Utilize such electromagnet can produce and draw back the flowing of direction of molten steel, and, do not make ingotism cataclasm, can obtain cleaning the effect of freezing interface because the flow velocity of the molten steel that is excited is low from solidifying the front.In Fig. 2 (front view), Fig. 3 (along the horizontal sectional view of the III-III line of Fig. 2), Fig. 4 (along the vertical cross-section diagram of the IV-IV line of Fig. 2), represent that schematically quantity for magnetic pole 28 is under four the situation, resolve and the example of the MOLTEN STEEL FLOW that the analytical Calculation that flows causes with oscillating magnetic field of the present invention according to electromagnetic field.III-III line among Fig. 2 is by the center of magnetic pole 28 in addition.Arrow a among Fig. 2 represents casting direction, and b represents the long side direction of casting mold, and c represents the local flow of molten steel 14.Arrow d among Fig. 3 represents the short side direction of casting mold.
As shown in Figure 5, the direction that flows that produces corresponding to the Lorentz force shown in the following formula is identical in the present invention, and only flow velocity V changed with half the cycle that applies electric current I.
F∝J×B ……(1)
Wherein J is an induced-current, and B is magnetic field.
If make exchange winding around on the contrary, even the phase place of electric current is identical, also can make the phasing back in magnetic field.
In No. 2917223 communique of special permission, delivered the low-frequency ac stationary magnetic field that does not move in time is provided; by exciting low frequency electromagnetic vibration solidifying the front; make the column ingotism that solidifies the front cataclasm; it is swum in the molten steel; the method that is conceived to make the solidified structure miniaturization and reduces center segregation; if make the cataclasm big like this electromagnetic force of ingotism, then surface quality is worsened because of the crystallizer protecting residue that is involved in above the molten steel but provide.Therefore wish to exchange the magnetic flux density of oscillating magnetic field less than 1000 Gausses.Utilize the configuration of winding under the situation about having, even more than 1000 Gausses, also can make ingotism not cataclasm.
The method that communique is delivered is speciallyyed permit in this external application No. 2917223, and the generation tree dendrite is cataclasm, becomes equiaxed grain structure from columanar structure.In ultra-low-carbon steel etc. and since when rolling only be columanar structure as the control easily of set tissue, exist because of equiax crystalization is difficult to make the problem of grain orientation unanimity, be important so utilize electromagnetic force to make to solidify the ingotism of front not cataclasm.
Can obtain as drawing a conclusion from above understanding, make the magnetic field vibration by long side direction at casting mold, cause in the thickness direction of strand and flowing of casting direction, by forming the molten steel flow that bubble and field trash are drawn back from the freezing interface, can prevent the capture of bubble and field trash effectively.
With the present invention the freezing interface is vibrated effectively, can suppress the capture of bubble and field trash, so can increase substantially slab surface quality.
Realize improving slab quality, from the result of the model experiment carried out and analog computation as can be seen, make above-mentioned oscillating magnetic field act on molten steel in the casting mold, minor face (thickness of strand just) the direction stack magnetostatic field at casting mold also is effective simultaneously.
As shown in Figure 6, can exemplify on structure as shown in Figure 1, increase the winding 34 that flows through DC current (below be called the direct current winding) again as the structure of such winding.
Like this by direct current winding 34 is set, the stack magnetostatic field, (wherein F is a Lorentz force owing to F=J * B, J is an induced-current, and B is magnetic field) magnetic field B Xiang Bianda, Lorentz force F is increased, and the direction of Lorentz force has a great difference with situation about not superposeing, molten steel flow also changes, because the mobile change of the width of strand and casting direction is big, so can expect to obtain in the bubble of freezing interface capture and the clean effect of field trash.
Utilize stack in addition, can be reduced in the molten steel flow speed of the thickness central authorities of strand, also can prevent to be involved in crystallizer protecting residue effectively.
Fig. 7 (front view), Fig. 8 (along the horizontal sectional view of the III-III line of Fig. 7), Fig. 9 (along the vertical cross-section diagram of the IV-IV line of Fig. 7) represent that schematically the number for magnetic pole 28 is under four the situation, resolve and the example of the MOLTEN STEEL FLOW sometime that the analytical Calculation that flows causes with oscillating magnetic field of the present invention by electromagnetic field.Arrow a among Fig. 7 represents casting direction, and b represents the long side direction of casting mold, and c represents the local flow of molten steel 14.Arrow d among Fig. 8 represents the short side direction of casting mold.Figure 10 (front view), Figure 11 (along the horizontal sectional view of the VI-VI line of Figure 10), Figure 12 (along the vertical cross-section diagram of the VII-VII line of Figure 10) schematically illustrate the MOLTEN STEEL FLOW in the next moment in addition.
As shown in figure 13, in the present invention, the direction that flows that produces according to the Lorentz force F shown in the following formula is with the periodic reversal identical with applying electric current I.
F∝J×Bt ……(2)
Bt＝Bdc+Bac＞0 ……(3)
Wherein J is an induced-current, and Bt is the total magnetic field, and Bdc is a D.C. magnetic field, and Bac is an AC magnetic field.
Be used to make the frequency of alternating current of magnetic field vibration also same as described above in this case, be fit to the scope from 1Hz to 8Hz.
From above understanding as can be seen, long side direction at casting mold makes the magnetic field vibration, thickness direction at strand applies D.C. magnetic field simultaneously, cause MOLTEN STEEL FLOW with prior art a great difference at the long side direction of casting mold and casting direction, the freezing interface is vibrated effectively, can suppress the capture of bubble and field trash, slab surface quality is increased substantially.
To work hard applying on the mode of AC magnetic field in addition, can obtain as drawing a conclusion from the model experiment carried out and the result of analog computation.
The mobile inhibition bubble of the macroscopic view that cause the shifting magnetic field and the capture of field trash on the freezing interface are involved in the crystallizer protecting residue increase but exist sometimes because of making, and make the situation of deterioration on the contrary.
When applying oscillating magnetic field, if be fixed by the position of oscillating magnetic field than strong cohesiveness, the position a little less than electromagnetic force can produce the part that can not fully suppress the capture of field trash sometimes.It is effective that the peak of the Lorentz force that oscillating magnetic field produces is moved.
The peak of Lorentz force is moved, also can become to make the phase place of interchange winding of center for last being contained in phase settings that interchange winding on three adjacent electromagnet or one group exchanges winding.Here so-called oscillating magnetic field be meant along with the time chien shih Lorentz force the magnetic field of direction counter-rotating.
Below the mobile of Lorentz force peak described.Each winding (that narrates later is shown in Figure 20) to the structure shown in Figure 14 broach shape winding 24 actual identical with Fig. 6 is given oscillating magnetic field, and each winding is made phase change.Figure 15～Figure 18 is the key diagram of phase place that each such winding is given.The numeral of each the winding traversal marker of interchange winding 24a, 24b among the figure is that at a time it exchanges the current phase angle (degree) of winding.Figure 15～Figure 17 is the situation of expression two-phase alternating current, Figure 18 is the situation of expression three-phase alternating current, Figure 15 represents the example of shifting magnetic field, and Figure 16 represents the example of oscillating magnetic field, and Figure 17 and Figure 18 represent to make the example of the local situation about moving of peak of oscillating magnetic field.
As Figure 17, shown in Figure 180, the electromagnet more than three side by side on the direction of the long limit of casting mold (width of strand just), the current phase of switching in adjacent electromagnet is not to increasing or reducing to folk prescription, but the phase place by setting at least the center for lags behind than the phase place of both sides, making magnetic field is not only to move to a direction, but local mobile while vibrating.
Utilization makes that the phase place of the interchange winding on the adjacent electromagnets in the above-mentioned electromagnet that is contained in like that more than three has n, 2n, n or n, (wherein n is 90 ° under the situation of two-phase alternating current for 3n, 2n, be 60 ° or 120 ° under the situation of three-phase alternating current) aligning part, can make local the moving of peak of oscillating magnetic field.
Wherein, under the situation of the oscillating magnetic field of inducting merely, the amplitude of oscillating magnetic field is changeable.This peak is local to be moved by making, and can clean the freezing interface on whole position.
Having exemplified the broach number that exchanges winding at this is 12 example, and the broach number can be selected from roots such as 4,6,8,10,12,16, and alternating current is a two-phase in addition, three-phase can.
So in the present invention, by along the long side direction of the casting mold electromagnet more than three side by side, produce oscillating magnetic field, the peak that makes this oscillating magnetic field simultaneously moves along the long side direction of casting mold, can solve above-mentioned problem.
In the present invention, the phase place that is contained in the winding on the adjacent electromagnets in three electromagnet preferably has the aligning part of n, 2n, n or n, 3n, 2n, and wherein under the situation of three-phase alternating current n=60 ° or 120 °, under the situation of two-phase alternating current n=90 °.Preferably except oscillating magnetic field, D.C. magnetic field also superposes on the thickness direction of strand in addition.
Preferably reduce in addition, prevent to provide the nozzle blocking of molten steel, be not blown into inactive gas and cast continuously from the mouth of a river to casting mold by the field trash fusing point that makes the not solidified molten steel in the casting mold.In this case, the molten steel that reduces the field trash fusing point is preferably and contains C≤0.020 quality %, Si≤0.2 quality %, Mn≤1.0 quality %, S≤0.050 quality %, Ti 〉=0.010 quality %, satisfies the Ultra-low carbon Ti dexidized steel that composition constituted of the condition of Al≤[quality %Ti]/5.Wherein [quality %Ti] is meant the content (quality %) of Ti.
Be suitable for molten steel of the present invention in addition, after at first molten steel being carried out carbonization treatment with vacuum degasser, with containing the deoxidation of Ti alloy, after this utilize in the deoxidation molten steel and to add one or both that contain Ca 〉=10 quality % and REM 〉=5 quality %, be selected from one or more field trash among Fe, Al, Si and the Ti and form to adjust and use alloy, make oxide in the molten steel in forming CaO and the REM oxide at least a content be 10 quality % above, below the 50 quality %, and preferably the oxide of Ti below 90 quality %, Al
2O
3Below 70 quality %.
This molten steel is after carbonization treatment, and preferably with before containing the Ti alloy and carrying out deoxidation treatment, by carrying out pre-deoxidation with among Al, Si, the Mn any one, the oxygen concentration that will be dissolved in the molten steel drops to below the 200ppm in advance.
The maximum that preferably makes the Lorentz force that is driven by oscillating magnetic field in the present invention is at 5000 (N/m
3) above, 13000 (N/m
3) below.The continuous casting of this peripheral hardware is V (m/s), is Fmax (N/m by the maximum of the Lorentz force of oscillating magnetic field driving with the flow velocity of the not solidified molten steel in the casting mold
3) time, preferably be adjusted to and make V * Fmax at 3000 (N/ (sm
2)) more than.
Description of drawings
Fig. 1 is the horizontal sectional view of an example that schematically illustrates the combination of electromagnet that the present invention uses and casting mold.
Fig. 2 is for principle of the present invention is described, schematically illustrates with electromagnetic field to resolve and the result's of the velocity of the MOLTEN STEEL FLOW that the analytical Calculation that flows causes in magnetic field front view.
Fig. 3 is the horizontal sectional view along the III-III line of Fig. 2.
Fig. 4 is the vertical cross-section diagram along the IV-IV line of Fig. 2.
Fig. 5 is the curve map that applies electric current and the time dependent state examples of molten steel flow speed among expression the present invention.
Fig. 6 is the horizontal sectional view of another example that schematically illustrates the combination of electromagnet that the present invention uses and casting mold.
Fig. 7 is for principle of the present invention is described, schematically illustrates with electromagnetic field to resolve and the result's of the velocity of the MOLTEN STEEL FLOW at a time that the analytical Calculation that flows causes in magnetic field front view.
Fig. 8 is the horizontal sectional view along the III-III line of Fig. 7.
Fig. 9 is the vertical cross-section diagram along the IV-IV line of Fig. 7.
Figure 10 is for principle of the present invention being described, schematically illustrating the next result's of the velocity of MOLTEN STEEL FLOW the front view constantly with the magnetic polarity reversal that electromagnetic field is resolved and the analytical Calculation that flows causes in magnetic field.
Figure 11 is the horizontal sectional view along the VI-VI line of Figure 10.
Figure 12 is the vertical cross-section diagram along the VII-VII line of Figure 10.
Figure 13 is the curve map that applies electric current and the time dependent state of molten steel flow speed among expression the present invention.
Figure 14 is the floor map of the relation of interchange winding, direct current winding and the casting mold of expression the present invention use.
Figure 15 is the schematic diagram that is illustrated in the phase place of the interchange winding under the situation of shifting magnetic field.
Figure 16 is the schematic diagram that is illustrated in the phase place of the interchange winding under the oscillating magnetic field situation.
Figure 17 makes the schematic diagram of the phase place of the interchange winding under the local situation of movement of peak of oscillating magnetic field for expression.
Figure 18 makes the other schematic diagram of the phase place of the interchange winding under the local situation of movement of peak of oscillating magnetic field for expression.
Figure 19 is the horizontal sectional view that schematically illustrates the continuous casting equipment of the 1st embodiment.
Figure 20 is the horizontal sectional view that schematically illustrates the continuous casting equipment of the 2nd embodiment.
Figure 21 is the curve map of expression effect of the present invention.
Figure 22 is the curve map of the effect under the situation of expression stack magnetostatic field of the present invention.
Figure 23 produces the time dependent key diagram of current phase of shifting magnetic field for expression.
Figure 24 makes the local time dependent key diagram of current phase that moves of peak of oscillating magnetic field for expression.
Figure 25 makes the local time dependent other key diagram of current phase that moves of peak of oscillating magnetic field for expression.
Figure 26 is the curve map of the relation of expression maximum Fmax of Lorentz force and defective incorporation rate.
Figure 27 is the curve map of the relation of expression maximum Fmax of Lorentz force and pore number density.
Figure 28 is the curve map of the relation of an expression maximum Fmax of Lorentz force and a slag inclusion number density.
Figure 29 schematically illustrates the perspective view that acts on the Lorentz force on the freezing interface.
Figure 30 is the curve map of expression Lorentz Density Distribution.
Figure 31 is the curve of the relation of expression mean value Fave of Lorentz force and defective incorporation rate.
Figure 32 is the curve map of the relation of expression mean value Fave of Lorentz force and pore number density.
Figure 33 is the curve map of the relation of an expression mean value Fave of Lorentz force and a slag inclusion number density.
Figure 34 is the curve map of the relation of expression molten steel flow speed V and defective incorporation rate.
Figure 35 is the curve of the relation of expression V * Fmax and defective incorporation rate.
Label declaration
10 casting molds
12 submersed nozzles
14 molten steel
20 oscillating magnetic field generating apparatus
22 interdigitated electrode structure iron cores
24 exchange winding
26a, 26b AC power
28 magnetic poles
30 magnetostatic field generating apparatus
32 dc sources
34 direct current windings
The specific embodiment
The present invention will be described with reference to figure.As shown in Figure 1, submersed nozzle 12 is hung from the bottom of the tundish (not shown) of top in the present invention, is immersed in the not solidified molten steel 14 in the casting mold 10, and molten steel 14 is provided.There is the oscillating magnetic field generating apparatus of the electromagnet (interchange winding) more than three to be configured in outside the long limit of this casting mold 10 side by side.In these electromagnet (interchange winding), apply the oscillating current that produces oscillating magnetic field respectively, apply oscillating current along the mode that the long side direction of casting mold 10 moves with the peak value of this oscillating current.This moves, and the aligning part that makes the phase place of adjacent interchange winding have n, 2n, n or n, 3n, 2n is applied in.
At first the 1st embodiment of the present invention that only makes the oscillating magnetic field effect with such device is elaborated.
In the 1st embodiment, by reducing the fusing point of the field trash in the molten steel, prevent to stop up the mouth of a river that molten steel is provided to casting mold, be not blown into inactive gas such as Ar and cast continuously from the mouth of a river, make oscillating magnetic field act on not solidified molten steel in the casting mold simultaneously.
Open flat 11-100611 communique has been delivered the fusing point of the reduction field trash that uses in so no gas continuous casting molten steel above-mentioned spy.Can exemplify and contain C≤0.020 quality %, Si≤0.2 quality %, Mn≤1.0 quality %, S≤0.050 quality %, Ti 〉=0.010 quality %, satisfy the Ultra-low carbon Ti dexidized steel that composition constituted of the condition of Al≤[quality %Ti]/5.This molten steel is when casting, after at first molten steel being carried out carbonization treatment with vacuum degasser, with containing the deoxidation of Ti alloy, after this by in the deoxidation molten steel, add contain Ca 〉=10 quality % and REM 〉=5 quality % one or both and be selected from one or more field trash among Fe, Al, Si and the Ti and form to adjust and use alloy, and make oxide in the molten steel in forming CaO and REM (rare earth element) oxide at least a content be 10 quality % above, below the 50 quality %, and preferably the oxide of Ti below 90 quality %, Al
2O
3Below 70 quality %.This moment is with before containing the Ti alloy and carrying out deoxidation treatment, and by the molten steel of carbonization treatment is carried out pre-deoxidation with among Al, Si, the Mn any one, the oxygen concentration that will be dissolved in the molten steel drops to below the 200ppm in advance.
When the molten steel of casting is not like this had the gas continuous casting,, reduce the blemish of strand by as described below the molten steel in the casting mold being carried out electromagnetic agitation.
An example representing the continuous casting equipment of suitable embodiment of the present invention among Figure 19 with the schematic diagram of horizontal cross-section.10 is casting mold in Figure 19, and 12 is submersed nozzle, and 14 is molten steel, and 20 is the oscillating magnetic field generating apparatus, and 22 is the interdigitated electrode structure iron core, and 24 for exchanging winding, and 26a, 26b are AC power, and 28 is magnetic pole.
To the molten steel 14 in the casting mold of being made up of relative long limit and minor face 10, the limit applies the limit, magnetic field and casts continuously in the present invention.The magnetic field (oscillating magnetic field just) in the long side direction vibration of casting mold 10 is adopted in the magnetic field that applies.The oscillating magnetic field that applies is with the long side direction of casting mold 10 AC magnetic field as the direction that applies, and is that this direction is periodically reversed, and does not cause the magnetic fields that molten steel 14 macroscopic views flow.
For example use oscillating magnetic field generating apparatus 20 shown in Figure 19 can generate oscillating magnetic field.In oscillating magnetic field generating apparatus 20 shown in Figure 19, the long side direction that is used in casting mold 10 has the interdigitated electrode structure iron core 22 of the broach that (among Figure 19 is 12) more than three, and configuration exchanges winding 24 and magnetic poles 28 on these broach.Magnetic pole 28, the winding method that adjust to exchange winding with flow through the alternating current that exchanges winding, make adjacent pole 28 have opposed polarity (N, the S utmost point) each other.In order to make adjacent pole 28 form different polarity (N, the S utmost point) each other, preferably making the method for winding of adjacent pole 28 interchange winding each other is rightabout, making the identical alternating current with assigned frequency of phase place is to flow through the electric current that exchanges winding, perhaps making the method for winding of adjacent pole 28 winding each other is equidirectional, makes the electric current that flows through winding at magnetic pole adjacent one another are 28 phase deviations and alternating current with assigned frequency.Flow through adjacent pole 28 the interchange winding alternating current phases depart from preferably more than 130 ° of in fact phasing back, below 230 °.
As the frequency of the regulation of alternating current, preferably 1～8Hz, further preferably 3～6Hz.Example shown in Figure 19 is in adjacent magnetic pole 28, and the method for winding that exchanges winding is an equidirectional, make the situation that flows through the AC current phase difference (in fact phasing back) that exchanges winding, but the present invention is not limited thereto.
In the present invention because adjacent magnetic pole 28 has different polarity mutually each other, in the electromagnetic force that acts on molten steel between the adjacent magnetic pole 28 with to act on its direction of electromagnetic force of molten steel 14 between its adjacent magnetic pole 28 roughly opposite, do not cause that the macroscopic view of molten steel 14 flows.In addition in the present invention, to flow through the electric current that exchanges winding be alternating current owing to make, thereby the polarity of each magnetic pole 28 is with the periodic reversal of regulation, can cause vibration near the molten steel 14 the freezing interface of the long side direction of casting mold 10.The capture of field trash and bubble can be suppressed like this, cc billet surface quality can be significantly improved to the freezing interface.
Under the situation of frequency that flows through the alternating current that exchanges winding, because underfrequency can not fully cause MOLTEN STEEL FLOW less than 1Hz.On the other hand as surpass 8Hz, molten steel 14 can not with the oscillating magnetic field servo-actuated, the effect that applies magnetic field reduces.Therefore making the frequency that flows through the alternating current that exchanges winding is 1～8Hz, and the vibration period that preferably makes oscillating magnetic field is 1/8～1s.
Among the present invention, the magnetic flux density of the oscillating magnetic field that preferably applies is less than 1000 Gausses.More than 1000 Gausses, not only can make ingotism cataclasm as magnetic flux density, and the liquid level change is big, has the problem that is involved in that promotes crystallizer protecting residue.
Apply above-mentioned oscillating magnetic field in the present invention, also apply magnetostatic field.As shown in figure 20, a side is provided with magnetostatic field generating apparatus 30 on the long limit of casting mold 10, applies magnetostatic field at the short side direction (thickness direction of strand) of casting mold 10.
Apply magnetostatic field by width, near the molten steel flow speed of casting mold 10 central parts is slowed down, can prevent being involved in of crystallizer protecting residue at casting mold 10.By the magnetostatic field that on the oscillating magnetic field that applies, superposes, can make the B item among F=J * B become big in addition, also have the effect that Lorentz force is increased.
In the present invention, apply the magnetic flux density of magnetostatic field preferably more than 200 Gausses, below 3000 Gausses.The effect that reduces molten steel flow speed in magnetic flux density under less than 200 Gausses' situation is little, in addition as surpass 3000 Gausses, brake excessively, and generation causes inhomogeneous coagulation problem.
Figure 20 is illustrated in the long limit one side configuration oscillating magnetic field generating apparatus 20 of casting mold 10, the example of magnetostatic field generating apparatus 30.Magnetostatic field generating apparatus 30 disposes a pair of magnetic pole 28 in the long limit of casting mold 10 side, casting mold 10 is clipped in the middle, making the electric current that flows through is DC current, flows to direct current winding 34 from dc source 32, applies magnetostatic field in minor face (thickness of the strand just) direction of casting mold 10.Magnetostatic field generating apparatus 30 and oscillating magnetic field generating apparatus 20 be provided with the position vertical direction is identical or different can.
Situation to the shifting magnetic field is elaborated along the local situation about moving of the long side direction of casting mold 10 with the peak that makes oscillating magnetic field below.
Figure 14 represents the vertical view of casting mold 10 and the example of alternating electromagnet (exchanging winding 24), DC electromagnet (direct current winding 34) arrangement.
Figure 15～Figure 18 uses numeral (value at phase angle) to charge to respectively and is illustrated in the PHASE DISTRIBUTION that some moments constitute oscillating magnetic field in 12 each windings that exchange winding 24a, 24b respectively.The peak of oscillating magnetic field is mobile in proper order along the long side direction of casting mold 10.
The phase difference that Figure 15 represents to apply adjacent interchange winding is 90 °, differ 180 ° on relative interchange winding 24a, 24b two-phase exchanges the shifting magnetic field.Figure 16 represents that the two-phase that phase difference is 180 °, phase place is identical on relative interchange winding 24a, 24b that applies adjacent interchange winding exchanges the shifting magnetic field.The phase difference that Figure 17 represents to apply adjacent interchange winding is 90 °, differ 180 ° halfwave rectifier on relative interchange winding 24a, 24b two-phase exchanges.The phase difference that Figure 18 represents to apply adjacent interchange winding is 120 °, differ the three-phase alternating current of 60 ° halfwave rectifier on relative interchange winding.
Wherein, in Figure 23,, the phase angle of electric current is represented over time corresponding to each winding that exchanges winding 24a for the shifting magnetic field of Figure 15.The phase angle of epimere T1 is identical with Figure 15, is downwards effluxion.It is over time identical to move expression for the part of the peak of the oscillating magnetic field of Figure 17, Figure 18 respectively among Figure 24, Figure 25 in addition.
Move by the peak that makes oscillating magnetic field is local as described above, and the freezing interface is vibrated effectively, can suppress the capture of bubble and field trash, so slab surface quality is increased substantially.
Below with reference to figure the 2nd embodiment of the present invention of stack magnetostatic field on oscillating magnetic field is elaborated.
An example representing the continuous casting equipment of suitable embodiment of the present invention among Figure 20 with the schematic diagram of horizontal cross-section.This figure is equivalent to be provided with simultaneously the figure of magnetostatic field generating apparatus 30 in Figure 19.
In the present invention, the molten steel limits in the casting mold 10 that relative long limit and minor face are constituted apply magnetic field, and the limit is cast continuously.The magnetic field that applies is at the magnetic field (oscillating magnetic field just) of the long side direction vibration of casting mold 10 and the magnetostatic field of thickness direction.The oscillating magnetic field that applies is that the long side direction with casting mold 10 is the AC magnetic field that applies direction, is that its direction is periodically reversed, and does not cause the magnetic field that the macroscopic view of molten steel 14 flows.
For example use oscillating magnetic field generating apparatus 20 shown in Figure 20, can generate oscillating magnetic field.Oscillating magnetic field generating apparatus 20 shown in Figure 20 has omitted detailed explanation because reality is identical with the oscillating magnetic field generating apparatus shown in Figure 19 of the 1st embodiment.
Apply in the present invention and the identical oscillating magnetic field of above-mentioned the 1st embodiment, also apply magnetostatic field.As shown in figure 20, a side is provided with magnetostatic field generating apparatus 30 on the long limit of casting mold 10, applies magnetostatic field at the short side direction (thickness direction of strand) of casting mold 10.
Apply magnetostatic field by short side direction, near the molten steel flow speed of central part of casting mold 10 is reduced, can prevent being involved in of crystallizer protecting residue at casting mold 10.By applying the magnetostatic field that superposes on the oscillating magnetic field,, also has the effect that Lorentz force is increased in addition owing to can make the B item among F+J * B become big.
The magnetic flux density of the magnetostatic field that applies in the present invention, is preferably more than 200 Gausses, below 3000 Gausses.The effect that reduces molten steel flow speed in magnetic flux density under less than 200 Gausses' situation is little, in addition as surpass 3000 Gausses, brake excessively, and generation causes inhomogeneous coagulation problem.
Figure 20 is illustrated in the long limit one side configuration oscillating magnetic field generating apparatus 20 of casting mold 10, the example of magnetostatic field generating apparatus 30.Magnetostatic field generating apparatus 30 disposes a pair of magnetic pole 28 in the long limit of casting mold 10 side, and casting mold 10 is clipped in the middle, and making the electric current that flows through is DC current, flows to direct current winding 34 from dc source 32, applies magnetostatic field at the width of casting mold 10.Magnetostatic field generating apparatus 30 and oscillating magnetic field generating apparatus 20 be provided with the position vertical direction is identical or different can.
Below with reference to figure the peak that makes oscillating magnetic field is elaborated along local the 3rd embodiment of the present invention that moves of the long side direction of casting mold 10.
Figure 14 is the vertical view of expression casting mold 10 and the example of the arrangement of alternating electromagnet (exchanging winding 24), DC electromagnet (direct current winding 34).
Figure 15～Figure 18 uses numeral (value at phase angle) to charge to respectively and is illustrated in the PHASE DISTRIBUTION that some moments constitute oscillating magnetic field in 12 each windings that exchange winding 24a, 24b respectively.The peak of oscillating magnetic field is mobile in proper order along the long side direction of casting mold 10.
The phase difference that Figure 15 represents to apply adjacent interchange winding is 90 °, differ 180 ° on relative interchange winding 24a, 24b two-phase exchanges the shifting magnetic field.Figure 16 represents that the two-phase that phase difference is 180 °, phase place is identical on relative interchange winding 24a, 24b that applies adjacent interchange winding exchanges the shifting magnetic field.The phase difference that Figure 17 represents to apply adjacent interchange winding is 90 °, differ 180 ° halfwave rectifier on relative interchange winding 24a, 24b two-phase exchanges.The phase difference that Figure 18 represents to apply adjacent interchange winding is 120 °, differ the three-phase alternating current of 60 ° halfwave rectifier on relative interchange winding.
According to the local method of the present invention that moves of the peak that makes oscillating magnetic field, by the molten steel identical with the situation of the 1st embodiment there not being the gas continuous casting, the freezing interface is vibrated effectively, can suppress the capture of field trash, so slab surface quality is increased substantially.
The 4th embodiment of the present invention that interaction with Lorentz force and molten steel flow speed is remained in the proper range is elaborated below.
In the 4th embodiment, establish molten steel flow speeds in the casting mold 10 and be V (m/s), be Fmax (N/m with the maximum of the Lorentz force of field drives
3), make V * Fmax at 3000 (N/ (sm
2)) above, 6000 (N/ (sm
2)) below.
Molten steel flow speed V is a measured value, and under the situation of detection difficult, the inventor can replace with the regression equation that experiment obtains.That is,
V(m/s)＝(43.0-0.047L
SEN+0.093θ+10.0Q
+0.791q
Ar-0.0398W)/100
L wherein
SEN: mouth of a river immersion depth (mm), Q: molten steel injection rate (t/min), θ: the submersed nozzle steel flow go out angle (°), q
Ar: the mouth of a river is blown into gas flow (l/min), W: casting mold width (mm).
Figure 34 represent according to and the result that casts continuously in the same manner of the 1st embodiment, the relation of defective incorporation rate and the molten steel flow speed that causes because of magnetic field.Figure 26 is the relation of the maximum Fmax of expression defective incorporation rate and Lorentz force.In addition as shown in figure 35, studying these results in more detail as can be seen, about the relation of molten steel flow speed V and Fmax, make V * Fmax more than 3000, is effective to reducing the defective incorporation rate.Even find out in addition to surpass 6000, its effect is also constant.
Is that the iron core of the broach shape of 12 utmost points is illustrated at this to number of poles, and the shape of number of magnetic poles and iron core is not limited thereto, and for example iron core is separated that also it doesn't matter.Be not limited in addition the to superpose situation of magnetostatic field for example also can be used the equipment of removing direct current winding 34 from Figure 20.
(embodiment)
(the 1st embodiment)
The representational example of molten steel 14 at first is described.Behind converter tapping, 300 tons molten steel, 14 usefulness RH vacuum degassers are carried out carbonization treatment, the composition of molten steel 14 is adjusted into C=0.035 quality %, Si=0.02 quality %, Mn=0.20 quality %, P=0.015 quality %, S=0.010 quality %, temperature is adjusted into 1600 ℃.In this molten steel 14, add the Al of 0.5kg/ ton, make the oxygen concentration that is dissolved in the molten steel 14 drop to 150ppm.Al concentration in the molten steel 14 is 0.003 quality % at this moment.The 70 quality %Ti-Fe alloys that add the 1.2kg/ ton in this molten steel 14 carry out deoxidation then.After this in molten steel 14, add 20 quality %Ca-10 quality %REM-50 quality %Ti-Fe alloys of 0.5kg/ ton, carry out the composition adjustment.Ti concentration after this handles is that 0.050 quality %, Al concentration are 0.003 quality %.
Cast experiment with continuous casting equipment shown in Figure 19 then.Field trash in the research tundish (not shown) at this moment, the result is 65 quality %Ti
2O
3-15 quality %CaO-10 quality %Ce
2O
3-10 quality %Al
2O
3Globular inclusion.The casting back does not almost have attachment in submersed nozzle.
The width of slab is 1500～1700mm, and thickness is 220mm, and the production capacity of molten steel 14 is 4～5 tons/minute scope.
The structure of winding uses the iron core that is divided into the broach shape of 12 equal portions at the strand width as shown in Figure 1, is configured to generate on the strand width magnetic field (oscillating magnetic field just) of phase alternation counter-rotating.
In Figure 21, concentrate the experiment condition and the experimental result (defective incorporation rate) of expression ultra-low-carbon steel.In this figure the defective incorporation rate be meant field trash, be involved in crystallizer protecting residue, pore and cause the defective of blemish.
The surface segregation of strand grinds after etching with slab, investigates every 1m by perusal
2On the segregation number.With the naked eye checked the blemish of the cold rolled strip coil after cold rolling,, investigated the number of defects that causes because of crystallizer protecting residue by getting defective sample post analysis rejected region.The field trash amount is to utilize the residue extraction method behind the 1/4 thickness position extraction field trash of strand, measures weight.Surface segregation is that crystallizer protecting residue defective and field trash amount are all become index, the condition that worsens most in the full terms is decided to be 10, so that its linear ratio is represented.
As can be seen from Figure 12, utilize exchange flux density can reduce surface segregation, be involved in defective, pore, non-metallic inclusion that crystallizer protecting residue causes.
If wherein the intensity of oscillating magnetic field is strong excessively, the situation that the covering slag of molten steel surface (flux) is involved in is serious, and surface quality is worsened; if frequency is too high; then the not servo-actuated of invar water has reduced the clean effect of freezing interface in magnetic field, and pore and inclusion defects increase.
Is that the iron core of the broach shape of 12 utmost points is illustrated at this to number of poles, and the shape of number of magnetic poles and iron core is not limited to this, for example iron core can be cut apart also that also it doesn't matter.
(the 2nd embodiment)
Use the molten steel 14 identical, with the continuous casting equipment block of Figure 20 with the 1st embodiment with converter smelting.Be that width of plate slab is 1500～1700mm this moment equally, and thickness is 220mm, and the production capacity of molten steel 14 is 4～5 tons/minute scope.
The structure of winding uses the iron core that is divided into the broach shape of 12 equal portions at the strand width as shown in Figure 6, is configured to generate on the strand width magnetic field (oscillating magnetic field just) of phase alternation counter-rotating.
Experiment condition and the experimental result of in Figure 22, concentrating the expression ultra-low-carbon steel under 1200 fixing Gausses D.C. magnetic field, to experimentize.The analytic method of the experimental result of being put down in writing in Figure 22 is identical with the 1st embodiment.
As can be seen from Figure 22, by magnetostatic field being superimposed upon on the oscillating magnetic field that applies, surface segregation be can reduce, defective, pore, non-metallic inclusion that crystallizer protecting residue causes are involved in.
In this case similarly, if the intensity of oscillating magnetic field is strong excessively, the situation of covering slag that then is involved in molten steel surface is serious; surface quality is worsened, and too high as frequency, then the not servo-actuated of invar water is in magnetic field; reduced the clean effect of freezing interface, pore and inclusion defects increase.
(the 3rd embodiment)
The structure of winding uses the iron core that is divided into the broach shape of 12 equal portions at the strand width as shown in figure 14, is configured to generate on the strand width magnetic field (oscillating magnetic field just) of phase alternation counter-rotating.The magnetic flux of AC magnetic field is set at maximum 1000 Gausses.
With experiment condition and the concentrated table 1 that is shown in of experimental result.The analytic method of experimental result is identical with the 1st embodiment.The symbol of the winding phase pattern in this appearance 1 is as follows.
A:n, 2n, n (embodiment)
B:n, 3n, 2n (embodiment)
C:0, n, 2n, 3n (comparative example)
D:0,2n, 0,2n (comparative example)
Wherein n is the phase angle, under the situation of two-phase alternating current n=90 °, and under the situation of three-phase alternating current n=60 ° or 120 °.
As can be seen from Table 1, surface segregation be can reduce by applying oscillating magnetic field, defective, pore, non-metallic inclusion that crystallizer protecting residue causes are involved in.
Identical with the 1st embodiment, if the intensity of oscillating magnetic field is strong excessively, the situation of covering slag that is involved in molten steel surface is serious; surface quality is worsened, and too high as frequency, then not servo-actuated of molten steel is in magnetic field; reduced the clean effect of freezing interface, pore and inclusion defects increase.
Table 1
| The winding phase pattern | The power supply number of phases | AC magnetic field (Gauss) | D.C. magnetic field (Gauss) | The defect index (-) that crystallizer protecting residue produces | The bubble of strand, field trash index (-) | Overall merit | |
| Comparative example 1 | Do not have | - | 0 | 0 | 5.2 | 10 | × |
| Comparative example 2 | | 3 | 1000 | 0 | 2.0 | 1.2 | △ |
| Comparative example 3 | | 2 | 1000 | 0 | 2.5 | 1.8 | △ |
| Comparative example 4 | | 3 | 2000 | 0 | 10 | 1.2 | × |
| Comparative example 5 | | 2 | 1000 | 1000 | 0.8 | 1.0 | ○ |
| Embodiment 1 | | 2 | 1000 | 0 | 0.1 | 0.3 | ◎ |
| Embodiment 2 | | 3 | 1000 | 500 | 0.1 | 0.2 | ◎ |
| Embodiment 3 | | 3 | 2000 | 1000 | 0.05 | 0.05 | ◎ |
| Embodiment 4 | | 2 | 500 | 0 | 0.1 | 0.3 | ◎ |
| Embodiment 5 | | 2 | 800 | 1000 | 0.1 | 0.1 | ◎ |
| Embodiment 6 | | 3 | 1000 | 0 | 0.2 | 0.3 | ◎ |
| Embodiment 7 | | 2 | 1000 | 1000 | 0.1 | 0.1 | ◎ |
| Embodiment 8 | | 3 | 1000 | 1000 | 0.05 | 0.05 | ◎ |
(the 4th embodiment)
With the about 300 tons molten steel 14 of converter smelting,, slab is cast with continuous casting equipment with the Al killed steel that RH is treated as ultra-low-carbon steel.Representational molten steel composition is shown in table 2.The width of slab is 1500～1700mm, and thickness is 220mm, and the production capacity of molten steel 14 is 4～5 tons/minute scope.
The structure of winding such as Fig. 6, shown in Figure 14 use the iron core that is divided into the broach shape of 12 equal portions at the strand width, are configured to generate on the strand width magnetic field (oscillating magnetic field just) of phase cycling variation.
Table 2
| C | Si | Mn | P | S | Al | Ti |
| 0.0015 | 0.02 | 0.08 | 0.015 | 0.004 | 0.04 | 0.04 |
With cast defective incorporation rate, the pore of the slab that obtains like this continuously, the check result of slag inclusion is shown in Figure 26, Figure 27, Figure 28.
Wherein, the defective incorporation rate among the figure be with the cold rolled strip coil total length after cold rolling as denominator, a blemish that causes because of bubble, field trash is thought 1m, as molecule, represent the value of its ratio with percentage.Pore and slag inclusion are in hole that casting billet surface demonstrates with casting and behind the skin cut 2mm of the strand after cutting off in addition; inside be the cavity situation under as pore; under the situation that the vestige of filling crystallizer protecting residue is arranged as slag inclusion; add up respectively, amass with the casting billet surface of investigating and remove the value that this numerical value obtains.
Transverse axis all is the maximum Fmax that acts on the Lorentz force of freezing interface among Figure 26～Figure 28.
The relation of the freezing interface of the molten steel that adheres on the inwall of interchange winding 24 that schematically illustrates as Figure 29 and the casting mold 10 represented with the mold steel plate, when flowing through the electric current that exchanges winding 24 and changing, Lorentz force F just acts on the molten steel 14 of freezing interface.
During the stack D.C. magnetic field, this Lorentz force F provides with above-mentioned (2), (3) formula on Fig. 6, oscillating magnetic field shown in Figure 19, and Bdc does not influence time-averaged power, but time dependent power only increases the amount corresponding with the increase of B.As representing the variation of electric current with phase place, transverse axis is equivalent to long limit shown in Figure 30 of casting mold 10, and corresponding each winding sexually revises the period of change of this Lorentz force F.
Applying under the situation of oscillating magnetic field, the logarithm value result calculated returns, and provides maximum (peak value) Fmax (N/m of Lorentz force with the following formula that obtains
3) and its mean value Fave (N/m by the time
3).
(vibration)
Fmax＝1.57×10
6Bac·Bdc+1.20×10
6Bac
2
Fave＝0
Vibration at shifting magnetic field, Figure 17 or Figure 18 of Figure 15 is moved under the situation of (move the part of the peak of oscillating magnetic field), provides with following formula too.
(moving)
Fmax＝2.28×10
6Bac·Bdc+4.17×10
6Bac
2
Fave＝1.76×10
6Bac
2
(vibration is moved)
Fmax＝1.86×10
6Bac·Bdc+2.31×10
6Bac
2
Fave＝6.36×10
5Bac
2
Each data of Figure 26～Figure 28 are to make when reality casts continuously corresponding with the maximum Fmax of the Lorentz force of above-mentioned various calculating and each check result and data that represent.
As can be seen from Figure 26, the defective incorporation rate is 5000 (N/m at Fmax
3) above, 13000 (N/m
3) below be effective.Also as can be seen, Fmax is 5000 (N/m in Figure 27, Figure 28
3) more than be effective.
As a reference, as shown in Figure 31～Figure 33 with relation Fave, the index when this Fave is not suitable for casting continuously, Fmax is effective as index.
(the 5th embodiment)
Identical with the 4th embodiment, cast with continuous casting equipment.Figure 34 represents the defective incorporation rate of the slab that obtains and the relation of molten steel flow speed.The relation of defective incorporation rate and Lorentz force maximum Fmax as shown in figure 26.
From these results as can be seen, study in great detail for molten steel flow speed V and Lorentz force maximum Fmax, its result as shown in figure 35, if the value of V * Fmax more than 3000, can reduce the defective incorporation rate.Even but the value of V * Fmax surpasses 6000, the effect that reduces the defective incorporation rate is saturated, and the defective incorporation rate remains on certain level.
Industrial applicibility
As adopt the present invention, and be not blown into inactive gas and cast continuously from submersed nozzle, can suppress being involved in of crystallizer protecting residue, improve the internal soundness of strand, and suppress the capture of field trash and bubble, improve the surface quality of strand.
Claims (25)
1. the continuous casing of a steel is characterized in that, the long side direction of edge continuous casting usefulness casting mold is the electromagnet more than three side by side, Yi Bian generate oscillating magnetic field, Yi Bian the peak of described oscillating magnetic field is moved along described long side direction.
2. the continuous casing of steel as claimed in claim 1 is characterized in that, in described electromagnet more than three, the phase place that is contained in the winding on the adjacent electromagnets has the aligning part of n, 3n, 2n.
3. the continuous casing of steel as claimed in claim 1, it is characterized in that, with the long side direction of the casting mold electromagnet more than four side by side, in above-mentioned magnet more than four, the phase place that is contained in the winding on the adjacent electromagnets has 0, the aligning part of n, 2n, n along continuous casting.
4. the continuous casing of steel as claimed in claim 1 is characterized in that, removes described oscillating magnetic field, and D.C. magnetic field also superposes on the thickness direction of strand.
5. the continuous casing of steel as claimed in claim 2 is characterized in that, removes described oscillating magnetic field, and D.C. magnetic field also superposes on the thickness direction of strand.
6. the continuous casing of steel as claimed in claim 3 is characterized in that, removes described oscillating magnetic field, and D.C. magnetic field also superposes on the thickness direction of strand.
7. as the continuous casing of each described steel in the claim 1～6, it is characterized in that, reduce by the field trash fusing point that makes the not solidified molten steel in the described casting mold, and prevent to provide the nozzle blocking of described molten steel to described casting mold, be not blown into inactive gas and cast continuously from the described mouth of a river.
8. the continuous casing of steel as claimed in claim 7, it is characterized in that, described molten steel is to contain C≤0.020 quality %, Si≤0.2 quality %, Mn≤1.0 quality %, S≤0.050 quality %, Ti 〉=0.010 quality %, satisfies the Ultra-low carbon Ti dexidized steel that composition constituted of the condition of Al≤[quality %Ti]/5.
9. the continuous casing of steel as claimed in claim 8, it is characterized in that, when making described molten steel, at first described molten steel is carried out carbonization treatment with vacuum degasser, carry out deoxidation with containing the Ti alloy then, after this by in the deoxidation molten steel, adding one or both that contain Ca 〉=10 quality % and REM 〉=5 quality %, with be selected from Fe, Al, the field trash of one or more among Si and the Ti is formed the adjustment alloy, and make oxide in the described molten steel in forming CaO and the REM oxide at least a arbitrarily content be more than the 10 quality %, below the 50 quality %, and make the Ti oxide below 90 quality %, Al
2O
3Below 70 quality %.
10. the continuous casing of steel as claimed in claim 9, it is characterized in that, to the molten steel after the described carbonization treatment, before carrying out deoxidation treatment with the described Ti of containing alloy, by carrying out pre-deoxidation with among Al, Si, the Mn any one, and the oxygen concentration that will be dissolved in the molten steel in advance drops to below the 200ppm.
11. the continuous casing as each described steel in the claim 1～6 is characterized in that, the maximum that makes the Lorentz force that is driven by described oscillating magnetic field is at 5000N/m
3More than, 13000N/m
3Below.
12. the continuous casing of steel as claimed in claim 7 is characterized in that, the maximum that makes the Lorentz force that is driven by described oscillating magnetic field is at 5000N/m
3More than, 13000N/m
3Below.
13. the continuous casing of steel as claimed in claim 8 is characterized in that, the maximum that makes the Lorentz force that is driven by described oscillating magnetic field is at 5000N/m
3More than, 13000N/m
3Below.
14. the continuous casing of steel as claimed in claim 9 is characterized in that, the maximum that makes the Lorentz force that is driven by described oscillating magnetic field is at 5000N/m
3More than, 13000N/m
3Below.
15. the continuous casing of steel as claimed in claim 10 is characterized in that, the maximum that makes the Lorentz force that is driven by described oscillating magnetic field is at 5000N/m
3More than, 13000N/m
3Below.
16. the continuous casing as each described steel in the claim 1～6 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
17. the continuous casing of steel as claimed in claim 7 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
18. the continuous casing of steel as claimed in claim 8 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
19. the continuous casing of steel as claimed in claim 9 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
20. the continuous casing of steel as claimed in claim 10 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
21. the continuous casing of steel as claimed in claim 11 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
22. the continuous casing of steel as claimed in claim 12 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
23. the continuous casing of steel as claimed in claim 13 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
24. the continuous casing of steel as claimed in claim 14 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
25. the continuous casing of steel as claimed in claim 15 is characterized in that, the maximum of the Lorentz force that establish not solidified molten steel flow speed in the described casting mold and be V m/s, is driven by described oscillating magnetic field is Fmax N/m
3The time, adjust so that V * Fmax at 3000N/ (sm
2) more than.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP108344/2003 | 2003-04-11 | ||
| JP2003108344A JP4348988B2 (en) | 2003-04-11 | 2003-04-11 | Steel continuous casting method |
| JP117340/2003 | 2003-04-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1771100A CN1771100A (en) | 2006-05-10 |
| CN100345647C true CN100345647C (en) | 2007-10-31 |
Family
ID=33469901
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004800095773A Expired - Lifetime CN100345647C (en) | 2003-04-11 | 2004-01-29 | Continuous casting method for steel |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4348988B2 (en) |
| CN (1) | CN100345647C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103998159A (en) * | 2011-12-22 | 2014-08-20 | Abb公司 | Arrangement and method for flow control of molten metal in a continuous casting process |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5045133B2 (en) * | 2007-02-06 | 2012-10-10 | Ｊｆｅスチール株式会社 | Steel continuous casting method and surface-treated steel plate manufacturing method |
| CN101720262B (en) * | 2007-06-06 | 2012-05-30 | 住友金属工业株式会社 | Steel continuous casting method and in-mold molten steel fluidity controller |
| WO2011111858A1 (en) * | 2010-03-10 | 2011-09-15 | Ｊｆｅスチール株式会社 | Method for continuously casting steel and process for producing steel sheet |
| JP5551297B1 (en) * | 2013-08-08 | 2014-07-16 | 高橋 謙三 | Molding device for continuous casting with stirring device |
| KR101594654B1 (en) * | 2013-12-20 | 2016-02-16 | 주식회사 포스코 | Mold vibrated apparatus for continuous caster |
| US10207318B2 (en) * | 2014-11-20 | 2019-02-19 | Abb Schweiz Ag | Electromagnetic brake system and method of controlling molten metal flow in a metal-making process |
| JP2018015791A (en) * | 2016-07-28 | 2018-02-01 | アイダエンジニアリング株式会社 | Manufacturing apparatus of metal molding |
| CN109261939B (en) * | 2017-07-17 | 2023-11-24 | 中国科学院大学 | Device and method for additive manufacturing by utilizing liquid metal |
| CN114231872B (en) * | 2021-12-17 | 2022-10-14 | 哈尔滨工业大学 | Electromagnetic slag removing device |
| CN117644188B (en) * | 2023-12-12 | 2024-06-04 | 北京科技大学 | Method for improving quality of ultra-thick plate blank |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1116833A (en) * | 1993-01-19 | 1996-02-14 | 瑞典通用电器勃朗勃威力公司 | Device in continuous casting in a mould |
| CN1148526A (en) * | 1995-07-19 | 1997-04-30 | 石川岛播磨重工业株式会社 | Method and apparatus for vibrating molten metal in a twin-roll continuous caster |
| JPH1110611A (en) * | 1997-06-26 | 1999-01-19 | Daiken Trade & Ind Co Ltd | Reinforced lengthy woody material |
| CN1332049A (en) * | 2000-07-10 | 2002-01-23 | 川崎制铁株式会社 | Method and device for continuous casting of metal |
| JP2002028763A (en) * | 2000-07-10 | 2002-01-29 | Kawasaki Steel Corp | Method for continuously casting metal |
| JP2003103348A (en) * | 2001-02-20 | 2003-04-08 | Kawasaki Steel Corp | Continuous casting method and facility for steel |
| JP2003103349A (en) * | 2001-02-20 | 2003-04-08 | Kawasaki Steel Corp | Continuous casting method and facility for steel |
-
2003
- 2003-04-11 JP JP2003108344A patent/JP4348988B2/en not_active Expired - Lifetime
-
2004
- 2004-01-29 CN CNB2004800095773A patent/CN100345647C/en not_active Expired - Lifetime
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1116833A (en) * | 1993-01-19 | 1996-02-14 | 瑞典通用电器勃朗勃威力公司 | Device in continuous casting in a mould |
| CN1148526A (en) * | 1995-07-19 | 1997-04-30 | 石川岛播磨重工业株式会社 | Method and apparatus for vibrating molten metal in a twin-roll continuous caster |
| JPH1110611A (en) * | 1997-06-26 | 1999-01-19 | Daiken Trade & Ind Co Ltd | Reinforced lengthy woody material |
| CN1332049A (en) * | 2000-07-10 | 2002-01-23 | 川崎制铁株式会社 | Method and device for continuous casting of metal |
| JP2002028763A (en) * | 2000-07-10 | 2002-01-29 | Kawasaki Steel Corp | Method for continuously casting metal |
| JP2003103348A (en) * | 2001-02-20 | 2003-04-08 | Kawasaki Steel Corp | Continuous casting method and facility for steel |
| JP2003103349A (en) * | 2001-02-20 | 2003-04-08 | Kawasaki Steel Corp | Continuous casting method and facility for steel |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103998159A (en) * | 2011-12-22 | 2014-08-20 | Abb公司 | Arrangement and method for flow control of molten metal in a continuous casting process |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4348988B2 (en) | 2009-10-21 |
| CN1771100A (en) | 2006-05-10 |
| JP2004314096A (en) | 2004-11-11 |
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