EP3589436A1

EP3589436A1 - Method and device for the continuous production of steel strip

Info

Publication number: EP3589436A1
Application number: EP18708678.0A
Authority: EP
Inventors: Klaus Weinzierl
Original assignee: Primetals Technologies Germany GmbH
Current assignee: Primetals Technologies Germany GmbH
Priority date: 2017-03-03
Filing date: 2018-03-02
Publication date: 2020-01-08
Also published as: WO2018158420A1; AT519697A1; AT519697B1

Abstract

The invention relates to a method for producing composite steel and/or hot strip in an energy-efficient and continuous manner and in large quantities wherein a continuous casting plant has a plurality of casting devices, preferably comprising moulds (3a, 3b, 3c), and each casting device has a downstream strand guide (4a, 4b, 4c), the casting devices being used to produce strands (5a, 5b, 5c) which are drawn off via the respective strand guide (4a, 4b, 4c) and rolled in a hot strip mill, at least two strands (5a, 5b, 5c) being arranged one above the other in a hot state in a common strand guide (8) downstream of the strand guides (4a, 4b, 4c).

Description

description

METHOD AND DEVICE FOR THE CONTINUOUS MANUFACTURE OF

STEEL STRIP

Technical area

The invention relates to a method for the continuous production of steel strip,

wherein a continuous casting plant has a plurality of casting devices, preferably comprising molds, and each casting device has a downstream strand guide,

- By means of the casting facilities strands arise, which are withdrawn via the j eweilige strand management and rolled in a hot strip mill.

In the continuous production of steel strip, strands, e.g. with slab cross section, preferably thin or medium slab cross section, passed from the continuous casting plant directly in the hot state in the hot strip mill and rolled there. The semicontinuous production of steel strip is also included, where the strand is cut in front of the hot strip mill and the resulting slabs are hot rolled to steel strip.

If pouring devices with molds, e.g. Both sides open Plattenkokillen of a copper material used, so each mold has a downstream strand guide; liquid metal is poured into the molds, resulting in strands which are drawn off via the respective strand guide.

State of the art In composites composite components, such as

For example, steel goods of different composition, assembled into a composite material. The intention is to be able to provide a composite material that combines the desired properties of the individual composite components in a composite material.

In CSP (Compact Strip Production) systems, the strip is produced in a continuous process. This means that the casting process and the rolling process immediately

successively from a heat take place. The WO

2007/073841 AI discloses a CSP plant in which between the caster and the rolling mill, both an induction furnace and a holding furnace is provided to keep the thin slab to temperature or. raise the temperature slightly, whereby both the holding furnace and the induction furnace are activated, deactivated or deactivated depending on the operating mode.

controlled or regulated. From the document WO 01/68293 Al a method is known in which in a casting process core and boundary layers to form the composite material are joined together by material fusion by superficial melting. Hot-rolled strip can be produced with the most diverse plant types. The material properties of the steel strip produced depend not only on the alloying elements, but also to a considerable extent on the process parameters during its production. Steel can also be produced and rolled in a layered structure. For example, in the production of a samurai sword, the steel is folded several times and forged again with a hammer. This makes it possible to produce particularly high-quality steels. This Potential is scarcely used in a hot strip mill until today and additionally in the production of hot strip much energy is consumed. Energy costs are therefore crucial for the economy of production

Cost factor.

In the so-called Endless Strip Production (Arvedi ESP), a slab is poured in a casting machine, which is about 70-100 mm thick. Immediately after the casting machine are scaffolds (HRM = High Reduction Mill), in which a high decrease in the strip thickness is achieved to about 12-25 mm.

Subsequently, the material passes through an inductive heater and a multi-stand finishing line, in which the thickness can be reduced to below 0, 8 mm. This is followed by a cooling of the strip in the cooling section to adjust the

Material properties and after this there is a reel on which the tape is wound into coils, thus completing the production process in the ESP plant. A problem of ESP systems is that the strand can not be cast at the speed with which one

Fertigstraße a Vorband can roll out to a finished strip. Usual mass flows during casting are 6-10mm * m / s, while rolling, 20-50mm * m / s. Due to the relatively low

Strand speed is the heat losses in the strand in the leadership of the strand between the units and high during rolling. In addition, an induction furnace in front of the finishing train is necessary in order to lower the

Avoid temperature in the finishing train. By the

Consumption of high-quality electrical energy for heating worsens the overall energy balance of the ESP system. The low rolling speed also has a detrimental effect on the material properties and surface, since between The time required for recrystallization and scaling remains at the individual stages of acceptance.

According to EP 2 944 386 AI strands or

Continuous cast slabs from different casting plants placed in a common rolling mill, either in

Continuous or semi-continuous. It should be possible to switch between the two types of procedure. For this purpose, the strands or continuous casting slabs are fed in their own guides a ransfereinrichtung in which

Continuous cast slabs can be lifted to the level of the following rolling mill or in a cooling area. Due to the brevity of the plant, seen in the direction of transport, the internal heat of the just-cast slabs can be better utilized. However, it would be desirable to generally further increase the utilization of the internal energy of the strands or slabs.

OBJECT OF THE INVENTION It is therefore an object of the present invention to overcome the disadvantages of the prior art and a

Propose process by means of which steel strip can be produced continuously, energy-efficiently and in large quantities using continuous casting.

Presentation of the invention

This object is achieved by a method for the continuous production of steel strip

wherein a continuous casting plant has a plurality of casting devices, preferably comprising molds, and each casting device has a downstream strand guide, - By means of the casting facilities strands arise which are withdrawn via the respective strand guide and rolled in a hot strip mill, wherein at least two strands are arranged after the j eweiligen strand guides and before hot rolling in the hot strip mill in hot condition in a common strand guide on top of each other.

When hot here means that the strands of the casting heat are still hot. They then typically have a temperature between 800 and 1300 ° C, preferably between 1100 and 1300 ° C, more preferably between 1200 and 1300 ° C, on. The strands reach the hot state at the beginning of the common strand guidance ie without external

Heater .

A common strand guide is understood here to mean that the strands in the common strand guide can exchange heat with one another. So are the strands in the

common strand guide not by means of fixed installations, such as plates or a housing, which in each case encloses only one strand, continuously separated from each other. However, each strand can be guided individually, for example on rollers, whereby heat can be exchanged through the free space between the guide elements, ie between the rollers. The extent of the heat exchange is naturally greater, the smaller the distance between the strands is to each other.

After the production of hot strip very much energy

required, it has proven to be extremely advantageous to use multiple molds and hot strands, especially immediately after the individual strand guides (but in any case before the first rolling) to be stacked so that the strands are characterized by the radiated heat heat each other. The strands are preferably aligned parallel to each other. "Strands" also include, in particular, so-called pre-bands, which may have a thickness of 60-100 mm and a width of 0.5-3 m, so that the effect according to the invention is particularly pronounced if the strands have a large width in relation to the thickness Because in the process, the heat radiated across the width largely becomes an upper or lower one

contained strand, while the going into emptiness heat radiation through the narrow side walls of the strand at the edge, so seen in strand guiding direction to the left and right, not so much importance. Solidified strands, strand pieces and slabs are usually plate-shaped, so anyway flat, and are therefore usually arranged one above the other in a flat shape. Preferably, the respective strands have the same width.

The casting devices, in particular the molds, for example, arranged in a vertical plane and the strands are congruent (each other) withdrawn from the eweiligen molds eweils the molds downstream strand guides and on a common strand guide, in which the downstream strand guides open, stacked. In a staggered arrangement of the pouring devices, in particular molds (not in a vertical plane but offset laterally, for example), the subordinate downstream strand guides are on the common

Strand guide merged. A superposition of the strands is difficult, but possible with simultaneous, spaced lateral merge, although with increasing width of the strands. The merge point of the strand guides of the respective molds on the common strand guide or the point at which the strand guide of a casting device, in particular a mold, which is closest to a finishing line empties into the common strand guide, will furthermore be referred to as a mouth point.

In order to ensure a particularly good heat exchange between the broad sides of the strands in the common strand guide, it can be provided that at least two strands have a maximum of two strand thicknesses, preferably a maximum of one strand thickness

Strand thickness, are spaced from each other. The distance is measured in the vertical direction between the bottom of an upper strand and the top of a lower strand normal to the transport direction of the strands.

To prevent the scaling of the individual strands resp. To eliminate as much as possible, it may be provided that the common strand guide, possibly in addition the strand guides downstream of the respective molds, has an inert or a reducing atmosphere. As a result, the oxidation of the individual strands in the common strand guide is at least reduced, as a result of which less scale is rolled through the rolls in the hot strip mill.

In a first preferred embodiment of the

According to the invention, at least two strands are hot, ie approximately directly after the individual

Strand guides on a downstream common

Strand guide, congruent superimposed so that they touch each other. By superimposing the hot strands directly on or after the mouth point, the strands induce each other heat. They stay hot for longer Reduced radiation of heat to the environment and without a material connection with each other, making a furnace in front of the rolling mill or before the finishing train is obsolete. Due to the fragility of a furnace along the

Strand management thus saves considerable costs.

By using multiple molds, the productivity of the plant is significantly increased, as larger amounts of

Molten metal in the same time period simultaneously cast into strands and in the following rolling mill

be further processed.

Particularly preferably, at least two endless strands contacting one another are joined together to form a strip by rolling in a first rolling stand of the hot strip mill. In order to avoid having to use a furnace for heating the metal strands in front of the first rolling stand, the rolling stand is arranged immediately after the opening point, in order to connect the metal strands which come into contact and / or one above the other. It has been found that two layers of a variety of steel grades bond together when overlaid and rolled at a temperature greater than or equal to 1200 ° C. As a result, the strands connect by rolling to a uniform thick strand or. Tape . This welding of various strands in the rolling mill produces composite steel that has a variety of outstanding material properties.

The entrance thickness of the strand into the first roll stand is determined by the sum of the strand thicknesses of the individual

strands; the exit thickness is lower according to the decrease (for example by 40%). The mass flow of the exiting band is the sum of the mass flows of all entering strands. However, it can not immediately be concluded that the mass flows of the incoming strands are the same for equal strand thicknesses. Depending on the material hardness (and temperature) of the incoming strands can be here

Differences arise. A reaction to the

Casting Mirror control is the inevitable consequence, and the casting speed of each strand is to be adapted to the mass flow of the continuous strand resulting from the consolidation. There is one Leitgießgeschwindigkeit that can be set independently, but all the others

Speeds are then at this guide speed over the casting mirror control according to the resulting

Partial mass flows coupled during merging. Because the

Forming depends on the strand temperatures, can over

Control of the strand temperatures also an indirect control of the casting speed of a strand can be achieved.

Preferably, in a second embodiment variant of the method according to the invention, at least two strands are cut by at least one cutting device and in an oven in superimposed receptacles for strands

stored one above the other. In this version, a furnace is present, which is located in front of the rolling mill, ie before the hot strip mill. After cutting, the strands resp. Strang pieces (slabs) supplied to the superimposed recordings of the furnace and stored there. The strands resp. Strand pieces (slabs) usually do not touch each other. By this storage of hot strands or. Stranded pieces (slabs) are also saved energy in this variant, since the pieces of slab (slabs) illuminate each other. The strands need not be stacked before or during cutting, although this would have a positive impact on the energy balance. According to a preferred embodiment of the

According to the invention, at least two strands are cut, laid one over the other and placed in the furnace

supplied superimposed state. This variant is recommended if two or more strands

superimposed, so touching each other, and thus to be supplied together to the rolling stand. For this purpose, the strand guide serves as a transport device and leads the superimposed strands, e.g. the lower intake of the oven too. Accordingly, this receptacle must be designed such that at least two superposed strands find space therein.

In a preferred embodiment of the method according to the invention, the distance between the strands in the furnace is at most two strand thicknesses, in particular at most one

Strand thickness. Thus, the distance is approximately for Vorvorbänder between 120-200 mm, in particular between 60 and 100 mm. Due to the particularly tight storage, the heating energy of the

Oven can be greatly reduced. It is also conceivable that heating of the furnace can be dispensed with altogether if the intrinsic radiation of the strand pieces (slabs) is reflected accordingly.

Strands are preferably supplied to the receptacles of the furnace by means of at least one TranSportvorrichtung, in particular a gripping device, selectively and / or removed. Thus, strands can be stored in selected recordings and taken specifically. The TransportVorrichtung can move the cut strand pieces (slabs) in the vertical direction (ie raise or lower) and / or move in the horizontal direction, so move about normal to the transport direction of the strand. In a further preferred embodiment of the variant with furnace, the strands are fed individually to the first rolling stand of the hot strip mill. The advantage of this approach is that thus a high utilization of the rolling mill is guaranteed, as always a strand piece (slab) is available for rolling. Also for example at the

Maintenance of a mold can be rolled in the meantime, the strands of the other molds.

It is conceivable in the variant with furnace also that the strands are jointly, namely superimposed, the first rolling mill of the hot strip mill fed. As a result, composite steel is also produced in a simple and efficient manner in this case. Depending on the selection of the compositions of the individual strands, composite steel can be produced which combines the desired properties of the individual composite components in a composite material. If necessary, at least one strand by means of

Cooling devices are cooled in front of the first rolling stand of the hot strip mill. By adjusting the temperature, desired properties of the respective alloys can be determined

or deliberately control compositions of the respective strands.

In a device for the continuous production of steel strip, in particular for carrying out the method according to the invention, has a continuous casting at least two

Casting, in particular comprising molds, and each pouring device on a downstream strand guide, wherein the pouring devices are arranged one behind the other and / or one above the other and / or side by side and the respective strand guides the pouring devices open in a common strand guide, in which the strands can be arranged one above the other. In contrast to the prior art, the strands are directly after or at the

Muzzle point on a common strand guide to

mutual heating arranged one above the other.

It can be provided that at least two strands a maximum of two strand thicknesses, preferably a maximum of one

Strand thickness, spaced apart can be arranged.

In a further preferred embodiment of the

Device according to the invention is provided, that the distance of the pouring devices, in particular the molds to each other less than or equal to 2m, preferably less than Im is about the touch, preferably congruent superposition of j eweiligen hot strands on the common

To enable strand guidance. This type of arrangement of multiple molds saves space on the one hand and

on the other hand allows different strands of different molds touch as quickly as possible or are superimposed so that thermal losses are kept as low as possible.

In a further preferred embodiment of the

Device according to the invention is a first rolling stand of the hot strip mill immediately after a mouth point of

Strand guides arranged in the common strand guide. Due to the direct connection of at least two hot strands, the use of a furnace (and a

Cutting device) before the hot strip mill in this

Design variant superfluous. The layered material connected to each other after the first rolling stand is fed to further rolling stands and to a preferred thickness and Rolled wide. The mass flow is a multiple of the value otherwise achieved in an ESP system,

For example, 20mm * m / s with three superimposed

Strands or 35mm * m / s (up to 40mm * m / s) with five strands laid one on top of the other. This value is in the range of one

ordinary HSM (Hot Strip Mil1) of usual order of magnitude.

According to the alternative embodiment of the

Device according to the invention is after the strand guides, in particular in front of the mouth point in the common

Strand guide, arranged at least one cutting device and has a arranged after the at least one cutting device and after the common strand guide oven

at least two, preferably three to five, superimposed recordings for strands. This has the advantage that strands of the same type of metal and strands of different metal types, especially in continuous casting at a desired length cut off and energy-saving

can be cached. With the strand guides here again those strand guides are meant, which the

Casting equipment or. Subsequent molds are responsible for the formation of an internally no longer liquid strand. This can be followed by further strand guides, which guide the strands in the common strand guide. These

common strand guide could be designed here as a feed to the furnace, which ensures that the strands or.

Strang pieces (slabs) then come to lie one above the other in the oven. As a rule, each strand has its own

Cutting device provided.

In the embodiment variant with a cutting device, the casting devices, that is to say the molds, can be juxtaposed be arranged and only the strands, more precisely the strand pieces or slabs are arranged one above the other.

In the respective pictures of the oven, e.g.

different metal strands are stored hot and selectively removed for further processing. If different alloys for the strand pieces in the einzeInen shots, preferably shafts used, for example, softer material for the shafts 2, 3 and 4 and harder material for the shafts 1 and 5, so steel can be produced, which is also high strength and flexibility. One can b'eispielsweise also corrosion-resistant, higher alloyed steel in the receptacles 1 and 5, cheap low-alloy steel in the receptacles 2, 3 and 4 bring and receives in this way

less expensive, yet corrosion-resistant composite steel when the strands are then rolled over one another. The production of such composite steels is of course also possible in the embodiment described above with the endless strands.

In an alternative embodiment of the

Device according to the invention is at least one

Transport device, in particular a gripping device, arranged before and / or after the furnace, whereby strands can be selectively fed to the receptacles of the furnace and removed again. There may be more than one transport device in front of the furnace and more than one transport device after the furnace. As a gripping device is in particular a crane in question. It is also possible to others

TranSportvorrichtungen to use to supply the recordings of the oven individual strands. For example, strand guides, roller conveyors or conveyor belts could be used here. The distance of the shots in the oven to each other in one embodiment is a maximum of two strand thicknesses, preferably at most one strand thickness.

Furthermore, it can be provided that cooling devices are arranged in front of the first rolling stand of the hot strip mill. If necessary, the cooling devices serve to set specific material properties.

According to a further preferred embodiment variant of the device according to the invention, a common pan is provided for the molds and has a plurality of pouring tubes arranged one behind the other. By this embodiment of the pan several molds are fed in a simple manner from only one pan. The control of the casting speed can be selectively adjusted by means of closure devices, such as plugs or valves, or by other means.

It would be possible that the pan at least one,

preferably has at least two chambers. By the

Use of a chamber can be made with this pan only strands of the same material. at

Using two or more chambers within the ladle, different metals or alloys can be poured into the same pan into the intermeshing chambers without mixing. More than two chambers in a pan are conceivable. This has the advantage that when using separate pipes for the eweiligen chambers from a pan over spaced molds arranged different metal strands of different metal types or different Alloys simultaneously or consecutively on the

applying common strand guidance.

In a further preferred embodiment, at least two pans are provided for the molds. Identical molten metals are filled into the respective pans or molten metals with different stoichiometric composition or even different metals are used. A superposition of the metal strands along the strand guide is, of course, again possible, as in the previously mentioned embodiment variant.

The production costs per ton of steel produced are significantly lower in the inventive method than in previously known types of equipment.

BRIEF DESCRIPTION OF THE FIGURES The invention will now be explained in more detail with reference to embodiments. The drawings are exemplary and are intended to illustrate the inventive idea, but in no way restrict it or even reproduce it. Showing:

Fig. 1 is a schematic view of an inventive

Process for the continuous production of steel strip with superimposed strands without a furnace,

Fig. 2 is a schematic view of a device according to the invention

Process for the continuous production of Steel strip with a furnace and semi-continuous production,

Fig. 3 is a schematic view of an inventive

Process for the continuous production of steel strip with a furnace and superimposed strands,

4 is a detail view of FIG. 2 in side view, for molds arranged one behind the other,

Fig. 5 is a perspective view of a furnace with two

Recordings,

Fig. FIG. 6 is a front view of a three-cavity oven. FIG.

Fig. 7 shows a detailed representation as a variant of FIG. 2 in

Top view, for juxtaposed molds.

Embodiment of the invention

Fig. 1 relates to the first embodiment of the invention. Fig. 1 shows a schematic view of a method according to the invention for the continuous production of steel strip with a ladle 1, which has two pouring tubes IIa, IIb, which pouring tubes IIa, IIb are connected in each case to a mold 3a, 3b. The eweilige, the dies 3a, 3b downstream

Strand guide 4a, 4b terminates at a mouth point M on a common strand guide 8. The common strand guide 8 may for example be designed as a roller conveyor. The molds 3a, 3b and the strand guides 4a, 4b are here in a common vertical plane, the plane of the drawing. Liquid metal 2 is filled from the ladle 1 via two separate casting tubes IIa, IIb into the respective molds 3a, 3b, and strands are drawn off via the intermediate mold guide 4a, 4b downstream of the molds 3a, 3b, and to which

Muzzle point M arranged one above the other, namely

congruent superimposed, here on each other. Directly after the mouth point M there is a first rolling stand 6 of a hot strip mill, which connects the superposed, hot individual strands 5a, 5b, which are located simultaneously in the common strand guide 8, to form a common strip 7. Of course, one or more rolling stands 15 of a roughing train and a finishing train 12 can be arranged downstream of the first rolling stand 6. To the finishing train 12 close as usual cutting and reeling devices, which are not shown here.

Fig. 2 and the following figures relate to the second

Embodiment of the invention where the strands 5a, 5b, 5c are cut. In Fig. 2 shows a schematic view of a method according to the invention for the semi-continuous production of steel strip, the corresponding device comprises three molds 3a, 3b, 3c, three strand guides 4a, 4b, 4c downstream of the molds, each with three individual hot strands 5a, 5b, 5c, a mouth point M, a symbolically illustrated cutting device 9, which represents three cutting devices 9a, 9b, 9c (see FIGS. 4 and 7), a common strand guide 8, an oven 10, and a first rolling mill 6 of a hot strip mill, which of course a plurality of rolling mills 15 may be downstream, followed by a finishing train 12. The molds 3a, 3b, 3c and the strand guides 4a, 4b, 4c may here, in addition to or Alternatively to the vertical offset, also laterally, so be normal to the plane offset.

In Fig. 4, the molds 3a, 3b, 3c are arranged in strand guide direction offset in height one above the other, the molds

3a, 3b, 3c and the strand guides 4a, 4b, 4c are here in a common vertical plane, the plane of the drawing. The

Strand guides 4a, 4b, 4c are then designed to guide the strands 5a, 5b, 5c straight into the common strand guide 8, where the strands 5a, 5b, 5c are again arranged one above the other and at a small distance from each other, for example in the opposite direction Distance of a maximum of two strand thicknesses, preferably a maximum of one strand thickness. The hot strands 5a, 5b, 5c are cut individually by cutting devices 9a, 9b, 9c, one of which is arranged per strand guide 4a, 4b, 4c, before the mouth point M.

In Fig. 4 it can be seen that the uppermost strand 5a has been cut some time ago and a strand piece

(Slab) already in the oven at the top of the topmost receptacle is (dashed lines), while the strand 5a already moves beyond the cutting device 9a. The middle strand 5b has been cut straight, one strand is being inserted straight into the furnace 10, into the middle intake, so that the strand pieces of the uppermost strand 5a, the lowest strand 5c and the middle strand 5b - in

Seen Höhenriehtung - congruent with a distance to each other and can heat each other. The lowest strand 5c has also been cut some time ago and a strand piece (slab) is already in the oven at the bottom in the lowest intake (shown in broken lines), while the strand 5c already on the

Cutting device 9c moved out. The strand pieces of the Strands 5a, 5b, 5c can be arranged congruently one above the other according to the respective cutting device 9a, 9b, 9c and are thus located between cutting device 9a, 9b, 9c and furnace 10 in a common strand guide 8. Since the strand pieces of the strands 5a, 5b, 5c can also be arranged one above the other in the furnace 10, and in the case shown this is the case for the uppermost 5a and the lowest strand 5c,

the common strand guide 8 extends into the furnace 10. By means of a feed device, such as a gripping device 13, such as a crane, the individual extrudates can be lifted from the oven 10 to the rolling plane of the rolling stand 6 (strand pieces of the strand 5c) or

are lowered (strand pieces of the strand 5a) while

Strand pieces of the strand 5b can be transported on the same level from the oven 10, for example by means of a roller conveyor.

Fig. 6 shows a front view of a furnace 10, as shown in FIG. 4 can be used with three shots 14, in which just three pieces of strands 5a, 5b, 5c on top of each other

are located . The viewing direction here is the transport direction of the strands 5a, 5b, 5c. Of course, the oven 10 may also have more than three, for example, five receptacles 14 and

pick up five strands accordingly. Due to the proximity of the receptacles 14 and, accordingly, the strands 5a, 5b, 5c

Heat losses of the strands 5a, 5b, 5c are greatly reduced, since they heat each other.

Of course, the method of FIG. 4 can be performed with only two strands, or with four or five strands. Fig. 5 shows, for example, a perspective view of a furnace 10 with two receptacles 14, wherein here in a receptacle 14 a piece of a strand 5a, 5b is received. FIG. 7 is a variant of FIGS. 2 and 4 and is in

Top view shown. The molds 3a, 3b, 3c and the

Strand guides 4a, 4b, 4c can here only, or in addition to the vertical displacement, laterally, so normal to the plane in FIG. 2, be offset. The strand guides 4a, 4c are then designed such that they guide the strands 5a, 5c laterally onto the common strand guide 8, which forms a continuation of the strand guide 5b in the transport direction of the strand 5b. In the common strand guide 8, the strands

5a, 5b, 5c, more precisely their cut strand pieces, again above one another and at a small distance from one another

arranged, e.g. a maximum of two strand thicknesses, preferably at most one strand thickness spaced from each other. The hot strands 5a, 5b, 5c are namely for high utilization of the rolling stands in the semi-continuous operation first by means of cutting devices 9a, 9b, 9c, which resemble the j

Strand guides 4a, 4b, 4c are arranged in front of

Muzzle point M cut individually. The common

Strand guide 8 and the furnace 10 can then again as shown in FIG. 4 be formed.

If the common strand guide 8 in front of the oven 10 not as shown in FIG. 4 is formed, but only reach the strand pieces in one plane to the furnace 10, approximately in a straight horizontal continuation of the strand guide 5b, the individual strand pieces by means of a gripping device 13, such as a crane, in the furnace 10 in the eweiligen receptacles 14 (see FIG 5 and 6) can be lifted or lowered, while strand pieces of the strand 5b can be transported in the same plane in the oven 10, for example by means of a roller conveyor. In furnace 10, the strand pieces in receptacles 14,

preferably shafts, stored one above the other and the furnace 10 by means of another gripping device 13 individually removed, if necessary raised or lowered, and

rolled one after the other. Downstream of the rolling stand 6, further rolling stands of a rough rolling mill can be arranged (not shown here), after which there is a

Finishing mill 12. Subsequent cutting and

Coiler devices are not shown.

3 shows a schematic view of a method according to the invention for the continuous production of steel strip, the corresponding device comprises two molds 3 a, 3 b, the strand guides 4 a, 4 b arranged downstream of the molds, two hot individual strands 5 a, 5 b, the mouth point M, a common strand guide 8 , a cutting device 9, a furnace 10 with two already almost entirely in it, one above the other

laid, so touching each other, strands, a first rolling stand 6, a first rolling stand 6 downstream rolling mill 15 of a hot strip mill, in which a strand or. The molds 3a, 3b and the strand guides 4a, 4b are here again, as shown in FIG. 1, in a common vertical plane, the

Drawing plane.

The strands 5a, 5b are withdrawn via the j subdivision of the molds 3a, 3b subordinate strand guide 4a, 4b and on the

Muzzle point M arranged one above the other, namely

congruent with vertical distance from each other in the common strand guide 8. The distance between the strands 5a, 5b is a maximum of two strand thicknesses, preferably at most one strand thickness. After the mouth point M is a cutting device 9, with which the strands 5a, 5b are cut together. However, the strands 5a, 5b can also be cut before the mouth M, preferably For each strand 5a, 5b then a separate cutting device 9a, 9b provided (analogous to FIG. 4).

The resulting strand pieces are transported into the oven 10 by means of common strand guide 8 and / or gripping device 13 and stored there one above the other. If two already superimposed strands 5a, 5b are cut together, they can be supplied to the furnace 10 lying on each other. From there they can selectively individually by means of

Gripping device 13 taken and then successively in a first rolling mill 6 and the following rolling stands 15 of the hot strip mill including the finishing train 12th

to be edited .

But it could also several pieces of strand removed from the oven 10 by means of gripping device 13, superimposed un in the first rolling stand 6 are rolled into a band, which simply produces composite steel and a high

Utilization of the rolling stands can be achieved. It is also conceivable that two superimposed, so touching strands 5a, 5b introduced into the oven 10, heated and introduced immediately thereafter in the rolling train and welded. In this variant would be one

GreifVorrichtung 13 before and after the furnace 10 obsolete and it would be sufficient a single strand guide, such as a roller conveyor, as a transport device. List of reference numbers:

1 pan

2 liquid metal

3a, 3b, 3c mold (casting device)

4a, 4b, c of the mold downstream strand guide

5a, 5b, 5c individual hot strand

6 first rolling stand of a hot strip mill

7 common band

8 common strand guidance

9 cutting device

9a, 9b, 9c cutting device for strand 5a, 5b, 5c

10 oven

IIa, IIb pouring pipe

12 finishing line

13 gripping device (transport device)

14 recording

15 rolling stand

M mouth point

Claims

claims

1. Process for the continuous production of steel strip,

- wherein a Stranggießanläge several pourers, preferably comprising molds (3a, 3b, 3c), and each

Casting a downstream strand guide

(4a, 4b, 4c),

- By means of the casting strands (5a, 5b, 5c) arise, which on the eweilige strand guide

(4a, 4b, 4c) and rolled in a hot strip mill,

characterized in that at least two strands (5a, 5b, 5c) after the strand guides (4a, 4b, 4c) in the hot state in a common strand guide (8)

be arranged one above the other.

2. The method according to claim 1, characterized in that at least two strands (5a, 5b, 5c) a maximum of two

Strip thicknesses, preferably at most one strand thickness, are spaced from each other. 3. The method according to claim 1 or 2, characterized in that at least two strands (5a, 5b, 5c) are superimposed in the hot state congruent so that they touch each other.

4. The method according to claim 3, characterized in that at least two mutually contacting endless strands

(5a, 5b, 5c) by rolling in a first rolling stand (6) of the hot strip mill together to form a strip (7)

get connected .

5. The method according to claim 1 or 2, characterized in that at least two strands by at least one

Cutting device (9) are cut and stored in a furnace (10) in superimposed recordings (14) for strands one above the other.

6. The method according to claim 5, characterized in that at least two strands (5a, 5b, 5c) cut,

arranged one above the other, in particular superimposed touching one another, and the oven (10) in superimposed state, in particular in

superimposed state, be supplied.

7. The method according to claim 5 or 6, characterized in that the distance between the strands (5a, 5b, 5c) in the furnace (10) is at most two strand thicknesses, in particular at most one strand thickness.

8. The method according to any one of claims 5 to 7, characterized

characterized in that strands (5a, 5b, 5c) the receptacles (14) of the furnace (10) by means of at least one Transport device, in particular a gripping device (13), selectively supplied and / or removed.

9. The method according to any one of claims 5 to 8, characterized

in that the strands (5a, 5b, 5c) are supplied individually to the first rolling stand (6) of the hot strip mill.

10. The method according to any one of claims 5 to 8, characterized in that the strands (5a, 5b, 5c) together, namely one above the other, the first rolling stand (6) are fed to the hot strip mill.

11. Apparatus for carrying out a method for

continuous production of steel strip, wherein a continuous casting at least two casting devices, in particular comprising molds (3a, 3b, 3c), and each casting device is a downstream strand guide

(4a, 4b, 4c), characterized in that the pouring devices are arranged at a distance one behind the other and / or above one another and / or next to one another and the respective strand guides (4a, 4b, 4c) of

Casting in a common strand guide (8) open, in which the strands (5a, 5b, 5c) can be arranged one above the other. Device according to the preceding claim, characterized in that at least two strands (5a, 5b, 5c) a maximum of two strand thicknesses, preferably at most one strand thickness, are spaced from each other can be arranged.

Apparatus according to claim 11 or 12, characterized

in that the spacing of the pouring devices, in particular of the molds (3a, 3b, 3c), is less than or equal to 2m, preferably less than or equal to Im, around the touch, preferably congruent one

Overlay of the respective hot strands

(5a, 5b, 5c) on the common strand guide (8) to allow.

Device according to one of claims 11 to 13, characterized in that a first rolling stand (6) of the

Hot strip mill immediately after a mouth point (M) of the strand guides (4a, 4b, 4c) in the common

Strand guide (8) is arranged.

Apparatus according to claim 14, characterized in that after the strand guides (4a, 4b, 4c), in particular before the mouth point (M) in the common strand guide (8), at least one cutting device (9) is arranged and after the at least one cutting device (9) and after the common strand guide (8) arranged furnace (10) at least two, preferably three to five, superimposed recordings (14) for strands

(5a, 5b, 5c).

16. The apparatus according to claim 15, characterized in that at least one transport device, in particular a gripping device (13), before and / or after the furnace (10) is arranged.

17. The apparatus of claim 15 or 16, characterized

characterized in that the distance of the receptacles (14) to each other is at most two strand thicknesses, preferably at most one strand thickness.

18. Device according to one of claims 11 to 17, characterized in that a common pan (1) for the molds (3a, 3b, 3c) is provided and a plurality

Having successively arranged pouring tubes (IIa, IIb).

19. Device according to the preceding claim, characterized

characterized in that the pan (1) has at least one, preferably at least two chambers.

20. Device according to one of claims 11 to 17, characterized in that at least two pans (1) for the dies (3a, 3b, 3c) are provided.