WO2017140891A1

WO2017140891A1 - Continuous rolling in a multi-strand csp plant

Info

Publication number: WO2017140891A1
Application number: PCT/EP2017/053697
Authority: WO
Inventors: Jürgen Seidel; Dieter Rosenthal; Christoph Klein; Peter Sudau; Jürgen Merz; Heinz-Adolf MÜLLER; Denis Anders
Original assignee: Sms Group Gmbh
Priority date: 2016-02-17
Filing date: 2017-02-17
Publication date: 2017-08-24
Also published as: WO2017140886A1

Abstract

The invention relates to a method concerning a plant (11) for producing hot-rolled strips from metal, preferably steel, according to the CSP plant concept, comprising at least two casting machines (12a, 12b) for casting thin slabs (i, i+1) having a thickness of < 150 mm and a downstream rolling train (15) for rolling the thin slabs (i, i+1) into thin strips in semi-continuous operation or continuous operation, characterized in that a device (1) for joining thin slabs (i, i+1) is arranged after the at least two casting machines (12a, 12b) and before the rolling train (15) in the production direction, wherein, in a defined time interval, the sum of the cast thin slab lengths from at least two casting machines (12a, 12b) and the thin slab length that enters the first roll stand (15) after the device (1) for joining thin slabs (i, i+1) satisfies equation (I) at least in a continuous production phase. The invention further relates to a corresponding method.

Description

Continuous rolling in a multi-strand CSP plant

1. Field of the invention

The invention relates to a plant for producing hot-rolled strips of metal, preferably steel, according to the CSP plant concept and a method for producing hot-rolled strips on a plant according to the CSP plant concept, in semi-continuous operation or endless operation , In CSP plants thin slabs are continuously cast on at least one casting machine and then substantially using the casting heat directly in a downstream mill train either in batch mode after cutting the

Thin slabs or in semi-continuous operation or continuous operation, optionally after the connection of pre-cut to length thin slabs, finish-rolled in the finishing train to thin strips.

2. State of the art

Means for connecting Vorbändern or billets before a finishing train for endless rolling have long been known. Examples of the prior art are DE 2 742 151 C2, DE 2 844 354 A1, EP 0 201 744 A2, EP 0 492 368 B1, EP 0 495 124 B1, EP 0 691 163 A1, US Pat EP 0 661 1 12 B1 and DE 10 062 193 B4. As connecting technologies, those skilled in the art are in principle the mechanical

Connect, for example, by riveting and subsequent co-rolling, by pressure welding, preferably for inductive preheating the joint, known by positive connection, arc welding and overlapping of the pre-bands and subsequent cutting and simultaneous pressing.

In particular, in CSP plants, the rolling speed must be substantially matched to the speed within the upstream casting machine, either to allow a direct use without cutting the cast thin slab or to use the finishing train in a business-wise meaningful way. In patent applications DE 10 2009 037 278 A1 and EP 0 889 762 B1 it is described by way of example to cast a thin slab endlessly in a single-strand casting installation and then to roll it down directly to the desired final thickness without interruption in a rolling train.

The disadvantage here is that with the mass flow of the casting plant must also be rolled and therefore often sets a relatively low Endwalztemperatur and / or additionally the Vorband must be rehashed consuming within the rolling mill. Furthermore, the productivity of the entire system is economically too low, since only one casting machine can be connected to the rolling train during continuous casting rolling, but the rolling train in principle allows a significantly higher mass flow than a single casting machine.

3. Object of the invention

It was therefore an object of the invention to provide a system and a method by means of which the abovementioned disadvantages can be overcome. This object is achieved on the device side with the features of claim 1 and the method side with the method features according to claim 12.

Advantageous embodiments of the invention are in both the dependent

Claims as well as in the detailed description of the invention. 4. Summary of the invention

The aim of the plant for producing hot-rolled strips of metal and the related method is to match the total mass flow of the casting strands and the mass flow of the rolling mill to each other. Excluded are, of course, the start-up and Ausfädelphase in the two parts of the plant and production steps in which areas of the thin slabs must be cut away with a pair of scissors. The material flow or the mass flow can also be in Form of a slab length flow. During the stationary production phase, therefore, the sum of the cast thin slab lengths must correspond substantially to the thin slab length which enters the first rolling stand behind the device for connecting thin slabs. So that this connection process allows trouble-free and the at least two casting machines with the rolling mill can actually be brought into operative connection so that a semi-continuous operation or an endless operation of the CSP plant is enabled, the equation

thus be ensured that the sum of the cast thin slab lengths (or mass flows) over all the casting strands in a given period of time, divided by an adjustment factor

Thin slab length (or mass flow) entering the first roll stand behind the thin slab joining device is within

Time period correspond.

The meaning of the variable in the above equation is as follows:

ITIG: number of casting machines,

V _Bm : average casting speed of the cast strand at the exit of the

Casting machine m,

V _F : average feed speed of the thin slab into the first

Roll stand behind the device for joining thin slabs, t- | ... t ₂ : time period in which the speeds or / and the mass flow is considered,

dt: integral time step,

K: adjustment factor. The adaptation factor K results in consideration of, for example, head losses or / and changes in the temperature expansion. The influence of Temperature change to the factor K in the range from the casting machine to the rolling mill

is calculated as follows: K (AT) = 1 -a ^* (T _G _{e e} ß-Twaizstr) with

TGieß: mean slab temperature at the casting machine

Twaizstr average slab temperature at the inlet of the rolling train

a: coefficient of thermal expansion.

Furthermore, an adjustment by means of an adjustment factor K may be necessary due to speed errors AV _F in the rolling train as a result of eg deviation in the advance determination or velocity errors AV _Bm in the casting by eg roll diameter deviation.

The adjustment factor is K = 0.95 ... 1.05, and more preferably K = 0.99 ... 1.00.

The total adaptation factor K in the mass flow equation or the

Corresponding corrected setting parameters for the casting speeds and finishing line feed speed can be defined by thin slab position monitoring or time monitoring of the slabs

Reference positions influenced and the value K in the form of a short and / or

Long-term adaptation to be corrected.

The values t- ₁ , t ₂ must be such that it is ensured that a

or that the buffer line in front of the welding machine does not "overflow", ie the values ti, t ₂ depend on the length ratios of the transport or kiln lines, possible transport times of the ferries and / or length of the The difference t ₂ -ti represents a time period in which the mass flow is considered.

Cyclically, the caster and rolling mill conditions, in particular the speeds, are queried and the conditions are considered in the period ti-1 ₂ . In continuous production mode (not start-up phase or end of production), the condition in the given equation must be kept constant.

The at least two casting machines are used in this case so that the thin slabs produced thereon run into a device for connecting thin slabs in front of the rolling train.

The plant according to the invention and the method according to the invention ensure that no gap arises in the course of the process and that the thin slabs can be welded together. On the other hand, there must be no congestion, for example due to excessive thin slab production. Therefore, the lengths produced in the various plant components should preferably be controlled and monitored by a process model. When

Adjustment parameters for the adjustment of the lengths serve both the

Ready-made strip speed within the permissible finished strip temperature tolerance and thus feed speed into the rolling train and on the other hand the

Casting speed of the individual casting strands themselves.

The casting thicknesses and the casting speeds can vary over the length

be different. However, it is desirable to keep the casting thickness as equal as possible. A cast strand can pour more slowly. Accordingly, the other strand, for example, a two-strand plant must pour faster to the

To keep the total thin slab length. Different materials can be cast for the different strands. However, the same materials simplify the process in the finishing train. Also, the finished strip thickness and usually also the rolling speed can vary over time, if, for example, is changed to a different thickness of the tape to be produced.

If the mean total thin slab length produced differs

Casters from the running into the rolling mill medium length, for example, because the rolling line speed is set too high, is switched from endless operation to batch operation and welding together exposed to the thin slabs. This can be done for example in Gießproblemen or failure of one or more casting strands, or because the final rolling temperature and thus the rolling speed must be set higher, or in other emergencies.

Those skilled in the art will appreciate that CSP plant concepts include not only those plants in which the cast thin slab enters the finishing train without any pre-deformation, but also those plant concepts in which the thin slabs are cast in a casting-rolling process poured into a slab and then brought close to the casting machine in a casting-rolling stand to the desired formed thin slab thickness. In this

if necessary, a last cut is made,

Reheating and / or connection of thin slabs from at least two casting machines before entering the finishing train, but only after this first transformation in the so-called cast-rolling framework. A rolling stand arranged directly behind the casting machine and endlessly connected to the casting machine (cast-rolling stand) is considered by definition to be a description or consideration of the method and apparatus as part of the casting plant and the products thus produced are referred to as thin slabs and so valued. The speed of the product leaking from this foundry rolling stand is also referred to as V _Bm .

Likewise, embodiments are to be understood as within the CSP plant concept, which optionally ovens before and / or after the device for

Connecting thin slabs comprise and / or scaffolds for pre-forming the cast thin slab prior to use in the finishing train. Likewise, embodiments are to be understood as within the CSP plant concept, which comprise, for example, so-called ferry modules, by means of which the cast products and / or pre-formed cast rolled products and / or preheated cast products are shifted between parallel production strands and / or or can be exchanged. According to the invention, the substantially independent operation of the casting machines and the finishing train brings particular advantages. The disadvantage of a single-strand continuous casting-rolling plant, as described for example in EP 0887962 B1, with lower productivity and the rolling with lower

Casting mass flow and too low Endwalztemperatur be avoided with the inventive system and the inventive method. An endless rolling in the finishing mill with flexible high speed at a suitable arbitrary Endwalztemperatur and regardless of the

Casting speed or the caster mass flow of a single

Casting machine is thus possible.

According to the invention, the mass flow of two or more casting strands is coordinated with the finishing train. As manipulated variables are preferably the

Casting speeds of the strands, which can be both the same and different, as well as the rolling speed of the finishing train at a given

Band thickness and preferably to be set interstitial cooling selected.

Preferably, an oven serves as a buffer and prevents the cooling of the

Thin slab end. The system according to the invention can be operated flexibly. For less critical products, in batch mode, i. H. with single bands, rolled in the finishing train and especially in thin and / or high-strength grades is the

Finishing mill operated in endless mode or semi-endless mode. When not using the thin slab connection device, thus in batch mode, this area is preferably thermally insulated, for example by means of

Insulating hoods within the transport line or by means of insulating hoods, which are brought into the transport line for this case.

According to the invention, the sum of the mass flows of the casting machines and the finishing train are matched within a period to be considered. Above all, the sum of the cast is considered

Thin slab lengths from the at least two casting machines and the Thin slab length, which in the first roll stand behind the device for

Connecting thin slabs shrinks. Preferably, for this purpose, the casting machine and finishing rolling conditions, in particular their

Queried speeds and in a corresponding rule and

Fed control model.

For example, if the casting speed of a single strand leaving a first casting machine decreases, the other strand must fall out of the other

Casting machine can be produced with a correspondingly higher casting speed. If in this case the speed limit of the individual casting machine is reached, a reduction of the drawing speed of the rolling train is preferably additionally or alternatively carried out.

The applicability of the method according to the invention and the usability of the system according to the invention typically apply to the following production conditions:

1. The continuous rolling at an average mass flow, defined as the product of

Casting speed in m / min and a thin slab thickness in m, each

Casting machine of> 0.25 m ² / min when using two casters and a mean mass flow per casting machine of <0.25 m ² / min when using three casting machines.

2. At a feed rate into the first roll stand behind the device for joining thin slabs of> 0.10 m / sec.

3. At an average mass flow into the rolling mill, defined as the product of ^draw- in speed in m / min and a thin-slab thickness in m, of> 0.50 m ² / min.

The use of the thin slab bonding apparatus and the endless or semi-continuous rolling or alternatively the batch rolling also depends on the rolled one Endbanddicke and produced material from. For example, in soft material (low carbon), strips with a thickness (limit of thickness that can be defined in the process model) of H> 1.5 mm are rolled in batch mode and strips of H <1.5 mm are produced by joining thin slabs and subsequent continuous rolling. The limit thickness for switching the rolling mode of, for example, 1, 5 mm is increased or adjusted for higher-strength grades.

According to the invention are as thin slab bonding method optionally the

Friction welding, resistance butt welding, flash butt welding, butt welding, laser welding, autogenous welding and any form of mechanical connection, normal compression after heating the joint or press cutting as it is

For example, in EP 0 770 434 B1 is described, or a combination of these connection methods conceivable.

However, preference is given to a system and a method that are capable and designed to the end faces of two on a conveyor to the

Finishing mill arranged thin slabs by means of friction welding together.

This results in a faster, more reliable and less expensive

Connection technology, which connects two hot products together for the first time. According to the invention, the linear friction welding or

Vibration welding applied. In contrast to the conventional one

Friction welding of cold components, as described for example in US 5,165,589 A, the thin slabs according to the invention are already in the area before the finishing train at a temperature level of> 900 ° C to above 1,100 ° C before. The expert speaks here of hot products, which are characterized in that they have a temperature above 2 Tuquidus. Of course, this temperature Tuquidus is dependent on material or alloy, but in the grades cast by CSP plants is regularly above 900 ° C or at

I Liquidus ^- 1,550 ° C. In this preferred embodiment of the invention is reduced by the friction welding of warm metallic products in the sense described above, the warm-up time of the surface and thus the connection time at Reibverschweißen itself. In friction welding is targeted by vibration and pressure very energy efficient heat generated at the joint level and near the surface, usually in a range <50 mm, measured from the contact surface, which produces the temperature required for welding together. Furthermore, in friction welding no additional media such as welding agents or others

Fasteners such as rivets, etc. needed. The effort required for assembly is small compared to other known technologies. Steels with a higher carbon content, in which other bonding methods either fail or are particularly expensive, can also be welded together particularly well.

Preferably, the apparatus for friction welding of warm metallic products comprises a conveyor for at least two successively arranged thin slabs and a pressing device for pressing the head of the trailing thin slab to the end of the leading thin slab. This pressing device preferably has a release part and a so-called fixed part in order to fix the contact surfaces of the thin slabs to each other, wherein the loose part relative to the fixed part can be vibrated so that the two consecutively arranged thin slabs together under the influence of

Friction energy between the contact surfaces are welded.

It is preferred if the pressing device is arranged to be movable along at least part of the conveyor. As a result, a device is provided which is capable of connecting two consecutive

Flexible and, where appropriate, in time with the promotion of the individual thin slabs to the finishing train to implement thin slabs. In this context, it is particularly preferred if the movability of the pressing device is designed to be synchronizable with the speed of the conveying device. Due to the fact that the system according to the invention with the preferred Reibverschweiß device to the still warm metallic products

must inevitably remove present and adhering scale before friction welding at least in significant parts, the system must be designed so that the scale in a suitable manner from the contact surfaces, thus the

End faces that can be removed from thin slabs. This can

for example, by moving the thin slab ends vertically in the thickness direction and / or horizontally in the width direction to each other, preferably at lower

Contact pressure and greater amplitude, done, whereby the scale can be scraped off or pushed away to a large extent. Alternatively, the majority of the scale can be laterally on the head sides immediately before assembly by mechanical brushing, milling, planing or filing, descaling the

Eliminate face surfaces by means of a jet of water or brief compression of the thin slabs in the head-to-tail area from the side or from the top using tinder breakers or pinch rolls. The latter is particularly advantageous, since at the same time the slab ends are directed and of eventual

Bulges are freed. Preferably, a pressing or clamping device preferably first detects and fixes the end of the leading thin slab. This so-called fixed part of the pressing device preferably follows the feeding speed of the thin slab into the rolling train. The lagging thin slab is by means of

Pressing device moves in front of the end of the leading thin slab. The so-called loose side of the pressing device then fixes the end and moves the head of the trailing thin slab against the end of the leading

Thin slab.

The Losseite the Andrückvorrichtung is preferably after the head and end of the successive thin slabs lie together at the same time

Applied applied predetermined pressure and / or temporally variable pressure waveform in vibratory motion. The lot side is thus moved opposite the fixed side, so that surface heating of the two contact surfaces of the thin slabs to be joined together is produced as a result of the friction energy at the contact surface.

Preferably, the contact pressure in the level is chosen to be slightly smaller than the yield strength of the material and controlled by a model. At unfavorable

Creation conditions (point or line contact) can lead to a

Roughness removal and plastic deformation come on the head sides, so that the friction surfaces are increasingly increased. The oscillation frequency is preferably <250 Hz and particularly preferably <50 Hz. After setting a sufficiently high joining zone temperature, preferably 65% of the solidus temperature to slightly below the solidus temperature, the deceleration of the vibration drive and the

Compressing the two ends against each other, preferably under a pressure which is set higher than the flow resistance of the material, and the actual bonding process or welding takes place.

The vibration amplitudes at the contact surfaces of the thin slab during the vibratory movements in the thickness direction are preferably <80% of the thickness of the product and / or in the width direction <50 mm.

Preferably, the pressure is maintained from the head opposite the end as long or avoided a train between the head and the end until the

Welding process or the necessary cooling process at the joint

is completed.

Preferably, before the head and the end of the successively arranged

Thin slabs are finally moved against each other for welding, the ends machined, preferably trimmed or cut in full, so that there is a clean, two-dimensional contact of the two joining ends, thereby also a simultaneous descaling can take place. This can be done for example by means of a punch, which is preferably moved synchronously with the two thin slabs when the ends are cut. In front and behind the In addition, scissors punches can be arranged with thin slab hold-downs to support the trimming or cutting process.

Preferably, the respective succeeding thin slabs are also laterally aligned before they enter the region of the connection device and / or before they are cut at the ends, so that they are positioned centrally and on average just in line with the leading thin slab.

The clamping process removes temperature from the thin slab surface. Preferably, therefore, by activation of an induction heater behind the connecting device, this thin-slab region can be locally reheated again. The roller table rollers of the conveyor in the connecting section are preferably moved out of the effective range of the pressing device during the friction welding process. Moreover, during the

Joining process temporarily swung or pushed thermal insulation in the transport area to minimize the temperature losses of the thin slabs.

The vibratory movement of the press-on or clamping device on the loose side may during the heating process in the width direction or alternatively in

Thickness direction or combined in both directions following an elliptical orbit and / or with a circular movement around the center of the

Slab contact surface are performed. Preferably, both can also be used in a heating process

Clamping devices of the pressing at the head and end are moved relative to each other relatively vibrating, ie, for example, in the thickness direction, the two ends against each other are swinging towards each other, so have two so-called loose parts. In this way, the oscillation amplitude of the respective sides can be reduced within the pressing device, whereby optionally vibrations transmitted to the environment can be reduced. The vibration application can be done mechanically by a crank drive or by hydraulic and servo valve technology or by electromagnetic drives. In the bonding process, it is preferred that the head and end of the thin slabs to be joined together have temperatures that are as equal as possible, a temperature difference of at most 50 ° C. being particularly preferred. This can be done by appropriate temperature control and flow rate within an upstream furnace, preferably a CSP furnace, a cooling of the warmer slab side, for example, with water or an inductive

Heating upstream of the connection path and / or local heating of the colder end can be achieved.

Preferably, the pressing device or at least parts thereof,

For example, the jaws, preferably along with other aggregates such as a pair of scissors, rollers and / or Dämmhauben etc. advanced during the bonding process in the material transport direction of the conveyor and performed linear. To intercept or damp the vibrations and transmit them

Vibrations to the adjacent vicinity of the thin slabs in the width and / or thickness direction are preferably drivers and / or lateral guide rollers provided at a predetermined distance from the joint. The clamping by means of the pressing device can both the upper and

Bottom and alternatively be performed on the side surfaces of the thin slabs. Also, a combined clamping on the side surfaces and locally in the middle region at the top and bottom is preferred. The bearing surface between the pressing device and the thin slab can be designed as a full-surface edition or alternatively with raised shapes to securely fix a clamp. When clamping between the top and bottom is preferably

at the same time the thin slab is pressed straight and possible bulges or waves eliminated. The hot side of the pressing device may be made of heat-resistant steel or of heat-insulating or heat loss-reducing material. In order to be able to optimally control the connection process and to minimize the heating time during friction welding, it can preferably be provided that

To measure surface temperature at the joint. From the measured

Maximum temperature is then preferably determined by a computer model depending on the thin slab material and the thickness of the temperature in the central region of the joint surface. After reaching the required Dünnbrammentemperatur and taking into account the friction time at the appropriate temperature is

Preferably, the heating process is terminated by braking the vibration process and the compression of the two ends against each other and the actual connection process or the welding process can take place.

The contact temperature or the time of the actual connection process can also be estimated as an alternative or in addition by calculating the frictional heat theoretically taking into account the mean relative velocity of the friction surfaces to each other, the average contact pressure, the amplitude or the average friction travel and the number of oscillations.

Of course, all temporal processes of the friction welding process and the

Activation of the above-mentioned devices and setting values (specific pressure, oscillation stroke, relative speed of the contact surfaces to each other,

Oscillation times, contact times) also depending on the to be connected

Materials, inlet temperatures and product thicknesses in a preferred

Embodiment of the invention predetermined and controlled by a process model.

The inventive method and the plant for producing hot-rolled strips of metal on a plant according to the CSP plant concept in semi-continuous operation or endless operation into thin strips comprises the steps of casting thin slabs on at least two casting machines, preferably at least two casters arranged parallel to each other, of at least two on a conveyor of the at least two

Casters to a rolling mill promoted hot thin slabs and the conveying of the interconnected thin slabs to the rolling train. In this case, according to the invention in a defined period of time, the sum of the cast thin slab lengths of at least two casting machines and the

Thin slab length, which in the first roll stand behind the device for

Connecting thin slabs enters, at least in a continuous

Production phase of the equation

suffice. Preferably, when the produced average total thin-slab length produced falls short of all within a defined period of time

Casting machines are switched from the endless rolling mode to the batch rolling mode from the middle length running into the first rolling mill behind the thin-sliver connecting device. In this way, a method is provided which is able to perform in principle the semi-continuous operation and / or the endless operation, if necessary, especially in emergency situations or at the beginning and end phases of the production process and / or changes in the

Production parameters and / or the products and / or educts to be used in a suitable manner.

It is particularly preferred if, when the thin-slab connecting device is not in use, heat-insulating means are moved in or pivoted in this region of the guide device in order to minimize temperature losses of the thin slabs. The description of the figures is explained in more detail below with reference to six figures. shows a schematic view of a first embodiment of a plant according to the CSP plant concept. shows a schematic view of a second embodiment of the system according to the invention according to the CSP plant concept. shows a schematic view of a plant according to the invention according to the CSP plant concept. shows a side view of a device for friction welding within a system according to the invention in an embodiment of the invention. shows a side and top view of a pressing device within a device for friction welding in a plant according to the invention, and shows a plan view of the pressing device as part of a device for friction welding warm metallic products during the step of moving the contact surfaces relative to each other within a plant according to the invention according to the CSP plant concept.

6. Detailed description of individual embodiments

Figure 1 shows an inventive system 11 according to the CSP plant concept, consisting of two parallel casters 12a, 12b and downstream (left to right in the drawing) downstream furnaces 13a, 13b. Thin slabs i, i + 1 extend from the casting machines 12a, 12b into the furnaces 13a, 13b and, if appropriate, are cut to length before the furnaces 13a, 13b. From the furnace 13b, thin slabs i + 1 cast by the casting machine 12b can be brought into the furnace 13a via a ferry 14. From the furnace 13a, in turn, the slabs i, i + 1 leave both casting machines 12a, 12b and enter the apparatus 1 for joining thin slabs i, i + 1. In this apparatus 1 for connecting the thin slabs i, i + 1, the friction welding of two successively arranged thin slabs i, i + 1 preferably takes place before they are conveyed into the finishing train 15 after friction welding.

FIG. 2 shows a further embodiment of a plant 11 according to the CSP plant concept with likewise two casting machines 12a, 12b, which are arranged parallel to one another as well as the downstream furnaces 13a, 13b. Behind the ovens 13a, 13b, in turn, a ferry 14 is arranged to transversely convey a transverse transport of the thin slabs i, i + 1 from the furnace 13b into the production line downstream of the furnace 13a. The thin slabs i, i + 1 from both casting machines 12a, 12b are subsequently conveyed into a device 1 for connecting the thin slabs i, i + 1 and connected to one another at the front side so that a semi-endless operation or an endless operation of the CSP Plant can be performed in total. After leaving the device 1 for joining the thin slabs i, i + 1, the interconnected thin slabs i, i + 1 first pass through a roughing stand 16 before the pre-rolled thin slabs i, i + 1 are introduced into another furnace 17, in order to produce the Finish rolling within the finishing train 5 required temperature of the thin slabs i, i + 1 provide. Instead of a roughing stand 16, a plurality of roughing stands (not shown) can also be used. FIG. 3 shows a further embodiment of a plant 1 according to the invention of the CSP plant concept, comprising two casting machines 12a, 12b arranged parallel to one another for casting two thin slabs i, i + 1. The

Thin slabs i, i + 1, after leaving the casting machines 12a, 12b, are passed through respective cast-rolling stands 18a, 18b and pre-rolled on thin strips of lesser thickness. After leaving the Gießwalzgerüste 18a, 18b enter the thin slabs i, i + 1 in the respective ovens 13a, 13b, which also in this embodiment, between the ovens 13a, 13b, a ferry 14 to

Transverse transport of the thin slab i + 1 from the furnace 13b is provided in the furnace 13a. Both pre-rolled thin slabs i, i + 1, after leaving the furnace 13a, enter the device 1 for joining the thin slabs i, i + 1 to thereby produce semi-continuous or endless thin slabs i, i + 1, which are then introduced into the finishing train 15 be finished there to thin ribbons. Instead of a casting roll stand 18a, 18b to be arranged behind each casting machine 12a, 12b, it is also possible to use a plurality of continuous casting stands 18a, 18b in series. Furthermore, the CSP plant 11 behind a casting machine 12a, 12b without subsequent casting stand 18a, 18b and behind another

Casting machine 12a, 12b be performed with subsequent casting stand (s) 18a, 18b.

FIG. 4 shows a side view of a device 1 for friction-welding warm metallic thin slabs i, i + 1, which consists of several (not shown)

Casting a CSP plant to a (not shown) finishing mill be promoted. In order to be able to switch this CSP system from batch mode to a semi-continuous rolling mode or an endless rolling mode, a plurality of thin slabs i, i conveyed within a conveyor 2, consisting of a roller conveyor having a plurality of rollers 2a to 2d, are connected +1. Both the end of the leading slab i and the head of the lagging thin slab i + 1 are cut within a means for processing 3, here a punch, on the one hand tinder to each other

to remove opposite contact surfaces and on the other hand to create complementary contact surfaces within the thin slabs i, i + 1. Of the Punch 3 followed by run the thin slabs i, i + 1 by driving or straightening rollers 4 and then by a Entzunderungsanlage 8 in the

Pressing device 6 into it. As an alternative to descaling the end faces, the area after cutting the two faces of the thin slabs i, i + 1 from the scissors 3 to the beginning of the friction welding process in the entire region of the connecting device 1 and / or only on the end faces of the thin slabs i, i + 1 be placed under the protective gas during transport or there almost under

Vacuum conditions are promoted. The pressing device 6 consists of two clamping devices 6a, 6b, the one lot side L at the head of the lagging

Thin slab i + 1 and a fixed side F at the end of the leading thin slab i includes. The entire pressure device 6 can be moved at least over a partial section of the conveyor 2. In addition, the clamping devices 6a, 6b can be moved relative to one another such that on the one hand the end of the leading

Thin slab i can be brought into contact with the head of the trailing thin slabs i + 1 and on the other hand, a desired contact pressure can be applied to the contact surfaces of the two thin slabs i, i + 1. In the illustrated

Embodiment can be applied by means of the Losseite L of the clamping device 6a, 6b required for the friction welding vibration to the head of the trailing thin slab i + 1. Over a partial length of the conveyor 2, a series of insulating hoods 7 are provided above the thin slabs i, i + 1 both in the conveying direction before and after the pressing device 6 to the

Reducing the temperature of the hot thin slabs i, i + 1 preferably restricted so that no further heating of the welded together thin slabs i, i + 1 can be done before use in the (not shown) finishing train. The pressing device 6 is also a deburring device 8 for removing an optionally produced during the friction welding process

Pressbarts provided. Finally, the rollers 2 a to 2 d of the conveying device 2 arranged in the area of the pressing device 6 can be moved away from the thin slabs i, i + 1 in order not to influence the action of the pressing device 6. Preferably, when all the roller table rollers 2a - 2d of the conveyor 2 arranged in the conveying direction pressing device 6 can be moved vertically away from the thin slabs i, i + 1. FIG. 5 (bottom) shows a plan view of a pressure device 6 within a device for friction welding as part of a system according to the invention and (top) a side view along the section AA of FIG. 5 (bottom). The pressing device 6 has two clamping devices 6a, 6b, wherein the

Clamping device 6b is designed as a fixed part F of the leading slab i following, and the clamping device 6a is assigned as a loose part of the subsequent slab i +1. The clamping devices 6a, 6b can be moved toward one another in such a way that the contact surfaces of the slabs i, i + 1 can be applied to one another under predetermined pressure. At least the lower saddles of the respective clamping devices 6a, 6b have, in this exemplary embodiment, for securely fixing the slabs i, i + 1, raised projections 10, which are in contact with the underside of the slabs i, i + 1. These raised projections 10 preferably extend over the entire width of the clamping device 6a, 6b, but at least over the entire width B of the slabs i, i + 1.

Figure 6 shows a plan view of the pressing device 6 as part of

Device for friction welding within the system according to the invention, designed for friction welding of warm metallic thin slabs i, i + 1. Both the slab i and the slab i + 1 are held by the respective clamping devices 6a, 6b. The contact surfaces of the slabs i, i + 1 are designed to be complementary to one another. On the clamping device 6a of the Losseite a vibratory movement in the width direction of the slab i + 1 is given by suitable means whereby the movements of the head of the trailing thin slab i + 1 shown with arrows 9 is induced relative to the fixed end of the leading slab i. The movement of the slab i + 1 may be in the width direction of a straight path or as shown here a curved trajectory (corresponding to the

Face shape). The fixed side of the clamping device 6b holds the

Slab end i in position with respect to width direction B. Optionally, under a predetermined pressure on the contact surfaces and preferably under suitable temperature measurement then the friction welding of the slab i with the slab i + 1. LIST OF REFERENCE NUMBERS

1 device for connection

2 rolls

3 means of processing, punching scissors

5 descaling unit

6 pressing device, clamping parts

7 insulating hoods

8 devastating device

9 arrows

10 protrusions

1 1 plant

12 casting machine

13 oven

14 ferry

15 finishing train

16 Vorgerüst

18 Cast rolling mill B Width of the slab

I, i + 1 slabs

F fixed side, fixed part

L Losseite, Losteil

Claims

claims

1. Plant (1 1) for producing hot-rolled strips of metal, preferably steel, according to the CSP plant concept, comprising at least two casting machines (12a, 12b) for casting thin slabs (i, i + 1) with a thickness of <150 mm, and a downstream rolling line (15) for rolling the thin slabs (i, i + 1) in semi-endless or endless to thin strips, characterized in that in the direction of production after the at least two casting machines (12a, 12b) and before the rolling mill (15 ) a device (1) for connecting

Thin slabs (i, i + 1) is arranged, wherein in a defined period of time, the sum of the cast thin slab lengths of at least two casting machines (12a, 12b) and the thin slab length, in the first rolling stand (15) behind the device (1) for connecting of thin slabs (i, i + 1) enters the equation at least in a continuous production phase

suffice, with:

ITIG: number of casting machines,

V _Bm : average casting speed of the cast strand at the exit of the

Casting machine m,

V _F : average feed speed of the thin slab into the first

Roll stand behind the device for joining thin slabs, t- | ... t ₂ : time period in which the speeds or / and the mass flow is considered, dt: integral time step,

K: adjustment factor.

Plant (1 1) according to claim 1, characterized in that the

Adjustment factor (K) has a value of 0.95 to 1.05, preferably from 0.99 to 1.00.

Plant (1 1) according to one of the preceding claims, characterized

characterized in that the device (1) for connection is a device for friction welding the end faces of two thin slabs (i, i + 1).

Plant (1 1) according to one of the preceding claims, characterized

characterized in that the device (1) for connecting thin slabs (i, i + 1) comprises a pressing device (6) for pressing the head of the trailing thin slab (i + 1) against the end of the leading thin slab (i), the pressing device (6) has a loose part (L) and a fixed part (F) or two loose parts (L) and for fixing the contact surfaces of the thin slabs (i, i + 1) to each other, wherein the loose part (L) relative to the fixed part (F) or the two loose parts (L) can be vibrated relative to one another in such a way that the two successive thin slabs (i, i + 1) can be welded together under the influence of the friction energy between the contact surfaces and under applied defined pressure.

Plant (1 1) according to claim 4, characterized in that the

Pressing device (6) along at least part of a

Conveying device (2) arranged for at least two consecutively

Thin slabs (i, i + 1) within the system (1 1) is movably arranged.

Plant (1 1) according to claim 5, characterized in that the

Movability of the pressing device (6) with the speed of the

Conveyor (2) is synchronized. Plant (1 1) according to one of the preceding claims, characterized in that it comprises means (3) for processing, preferably

Having cut, the end of the leading thin slab (i) and / or the head of the trailing thin slab (i + 1).

Installation (1 1) according to claim 7, characterized in that the at least one means (3) for processing a device (5) for removing scale at least on the contact surfaces of the thin strips (i, i + 1).

Plant (1 1) according to one of claims 4 to 8, characterized in that the pressing device (6) and / or the transport path in

Having conveying direction in front of the pressing device (6) means for centering the thin slabs on the conveyor (2).

Installation (1 1) according to one of claims 4 to 9, characterized in that the pressing device 6 has a means for aligning the head of the trailing thin slab (i + 1) corresponding to the position of the end of the leading thin slab (i).

Plant (1 1) according to one of the preceding claims, characterized in that driving, hold-down, guide and / or straightening rollers (4) for aligning the end of the leading thin slab (i) and the head of the trailing thin slab (i + 1 ) and / or the entire trailing thin slab (i + 1) are provided.

Method for producing hot-rolled strips of metal, preferably steel, on a plant (1 1) according to the CSP plant concept, in semi-continuous operation or endless operation into thin strips, comprising the steps of (A) casting thin slabs (i, i + 1) on at least two casting machines (12a, 12b), preferably at least two parallel to each other

arranged casting machines (12a, 12b),

(b) connecting at least two hot thin slabs (i, i + 1) conveyed on a conveyor (2) from the at least two casting machines (12a, 12b) to a rolling train (15),

(c) conveying the interconnected thin slabs (i, i + 1) to the

Walzstraße (15), wherein in a defined period of time, the sum of the cast

Thin slab lengths of at least two casting machines (12a, 12b) and the thin slab length entering the first rolling stand (15) behind the thin slab joining apparatus (i, i + 1), at least in a continuous production phase of the equation

suffice, with:

ITIG: number of casting machines,

V _Bm : average casting speed of the cast strand at the exit of the

Casting machine m,

V _F : average feed speed of the thin slab into the first

dt: integral time step,

K: adjustment factor. A method according to claim 12, characterized in that two

Thin slabs (i, i + 1), in particular their end faces are joined together by friction welding.

Method according to one of claims 12 or 13, characterized in that the sum of the mean mass flow of the cast thin slabs (i, i + 1) from at least two casting machines (12a, 12b) and the average mass flow through the rolling train (15) at least in one continuous production phase are the same.

A method according to any one of claims 12 to 14, characterized in that when the produced mean total thin slab length of a defined period for all casting plants from the in the first rolling stand (15) behind the device (1) for connecting thin slabs (i, i + 1) of the same period of time from the endless rolling mode to the batch rolling mode.

A method according to any one of claims 12 to 15, characterized in that when the target casting speed is undershot a

Casting machine (12a, 12b) at least one other casting machine (12a, 12b) with increased casting speed and / or the rolling train (15) is operated at a reduced speed.

A method according to any one of claims 12 to 16, characterized in that the thin slab bonding device (1) and the endless or semi-endless rolling or the batch rolling depending on the endband thickness to be rolled, the material produced and / or of the

Casting speeds selected and adjusted by a process model and monitored.

18. The method according to any one of claims 12 to 17, characterized in that are used as actuators for setting the casting speeds V _Bm and / or the feed speed V _F in the rolling train (15).

19. The method according to any one of claims 12 to 18, characterized in that as a thin slab bonding method optional friction welding, resistance butt welding, flash butt welding, butt welding, laser welding, autogenous welding, mechanical

Join, compress after heating the joint or press cutting or advantageously a combination of these

Thin slab joining method is used.

20. The method according to any one of claims 12 to 19, characterized in that when not using the thin slab connecting device (1) this area is thermally insulated by driving in or pivoting of thermal insulation means (7) to minimize temperature losses.