EP4408595B1 - System and method for producing flat rolled products - Google Patents

Description

The present invention relates to a plant and a method for producing flat rolled products from thick-cast steel and/or non-ferrous metal slabs, and in a further aspect to the use of at least one electric heating device arranged in the transport direction upstream of a hot rolling mill, in particular an electric heating device for direct hot insertion, for heating thick slabs with a thickness of at least 160 mm to a hot rolling temperature.

The prior art includes systems and processes in which thick slabs are heated directly using the casting heat, or only after intermediate storage in a slab storage facility, first by means of gas-operated heating devices and then fed to a hot rolling mill, see e.g. EP 06 10 028 A2 .

Heating thick slabs in a gas-fired heating system requires, firstly, large quantities of fuel, especially when the slabs, coming from a slab storage area, need to be heated from near-room temperatures to at least 1000 °C, and secondly, long heating times. Furthermore, the use of fossil fuels, particularly natural gas, results in high _CO₂ emissions.

From the Japanese patent specification JP 6562223 B2 A system is known by which thick slabs are fed directly to a hot rolling mill, utilizing the heat from the casting process. In this system, the edges of the thick slabs are heated to the appropriate hot rolling temperature by means of a series of inductive edge heaters arranged in series. While the targeted heating of the edges suppresses the cooling of the slab's center section, such a heating device does not allow for targeted heating of the entire thick slab.

Against this background, the present invention is based on the objective of providing an improved plant and a process for producing a flat rolled product from thick-cast steel and/or non-ferrous metal slabs, compared to the prior art.

Description of the invention

According to the invention, the problem is solved by a system with the features of claim 1 and by a method with the features of claim 12.

The inventive plant for the production of flat rolled products from thick-cast steel and/or non-ferrous metal slabs comprises a continuous casting device by means of which a continuous material with a thickness of at least 160 mm can be cast continuously; a separating device arranged downstream of the continuous casting device by means of which the flat continuous material can be separated into individual thick slabs; a hot rolling mill in which the thick slabs can be rolled into the flat rolled product, wherein the hot rolling mill comprises a roughing mill and a finishing mill, each with at least one rolling stand, and is arranged in a common (first) conveying line with the at least one continuous casting device; at least one thick slab feeding device arranged transversely to the conveying line and positioned between the separating device and the rolling mill; as well as at least one electric heating device arranged in the direction of transport in front of the pre-rolling mill, for direct hot use, via which at least those thick slabs can be heated over their entire surface to a hot rolling temperature which come from the continuous casting device arranged in a common transport line.

Using the system according to the invention, the thick slabs can be heated to the specified rolling temperature as required. The at least one [heating element] is located in the transport direction upstream of the hot rolling mill, in particular in the transport direction before [the hot rolling mill]. The electric heating device for direct hot insertion, arranged in the pre-rolling mill, thus enables individual temperature control depending on the grade of steel being cast.

For the purposes of the present invention, the term "thick slab" means a slab having a minimum thickness of at least 160 mm, preferably a minimum thickness of at least 180 mm, and more preferably a minimum thickness of at least 200 mm. Since the maximum thickness of thick slabs is technologically limited by currently available continuous casting equipment, the maximum thickness is preferably 300 mm, and more preferably 250 mm. Such thick slabs typically have widths in the range of 800 to 2500 mm, and more preferably widths in the range of 1000 to 2300 mm.

Producing thick slabs compared to thin slabs offers several advantages. Firstly, the throughput alone increases the output, allowing for higher utilization of the hot rolling mill. Thick slabs also offer a significant quality advantage over thin slabs. Compared to thin slabs, thick slabs have a smaller surface area per ton of material cast. This reduces temperature variations in slabs transported on the line. The smaller surface area per ton of material cast also reduces scale formation, resulting in fewer casting residues and surface defects, thus minimizing material losses due to their removal.

The term "electric heating device," which in the present application is also referred to as an electric heating device for direct hot insertion, an electric thick slab preheating device, an electric thick slab postheating device, an electric pre-strip heating device, or an electric supplementary thick slab heating device, generally refers to an electrically operated device by which the thick slabs can be heated by means of electric current. The heating device can advantageously comprise inductive heating devices, conductive heating devices, and/or electric heating devices with indirect resistance heating. It is particularly preferred that the electric heating device be an inductive or a conductive heating device. Due to the thickness range of the thick slabs, an inductive heating device is advantageously operable according to the longitudinal field principle and, due to its high energy density, enables rapid heating. In a conductive heating device, the respective thick slab forms part of the circuit and is thus heated directly by the electric current passed through it, thereby enabling a very high efficiency (close to 1) and particularly rapid heating.

An inductive and/or conductive electric heating device also has the advantage that it can be designed from a series connection of individual units for both the core and the near-surface areas of the thick slabs.

Alternatively and/or additionally, an electric tunnel furnace operated via resistance heating can also be provided.

The system according to the invention allows a temperature profile to be set in the respective thick slab, which is specifically tailored to the subsequent pre-rolling process, in particular the cooling that occurs during pre-rolling. If cold spots (so-called "skid marks") are detected on the thick slab surface, which occur, for example, when using walking beam furnaces, these can be specifically eliminated by targeted heating, thereby improving the quality of the subsequently produced flat-rolled product. The short heating times also reduce scale formation, which improves both the output quantity and the surface quality.

Furthermore, the system according to the invention enables each thick slab to be individually heated to the technologically required temperature level without overheating or undercooling.

For the purposes of the present invention, the term "full surface" means that the thick slabs are heated to a predetermined nominal temperature over their entire surface and at a specific thickness when passing through the electric heating device.

The nominal temperature of the thick slab is largely uniform and/or identical in three dimensions, whereby permissible temperature differences can be ≤ ± 80 °C, preferably ≤ ± 50 °C, particularly preferably ≤ ± 20 °C of a target/nominal temperature.

The nominal temperature simplifies further processing of the thick slab. Unevenly heated thick slabs can lead to varying forming conditions during further processing, such as rolling. This can result in inconsistent forming across the length and/or width of the slab, increasing the scrap content during necessary finishing cuts. Uneven temperatures can also cause inconsistent microstructural changes and geometric defects, such as flatness errors. By establishing a uniform temperature level across the entire surface early on, these problems and defects are avoided or at least mitigated. Complex setups and processes to compensate for these defects can be simplified or even eliminated. Interference between desired effects and reactions resulting from an uneven temperature level is also minimized.

Preferably, the electric heating device for direct hot application is designed such that the thick slabs can be heated across their entire surface. In other words, such a heating device enables not only specific heating of the edges, but also heating of the area between the edges. the central section of the thick slab. A further advantage of such an electric heating device for direct hot insertion, arranged in the transport direction upstream of the hot rolling mill, particularly upstream of the roughing mill, is that it enables maximum utilization of the casting heat, thus allowing energy savings of more than 70% compared to conventional removal from a slab storage area.

Further advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined in a technologically meaningful manner and can define further embodiments of the invention. Furthermore, the features specified in the claims are specified and explained in more detail in the description, which also presents further preferred embodiments of the invention.

It should be noted that the present plant according to the invention is suitable and intended solely for the production of flat rolled products from thick-cast steel and/or non-ferrous metal slabs. In such plants, the thick slabs produced can be easily temporarily stored or transported from a second conveyor line due to their typical dimensions, unlike plants designed for the production of thin slabs. Thick slabs are usually less than 12 meters long, sometimes less than 10 meters, whereas thin slabs typically have lengths of at least 25 meters and are therefore more complex to transport and store. Furthermore, the flat rolled products from such plants also differ from those produced by plants designed for the production of thin slabs. For example, specific steel grades, such as peritectic steel grades or steel grades with very high surface quality requirements, cannot be produced to the required quality on conventional thin slab mills.

The length of a given thick slab, especially for hot applications, can correspond not only to a single coil length but also to a multiple thereof, since transport across the transport line and further handling steps are eliminated.

Preferably, the continuous casting device is designed such that a continuous material with a thickness of at least 160 mm can be cast using it. The continuous casting device can, for example, be designed as a single-strand or a multi-strand continuous casting device.

In an advantageous embodiment, the system can include at least one electric pre-heating unit arranged upstream of the finishing mill in the transport direction. This unit is particularly preferably designed to heat the rolled flat-rolled semi-finished product across its entire surface. This allows the rolled flat-rolled semi-finished products, which leave the pre-rolling mill at a temperature below 1000 °C, for example, to be heated with exceptional energy efficiency to a temperature specifically predetermined for the finishing rolling process. This enables the desired properties of the flat-rolled product to be adjusted. For instance, temperature differences between the head and the end of a rolled flat-rolled semi-finished product can be effectively compensated, resulting in greater rolling stability and thus higher output. The resulting more homogeneous temperature distribution also allows for thinner end strips and more homogeneous mechanical properties of the produced flat-rolled product.

If absolute temperature values are specified in the present application, these are exclusively average temperatures of the respective substrate.

The at least one thick slab feeding device is preferably designed as a transport and heating device, via which transported and/or temporarily stored thick slabs are heated, if necessary over their entire surface, to the hot rolling temperature. are heatable. The transport and heating device can be designed to allow for temperature increases and/or temperature maintenance simultaneously or sequentially with transport. Preferably, the thick slab feeding device is designed in the form of a walking beam furnace, which includes at least one segment comprising electrically operated heating elements and/or gas-powered burners.

A plant designed in this way comprises a first transport line, via which the thick slabs can be briefly heated to hot rolling temperature using the electric heating device for direct hot insertion, utilizing the casting heat, and then fed into the hot rolling mill. Parallel to the first transport line, a second transport line can also be provided, via which intermediately stored and/or cooled thick slabs (usually stored in a slab storage area and/or a holding pit) are heated directly to hot rolling temperature via the thick slab feeding device and then fed into the rolling process. Alternatively and/or additionally, thick slabs cast in a second continuous casting unit can also be fed into the rolling process via the thick slab feeding device.

In an advantageous embodiment, at least one, preferably two or a plurality of the thick slab feeding devices are arranged between the electric heating device for direct hot insertion and the roughing mill. In a further advantageous embodiment, the system can also include at least one, preferably two or a plurality of the thick slab feeding devices between the cutting device and the electric heating device for direct hot insertion.

In addition to at least one thick slab feeding device, preferably at least one electric thick slab preheating device can be installed upstream on the inlet side, which is particularly preferably designed such that the thick slabs can be heated across their entire surface. An electric thick slab preheating unit is particularly suitable when higher temperatures are required at short notice to adjust the mechanical properties, such as strength, of the flat rolled products to be produced, and the subsequent thick slab feeding unit can be operated at a lower temperature level required for the flat rolled products to be produced.

In a further advantageous embodiment, at least one electric slab reheating unit can be connected downstream of the at least one thick slab feeding device. This unit is particularly preferably designed to allow the thick slabs to be heated across their entire surface. It is especially preferred that the at least one electric slab reheating unit is arranged between the at least one thick slab feeding device and the roughing mill. The outlet-side electric slab reheating unit further increases the flexibility of the plant, enabling both energy-efficient production and optimal fulfillment of the logistical and technological requirements of the rolling mill.

Furthermore, the system can include at least one supplementary electric thick slab heating device, which is preferably connected upstream of at least one electric thick slab reheating device.

To reduce production losses due to transition widths when changing casting widths, and to ensure more even wear of the work rolls in the finishing mill, as well as optimal results for strip profile and/or flatness over the longest possible journey through the plant, the rolling mill should allow for specific rolling program profiles. This is because using the same slab widths reduces availability in the hot rolling mill due to an increase in the number of necessary work roll changes. Therefore, the roughing mill advantageously includes, in the transport direction... In addition to a first and/or a second roughing stand, at least one upsetting unit is required. Preferably, the upsetting unit comprises at least one slab upsetting press and/or, optionally, at least one, preferably multiple, upsetting units. The use of an upsetting unit, such as the slab upsetting press, optionally in combination with at least one upsetting unit, ensures a necessary width- and profile-optimized rolling program, as larger and/or constant slab widths can be cast. Advantageously, the upsetting unit is designed to allow a reduction in slab width of up to 450 mm, preferably up to 350 mm. Furthermore, the use of additional upsetting units enables a further reduction in slab width of up to 100 mm per upsetting unit.

Furthermore, in an advantageous embodiment, the system can include a control unit with an associated calculation unit, wherein the control unit is designed to control and/or regulate the system on the basis of minimized energy consumption and/or maximum throughput, and/or on the basis of product characteristics and/or product dimensions.

To configure the system based on minimized energy consumption, factors such as the required temperature level, possible heating cycles, available heating devices, potential temperature losses, and/or potential temperature inputs within the system can be optimized to achieve the lowest possible energy consumption. The calculation unit can preferably use a physical process model that represents the thermal conditions and generates suggestions for system settings.

Alternatively or additionally, the control unit can control the system in such a way as to achieve maximum throughput. This can be achieved by optimizing groups of batches with specific thickness, width, and/or length dimensions. The casting sequences, the insertion sequences, the transport system, and/or the operation of the rolling mill at its design limits can be used to increase throughput. In particular, maintenance cycles such as roll changeover times, mold changeover times, and/or mold conversion times can be taken into account. Grouping batches and/or sequences according to product dimensions has the advantage of minimizing material losses due to transition pieces when width or thickness changes occur. The system can also be controlled according to product properties by the control unit. For example, if a very high surface quality is required, the control unit can adjust the casting speed accordingly, the descaling process, the temperature, etc. Similarly, the system settings can be optimized to achieve optimal magnetic, mechanical, and/or geometric properties.

To effectively reduce energy and/or temperature losses of the thick slabs and/or the flat-rolled semi-finished product in the roughing mill during transport, the system can also include several specifically arranged thermal insulation hoods. These thermal insulation hoods can be designed as passive or active thermal insulation hoods. The active thermal insulation hoods are preferably operated with burners using "green" produced hydrogen as fuel or electrically.

In an advantageous embodiment, the system can include a plurality of thermal insulation hoods between the separating device and the electric heating device for direct hot insertion, and possibly between the electric heating device for direct hot insertion and the hot rolling mill, in particular the roughing mill.

In another advantageous design variant, the system can also include a multiple thermal insulation hoods within the pre-rolling line.

These can be arranged, for example, in the direction of transport in front of and/or behind a compression device, as well as, if necessary, in front of and/or behind one and/or each pre-rolling stand.

• i) kontinuierliches Gießen eines flachen Strangguts mit einer Dicke von zumindest 160 mm, welches im Anschluss in einzelne Dickbrammen getrennt wird;
• iia) Erhitzen der Dickbrammen auf eine Temperatur von zumindest 1000 °C mittels einer elektrischen Heizeinrichtung für den direkten Heißeinsatz, wenn die Dickbramme von der in gemeinsamer Transportlinie angeordneten Stranggießeinrichtung kommt; und
• iib) Erhitzen der Dickbrammen auf eine Temperatur von zumindest 1000 °C mittels zumindest einer ergänzenden Heizeinrichtung und/oder mittels einer Dickbrammeneintrageeinrichtung, wenn die Dickbramme aus einer zweiten Transportlinie quer in die erste Transportlinie transportiert wird, und
• iii) Warmwalzen der auf eine Warmwalztemperatur erhitzten Dickbrammen zu dem Flachwalzprodukt, indem diese zunächst vorgewalzt und anschließend fertiggewalzt werden.

In a further aspect, the present invention also relates to a method for producing flat rolled products from thick-cast steel and/or non-ferrous metal slabs using the plant according to the invention, comprising the process steps:

• i) continuous casting of a flat strand material with a thickness of at least 160 mm, which is subsequently separated into individual thick slabs;
• (iia) Heating the thick slabs to a temperature of at least 1000 °C using an electric heating device for direct hot insertion when the thick slab comes from the continuous casting apparatus arranged in a common transport line; and
• (iib) Heating the thick slabs to a temperature of at least 1000 °C by means of at least one supplementary heating device and/or by means of a thick slab feeding device when the thick slab is transported from a second transport line transversely into the first transport line, and
• iii) Hot rolling of the thick slabs heated to a hot rolling temperature to produce the flat rolled product by first pre-rolling and then finish-rolling.

Preferably, the thick slabs are fed to the first electric heating device for direct hot insertion at a temperature of at least 500 °C. Furthermore, it is preferably provided that the pre-rolled flat product is heated to a temperature of at least 950 °C by means of an electric pre-strip heating device before it is finished-rolled into the flat product.

In a further aspect, the present invention also relates to the use of at least one electric heating device arranged in the transport direction upstream of a hot rolling mill for direct hot insertion, in particular an inductive heating device, for heating thick slabs with a thickness of at least 160 mm to a hot rolling temperature.

Character designation

• Fig. 1 eine erste Ausführungsvariante der erfindungsgemäßen Anlage,
• Fig. 2 eine zweite Ausführungsvariante der erfindungsgemäßen Anlage,
• Fig. 3 eine dritte Ausführungsvariante der erfindungsgemäßen Anlage,
• Fig. 4 eine vierte Ausführungsvariante der erfindungsgemäßen Anlage,
• Fig. 5 eine fünfte Ausführungsvariante der erfindungsgemäßen Anlage, und
• Fig. 6 eine Ausführungsvariante einer Vorwalzstraße.

The invention and its technical context are explained in more detail below with reference to the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations explained in the figures and combine them with other elements and findings from the present description and/or figures. It should be noted in particular that the figures, and especially the depicted proportions, are only schematic. The same reference numerals denote the same objects, so that explanations from other figures can be consulted as needed. The figures show:

• Fig. 1 a first embodiment of the system according to the invention,
• Fig. 2 a second embodiment of the system according to the invention,
• Fig. 3 a third embodiment of the system according to the invention,
• Fig. 4 a fourth embodiment of the system according to the invention,
• Fig. 5 a fifth embodiment of the system according to the invention, and
• Fig. 6 a variant design of a pre-rolling mill.

In Figure 1 Figure 1 shows a first embodiment of plant 1 for the production of rolled products from thick-cast steel and/or non-ferrous metal slabs. Plant 1 comprises a continuous casting unit 3 arranged in a transport line T, which is configured here to continuously produce a The continuous material with a thickness in the range of 200 to 250 mm is cast. The resulting continuous material (not shown) is then immediately separated into individual thick slabs by means of a separating device 4, for example a pendulum shear or continuous material burning device, and fed directly to a hot rolling mill 5, utilizing the casting heat, where it is first pre-rolled and then finish-rolled.

For this purpose, plant 1 has a roller conveyor 6 in the first transport line T, which extends through plant 1. The roller conveyor 6 can be covered segmentally with a plurality of active or passive thermal insulation hoods 22, of which two are shown purely as examples in the present embodiment. This allows the energy and temperature losses of the thick slabs on the transport route to the hot rolling mill 5 to be kept as low as possible.

Despite the thermal shielding, the thick slabs typically cool to an average temperature of 800 to 900 °C during transport to the hot rolling mill 5. Therefore, according to the invention, the thick slabs are heated to a hot rolling temperature of 1100 to 1300 °C in the transport direction before entering the hot rolling mill 5 by means of an electric heating device 7 for direct hot insertion. In the present embodiment, the electric heating device 7 is designed as a longitudinal field inductor and thus enables the short-term heating of the cooled thick slab to the specific hot rolling temperature.

Furthermore, the in Figure 1 The depicted embodiment includes a control unit S, which incorporates a calculation unit B. This unit can determine the operating settings that minimize energy consumption. The control unit S is connected to the system 1 via a signal connection and makes the necessary adjustments to the system 1 for the production of the thick slab. Similarly, and/or alternatively, the operating settings can be optimized according to... maximum throughput, and/or product characteristics and/or product dimensions.

In Figure 2 Another embodiment of the inventive system 1 is shown. In contrast to the one in Figure 1 In the illustrated embodiment, system 1, located between a roughing mill 8 and a finishing mill 9 of the hot rolling mill 5, additionally includes an electric pre-strip heating unit 10. The electric pre-strip heating unit 10 is also designed as a longitudinal field inductor or inductor combination, such that the pre-rolled flat products can be heated across their entire surface. By means of the electric pre-strip heating unit 10, the pre-rolled flat products, which leave the roughing mill 8 at a temperature below 1100 °C, are heated with particular energy efficiency to a temperature of 950 to 1100 °C specifically specified for the finishing rolling process.

Figure 3 Figure 1 shows a further embodiment of the system according to the invention. In addition to the one shown in Figure 2 In the illustrated embodiment, plant 1 comprises a second transport line T2 arranged parallel to the first transport line T1, comprising a second roller conveyor 6.2, a second continuous casting unit 11, which is also configured to continuously cast a continuous material with a thickness in the range of 200 to 250 mm, and a second cutting unit 12. The second cutting unit 12 can also be designed in the form of a pendulum shear or a continuous material burning unit. The second roller conveyor 6.2 can also be covered segmentally with a plurality of active or passive thermal insulation hoods 22, as can be seen from the different

The thick slabs produced in this line can be temporarily stored and cooled in a slab storage area 13 located directly downstream of the second cutting unit 12. Alternatively, the individual thick slabs can be temporarily stored in a holding pit 14 with lower temperature losses.

As shown in Figure 3 As can be further seen, in this embodiment, Annex 1 also includes a thick slab feeding device 15, which is designed as a gas-powered transport and heating device. The thick slab feeding device 15 is arranged between the electric heating device for direct hot insertion 7 and the pre-rolling mill 8, and transversely to the transport direction.

In addition to the thick slab feeding device 15, the system 1 comprises two electric thick slab preheating devices 16.1, 16.2, which are connected upstream of the thick slab feeding device 15 on the inlet side. The two preheating devices 16.1, 16.2 are also designed as longitudinal field inductors or inductor combinations, such that the thick slabs can be heated across their entire surface.

In the two Figures 4 and 5 Two alternative embodiments of the inventive system 1 are shown. In the Figure 4 In the illustrated embodiment, system 1 comprises a sequence of two electric heating devices 7, 17, arranged in the transport direction between the slab storage 13 and the pre-rolling road 8. In contrast, in the embodiment according to Figure 5 A series of three electric heating devices 7, 17, 18 are arranged between the slab storage area 13 and the pre-rolling road 8. Furthermore, the [system] comprises Figure 5 The illustrated embodiment includes the electric heating devices 16.1, 16.2 arranged in the second transport line T2. This large number of heating devices 7, 16.1, 16.2, 17, 18 makes it possible to design and operate them in a particularly individual and performance-related manner, without power losses or over-dimensioning.

All heating devices 7, 10, 16.1, 16.2, 17, 18 of the exemplary embodiments are shown only schematically and typically comprise a number of individual inductors that can be sequentially cycled through. Individual switching on and off, as well as individual power settings, are not possible. This allows for very precise adjustment of the desired or necessary temperature rise. In addition to inductors designed exclusively as longitudinal field inductors, combination sequences of longitudinal and transverse field inductors are also available, which can be traversed sequentially.

In the version according to Figure 1 Furthermore, additional thick slabs can be introduced into the first transport line T1 by means of a thick slab feeding device 15, at a position located upstream or downstream of the heating device for direct hot insertion 7. The fully or partially cooled thick slabs can be introduced from a slab storage area 13 into the thick slab feeding device 15 and simultaneously heated to a hot rolling temperature and transported.

In the version according to Figure 2 Additional thick slabs can also be fed into the first transport line T1 via the thick slab feeding device 15, at a position located upstream of the heating device for direct hot insertion 7. The fully or partially cooled thick slabs can be fed into the thick slab feeding device 15 from a slab storage area 13 or, alternatively, from a holding pit 14, and simultaneously heated to a hot rolling temperature and transported.

The arrangement and number of the thick slab feeding devices 15 can be varied as desired. In a known design, the thick slab feeding device 15 can be an electrically and/or gas-operated continuous furnace and/or walking beam furnace. Alternatively, a heating device belonging to the thick slab feeding device 15 can preheat the thick slab to a slightly elevated temperature; the transport itself then takes place without active heat input via a preferably insulated transport walkway or walking beam.

The thick slabs temporarily stored and cooled in the slab storage area 13 or those in the holding pit can be transferred via the thick slab feeding device 15. 14 thick slabs, which have been temporarily stored at 200 to 800 °C and slightly cooled, are heated to a hot rolling temperature before being fed into the rolling process via the first roller stage 6.1.

In Figure 6 Furthermore, a variant embodiment of a pre-rolling mill 8 is shown, which comprises a compression device 19 in the transport direction, as well as at least one first and preferably one second pre-rolling stand 20, 21, each of which has a horizontal and preferably a vertical stand. In order to keep the energy and/or temperature losses of the thick slabs or the pre-rolled flat product in the pre-rolling mill 8 low, a series of thermal insulation hoods 22 are provided.

Reference symbol list

1

Attachment

3

(first) continuous casting plant

4

(First) Separation Device / Stranded Material Shear

5

Hot rolling mill

6.1

first roller walk

6.2

second roller conveyor

7

Heating device for direct hot use

8

Vorwalzstraße

9

Finishing mill

10

Pre-band heating system

11

(second) continuous casting machine

12

second separation device

13

Slab storage

14

Warming pit

15

Thick slab insertion device

16.1

Preheating heating device

16.2

Preheating heating device

17

supplementary (after-heating) heating device

18

supplementary (after-heating) heating device

19

Compression device

20

first rolling mill

21

second rolling mill

22

Thermal insulation hoods

T(1)

(first) transport line

T(2)

(second) transport line

S

Control unit

B

Unit of calculation

Claims (15)

1. Plant (1) for producing flat rolled products from thick-cast steel and/or non-ferrous metal slabs, comprising:

   i) at least one continuous casting device (3), by means of which a flat strip material with a thickness of at least 160 mm can be continuously cast;

   ii) a separating device (4) which is arranged to follow the at least one continuous casting device (3) and by means of which the flat strip material is separable into individual thick slabs;

   iii) a hot-rolling mill (5) by way of which the thick slabs can be rolled to form the flat rolled product, wherein the hot-rolling mill (5) comprises a roughing rolling train (8) and a finishing rolling train (9) each with at least one roll stand and is arranged in a transport line (T1) common to the at least one continuous casting device (3);

   iv) at least one thick-slab intake device (15) arranged transversely to the transport direction (T1) and positioned between the separating device (4) and the rolling mill (5); and

   v) at least one electric heating device (7), which is arranged upstream of the roughing rolling train (8) of the hot-rolling mill (5) in transport direction, for direct input of heat, by way of which at least those thick slabs coming from the continuous casting device (3) arranged in the common transport line are heatable over the whole area to a hot-rolling temperature.
2. Plant (1) according to claim 1, further comprising at least one electric pre-strip heating device (10) arranged upstream of the finishing rolling train (9) in transport direction.
3. Plant (1) according to claim 1 or 2, wherein the at least one thick-slab intake device (15) is realised as a transport and heating device, by way of which the transported and/or intermediately stored thick slabs are heatable to a hot-rolling temperature.
4. Plant (1) according to claim 3, wherein the at least one thick-slab intake device (15) is arranged between the electric heating device (7) for direct input of heat and the roughing rolling train (8).
5. Plant (1) according to any one of the preceding claims, wherein at least one electric thick-slab pre-heating heating device (16.1, 16.2) is arranged upstream at the inlet side of the at least thick-slab intake device (15) preferably realised as a transport and heating device.
6. Plant (1) according to any one of the preceding claims, wherein at least one supplementary electric thick-slab heating device (17) is arranged downstream at the outlet side of the at least one thick-slab intake device (15) preferably realised as a transport and heating device.
7. Plant (1) according to claim 6, wherein the at least one supplementary electric thick-slab heating device (17) is arranged between the at least one thick-slab intake device (15) and the roughing rolling train (8).
8. Plant (1) according to claim 6 or 7, further comprising at least one further supplementary electric thick-slab heating device (18), which is preferably arranged upstream of the electric thick-slab heating device (17).
9. Plant (1) according to any one of the preceding claims, further comprising a control device (S) with an individual computing unit (B), wherein the control device (S) is configured for the purpose of controlling and/or regulating the plant (1) on the basis of a minimised energy consumption and/or a maximum throughput and/or on the basis of product characteristics and/or product dimensions.
10. Plant (1) according to any one of the preceding claims, wherein the roughing rolling train (8) comprises in transport direction at least one upsetting device (19) and at least one first, preferably a second, roughing rolling stand (20, 21).
11. Plant (1) according to claim 10, wherein the upsetting device (19) comprises at least one slab upsetting press and/or optionally at least one upsetter, preferably a plurality of upsetters.
12. Method of producing flat rolled products from thick-cast steel and/or non-ferrous metal slabs by means of a plant (1) according to any one of the preceding claims, comprising the method steps:

    i) continuous casting of a flat strip material with a thickness of at least 160 mm, which is subsequently separated into individual thick slabs;

    iia) heating the thick slabs to a temperature of at least 1,000° C by means of an electric heating device (7) for direct input of heat when the thick slab comes from the continuous casting device (3) arranged in the common transport line (T1); and

    iib) heating the thick slab to a temperature of at least 1,000° C by means of at least one supplementary heating device (16.1, 16.2) and/or by means of a thick-slab intake device (15) when the thick slab is transported from a second transport line (T2) transversely into the first transport line (T1); and

    iii) hot-rolling the thick slabs, which are heated to a hot-rolling temperature, to form the flat rolled product in that these are initially rough-rolled and subsequently finish-rolled.
13. Method according to claim 12, wherein the thick slabs are fed at a temperature of at least 500° C to the electric heating device (7) for direct input of heat.
14. Method according to claim 12 or 13, wherein the rough-rolled flat rolled product is heated to a temperature of at least 950° C by means of an electric pre-strip heating device (10) before it is finish-rolled to form the flat rolled product.
15. Method according to any one of the preceding claims 12 to 14, wherein the step ii) and/or the step iii) is or are so controlled by means of a control unit (S) that a minimum energy consumption and/or a maximum throughput, which is or are determined by a computing unit (B), and/or a product characteristic and/or a product dimension is or are achieved.