Composite casting and rolling system and method for producing hot strip having a final thickness of less than 1.2 mm on the composite casting and rolling system

Abstract

The invention relates to a casting-rolling integrated plant and to a method for producing a hot strip with a final thickness of < 1.2 mm on the casting-rolling integrated plant. The problem addressed by the invention is that of specifying a casting-rolling integrated plant of this kind and a method of this kind, by means of which high-quality ultra-thin hot strip with high capacitance, i.e. with a capacitance between 3.5 and 5.5 M t / a, can be produced by extrusion and hot rolling on the casting-rolling integrated plant. This problem is solved by a casting-rolling integrated plant according to claim 1.

Description

field of technology

[0001] The present invention relates to the technical field of iron and steel metallurgy.

[0002] On the one hand, the invention relates to a casting-rolling composite plant for the production of hot strip with a final thickness < 1.2 mm.

[0003] On the other hand, the invention relates to a method for producing hot-rolled strip with a final thickness < 1.2 mm on a casting-rolling composite machine. State of the art

[0004] Casting-rolling composite plants for the production of hot strip by combining continuous casting and hot rolling are known, e.g. a CSP plant from SMS, an Arvedi ESP plant from Primetals Technologies or a QSP DUE plant from Danieli.

[0005] Currently, no energy-efficient process is available for producing ultrathin, hot-rolled strips with a production capacity of > 3 million tons / year (3 M t / a). Arvedi ESP plants have a maximum capacity of approximately 3 M t / a. To ensure stable casting conditions, increasing the capacity is not possible with currently available resources. The casting speed is limited to approximately 6 m / min, and the throughput to 6-8 t / min. Integrating an additional casting unit into the continuous operation of the compact plant is not an option.

[0006] Traditional hot rolling mills (English) hot strip mills, HSMs (short for high-speed laser sintering) can achieve high throughputs, but are not capable of producing ultrathin ribbon (final thickness < 1.2 mm). In the case of 2-strand " Thin slab casting and rolling (TSCR) processes theoretically allow for high production rates, however, the capacity is dramatically reduced in the endless production of very thin strips, as only one casting strand can be used.

[0007] Plant types for high production capacity include: HSM: Very high capacity (> 4 M t / a), no thin or ultrathin tapes, as only discontinuous operation is possible; 2-strand TSCR: High capacity (> 3 M t / a) in discontinuous operation, low capacity (< 3 M t / a) in continuous operation.

[0008] For the aforementioned reasons, high-capacity hot strip production is currently carried out using conventional hot rolling mills (HSM) or 2-strand TSCR plants.

[0009] Hot rolling mills use slabs from conventional continuous casting plants, which must be heated from ambient temperature to the desired forming temperature before hot forming (high energy consumption). Hot rolling mills are capable of processing many steel grades in large quantities. One of their biggest disadvantages is that the final strip thicknesses must exceed 1.2 mm to comply with the applicable draw-in conditions. The production of ultra-thin strips therefore always requires a subsequent cold rolling process.

[0010] In two-strand TSCR processes, such as CSP or QSP / DUE, two continuous casting plants are connected to the hot rolling mill via tunnel furnaces; the casting heat is utilized, and high capacities are theoretically possible (depending on the product portfolio). A major disadvantage lies in capacity reductions during the production of thin or ultra-thin strip. Due to the continuous process, one casting strand is decoupled from the rolling mill, and output decreases by 50%.

[0011] From DE 197 32 538 A1, a casting-rolling composite plant for the production of hot-rolled strip with a final thickness of < 1.0 mm is known, comprising a first and a second continuous casting plant 2, 2' for casting liquid steel into slabs, a first roller hearth furnace 4 for heating the slabs from the first continuous casting plant 2 to rolling temperature, and a separate second roller hearth furnace 4' for heating the slabs from the second continuous casting plant 2' to rolling temperature, and a transfer unit 5 for feeding slabs from the second continuous casting plant 2' into the first roller hearth furnace 4. The slabs are then pre-rolled into a roughing strip in a reversing stand 7 and wound up in a spooling furnace. Subsequently, the roughing strips are welded together by a welding machine to form a continuous roughing strip and finished rolling in the finishing mill 15.Since the slabs of the first and second continuous casting plant 2, 2' are heated differently in the rolling hearth furnaces, the plant is not suitable for the production of high-quality hot strip. Summary of the invention

[0012] The object of the invention is to provide a novel casting-rolling composite plant for the production of hot-rolled strip with a final thickness < 1.2 mm, preferably ≤ 1.0 mm, and to provide a method for producing hot-rolled strip with a final thickness < 1.2 mm, preferably ≤ 1.0 mm, on a casting-rolling composite plant, in which high-quality ultra-thin hot-rolled strip with high capacity, i.e., with a capacity between 3.5 and 5.5 M t / a, can be produced by continuous casting and hot rolling on the casting-rolling composite plant.

[0013] The part of the invention relating to the casting-rolling composite plant is solved by a casting-rolling composite plant according to claim 1. Preferred embodiments are the subject of the dependent claims.

[0014] Specifically, the solution is achieved by a casting-rolling composite plant for the production of hot-rolled strip with a final thickness < 1.2 mm, preferably ≤ 1.0 mm, having at least one first continuous casting plant and one second continuous casting plant, each continuous casting plant casting liquid steel into slabs; a slab manipulator for transporting the slabs from the continuous casting plants to a walking beam furnace, for transporting the slabs from the slab manipulator to a rolling mill and for heating the slabs to rolling temperature, wherein slabs from the first continuous casting plant and slabs from the second continuous casting plant pass completely through the walking beam furnace and are heated uniformly; the rolling mill, comprising: a roughing mill for pre-rolling the heated slabs into a roughing strip; a coil box, preferably thermally insulated, for winding the roughing strip into a reel and for unwinding the roughing strip; a joining device for joining, without filler metal, the foot of a leading roughing strip to the head of a lagging roughing strip to form an endless roughing strip.-- a multi-stand finishing mill for finishing the endless roughing strip into a finished strip with the final thickness, -- a cooling section for cooling the finished strip to the hot strip, and -- several coiling devices for coiling the hot strip, wherein the roughing mill, the coil box, the joining device, the multi-stand finishing mill, the cooling section and the coiling devices of the rolling mill are arranged in-line one after the other and the first continuous casting mill has a first offset in a first direction to the rolling mill and the second continuous casting mill has a second offset in the first direction to the rolling mill.

[0015] According to the invention, the casting-rolling composite plant comprises at least two separate continuous casting plants, each with its own separate mold and arc-shaped strand guides. The continuous casting of two or three strands (English: twin- or triple-casting The method of casting slabs using a split mold on a continuous casting plant is not according to the invention, as there are no separate continuous casting plants. Each continuous casting plant pours liquid steel into slabs. The slabs can be thin or medium slabs with a thickness of 140 to 240 mm and a width between 1100 and 2300 mm. The slab length is typically between 11.5 and 26 m. The slabs produced on the continuous casting plants are thermally insulated and fed to a slab manipulator, which transfers the slabs from the continuous casting plants to a walking beam furnace. In the walking beam furnace, which is, for example, gas- or oil-fired, the slabs from the continuous casting plants are heated uniformly to rolling temperature and transferred to a rolling mill. All slabs pass completely through the walking beam furnace from an inlet to an outlet, regardless of their origin (i.e., whether they come from the first or the second continuous casting plant).The walking beam kiln has several beams that lift the slab and place it down a short distance further along the transport direction. This transports the slab through the kiln. In contrast, a rolling hearth kiln has rollers that transport the slab through the kiln by "rolling." Walking beam kilns are very robust and have low wear; however, the rollers, and especially the roller bearings, in rolling hearth kilns are subject to significant wear at temperatures ≥ 1000 °C.The rolling mill comprises a roughing mill for pre-rolling the heated slabs into a strip, a coil box (preferably thermally insulated) for winding the strip into a reel and unwinding it, a joining device for connecting the end of a leading strip to the end of a trailing strip to form an endless strip without the use of welding filler material, a multi-stand finishing mill for finishing the endless strip into a finished strip with the final thickness, a cooling section for cooling the finished strip to the hot strip, and several reeling devices for coiling the hot strip. The roughing mill, the coil box, the joining device, the multi-stand finishing mill, the cooling section, and the reeling devices of the rolling mill are arranged in-line.The first continuous casting plant has a first offset in a first direction towards the rolling mill, and the second continuous casting plant has a second offset, which is smaller or larger than the first offset, in the first direction towards the rolling mill. Since all slabs pass through the walking beam furnace, they have a relatively constant temperature at the furnace exit. After the walking beam furnace, the heated slabs are pre-rolled into a strip in the roughing mill. Preferably, the roughing mill is a single-stand, reversing roughing mill. Alternatively, the roughing mill can also be designed with multiple stands, e.g., with a second stand.

[0016] After pre-rolling, the strip is wound into a coil box. After unwinding, the foot of a leading strip is joined to the head of a trailing strip in a joining device to form an endless strip. The endless strip is then finished in a multi-stand finishing mill (e.g., with 5, 6, or 7 finishing stands) to form a finished strip with the final thickness, cooled in a cooling section to become hot strip, and wound through several coiling units. Before being wound into the coiling units, the hot strip is subjected to a so-called " high speed shear "cut".

[0017] The problem of low production capacity in state-of-the-art plants is solved by using multiple casting lines. A multi-line casting plant or several individual casting plants (for thin slabs or conventional slabs) are connected to the rolling mill via a walking beam furnace. The temperature of the loaded slabs is between 900 and 1100°C under normal operating conditions, depending on the casting parameters. The discharge temperatures from the walking beam furnace are typically between 1050 and 1200°C to achieve the desired forming process. Hot insertion is carried out using a slab manipulator, which can operate flexibly between the two lines. It is also possible to remove slabs from the process before or insert them into the process before the furnace. This ensures that the casting operation is not affected by downtime in the rolling mill and that cold insertion of slabs is possible.None of the casting plants should be positioned in-line with the rolling mill, thus ensuring uniform heating for all slabs (constant rolling conditions, uniform strip properties, high quality) and simplifying production planning. The roughing mill preferably consists of a reversing rolling stand. For higher capacities, another stand (e.g., a duo rolling stand) can be added. Optionally, the roughing mill can be equipped with a [missing information]. Edger Upstream of the mill, a coil box is used to adjust the strip width. The rolling mill is designed for thin strips below 1.2 mm. For this purpose, the rolling mill features a coil box and a joining device (also known as a joining device). Super deformation joiner, The SDJ (short for SDJ) connects the intermediate strips, enabling the finishing mill to operate in continuous mode with all its advantages (constant process conditions, uniform properties, roll thicknesses < 1.2 mm). This makes it possible to continuously produce two or more strands on a single finishing mill. All areas between the individual units are preferably thermally insulated to conserve maximum heat energy.

[0018] In the manufacturing process, the continuous casting plants are coordinated with the rolling mill to achieve the desired production capacity of 3.5–5.5 million tons per year in continuous operation. To achieve this capacity with a specific mass per coil of 18–21 kg / mm², a coil rewind time of 2–4 minutes is required. The continuous casting plants preferably have a production rate of 9–14 tons per minute.

[0019] To achieve the aforementioned capacities in continuous operation, further boundary conditions must be considered. Depending on the slab thickness, 3-5 passes in the roughing mill are advantageous to achieve a desired intermediate strip thickness of 25-35 mm. From the start of the rolling mill to the wound intermediate strip in the coil box (cycle time of the roughing sequence), approximately 100-220 seconds elapse. It typically takes 140-250 seconds until the base of the intermediate strip leaves the coil box again (cycle time per strip in the finishing mill). This results in a minimum required discharge rate from the walking beam furnace of 0.2-0.4 slabs per minute or 6-13 t / min. This mass flow is achieved by the continuous casting plants to maintain the continuous operation of the finishing mill. As shown above, this is easily accomplished by the aforementioned casting parameters. The key control parameter of the plant is the end-of-roll temperature, which is controlled, among other things, by the rolling speed.Additional cooling systems in the finishing mill enable a maximum rolling speed of 15-20 m / s. In continuous operation, the finishing mill thus dictates the mass flow. All units, from the roughing mill and walking beam furnace to the slab manipulator and casting systems, are dimensioned to follow this production pace.

[0020] Typical conditions for achieving a production capacity of 3.5-5.5 M t / a in continuous operation: - Cycle time per strip in the finishing mill is defined by the mass flow (9-14 t / h) - Cycle time of the pre-rolling sequence (strip repetition time) ≤ Cycle time per strip in the finishing mill - Minimum discharge rate of the walking beam furnace ≤ Cycle time of the pre-rolling sequence - Casting time per slab ≤ Minimum discharge rate of the walking beam furnace

[0021] Short-term deviations from these conditions can be compensated for by a built-in buffer in the walking beam and / or the coil box. In exceptional cases (rolling mill shutdown), the casting process does not need to be interrupted. Slabs can be buffered in the walking beam furnace or, in the event of longer interruptions, diverted from the process before the furnace. They can later be reintroduced into the process at this point. In addition to high capacity, high quality standards and low energy consumption must be met. Energy consumption is reduced to a minimum through an optimized secondary cooling strategy. Maintaining the furnace inlet temperature above 900 °C is advantageous to reduce the walking beam furnace's gas consumption. However, the cooling strategy and slab temperature must always be selected in accordance with the required slab quality.Another key focus is the proximity of the casting plants to the walking beam furnace and the rolling mill, thus minimizing heat loss. Compared to other furnace types, such as the tunnel furnace, the walking beam furnace achieves superior surface quality. In combination with the slab manipulator, it also offers flexible production planning. The strands can be operated flexibly, depending on current availability, without affecting the other strands.

[0022] The main advantages of the solution according to the invention are: - High production capacity of > 3 M t / a in continuous operation, - Continuous rolling for strip thicknesses <1.2 mm, - Hot insertion of slabs reduces energy consumption compared to conventional hot rolling mills, and - Thicker slabs enable the processing of IF steel and peritectic grades.

[0023] Preferably, the first direction is horizontal, meaning that the discharge area of ​​the first continuous casting plant, the discharge area of ​​the second continuous casting plant, and the rolling mill are arranged horizontally adjacent to one another. The slab manipulator connects the discharge areas of the continuous casting plants to an inlet area of ​​the walking beam furnace, such that the horizontal distance between the discharge area of ​​the first continuous casting plant and the rolling mill is greater than the horizontal distance between the discharge area of ​​the second continuous casting plant and the rolling mill.

[0024] Preferably, the finishing rolling mill has 5, 6 or 7 finishing rolling stands.

[0025] It is also preferred that a first descaling unit is arranged after the walking beam furnace and before the roughing mill, and / or that a second and a third descaling unit are arranged before the joining unit and before the finishing mill. In this case, the first descaling unit descales the heated slabs, the second descaling unit partially descales the roughing strips before joining them to form a continuous roughing strip, and the third descaling unit descales the roughing strips before finish rolling.

[0026] In order to maintain production operations even during interruptions of the rolling mill on the one hand and a continuous casting plant on the other, it is advantageous that the slab manipulator can divert slabs produced by the continuous casting plants from the continuous casting plants to the walking beam furnace transversely to the transport direction, and that the slab manipulator can divert slabs that were not produced in the continuous casting plants of the casting-rolling composite plant transversely to the transport direction from the continuous casting plants to the walking beam furnace.

[0027] The part of the invention relating to the manufacturing process is solved by a method for producing a hot-rolled strip with a final thickness of < 1.2 mm on a casting-rolling composite machine according to claim 8. Preferred embodiments are the subject of the dependent claims.

[0028] Specifically, the solution is achieved by a method for producing a hot-rolled strip with a final thickness < 1.2 mm, preferably ≤ 1.0 mm, on a casting-rolling composite machine, in particular according to one of the preceding claims, comprising the following steps: - Continuous casting of liquid steel into slabs on at least one first continuous casting plant and a second continuous casting plant; - Transporting the slabs from the continuous casting plants to an inlet section of a walking beam furnace; - Transporting the slabs from the inlet section through the walking beam furnace to an outlet section of the walking beam furnace, heating the slabs to rolling temperature; - Pre-rolling the heated slabs into a strip; - Winding the strip into a coil and preferably thermally insulating, particularly preferably heating, the coil; - Unwinding the strip from the coil; - Joining the foot of a leading strip to the head of a lagging strip to form an endless strip; - Finish rolling the endless strip into a finished strip with the final thickness by several rolling passes in a multi-stand finishing mill; - Cooling the finished strip to the hot strip; - Cutting the hot strip; and - Coiling the hot strip.

[0029] Preferably, pre-rolling is carried out by several, preferably 3-5, rolling passes in a reversing pre-rolling mill.

[0030] When joining the pre-strips to form the endless pre-strip, preferably the foot of the leading pre-strip is first overlapped with a head of the lagging pre-strip, and then the overlapping area of ​​the pre-strips is pressed together, thereby aligning the vertical position of the pre-strips.

[0031] To achieve high productivity, it is advantageous if the slabs have a thickness of 140 to 240 mm and a width between 1100 and 2300 mm and / or the pre-strip has a thickness between 25 and 35 mm.

[0032] The overall energy consumption of the manufacturing process is low if the slabs are placed in the walking beam furnace at a temperature ≥ 900 °C.

[0033] Low-downtime operation of the continuous casting plants is ensured if the continuous casting plants produce slabs with a thickness of 150 to 190 mm at a casting speed of 4 to 5 m / min and slabs with a thickness of 191 to 230 mm at a casting speed of 2 to 4 m / min. Brief description of the drawings

[0034] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of an exemplary embodiment, which is explained in more detail in conjunction with the drawings. These drawings show: Fig 1 a schematic diagram of a casting-rolling composite plant, Fig 1a a front section of the casting-rolling composite plant made of Fig 1 , Fig 1b a middle section of the casting-rolling composite plant made of Fig 1 , Fig 2 a cross-sectional view of the casting-rolling composite plant made of Fig 1 , and Fig 3 A schematic representation of the steps involved in joining two pre-strips to form an endless pre-strip. Description of the embodiments

[0035] In the Fig 1 , 1a und 1b The casting-rolling composite plant according to the invention is shown schematically. The casting-rolling composite plant comprises two continuous casting plants 1a and 1b (more than two continuous casting plants are of course possible), which are connected to a rolling mill 5 via a slab manipulator 3 and a walking beam furnace 4. Liquid steel is cast into slabs 2 on each continuous casting plant 1a, 1b. The continuous casting plants each comprise a mold, an arc-shaped strand guide, and a horizontal discharge area enclosed in thermal insulation 13. The slab strands of the continuous casting plants 1a and 1b are cut by shearing into slabs with a length between 11.5 and 26 m, typically about 14 m. The produced slabs 2 are transported horizontally by the slab manipulator 3 into the gas-fired walking beam furnace 4, where they are heated to rolling temperature and transported to the rolling mill 5.

[0036] In the entry area of ​​the rolling mill 5, the slab 2 is first descaled by a first descaling unit 12a and then rolled into a roughing strip by a single-stand, reversing roughing mill 6 through 3 to 5 rolling passes. The roughing strip is then wound into a reel in the coil box 7, which is preferably thermally insulated. After the coil box is rotated 180°, the reel is unwound and fed to the joining unit 8. To ensure a secure connection of the roughing strips, the roughing strips are partially descaled by a second descaling unit 12b. In the joining unit 8, the end of a leading roughing strip is joined to the end of a trailing roughing strip to form an endless roughing strip (see also the Fig 3 ).

[0037] The endless strip is then descaled by a third descaling unit 12c and finished in the five-stand finishing mill to a finished strip with a final thickness of 0.8 mm. The finished strip is then cooled in the cooling section 10 and cut by a high-speed shear. high speed shears or flying shears) cut off and wound through several - here for example three - reeling devices 11a... 11c.

[0038] Between the first descaling unit 12a and the roughing mill 6, between the roughing mill 6 and the coil box 7, and in the area of ​​the coil box 7, the slabs 2, the strip, or the coiled strip are thermally insulated. Depending on the steel grade produced, it may also be necessary not to cool the hot strip in the cooling section 10, but to thermally insulate it.

[0039] According to the invention, several continuous casting plants (here 1a, 1b) generate the necessary mass flow of 3.5 to 5.5 M t / a. The discrete slabs are heated to rolling temperature via the slab manipulator and the walking beam furnace and fed to the rolling mill 5. In the rolling mill 5, a coil of a pre-strip is first produced from a slab 2 by pre-rolling. Subsequently, the coil is unwound, and the head of the lagging, i.e., unwound, pre-strip is joined to the foot of a leading pre-strip to form an endless pre-strip. The joining is achieved by joining, specifically by pressing the pre-strips together, without welding them with a welding filler material. The endless pre-strip is finished-rolled in continuous operation in the finishing mill, which allows for the easy production of ultra-thin hot-rolled strips with a thickness of < 1.2 mm, preferably even ≤ 1.0 mm.

[0040] The Fig 2 shows a cross-sectional view of the casting-rolling composite plant made of Fig 1 It can be seen that the horizontal discharge areas of the two continuous casting plants 1a and 1b are located at approximately the same height vertically as the inlet area of ​​the rolling mill 5. However, neither continuous casting plant is connected in-line to the rolling mill 5, as the slabs 2 are first fed into the rolling mill via the slab manipulator 3 and then the walking beam furnace 4. This ensures that the slabs have a constant temperature, regardless of whether they were produced in the first or second continuous casting plant 1a, 1b, or even introduced externally into the slab manipulator. Specifically, the discharge area of ​​the first continuous casting plant 1a has a larger offset A1 in the horizontal direction relative to the rolling mill 5 than the offset A2 in the horizontal direction between the discharge area of ​​the second continuous casting plant 1b and the rolling mill 5.

[0041] In Fig 3The steps for joining two pre-strips 20, 21 to form an endless pre-strip are shown. First, the head of the lagging pre-strip 21 is overlapped with the foot of the leading pre-strip 20, creating an overlapping area 23. Then, the pre-strips 20, 21 are pressed together by pressing and cutting forces 24, 25, whereby cutting edges 22 act on the underside of the leading pre-strip 20 and the top side of the lagging pre-strip 21. The pressing and cutting of the pre-strips 20, 21 creates an endless pre-strip in the central area and two sections 26 above and below the central area.

[0042] The sections are removed either mechanically or by fluid jets from the second descaling unit 12b and then finished rolling.

[0043] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived by the person skilled in the art without leaving the scope of protection of the invention as defined by the claims. Reference symbol list

[0044] 1 Continuous casting plant 1a first continuous casting plant 1b second continuous casting plant 2 Slab 3 Slab manipulator 4 Walking beam furnace 5 Rolling mill 6 Pre-rolling mill 7 Coil box 8 Joining device 9 Finishing mill 10 Cooling section 11a... 11c Reeling device 12a first descaling device 12b second descaling device 12c third descaling device 13 Thermal insulation 20 Leading pre-strip 21 Trailing pre-strip 22 Cutting edge 23 Overlapping area of ​​pre-strips 24 Pressing force 25 Support force 26 Sections A1, A2 first offset, second offset

Claims

1. Combined casting and rolling installation for producing hot-rolled strip with a final thickness < 1.2 mm, preferably ≤ 1.0 mm, comprising - at least a first continuous casting installation (1a) and a second continuous casting installation (1b), wherein each continuous casting installation (1a, 1b) casts liquid steel into slabs (2); - a slab manipulator (3) for conveying the slabs (2) from the continuous casting installations (1a, 1b) into a walking beam furnace (4) for conveying the slabs (2) from the slab manipulator (3) into a rolling installation (5) and for heating the slabs (2) to rolling temperature, wherein slabs (2) from the first continuous casting installation (1a) and slabs (2) from the second continuous casting installation (1b) pass completely through the walking beam furnace (4) and are uniformly heated in the process; - the rolling installation (5), comprising -- a roughing rolling mill (6) for rough rolling the heated slabs (2) to form a rough-rolled strip, -- a preferably thermally insulated coil box (7) for winding up the rough-rolled strip to form a coil and for unwinding the rough-rolled strip, -- a joining device (8) for connecting, without filler material, a foot of a leading rough-rolled strip (20) to a head of a trailing rough-rolled strip (21) to form an endless rough-rolled strip, -- a multi-stand finishing rolling mill (9) for finish rolling the endless rough-rolled strip to form a finished strip with the final thickness, -- a cooling section (10) for cooling the finished strip to form the hot-rolled strip, and -- a plurality of coiling devices (11a...11c) for coiling the hot-rolled strip, wherein the roughing rolling mill (6), the coil box (7), the joining device (8), the multi-stand finishing rolling mill (9), the cooling section (10) and the coiling devices (11a...11c) of the rolling installation (5) are arranged in-line one behind the other, and the first continuous casting installation (1a) has a first offset (A1) in a first direction with respect to the rolling installation (5) and the second continuous casting installation (1b) has a second offset (A2) in the first direction with respect to the rolling installation (5).

2. Combined casting and rolling installation according to Claim 1, characterized in that the continuous casting installations (1a, 1b) are configured to generate slabs with a thickness of 140 to 240 mm and a width of between 1100 and 2300 mm.

3. Combined casting and rolling installation according to either of the preceding claims, characterized in that the roughing rolling mill (6) is a reversing, preferably one-stand, roughing rolling mill.

4. Combined casting and rolling installation according to one of the preceding claims, characterized in that the first direction is the horizontal.

5. Combined casting and rolling installation according to one of the preceding claims, characterized in that the finishing rolling mill (9) comprises five to seven finishing roll stands.

6. Combined casting and rolling installation according to one of the preceding claims, characterized in that a first descaling device (12a) is arranged downstream of the walking beam furnace (4) and upstream of the roughing rolling mill (6), and / or in that a second descaling device (12b) is arranged upstream of the joining device (8) and a third descaling device (12c) is arranged upstream of the finishing rolling mill (9).

7. Combined casting and rolling installation according to one of the preceding claims, characterized in that the slab manipulator (3) can discharge slabs (2) generated by the continuous casting installations (1a, 1b) transversely with respect to the conveying direction from the continuous casting installations (1a, 1b) to the walking beam furnace (4), and the slab manipulator (3) can introduce slabs (2) which have not been generated in the continuous casting installations (1a, 1b) of the combined casting and rolling installation transversely with respect to the conveying direction from the continuous casting installations (1a, 1b) to the walking beam furnace (4).

8. Method for producing a hot-rolled strip with a final thickness < 1.2 mm, preferably ≤ 1.0 mm, on a combined casting and rolling installation, in particular according to one of the preceding claims, comprising the following steps: - continuously casting liquid steel into slabs (2) on at least a first continuous casting installation (1a) and a second continuous casting installation (1b); - conveying the slabs (2) from the continuous casting installations (1a, 1b) into an inlet region of a walking beam furnace (4); - conveying the slabs (2) from the inlet region through the walking beam furnace (4) into an outlet region of the walking beam furnace (4), wherein the slabs (2) are heated to rolling temperature; - rough rolling the heated slabs (2) to form a rough-rolled strip; - winding up the rough-rolled strip to form a coil and preferably thermally insulating, particularly preferably heating, the coil; - unwinding the rough-rolled strip from the coil; - connecting, without filler material, a foot of a leading rough-rolled strip (20) to a head of a trailing rough-rolled strip (21) to form an endless rough-rolled strip; - finish rolling the endless rough-rolled strip to form a finished strip with the final thickness by way of multiple rolling passes in a multi-stand finishing rolling mill (9); - cooling the finished strip to form the hot-rolled strip; - cutting the hot-rolled strip; and - coiling the hot-rolled strip.

9. Method according to Claim 8, characterized in that the rough rolling is effected by way of multiple, preferably 3-5, rolling passes in a reversing roughing rolling mill (6).

10. Method according to one of Claims 8 to 10, characterized in that when connecting the rough-rolled strips to form the endless rough-rolled strip, the foot of the leading rough-rolled strip (20) is firstly overlapped with a head of the trailing rough-rolled strip (21), and then the overlapping region of the rough-rolled strips (20, 21) is compressed, wherein the vertical positions of the rough-rolled strips (20, 21) are aligned with one another.

11. Method according to one of Claims 8 to 10, characterized in that the rough-rolled strips (20, 21) are descaled after the unwinding and prior to the connecting.

12. Method according to one of Claims 8 to 11, characterized in that the slabs (2) have a thickness of 140 to 240 mm and a width of between 1100 and 2300 mm, and / or the rough-rolled strip has a thickness of between 25 and 35 mm.

13. Method according to one of Claims 8 to 12, characterized in that the slabs (2) are charged at a temperature ≥ 900°C into the walking beam furnace (4).

14. Method according to one of Claims 8 to 13, characterized in that the combined casting and rolling installation has an annual production capacity of between 3 and 6 million tons, in particular between 3.5 and 5.5 million tons.

15. Method according to one of Claims 8 to 14, characterized in that the continuous casting installations (1a, 1b) produce slabs (2) with a thickness of 150 to 190 mm at a casting rate of 4 to 5 m / min and slabs (2) with a thickness of 191 to 230 mm at a casting rate of 2 to 4 m / min.

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