Foundry and rolling production line and corresponding method

Abstract

The casting and rolling production line (10) for producing flat metal products (100) includes at least a casting machine (11), a preheating furnace (19), and a rolling mill (25).

Description

Technical Field

[0001] This invention relates to casting and rolling production lines for producing flat metal products, such as, in particular, sheet metal, and corresponding methods. Background Technology

[0002] Currently, the production of flat metal products (such as sheet metal) is provided in foundry and rolling mills, which are typically not on the same production line and may even be located in separate buildings. Metal semi-finished products or slabs from casting are loaded into at least one heating furnace located upstream of the rolling mill before being rolled to reduce their thickness to the desired value.

[0003] A warehouse is needed between the casting production line and the rolling mill to coordinate the independent production of these lines.

[0004] The heating furnaces are typically gas-fired furnace solutions of the "walking beam" or "pusher" type, compatible with production capacities ranging from 0.5 to 2 million tons per year.

[0005] When the casting production line is located near the rolling production line, the semi-finished product can be loaded into an already heated furnace or into a cold furnace to reach a temperature suitable for rolling, typically in the range of 1150°C to 1250°C. It is followed by at least one rolling stand to achieve the desired thickness, and by at least one leveling mill to reduce any flatness defects (wrinkles) in the product caused by rolling.

[0006] The frame or individual frames are reversible and operate multiple alternating channels (which can be very numerous, typically between 15 and 25), in which products move due to electric roller tables.

[0007] Typically, cast slabs are quite large (e.g., about 10 m-12 m) and usually need to be cut to size before being loaded into the furnace to obtain semi-finished products suitable for manufacturing slabs with dimensions and weights conforming to the order at the end of the processing. However, this results in waste.

[0008] Alternatively, the casting dimensions can be directly corresponding to the rolled slab, so that the dimensions directly correspond to the dimensions that will be used as the final sheet, especially when the ordered sheet has a large size, thereby minimizing waste.

[0009] Considering the length of the furnace, the space for various reversible passages, and the progressive work area for dividing the slabs before arbitrary stacking for storage, this type of plant is approximately 500 m to 1000 m long depending on the production capacity. Therefore, it is often not energy-efficient, as it typically requires heating the slabs loaded upstream from ambient temperature or, in any case, from a low temperature to the rolling temperature, and these furnaces often use fossil fuels, thus generating environmental emissions.

[0010] Because these plants are very expensive in terms of investment (CapEx) and management (OpEx), they are constructed to achieve large production capacities of approximately 0.5-2 million tons per year, allowing these investments to be amortized. However, this has an impact on environmental emissions because it is necessary to supply high thermal power to the semi-finished products to be heated to rolling temperature: in fact, the heating furnaces are often used in a continuous circulation manner to minimize the use of gases for heat recovery. However, this requires the near-continuous generation of environmental emissions, which significantly impacts the production line.

[0011] Therefore, there is a need to improve casting and rolling production lines that can overcome at least one of the shortcomings of existing technologies.

[0012] Therefore, it is necessary to solve the technical problem of optimizing the energy consumption required to heat the semi-finished product to be rolled to the rolling temperature and maintain it at that temperature.

[0013] In particular, an object of the present invention is to provide a casting and rolling production line and a corresponding method that has lower cost and lower environmental impact compared with the prior art.

[0014] The applicant has designed, tested and implemented the present invention to overcome the disadvantages of the prior art and to obtain these and other objectives and advantages. Summary of the Invention

[0015] The invention is set forth and characterized in the independent claims. The dependent claims describe other features or variations of the main inventive concept of the invention.

[0016] In accordance with the above objectives, and in order to solve the above-mentioned technical problems in a novel and original manner, and also in order to achieve significant advantages compared with the prior art, the casting and rolling production line for producing flat metal products (especially sheet metal) according to the present invention comprises at least a casting machine, a preheating furnace, and a rolling mill unit formed by at least one or more reversible rolling stands.

[0017] The casting machine is configured to supply primary metal semi-finished products to be prepared for rolling. The preheating furnace is configured to heat and hold the individual metal semi-finished products to be prepared for rolling at a preheating temperature. The rolling mill is configured to hot roll the slabs obtained from the metal semi-finished products.

[0018] According to one aspect of the invention, the casting and rolling production line further includes a rapid heating device downstream of the preheating furnace, the rapid heating device being configured to heat at least one head of each metal semi-finished product to be prepared for rolling to the rolling temperature; the casting and rolling production line further includes a cutting unit between the rapid heating device and the rolling mill, the cutting unit being configured to cut each heated head of the metal semi-finished product to be prepared for rolling, thereby obtaining a slab to be rolled.

[0019] This production line configuration allows for the limitation of heat dissipation from the semi-finished metal during its processing, thus reducing the energy consumption associated with this process. Furthermore, the semi-finished metal is maintained at a temperature below the rolling temperature within the preheating furnace, and for each operating cycle, only the portion forming the slab to be rolled is brought to the rolling temperature. This allows for economic advantages in terms of the energy used to power the preheating furnace. This casting and rolling production line is more compact and energy-efficient than currently used plants, making it economically feasible even for low-volume plants (i.e., less than 500,000 tons / year) in terms of investment and management costs.

[0020] According to another aspect of the invention, the preheating furnace is a tunnel furnace, preferably electrically powered.

[0021] According to another aspect of the invention, the rapid heating device is an induction heater.

[0022] According to another aspect of the invention, the casting machine is fed with molten metal from an electric steel mill.

[0023] This enables the production of metal products using machines and tools powered solely by electricity (i.e., without the use of fossil fuels) from the melting of raw metals to the completion of the final metal product. This results in a production line according to the invention having a lower environmental impact than known casting and rolling production lines due to reduced direct emissions (and, depending on the country, also reduced indirect emissions).

[0024] According to another aspect of the invention, the preheating furnace includes an internal transport device configured to transport the metal semi-finished product to be prepared for rolling in two directions of travel, i.e., from its first aperture to a second aperture corresponding to its opposite end, or vice versa, from the second aperture to the first aperture.

[0025] According to another aspect of the invention, the casting and rolling production line includes a moving device disposed upstream of the rolling mill, the moving device being configured to feed slabs to the rolling mill and, where possible, selectively rotate each slab by 90° before feeding it to the rolling mill, performing so-called transverse rolling.

[0026] According to another aspect of the invention, the casting machine is of the vertical type, so as to shorten the production line compared with the curved casting machine.

[0027] The present invention also relates to a casting and rolling method for producing flat metal products using the above-described production line.

[0028] According to another aspect of the invention, the method preheats the metal semi-finished products to be rolled to a preheating temperature in a preheating step. The method then heats at least one head of each of the metal semi-finished products to the rolling temperature using a rapid heating device in a rapid heating step. The method also cuts the heads in a cutting step using a cutting unit to obtain a slab to be rolled with the desired dimensions. The remaining portion of the metal semi-finished product is returned to the preheating furnace to avoid heat loss. Furthermore, in the rolling step, the method rolls the slab using a rolling mill to obtain a rolled semi-finished product with a thickness substantially equal to the final thickness of the desired metal product. Simultaneously, in a new preheating step, the remaining portion is substantially maintained at the preheating temperature using a preheating furnace. The rapid heating step, cutting step, and rolling step can then be repeated for the remaining portion until the remaining portion is exhausted.

[0029] According to another aspect of the invention, the rolling step includes, in a pre-rolling sub-step, pre-rolling the slab to obtain an intermediate semi-finished product to be prepared for rolling, having an intermediate thickness between the thickness of the slab and the thickness of the metal product. Then, the rolling step includes, in an additional preheating sub-step, preheating each of the intermediate semi-finished products to be prepared for rolling to a preheating temperature. Subsequently, in an additional rapid heating sub-step, the method includes heating at least one head of each intermediate semi-finished product to a rolling temperature by means of a rapid heating device. In an additional cutting sub-step, the method involves cutting the heads by means of a cutting unit to obtain an additional slab to be rolled and a residual portion of the intermediate semi-finished product to be prepared for rolling. This residual portion is returned to the preheating furnace. Furthermore, in a final rolling sub-step, the rolling step rolls the additional slab by means of a rolling mill to obtain a rolled semi-finished product. Simultaneously, in a new additional preheating sub-step, the residual portion is substantially maintained at the preheating temperature by means of a preheating furnace. The additional rapid heating step, additional cutting step, and final rolling sub-step can be repeated for the remaining portion until the remaining portion is exhausted.

[0030] According to another aspect of the invention, in the rolling step, the rolling of the slab can be selectively performed in terms of length or width. Attached Figure Description

[0031] These and other aspects, features, and advantages of the invention will become apparent from the following description of some embodiments given by way of non-limiting example with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of a casting and rolling production line according to the present invention; Figure 2 It is a graphical representation of the casting and rolling method according to the present invention; Figure 3 yes Figure 2 A graphical representation of the preheating step of the method; Figure 4 yes Figure 2 A graphical representation of a possible embodiment of the rolling steps of the method; Figure 5 yes Figure 2 Graphical representation of possible alternative embodiments of the rolling steps of the method; Figure 6 yes Figure 2 A schematic diagram of the rapid heating steps of the method; Figure 7 yes Figure 2 A schematic diagram of the cutting steps of the method; Figure 8 yes Figure 2 A schematic diagram of the pre-rolling sub-step of the method; Figure 9 yes Figure 2 A schematic diagram of another preheating sub-step in the method; Figure 10 yes Figure 2 A schematic diagram of another rapid heating sub-step of the method.

[0032] We must clarify that the wording and terminology used in this specification, as well as the figures in the described drawings, serve only to better illustrate and explain the invention. Their purpose is to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0033] For ease of understanding, the same reference numerals are used to identify the same common elements in the figures where possible. It should be understood that elements and features of one embodiment can be readily combined or integrated into other embodiments without further explanation. Detailed Implementation

[0034] Reference Figure 1The casting and rolling production line 10 according to the present invention is suitable for and can be used to produce flat metal products 100, such as sheet metal.

[0035] During its operation, production line 10 processes and transforms metal semi-finished products of various shapes and sizes, depending on the processing steps in the process and the specific metal product 100 to be produced.

[0036] For example, production line 10 may be part of a plant that produces sheet metal with an annual production capacity of 100,000 tons to 200,000 tons per year.

[0037] As a non-limiting example, the metal product 100 may be made of a suitable type of steel.

[0038] exist Figure 1 In the possible non-limiting embodiments shown, production line 10 is adapted to operate in a semi-continuous mode and includes a casting machine 11 configured to supply semi-finished metal products to subsequent components of production line 10. For example, casting machine 11 may be configured to produce generally medium or thin slabs.

[0039] exist Figure 1 In the illustrated embodiment, the casting machine 11 is of the vertical type, i.e., it is configured to perform vertical casting. Furthermore, the casting machine is configured with a ladle 12, a tundish 13, and a crystallizer 14 in a known manner, followed by an initial cutting unit 16, which is configured to cut the casting material to size to obtain a primary metal semi-finished product 101 to be prepared for rolling.

[0040] According to possible embodiments, each metal semi-finished product 101 may have a thickness between about 120 mm and about 200 mm, a width between about 800 mm and about 1500 mm, and a length determined by vertical casting between about 5000 mm and about 12000 mm.

[0041] In a possible embodiment, a small-scale electric arc furnace (EAF) steelmaking facility can be located upstream of the production line 10 itself in the plant where the production line 10 is installed, capable of feeding molten metal to the casting machine 11. Such an EAF steelmaking facility can, for example, have a ladle of about 15 to 30 tons and a corresponding electric arc furnace (EAF) of about 35 to 40 tons (including slag), as well as any other known equipment for appropriate pretreatment (such as vacuum degassing) prior to casting.

[0042] According to a possible embodiment, production line 10 may include an inclined member 17 immediately downstream of casting machine 11, which is configured to support the metal semi-finished product in a vertical position during casting, and then allow horizontal tilting and transfer to a device 18 for the initial transport of the shaped and sized metal semi-finished product 101.

[0043] For example, the initial transport device 18 may include transport rollers, etc.

[0044] The initial transport device 18 is configured to transport the metal semi-finished product 101 from the casting machine 11 to the subsequent components of the production line 10.

[0045] In some embodiments, the preheating furnace 19 is disposed downstream of the inclined member 17. The initial transport device 18 is configured to transport the individual metal semi-finished products 101 from the inclined member 17 to the preheating furnace 19.

[0046] The preheating furnace 19 is of a known type, preferably a fully electric tunnel furnace, which is configured to maintain a chamber temperature TC therein. The chamber temperature TC can, for example, have a value of about 800 °C to 1000 °C.

[0047] The preheating furnace 19 includes at least a first opening 20 facing the initial transport device 18 and at least a second opening 21 corresponding to the opposite end.

[0048] In some embodiments, the preheating furnace 19 is configured to heat and hold metal semi-finished products, such as metal semi-finished product 101, inside it at a preheating temperature TP for preparation for rolling.

[0049] For example, the preheating temperature TP can have a value of approximately 600 ℃-700 ℃.

[0050] According to possible embodiments, the preheating furnace 19 may include suitable internal transport devices 19a inside it, such as multiple rollers provided with internal cooling, or multiple rollers without internal cooling (also known as drying), or similar transport devices.

[0051] The internal transport device 19a can be configured to transport metal semi-finished products, such as metal semi-finished product 101, to be prepared for rolling within the preheating furnace 19 along its entire length or along its suitable segments.

[0052] Furthermore, the internal transport device 19a can be configured to transport metal semi-finished products, such as metal semi-finished product 101, to be prepared for rolling inside the preheating furnace 19 in two directions of travel (i.e. from the first opening 20 to the second opening 21, or vice versa, from the second opening 21 to the first opening 20).

[0053] In this way, the preheating furnace 19 can also be used as an accumulation buffer for preheated metal semi-finished products (such as metal semi-finished product 101 or other semi-finished products, or portions of semi-finished products) to be prepared for rolling, as described in more detail below, thereby facilitating the coordinated operation of all components of the production line 10.

[0054] In some embodiments, a rapid heating device 22, such as an induction heater or furnace, is provided downstream of the preheating furnace 19, which is configured to heat at least the head of a metal semi-finished product (such as metal semi-finished product 101) to be prepared for rolling to a rolling temperature TL.

[0055] For example, the rolling temperature TL can have a value of approximately 1150 °C to 1250 °C.

[0056] According to a possible embodiment, a cutting unit 23 is provided downstream of the rapid heating device 22, which is configured to cut the head of the metal semi-finished product 101 (or more generally, the metal semi-finished product to be prepared for rolling) to a planned length after the head has reached the rolling temperature TL, thereby obtaining a slab 102 to be rolled.

[0057] The cutting unit 23 may include, for example, a hydraulic shearing machine.

[0058] For example, slab 102 may have a length between about 800 mm and about 2500 mm. Typically, about 4 to 18 slabs 102 can be obtained from one metal semi-finished product 101.

[0059] In some embodiments, the rolling mill 25 is located downstream of the cutting unit 23 and is configured to hot roll the slab 102 to obtain the rolled semi-finished product 103.

[0060] For example, the thickness of the rolled semi-finished product 103 can be between approximately 30 mm and approximately 50 mm.

[0061] The rolling mill 25 includes at least one rolling stand 26, which is configured to perform rolling in a known manner, and, where possible, width adjustment by means of a suitable side stand (also known as a sizing mill).

[0062] Preferably, but not necessarily, the rolling mill 26 is a reversible mill with a roller table of approximately 1800 mm to approximately 2700 mm, depending on the characteristics of the metal product 100 to be obtained. Note that the length of the roller table determines the maximum possible length of the slab 102.

[0063] According to possible embodiments, the mill 25 may be preceded by a descaling machine (not shown in the figures), such as a high-pressure water descaling machine (220 bar-240 bar), which is configured to perform descaling of the slab 102 in a known manner.

[0064] In some embodiments, the moving device 24 may be positioned immediately upstream of the rolling mill 25, at least capable of feeding the slab 102 (typically the slab to be rolled) to the rolling mill 25. The moving device 24 may be configured to move each of the slabs to be rolled toward the rolling mill 25, which has a larger dimension or length than the slabs to be rolled, and the slabs are oriented parallel to the direction of movement for longitudinal rolling of the slabs to be rolled.

[0065] In a possible embodiment, the moving device 24 is configured to selectively rotate the slab to be rolled (e.g., slab 102) by 90°, where possible, before feeding it into the rolling mill 25, thereby performing rolling of the slab in the transverse direction (i.e., in the direction perpendicular to its length). For example, the moving device 24 may include a plurality of counter-rotating rolls configured to achieve the desired rotation if necessary.

[0066] According to a possible embodiment, at least one straightening device 27 (such as a leveler) may be provided downstream of the rolling mill 25, which is configured to thermally level the rolled semi-finished product 103.

[0067] Following the straightening device is a final cutting unit 28, which is configured to cut the rolled semi-finished product 103 to size to obtain the metal product 100.

[0068] In some embodiments, a cooling bed 29 is provided downstream of the final cutting unit 28, which is configured to allow cooling of the metal product 100.

[0069] According to a possible embodiment, following the cooling bed 29 is a packaging device 30, which is configured to prepare the metal product 100 for storage.

[0070] For example, packaging device 30 may include stacker 31 or similar device for preparing for storage in a known manner.

[0071] Production line 10 may be equipped with additional suitable processing equipment in a known manner, which is also selected according to the specific metal product 100 and is not shown in the accompanying drawings, such as known cooling or finishing equipment.

[0072] The operation of production line 10 described so far corresponds to the method according to the invention (in Figure 2 (Illustrated in the figure), the method includes at least: casting step 40, initial cutting step 50, tilting step 60, preheating step 70, rapid heating step 80, cutting step 90, rolling step 110 and additional post-rolling finishing steps.

[0073] It should be understood that during the operation of production line 10, the components of production line 10 operate in a manner that is appropriately coordinated so as to allow these steps to be performed simultaneously on different metal semi-finished products at different stages of processing.

[0074] Initially, in casting step 40, casting machine 11 produces metal semi-finished products by casting. For example, casting machine 11 can perform vertical casting, and the corresponding metal semi-finished products are supported in a vertical position by inclined members 17.

[0075] The metal semi-finished product obtained in casting step 40 is cut to size in the subsequent initial cutting step 50. In the initial cutting step 50, the initial cutting unit 16 cuts the metal semi-finished product to a suitable length, for example, between about 5000 mm and about 12000 mm, thereby obtaining metal semi-finished product 101.

[0076] We must clarify that the descriptions above and below concerning a single metal semi-finished product 101 are valid for every metal semi-finished product 101 used to manufacture the metal product 100.

[0077] Subsequently, tilting step 60 tilts the metal semi-finished product 101 from the vertical position formed by vertical casting to a horizontal position, which is more functional for subsequent processing steps. Therefore, in tilting step 60, tilting device 17 tilts the metal semi-finished product 101 and transfers it to the initial transport device 18.

[0078] Subsequently, preheating step 70 ( Figure 3 The metal semi-finished product 101 (or more generally, the metal semi-finished product to be prepared for rolling) is preheated at a preheating temperature TP and held at that temperature.

[0079] In the entry sub-step 71 of the preheating step 70, the metal semi-finished product to be prepared for rolling enters the preheating furnace 19, for example, through the first opening 20 or through the second opening 21.

[0080] In a possible embodiment, the initial transport device 18 transports the metal semi-finished product 101 to the preheating furnace 19, and the metal semi-finished product 101 enters the preheating furnace 19 through the first opening 20.

[0081] According to a possible embodiment, the metal semi-finished product 101 enters the preheating furnace 19 in a "hot" state (i.e., at an entry temperature TI significantly higher than ambient temperature) due to the recent casting step 40, in which, advantageously, the metal semi-finished product 101 is not completely cooled, but only sufficiently cooled to achieve product crystallization. The entry temperature TI can, for example, have a value in the range of about 500 °C to 600 °C.

[0082] The heat entering the preheating furnace 19 allows for the limitation of the dissipation of residual heat from the casting step 40, thereby reducing the thermal jump that the preheating furnace 19 would have to subject the metal semi-finished product 101 to, as detailed below, and thus making the entire process more efficient.

[0083] Then, in the temperature setting sub-step 72 of the preheating step 70, the preheating furnace 19 heats the metal semi-finished product 101 to the preheating temperature TP in a known manner. At the same time, if necessary, the metal semi-finished product 101 can be moved within the preheating furnace 19 by means of the internal transport device 19a.

[0084] Advantageously, the temperature setting sub-step 72 can be followed by a temperature holding sub-step 73, in which the internal transport device 19a alternately reciprocates the metal semi-finished product 101, i.e., from the interior of the preheating furnace 19 toward its second opening 21 and from the second opening 21 toward the interior of the preheating furnace 19, so as to maintain the metal semi-finished product 101 within the preheating furnace 19 substantially at the preheating temperature TP. Depending on the construction of the preheating furnace 19 and the requirements of the production process, this reciprocating transport can be carried out along the entire length of the preheating furnace 19, or only along its dedicated sections, such as its end section near the second opening 21.

[0085] In this way, the preheating furnace 19 essentially serves as an accumulation buffer for preheated metal semi-finished products 101 that cannot yet proceed to subsequent processing steps, for example, because the rolling mill 25 is occupied by previously processed metal semi-finished products. This advantageously facilitates the coordinated operation of all components of the production line 10.

[0086] Preheating step 70 is followed by rapid heating step 80. Figure 6 The rapid heating device 22 heats at least the head of the metal semi-finished product 101 to the rolling temperature TL.

[0087] In a possible embodiment, the head of the metal semi-finished product 101, which is substantially the same length as the slab 102, is transported back and forth within the rapid heating device 22 until it reaches the rolling temperature TL.

[0088] Subsequently, cutting step 90 ( Figure 7 The head is cut off at the rolling temperature TL of the semi-finished metal product 101 to obtain the slab 102 and the residual portion 101' of the semi-finished metal product 101. The residual portion 101' can also be considered as a semi-finished metal product to be prepared for rolling.

[0089] Advantageously, the residual portion 101' can be returned to the preheating furnace 19, where it re-enters the preheating step 70: the residual portion 101' can enter the preheating furnace 19 through the second opening 21 in a new entry sub-step 71, possibly but not necessarily undergoing a new temperature setting sub-step 72 and subsequently undergoing a new temperature holding sub-step 73.

[0090] In this new temperature holding sub-step 73, the residual portion 101' is substantially maintained at the preheating temperature TP while the slab 102 is processed by the rolling mill 25, as described below. Therefore, the heat absorbed by the residual portion 101' during the temperature setting sub-step 72 of the metal semi-finished product 101 is not dissipated except for a minimal portion during the processing of the slab 102, thus contributing to a more energy-efficient overall process.

[0091] In this way, the preheating furnace 19 also serves essentially as a cumulative buffer for the preheated residue 101' that cannot yet proceed to subsequent processing steps.

[0092] Furthermore, advantageously, in this way, the duration of the rapid heating step 80 (which is the most energy-intensive step) is reduced to the minimum required, thereby achieving significant energy savings. Additionally, due to the preceding preheating step 70, the rapid heating device 22 must ensure that the head of the metal semi-finished product 101 experiences relatively low thermal jumps, thus achieving further energy savings.

[0093] It should be understood that once the rolling of the slab 102 as described below has been completed, the residual portion 101' can undergo a new rapid heating step 80 and then a new cutting step 90 to obtain a new slab 102 and possibly a new, shorter residual portion 101', and these steps can be repeated until the residual portion 101' is exhausted.

[0094] Typically, approximately 4-18 slabs 102 can be obtained from a single metal semi-finished product 101. It should be noted that the last piece of the casting can be discarded if necessary.

[0095] According to a possible embodiment, after the cutting step 90, a descaling step can be performed in a known manner, for example under high pressure, as not shown in the figures.

[0096] In the subsequent rolling step 110, the slab 102 is rolled in such a way that its thickness is reduced from an initial value to a lower value that is substantially equal to the final thickness of the metal product 100 to be obtained. For example, the initial thickness of the slab 102 may be in the range of about 120 mm to 200 mm, while the final thickness of the metal product 100 may be in the range of about 3 mm to 50 mm.

[0097] Rolling step 110 rolls slab 102 in a known manner (basically at rolling temperature TL) by means of rolling mill 25.

[0098] According to possible embodiments, rolling step 110 includes a final rolling sub-step 112 ( Figure 4 ( ), wherein at least one rolling stand 26 performs the rolling of slab 102 in a known manner.

[0099] The moving device 24 transports the slab 102 inside the rolling mill 25 to at least the rolling stand 26. Entry into the rolling mill can occur in a direction parallel to the length of the slab 102 to perform longitudinal rolling, or after the slab 102 has been rotated 90°, in a direction perpendicular to the length of the slab 102 to perform transverse rolling.

[0100] After the final rolling sub-step 112, a rolled semi-finished product 103 is obtained, the thickness of which is substantially equal to the final thickness of the metal product 100 to be obtained.

[0101] If necessary, during rolling step 110, the width of the rolled semi-finished product 103 can be adjusted by means of a suitable side stand or edge rolling mill.

[0102] In some embodiments, particularly if the final thickness of the metal product 100 is particularly small, for example about 3 mm to 4 mm, a pre-rolling sub-step 111 may precede the final rolling sub-step 112. Figure 5 ).

[0103] In the pre-rolling process step 111 ( Figure 8 During this period, at least one rolling stand 26 performs rolling of the slab 102 in a known manner until a pre-rolled intermediate semi-finished product 103' is obtained, which has an intermediate thickness between the thickness of the slab 102 and the thickness of the metal product 100 to be obtained.

[0104] The intermediate semi-finished product 103' can be considered as a metal semi-finished product to be prepared for rolling.

[0105] The pre-rolling sub-step 111 can be performed longitudinally or laterally, similar to the description above for the final rolling sub-step 112.

[0106] For example, the intermediate semi-finished product 103' can have a thickness in the range of about 30 mm to 50 mm.

[0107] In this case, the pre-rolling sub-step 111 is followed by an additional preheating sub-step 70' ( Figure 9 ) and additional rapid heating sub-step 80' ( Figure 10They are exactly similar to the preheating arrangement 70 and the rapid heating step 80, but during this period, the intermediate semi-finished product 103' (instead of the metal semi-finished product 101) is preheated and heated to prepare the intermediate semi-finished product 103' for rolling.

[0108] Subsequently, in the additional cutting sub-step 90', the head of the intermediate semi-finished product 103', which has been appropriately heated to the rolling temperature TL, can be cut by means of the cutting unit 23, thereby obtaining the residual portion 103" of the additional slab 102' to be rolled and the intermediate semi-finished product 103'. The residual portion 103" can also be considered as a metal semi-finished product to be prepared for rolling.

[0109] In the final rolling sub-step 112, the additional slab 102' may be descaled and then rolled further to obtain the rolled semi-finished product 103, for example, with a thickness in the range of 3 mm to 4 mm.

[0110] Meanwhile, the remaining portion 103” can be returned to the preheating furnace 19, where it enters a new additional preheating sub-step 70’, that is, it is essentially held at the preheating temperature TP until its next processing becomes possible.

[0111] In this way, the preheating furnace 19 also serves essentially as a cumulative buffer for the preheated residue 103” that cannot yet proceed to subsequent processing steps.

[0112] It should be understood that once the final rolling sub-step 112 as described above has been completed, the residual portion 103” can be subjected to additional preheating 70’ and / or additional rapid heating 80’ and / or additional cutting 90’ and / or descaling as needed, and finally undergo a new sub-step of final rolling 112, thereby obtaining a new rolled semi-finished product 103 and possibly a new shorter residual portion 103”, and these sub-steps can be repeated until the residual portion 103” is exhausted.

[0113] During some or all of the sub-steps of rolling step 110, the concurrent casting process may be temporarily stopped and sustained for an appropriate period of time to allow proper coordination of the various components of production line 10, for example, to allow rolling step 110 to be performed without overcrowding production line 10.

[0114] According to possible embodiments, if a post-rolling finishing step is required to obtain a particular metal product 100, the method may subsequently provide one or more post-rolling finishing steps, such as one or more known cooling and / or hot leveling and / or dimensional cutting and / or trimming and / or packaging steps, in the most suitable order.

[0115] For example, in some embodiments, more than one straightening device 27 may be used to provide more than one leveling step 120.

[0116] At least one leveling step 120 levels the rolled semi-finished product 103, for example, by hot leveling.

[0117] Some exemplary embodiments then provide a dimensional cutting step 130, which includes dimensionally cutting the rolled semi-finished product 103 by means of a final cutting unit 28 to obtain a metal product 100.

[0118] For example, the length of metal product 100 can be in the range of 3000 mm to 12000 mm.

[0119] If necessary, the metal product 100 can be finished in a known manner in subsequent finishing steps.

[0120] For example, the width of metal product 100 can be in the range of 1000 mm to 2500 mm.

[0121] According to a possible embodiment, in the final cooling step 140, the metal product 100 is cooled to the final temperature TF in a known manner in the cooling bed 29.

[0122] The subsequent packaging step 150 can use packaging device 30 to prepare metal product 100 for storage.

[0123] For example, metal products 100, such as sheet metal, can be stacked using stacker 31.

[0124] It is obvious that modifications and / or additions can be made to the casting and rolling production line 10 and the corresponding methods as described above without departing from the scope and range of the invention as defined in the claims.

[0125] It is equally apparent that, although the invention has been described with reference to certain specific examples, those skilled in the art should be able to implement other equivalent forms of casting and rolling production lines and corresponding methods, which have the features set forth in the claims, and thus all fall within the scope of protection defined therein.

[0126] In the following claims, the reference numerals in parentheses are for ease of reading and should not be considered as limiting factors regarding the scope of protection defined in the claims.

Claims

1. Casting and rolling production line (10) for the production of flat metal products (100), comprising: At least one casting machine (11) configured to supply primary metal semi-finished products (101) to be prepared for rolling; at least one preheating furnace (19) configured to heat and hold the metal semi-finished products (101, 101', 103', 103) to be prepared for rolling at a preheating temperature (TP); and at least one rolling mill unit (25) formed by at least one reversible rolling support (26), characterized in that it further includes: a rapid heating device (22) downstream of the preheating furnace (19). The device is configured to heat at least one head of each of the metal semi-finished products (101, 101', 103', 103") to the rolling temperature (TL), and a cutting unit (23) between the rapid heating device (22) and the rolling mill (25) is configured to cut the heated head of each of the metal semi-finished products (101, 101', 103', 103") to obtain a slab (102, 102') to be rolled.

2. The production line (10) according to claim 1, characterized in that The preheating furnace (19) is an electric tunnel furnace.

3. - The production line (10) according to any one of the preceding claims, characterized in that, The rapid heating device (22) is an induction heater.

4. - The production line (10) according to any one of the preceding claims, characterized in that, The casting machine (11) is a vertical type.

5. - The production line (10) according to any one of the preceding claims, characterized in that, The preheating furnace (19) includes an internal transport device (19a) configured to transport the metal semi-finished product (101, 101', 103', 103") to be prepared for rolling in two directions of travel of the preheating furnace (19), that is, from its first opening (20) to its second opening (21) corresponding to its opposite end, or vice versa, from the second opening (21) to the first opening (20).

6. The production line (10) according to any one of the preceding claims, characterized in that, It includes a moving device (24) disposed upstream of the rolling mill (25), the moving device (24) being configured to feed the slabs (102, 102') to the rolling mill (25) and, where possible, selectively rotate each slab (102, 102') by 90° before feeding it to the rolling mill (25).

7. The production line (10) according to any one of the preceding claims, characterized in that, The casting machine (11) is fed with molten metal from an electric arc furnace steelmaking facility.

8. A casting and rolling method for producing flat metal products (100) in a casting and rolling production line (10), said production line (10) comprising at least one casting machine (11), at least one preheating furnace (19) and at least one rolling mill (25), said method being characterized in that, in a preheating step (70), metal semi-finished products (101, 101') to be prepared for rolling are preheated to a preheating temperature (TP); in a rapid heating step (80), at least one head of each metal semi-finished product (101, 101') to be prepared for rolling is heated to a rolling temperature (TL) by means of a rapid heating device (22) disposed between said preheating furnace (19) and said rolling mill (25); in a cutting step (90), by means of said rapid heating device (22) and said rolling mill (100) The cutting unit (23) between 25) cuts the head to obtain a slab (102) to be rolled, and the residual portion (101') of the metal semi-finished product (101, 101') is returned to the preheating furnace (19); and in the rolling step (110), the slab (102) is rolled by means of the rolling mill (25) to obtain a rolled semi-finished product (103) with a thickness substantially equal to the final thickness of the metal product (100), and in the new preheating step (70), the residual portion (101') is simultaneously substantially maintained at the preheating temperature (TP) by means of the preheating furnace (19), and the rapid heating step (80), the cutting step (90) and the rolling step (110) can be repeated on the residual portion (101') until the residual portion (101') is exhausted.

9. The method according to claim 8, characterized in that, The rolling step (110) includes: pre-rolling the slab (102) in a pre-rolling sub-step (111) to obtain intermediate semi-finished products (103') to be prepared for rolling, having an intermediate thickness between the thickness of the slab (102) and the thickness of the metal product (100); in an additional preheating sub-step (70'), preheating each intermediate semi-finished product (103', 103") to the preheating temperature (TP); in an additional rapid heating sub-step (80'), heating at least one head of each intermediate semi-finished product (103', 103") to the rolling temperature (TL) by means of the rapid heating device (22); and in an additional cutting sub-step (90'), cutting the head by means of the cutting unit (23) to obtain The additional slab (102') to be rolled, the residual portion (103") of the intermediate semi-finished product (103', 103") to be prepared for rolling is returned to the preheating furnace (19); and, in the final rolling sub-step (112), the additional slab (102') is rolled by means of the rolling mill (25) to obtain the rolled semi-finished product (103), in the new additional preheating sub-step (70'), the residual portion (103") is kept substantially at the preheating temperature (TP) by means of the preheating furnace (19), and the additional rapid heating sub-step (80'), additional cutting sub-step (90') and final rolling sub-step (112) can be repeated on the residual portion (103") until the residual portion (103") is exhausted.

10. The method according to claim 8 or 9, characterized in that, The step (110) of rolling the slab (102, 102') can be selectively performed in length or width.

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