Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
  • B21B1/466—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting in a non-continuous process, i.e. the cast being cut before rolling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/46—Roll speed or drive motor control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
  • B21B38/006—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring temperature

Definitions

• the present invention relates to a casting and rolling plant and a method for the continuous production of hot strip.
• hot-rolled metal strip i.e., hot-rolled metal strip
• so-called combined casting-rolling plants, or casting-rolling plants for short are often used.
• the casting process in which a metal strand is cast from liquid metal, is linked to the rolling process.
• continuous operation involves a continuous mass flow between a casting machine and one or more rolling stand groups, for example, a first rolling stand group, also known as a "roughing mill,” and a second rolling stand group, also known as a "finishing mill.”
• the aforementioned components are expediently arranged in the specified order.
• the rolling stand group, the cooling section, the second separating device, and the at least two coilers are preferably arranged directly one after the other. This means that no further components for handling the rolled hot strip are provided between them.
• Continuous production within the meaning of the present invention is preferably a substantially uninterrupted production of hot strip during a casting sequence, i.e. between a ramp-up or start of hot strip production and a ramp-down or end of hot strip production.
• the casting-rolling mill can have a scarfing device for scarfing the cast metal strand.
• the scarfing device is expediently arranged between the casting machine and the first separating device.
• the scarfing device can be arranged between the first separating device and the descaling device, or optionally also between the first separating device and the inductive heating arrangement.
• at least part of the strand surface can be removed using the scarfing device. Since scarfing of the cast metal strand is usually not necessary for all grades, it is expedient to design the scarfing device as an extendable device.
• the casting-rolling mill may have a discharge device in the area of the cooling section for discharging slabs or plates before they reach the at least two coilers. This also allows unrolled strand sections, which have been separated from the cast metal strand by the first separating device and pass through the rolling stand group unrolled, to be discharged from the casting-rolling mill.
• the metal strand can be severed if a strand temperature drops below a predetermined rolling temperature or threatens to drop due to a casting speed that is initially too low or reduced at the end of the casting sequence when entering or exiting the rolling stand group. This can prevent the rolling process from being started or the casting machine and the rolling stand group from being coupled before a stable casting process or a strand temperature sufficient for further processing has been established. This prevents the casting machine and the rolling stand group from remaining coupled for too long.
• a metal strand with a length of, for example, 5 m is usually cast until a strand temperature sufficient for the rolling process has been reached. Accordingly, it is preferred to use the first cutting device to cut off a strand section with a length of, for example, 5 m when starting up hot strip production and to remove it from the transport line, for example using the removal system. If a heating arrangement is switched on during start-up, the length of the strand section to be cut off can be reduced to, for example, 2 m.
• the metal strand is preferred to heat the metal strand using the inductive heating arrangement when starting up hot strip production and to use the first cutting device to cut off a strand section with a length of less than 10 m, preferably 5 m or less, particularly preferably 2 m or less, from the cast strand and to remove it from the transport line, for example using the removal system.
• the metal strand is separated at least once by means of the first separating device as soon as the metal strand no longer reaches a predetermined rolling temperature or can no longer be heated to the temperature suitable for reaching the predetermined rolling temperature by means of an inductive heating arrangement arranged, in particular, directly upstream of the rolling stand group.
• an inductive heating arrangement arranged, in particular, directly upstream of the rolling stand group.
• the strand temperature is preferably recorded, for example by sensor, modeling or a combination thereof.
• the cast metal strand is heated by means of an inductive heating arrangement arranged, in particular, directly in front of the rolling stand group, to a temperature suitable for reaching the predetermined rolling temperature for the rolling stand group.
• This heating preferably takes place during the ramp-up of hot strip production until the cast metal strand already contains sufficient heat upon exiting the casting machine to reach the predetermined rolling temperature even without heating by means of the inductive heating arrangement.
• this heating takes place during the ramp-down of the Hot strip production until the heat output of the inductive heating system is no longer sufficient to heat the cast strand to the temperature required to reach the rolling temperature. This can increase the productivity of the casting-rolling plant because a larger portion of the cast strand can be rolled into hot strip.
• At least one strand piece is severed from the cast metal strand by means of the first separating device and removed from a transport path defined between the casting machine and the rolling stand group.
• This removal is expediently carried out by means of the removal system.
• the mass flow from the casting machine can thus be diverted, namely out of the casting and rolling mill.
• the casting machine can continue to operate essentially without interruption, and cooling of the metal strand in a casting arc of the casting machine can be avoided.
• the cast metal strand is separated by means of the first separating device, and the separated strand portion is lifted in the region of a foot end facing the first separating device, for example by means of the lifting device. Consequently, strand pieces separated from the cast metal strand can be removed from the transport path below the raised foot end by means of the first separating device, for example by means of the conveyor device. This procedure allows for particularly rapid access to This allows for a rapid response to a malfunction, as stopping the casting device is not necessary.
• the casting operation can initially be temporarily suspended to cut the initial strand piece from the strand.
• the base end of the (stuck) strand section can be raised to facilitate the subsequent cutting and removal of the multiple strand pieces after the resumption of casting.
• FIG 1 shows an example of a casting-rolling plant 10 and a method 200 for the continuous production of hot strip 12.
• the casting-rolling plant 10 comprises a casting machine 20 with a mold 22 and a casting arch 24, a first separating device 30, a descaling device 40, a single rolling stand group 50 with at least one, in the present example six, rolling stands 51, 52, 53, 54, 55, 56, a cooling section 60, a second separating device 70 and at least, in the present example precisely, two coilers 80, 82.
• a scarfing device 90 and in the area A removal system 100 with a collecting container 102 is provided next to the first separating device 30.
• An inductive heating arrangement 110 is arranged directly upstream of the descaling device 40. Furthermore, the casting-rolling plant 10 comprises a third separating device 120, which is arranged in the region of the second separating device 70, i.e., between the cooling section 60 and the two coilers 80, 82.
• the casting machine 20 can cast liquid metal into a metal strand 14 at a rate of preferably more than 3.5 t per minute and meter of width, preferably more than 4 t per minute and meter of width, in particular up to 5 t per minute and meter of width.
• a metal strand 14 expediently has a thickness of between 80 mm and 240 mm and a width of between 500 mm and 2500 mm.
• the casting heat still contained in the cast metal strand 14 upon exiting the casting machine 20 can be retained at least for the most part until it reaches the rolling stand group 50, in particular the first rolling stand 51. Because only a single rolling stand group 50 is provided, this casting heat still contained in the metal strand 14 can then be used for the deformation until the finished hot strip 12 is formed. In normal operation, reheating of the metal strand 14 by the inductive heating arrangement 110 can therefore be dispensed with.
• a sample of the metal strand 14 can be cut out by means of the first cutting device 30 even during ongoing operation, i.e. during regular hot strip production, and removed from the transport path S by means of the removal system 100.
• the metal strand 14 is rolled into hot strip 12 in the rolling stand group 50.
• the metal strand 14 is expediently brought into engagement with all or at least some of the rolling stands 51-56.
• the rolling stands 51-56 are preferably designed as four-high stands.
• the first stand 51 can also be designed as a two-high stand.
• the last or the last two stands 55, 56 can also be designed as six-high stands.
• the hot strip 12 is cooled in a controlled manner on the cooling section 60 to a coiling temperature. This allows it to be coiled into a coil by means of one of the coilers 80, 82 in a further process step S5.
• the coiled hot strip 12 i.e., the coil, is separated from the subsequent hot strip 12 by means of the second separating device 70 or the third separating device 120.
• Which of the two separating devices 70, 120 which are preferably both designed as drum shears, is used to separate the hot strip 12 can depend on its thickness.
• the second separating device 70 is expediently designed for separating hot strip 12 with a thickness of 1 mm to 12 mm, preferably 2 mm to 12 mm.
• the third cutting device 120 is then preferably configured for cutting hot strips 12 with a thickness of 12 mm or more.
• the second cutting device 70 is preferably arranged downstream of the third cutting device 120.
• the severed strand section 18 can fall into the collecting container 102 by gravity. Due to the resulting gap between the base end 16a of the strand section 16 and the head end 14a of the metal strand 14, the metal strand 14 can be moved further in the transport direction R. Subsequently, further strand sections 18 can then be severed by means of the first separating device 30.
• the separating device 30 expediently cuts in the rear cutting position 38b as soon as the head end 14a threatens to meet the base end 16a. In this way, a casting interruption can be avoided in the event of a malfunction in which the strand section 16 can no longer be conveyed.
• the metal strand 14 can continue to move in the transport direction R even when the strand section 16 is at a standstill, for example because a malfunction has occurred in a rolling stand (not shown) that has engaged the strand section 16.
• a head end 14a of the metal strand 14 slides under the raised base end 16a.
• the strand section 18 can then be severed and conveyed out so that the resulting new head end 14a of the metal strand 14 can also be pushed under the raised base end 16a. In this way, further strand sections 18 can be severed and conveyed out in succession. This procedure can be maintained until the malfunction has been rectified or a casting machine producing the metal strand 14 has been shut down in a controlled manner.
• the liquid metal is initially poured slowly. Due to the low specific mass flow, the metal strand cannot maintain sufficiently high rolling temperatures for rolling in the individual stands of the rolling stand group. The temperatures of the rolled stock as it passes through the rolling stand group would therefore initially be insufficient for the rolling process.
• the mass flow and thus the casting speed can be increased subsequently. This increases the temperature of the metal strand upon reaching the rolling stand group.
• a check is therefore carried out to determine whether a predetermined rolling criterion has been met. For example, it can be checked whether the metal strand in the casting arch or the casting process has stabilized and/or whether the temperature and/or the specific mass flow of the metal strand are sufficient to carry out the rolling process, possibly after additional heating by means of an inductive heating arrangement arranged upstream of the rolling stand group. This check can be carried out by sensory recording, among other things, of the strand temperature, taking the specific mass flow into account. Alternatively, it is also conceivable to model the strand temperature based on operating parameters of the casting and rolling plant, in particular the casting machine. Such operating parameters can include, for example, the casting speed, a width-dependent mass flow into or out of the mold, the strand width and thickness, a cooling capacity at the casting arch, and/or the like.
• the first separating device separates strand pieces from the metal strand, essentially as soon as its head end exits the casting machine.
• the separation of strand pieces ends when the rolling temperature is reached or can be reached.
• the strand section is therefore not present as a whole, but only in the form of the strand pieces successively separated from the metal strand, which can considerably simplify processing.
• the metal strand is heated by means of the inductive heating arrangement to the rolling temperature or a temperature sufficient to reach the rolling temperature, provided that the casting heat alone is not sufficient for the rolling process.
• FIG 5 shows an example of a shutdown Z of a casting and rolling mill.
• step Z1 the casting speed of a casting machine for casting a metal strand is reduced. This reduces the mass flow and thus the strand temperature as it passes through a rolling stand group located downstream of the casting machine. If this temperature falls below a predetermined rolling temperature required or desired for rolling the metal strand, the rolling process must be stopped.
• the strand temperature is therefore recorded or modeled by sensors in a step Z2, for example upon exiting the casting machine, upon entering the rolling stand group, or upon exiting the last rolling stand in the rolling stand group.
• an inductive heating arrangement can be switched on in an optional step Z3.
• the metal strand is then expediently heated again using the inductive heating arrangement before entering the rolling stand group. This allows the casting speed to be reduced even further without the desired minimum rolling temperature or final rolling temperature being undershot - even if, due to the low casting speed, additional heat is lost on the transport path between the casting machine and the rolling stand group or between the individual rolling stands in the rolling stand group.
• the metal strand is separated by means of a first separating device in a further step Z4, thus interrupting the mass flow between the casting machine and the rolling stand group.
• the strand portion separated during separation from the cast metal strand still emerging from the casting machine can still be rolled into the desired hot strip.
• the remaining metal strand, or the metal strand still produced during the controlled stopping of the casting machine is expediently removed from the casting and rolling mill in a further step Z5, for example by means of a removal system.
• strand pieces can be separated successively from the metal strand by means of the separating device and individually dropped into a collecting container of the removal system or removed, for example, laterally, by means of a conveyor device of the removal system.

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• Mechanical Engineering (AREA)
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• 2024
  • 2024-03-28 EP EP24167444.9A patent/EP4624065A1/fr active Pending
• 2025
  • 2025-03-04 WO PCT/EP2025/055863 patent/WO2025201813A1/fr active Pending

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