Installation and method for heat treatment of a metal strip

Abstract

Plant (1) and method for the heat treatment of a metal strip (2), preferably made of an aluminum alloy, which is transportable in a strip direction (R) at a strip speed, wherein the plant (1) comprises: a solution annealing device (10) configured to heat the metal strip (2) to a first temperature (T1), preferably in the range of 350 °C to 650 °C; a quenching device (20) arranged downstream of the solution annealing device (10) in the strip direction (R) and configured to cool the metal strip (2) to a second temperature (T2), preferably in the range of 70 °C to 250 °C, by applying a coolant; and a pre-aging device (30) which, viewed in the direction of belt travel (R), is arranged downstream of the quenching device (20) and is configured to heat the metal strip (2) to a third temperature (T3), preferably in the range of 100 °C to 350 °C;wherein the solution annealing device (10), the quenching device (20) and the pre-aging device (30) are arranged in a common, continuous production line; and the pre-aging device (30) is designed as an electric rapid heating device, preferably an induction heating device.

Description

Technical field

[0001] The invention relates to a system and a method for the heat treatment of a metal strip, in particular a strip made of an aluminum alloy. Background of the invention

[0002] Precipitation-hardening aluminum alloys are characterized by at least one alloying element whose solubility in aluminum decreases with decreasing temperature. The mechanical properties of such precipitation-hardening aluminum alloys are adjusted through the processes of solution annealing, quenching, and aging.

[0003] In the solution annealing process, the alloying element in the aluminum strip is usually completely dissolved at a first temperature (e.g., 350 °C to 650 °C). Atmospheric temperatures of, for example, 350 °C to 700 °C prevail inside the solution annealing apparatus. During the quenching process, the strip is then cooled so rapidly to a second temperature (e.g., 70 °C to 150 °C) that the alloying elements cannot precipitate but remain in solution, contrary to the thermodynamic equilibrium. Subsequent aging causes the alloying elements in this non-equilibrium state to precipitate to the desired extent.

[0004] Solution annealing and quenching processes are typically carried out in continuous belt furnaces, such as fluidized belt furnaces. Purely natural aging requires long storage periods. Therefore, the aging process can be carried out, at least partially, for example in the form of a so-called pre-aging treatment, in the same belt furnace as the solution annealing and quenching.

[0005] WO 2019 / 141682 A1 describes a continuous furnace system for heat-treating an aluminium strip, comprising a first heating unit for solution annealing the aluminium strip, a cooling unit and a second heating unit which is directly connected to the cooling zone of the cooling unit for pre-aging.

[0006] Conventional inline pre-aging requires a considerable installation space, for example, up to 25 m². The flexibility of the heating process in this area is also limited by the throughput speed of the aluminum strip in the overall system and the length of the heating zone. Inline pre-aging before the downcoiler does not occur at a constant process speed and therefore requires complex process control to ensure consistent mechanical properties. Artificial over-aging in separate annealing processes requires additional equipment and process steps. Description of the invention

[0007] One object of the present invention is to provide an improved system and an improved method for the heat treatment of a metal strip, in particular made of an aluminum alloy.

[0008] The problem is solved by a system with the features of claim 1 and a method with the features of the dependent method claim. Advantageous embodiments follow from the dependent claims, the following description of the invention, and the description of preferred embodiments.

[0009] The plant is used for the heat treatment of a metal strip, in particular a strip made of an aluminum alloy. Heat treatment is part of the production of strips, foils, or other flat products, especially rolled flat products. During heat treatment, the metal strip is transported by a conveying device in one direction at a specific speed.

[0010] The system comprises a solution annealing device configured to heat the metal strip to a first temperature, preferably in the range of 350 °C to 650 °C; a quenching device arranged downstream of the solution annealing device in the direction of strip travel and configured to cool the metal strip to a second temperature, preferably in the range of 70 °C to 250 °C, by applying a coolant, for example, water or a water / air mixture; and a pre-aging device arranged downstream of the quenching device in the direction of strip travel and configured to heat the metal strip to a third temperature. The third temperature is approximately in the range of 100 °C to 350 °C, preferably 150 °C to 300 °C, and particularly preferably 175 °C to 275 °C.

[0011] The solution annealing device, the quenching device, and the pre-aging device are arranged in a common, continuous production line. The pre-aging device is designed as an electric rapid heating device, preferably an induction heating device.

[0012] Terms used to describe spatial relations, such as "in front", "behind", "between", "upstream", "downstream", etc., refer here to the direction of travel of the metal belt through the system during intended use and are therefore unambiguous.

[0013] The pre-aging unit, integrated with the solution annealing and quenching units in a shared, continuous production line and based on an electric rapid heating device, enables the execution of an aging treatment (or at least a portion thereof, "pre-aging") in an inline process with material-optimized heating rates. The system allows for the flexible use of metallurgical processes that are only possible immediately after quenching. The compact design of the system also enables short pre-aging process times, with correspondingly positive effects on specific energy consumption. The pre-aging process is integrated into the continuous production line, which, in addition to the aforementioned advantages, also ensures particularly uniform treatment along the entire strip length.

[0014] The system is preferably suitable for processing aluminium strips with a thickness of 0.2 mm to 7.0 mm, preferably with a thickness of 0.5 mm to 2.0 mm.

[0015] The transport speed is preferably between 5 m / min and 120 m / min.

[0016] The quenching device is configured to set a cooling rate preferably between 1 K / sec and 100 K / sec, particularly preferably between 5 K / sec and 75 K / sec.

[0017] The electric rapid heating device is configured to perform a temperature increase of preferably more than 10 K / sec, particularly preferably more than 30 K / sec. The electric rapid heating device is also configured to perform a temperature increase of less than 100 K / sec, preferably less than 75 K / sec.

[0018] The pre-aging device, in particular its heating zone, is preferably less than 5 m long.

[0019] If the pre-aging device is designed as an electric rapid heating device, preferably an induction heating device, it can be particularly advantageous and compact. The induction heating device can consist of one or more inductors, which can be configured as longitudinal field inductors, transverse field inductors, or a combination thereof.

[0020] The power and frequency range can be adapted to the specific characteristics of the aluminum alloy and the respective strip thickness.

[0021] Due to the compact design of the system, especially the pre-aging device, it may be necessary or advisable to protect the pre-aging device from the coolant from the immediately adjacent quenching device.

[0022] For this purpose, the system preferably has a blow-off device which is arranged and configured between the quenching device and the pre-aging device to blow the coolant off the metal strip with a high-pressure gas, preferably a high-pressure air stream, from one or more blow-off nozzles.

[0023] The blow-off device preferably comprises one or more, in particular two, pairs of blow-off nozzles arranged in series, each pair of blow-off nozzles comprising an upper blow-off nozzle for treating the top side of the metal strip and a lower blow-off nozzle for treating the underside of the metal strip. In this way, the strip can be reliably cleaned of any coolant residues in a small installation space, thereby further shortening the treatment distance.

[0024] Alternatively or additionally, the system can have one or more protective rollers arranged between the quenching device and the pre-aging device, which are in contact with the metal strip at least temporarily. To prevent damage to the strip surface, the at least one protective roller is preferably rubberized. The peripheral speed of the protective roller(s) is preferably adapted to the strip speed.

[0025] Alternatively or additionally, the belt guidance between the quenching device and the pre-aging device is carried out, at least section by section, at an upward angle α, where in particular: 0° < α <= 5°. At least one of the protective rollers can be used synergistically to deflect the metal belt from the horizontal position into the upward position.

[0026] Alternatively or additionally, a mechanical splash guard made of an electrically non-conductive material, such as Plexiglas or epoxy resin, can be arranged between the quenching device and the pre-aging device. The mechanical splash guard can be designed as a housing or part of a housing for the pre-aging device.

[0027] Preferably, the system comprises a drying device or a combined drying and pre-aging device, comprising a drying section and a pre-aging section, wherein the drying device or the drying section of the combined drying and pre-aging device can be configured to dry the metal strip at a temperature in the range of 130 °C to 170 °C. Such a drying device or such a drying section is particularly suitable in combination with a coating device for coating one or both strip surfaces. By increasing the temperature in the drying device or in the drying section of the combined drying and pre-aging device, it is possible to initiate at least partial aging, thereby saving energy in the dedicated pre-aging device.

[0028] The aforementioned problem is further solved by a method for the heat treatment of a metal strip, in particular made of an aluminum alloy, which is transported in a strip direction at a strip speed, wherein the method comprises: heating the metal strip to a first temperature, preferably in the range of 350 °C to 650 °C, by means of a solution annealing device; then cooling the metal strip to a second temperature, preferably in the range of 70 °C to 250 °C, by means of a quenching device by means of a coolant; and then heating the metal strip to a third temperature, preferably in the range of 100 °C to 350 °C, by means of a pre-aging device; wherein the heating of the metal strip to the third temperature in the pre-aging device is carried out by means of an electric rapid heating device, in particular an induction heating device.

[0029] The features, technical effects, advantages and embodiments described in relation to the plant apply analogously to the process.

[0030] For the reasons mentioned above, a blow-off device is preferably arranged between the quenching device and the pre-aging device. This blow-off device blows coolant off the metal strip with a high-pressure gas, preferably a high-pressure air stream, from one or more blow-off nozzles. The blow-off device preferably has one or more, in particular two, pairs of blow-off nozzles arranged in series, each pair comprising an upper blow-off nozzle for treating the top side of the metal strip and a lower blow-off nozzle for treating the underside of the metal strip.

[0031] Preferably, for the reasons mentioned above, one or more protective rollers are arranged between the quenching device and the pre-aging device, which are in contact with the metal strip at least temporarily, wherein the one or more protective rollers are preferably rubberized, and wherein the circumferential speed of the one or more protective rollers is preferably adapted to the strip running speed.

[0032] Preferably, for the reasons mentioned above, the metal strip between the quenching device and the pre-aging device is guided at least sectionally at an upward angle α, wherein in particular: 0° < α ≤ 5°. Preferably, the metal strip is deflected from the horizontal position into the upward position by at least one of the protective rollers.

[0033] Preferably, the metal strip to be treated is a strip made of an aluminum alloy whose main alloying elements are magnesium and silicon, or whose main alloying element is copper, or whose main alloying element is zinc.

[0034] Further advantages and features of the present invention will become apparent from the following description of preferred embodiments. The features described therein can be implemented individually or in combination with one or more of the features set out above, provided that the features do not contradict each other. The following description of preferred embodiments is given with reference to the accompanying drawings. Brief description of the characters

[0035] Preferred further embodiments of the invention are explained in more detail by the following description of the figures. These show: Figure 1 schematically shows a system for the heat treatment of a metal strip according to one embodiment, as well as a graphical representation showing an exemplary development of the temperature of the metal strip as a function of the system position or process time; Figure 2 shows a section of a system for the heat treatment of a metal strip according to a further embodiment; Figure 3 schematically shows a system for the heat treatment of a metal strip according to a further embodiment; and Figure 4 schematically shows a system for the heat treatment of a metal strip according to a further embodiment. Detailed description of preferred embodiments

[0036] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the figures are designated with identical reference numerals, and repeated descriptions of these elements are sometimes omitted to avoid redundancy.

[0037] The Figure 1 Figure 1 schematically shows a system 1 for the heat treatment of a metal strip 2, in particular made of aluminum or an aluminum alloy, as well as a graphic representation which shows an exemplary development of the temperature T of the metal strip 2 as a function of the system position x or process time t.

[0038] The system 1 comprises a solution annealing device 10, a quenching device 20 and a pre-aging device 30, which are arranged in a common, continuous production line.

[0039] The solution annealing device 10 is configured to heat the metal strip 2 to a first temperature T1 at which at least one alloying element is dissolved, preferably to a first temperature T1 in the range of 350 °C to 650 °C. The metal strip 2 is transported through the system 1, or solution annealing device 10, along a strip travel direction R by means of a suitable transport device (not shown). The solution annealing device 10 has a suitable heating device that heats the metal strip 2, for example, by means of fuel gas or via induction. The solution annealing in the solution annealing device 10 can be carried out under a protective gas.

[0040] In the quenching device 20, which is connected to the solution annealing device 10 in the strip direction R, the metal strip 2 is cooled to a second temperature T2, preferably to a second temperature T2 in the range of 70 °C to 250 °C, at which the relevant alloying elements cannot precipitate but remain in solution, contrary to the thermodynamic equilibrium state. The quenching rate required for this process is preferably in the range of 5 K / s to 100 K / s, particularly preferably in the range of 10 K / s to 75 K / s. A high quenching rate from the solvus temperature up to 200 °C is particularly important for suppressing the premature precipitation of the alloying elements. The quenching device 20 can be equipped with spray bars 21 on the top and optionally on the bottom (see Figure 2). Figure 2) each have a plurality of nozzles that apply a coolant, for example water or a water / air mixture, to the metal strip 2. However, alternative cooling concepts are also possible.

[0041] Downstream of the quenching device 20 is the pre-aging device 30, which is set up to heat the metal strip 2 to a third temperature T3 in order to adjust the desired mechanical properties of the metal strip 2.

[0042] Immediately after the quenching process, diffusion-induced precipitation of the alloying elements begins. This process starts with the formation of so-called clusters of alloying element atoms. The type of clusters formed is temperature-dependent and defines the maximum achievable strength of the alloy. The goal of pre-aging is to promote the formation of clusters that enable a better property profile and to stabilize them. Such clusters form at temperatures above 60 °C. Since this process is diffusion-controlled, it is more intense at higher temperatures, particularly in the range of 175 °C to 275 °C. Therefore, it is especially important to reheat the aluminum strip immediately after quenching to the temperature at which the preferred clusters form and stabilize within a short time of just a few seconds.The third temperature T3 is approximately in the range of 100 °C to 350 °C, preferably 150 °C to 300 °C, and particularly preferably 175 °C to 275 °C. The pre-aging device 30 enables inline pre-aging and is designed as an electric rapid heating device based on induction. For this purpose, the pre-aging device 30 has corresponding induction coils 31 (see Figure 3). Figure 2 The heating of the metal strip 2 in the pre-aging device 30 preferably takes place within a few seconds. A heating rate of 10 K / s to 75 K / s should preferably be achieved.

[0043] The solution annealing device 10, the quenching device 20 and the pre-aging device 30 can be installed on a common support structure or on separate support structures, in particular steel structures, with respective fixed points of thermal expansion.

[0044] The material of the metal strip to be processed is preferably an aluminum alloy, in particular an aluminum-magnesium-silicon alloy (Al-Mg-Si). A prerequisite for stabilizing the microstructure of Al-Mg-Si alloys for potential further long-term storage before final hardening is the promotion of the formation of balanced Mg-Si clusters. This is achieved by pre-aging treatment using the pre-aging device 30, ideally immediately after quenching by the quenching device 20 following solution annealing. Since the formation process of these clusters is diffusion-controlled, its intensity increases with rising temperature T3. At temperatures T3 in the range of 190 °C to 250 °C, a few seconds are sufficient for successful stabilization.

[0045] The shortened process time offers advantages for the overall technological process, particularly in conjunction with a similarly shortened heating time from the quenching temperature T2 to a holding temperature before pre-aging. This enables a particularly compact design for the pre-aging device 30 and its placement in the curing line immediately after the quenching device 20. The heating zone of the pre-aging device 30 is preferably less than 5 m long.

[0046] The brief heating and subsequent brief exposure of the metal strip 2 to the third temperature T3 offers energetic advantages compared to a pre-aging treatment lasting several hours, for example, in the state of a wound coil. Furthermore, some exothermic reactions can be suppressed at the higher heating rates, thereby modifying the conventional precipitation sequence for Al-Mg-Si alloys in favor of a controlled formation of the intermetallic phases.

[0047] For a freshly quenched Al-Mg-Si-Fe alloy, a higher heating rate up to a temperature range of 175 °C to 275 °C leads to lower hardness values ​​in the stabilized material by suppressing hardening. This is beneficial for any immediately subsequent straightening processes and / or later sheet forming. Hardening already occurs within this temperature range, and it is important to bring the strip into this temperature range quickly, i.e., with the higher heating rate.

[0048] Due to the compact design of system 1, in particular the pre-aging device 30, it may be necessary or advantageous to protect the pre-aging device 30 from the coolant from the immediately adjacent quenching device 20. One or more measures may be taken for this purpose.

[0049] The Figure 2In this regard, Figure 1 shows an excerpt of Annex 1, comprising the quenching device 20 and the pre-aging device 30, according to a further embodiment.

[0050] The system 1 can include a blow-off device 40, which is arranged between the quenching device 20 and the pre-aging device 30 and is configured to blow the coolant off the metal strip 2 with a high-pressure air stream from one or more blow-off nozzles 41 designed for this purpose. Preferably, the blow-off nozzles 41 are arranged in pairs to treat the top and bottom sides of the metal strip 2. Preferably, two pairs of blow-off nozzles 41 are installed.

[0051] Alternatively or additionally, one or more protective rollers 50 can be installed between the quenching device 20 and the pre-aging device 30, which are in contact with the metal strip 2 at least temporarily. To prevent damage to the strip surface, the protective rollers 50 are preferably rubberized. The peripheral speed of the protective roller(s) 50 is adapted to the strip running speed.

[0052] Alternatively or additionally, the belt guidance between the quenching device 20 and the pre-aging device 30 can be at an upward angle α, preferably 0° < α ≤ 5°. The protective roller 50 can be used synergistically to deflect the metal belt 2 from the horizontal position into the upward position.

[0053] Alternatively or additionally, a mechanical splash guard 32 made of an electrically non-conductive material, for example Plexiglas or epoxy resin, can be installed between the quenching device 20 and the pre-aging device 30 to protect the induction coils 31. The mechanical splash guard 32 can be designed as a housing or as part of a housing for the pre-aging device 30.

[0054] Preferably, the dew point of the atmosphere between the quenching device 20 and the pre-aging device 30 lies below a permissible minimum temperature (PMT) in order to avoid undesirable condensation.

[0055] The pre-aging device 30 can be flexibly designed, comprising, for example, several inductors or a combination of one or more inductors and another heating device, in order to be able to achieve lower heating speeds at the same belt speed in addition to the maximum heating speeds.

[0056] The Figure 3 Figure 1 schematically shows a system 1 for the heat treatment of a metal strip 2 according to a further embodiment.

[0057] Based on Annex 1 of the Figure 1Furthermore, in the common continuous production line, a straightening device 60 for improving the flatness of the metal strip 2, a cleaning device 70 for cleaning the strip surfaces, and a coating device 80 for coating one or both strip surfaces are arranged. The straightening device 60, the cleaning device 70, and the coating device 80 are installed in this order downstream of the quenching device 20. In the exemplary embodiment of the Figure 3 Furthermore, the pre-aging is carried out in a combined drying and pre-aging device 30', comprising a drying section and a pre-aging section.

[0058] The metal strip 2 is supplied to the continuous process via an unwinding device 3, which unwinds a coiled metal strip 2 and provides it to the system 1. After treatment in the system 1, the metal strip 2 is rewound into a coil by a winding device 4.

[0059] The exemplary embodiment of the Figure 4 differs from that of the Figure 3 This is achieved by pre-aging in the pre-aging device 30 immediately following cooling in the quenching device 20. After coating, the metal strip 2 is dried in a drying device 90 before being wound into a coil by the winding device 4.

[0060] In Annex 1 according to the exemplary embodiments of the Figures 3 and 4Is it possible to initiate at least partial aging by raising the temperature in the drying device 90 or in the drying section of the combined drying and pre-aging device 30' after coating, thereby saving energy in the dedicated pre-aging device 30? The temperature of the drying device 90 or of the drying section of the combined drying and pre-aging device 30' is preferably set to a range of 130 °C to 170 °C, particularly to approximately 150 °C. A section can also be provided in which the metal strip 2 is heated above this temperature for a few seconds, for example, to a temperature in the range of 170 °C to 230 °C.

[0061] System 1 allows for the flexible use of metallurgical processes that can only be carried out immediately after quenching by the quenching device 20. The compact design of System 1 enables short pre-aging process times, with corresponding positive effects on specific energy consumption. The pre-aging process by the pre-aging device 30 is integrated into the continuous production line, which, in addition to the aforementioned advantages, also enables particularly uniform treatment along the entire strip length.

[0062] Where applicable, all individual features shown in the exemplary embodiments can be combined and / or exchanged without leaving the scope of the invention. Reference symbol list

[0063] 1 Heat treatment plant for a metal strip 2 Metal strip 3 Unwinding device 4 Winding device 10 Solution annealing device 20 Quenching device 21 Spray bar 30 Pre-aging device 30 Drying and pre-aging device 31 Induction coil 32 Mechanical splash guard 40 Blow-off device 41 Blow-off nozzle 50 Protective roller 60 Straightening device 70 Cleaning device 80 Coating device 90 Drying device Belt direction

Claims

1. Plant (1) for the heat treatment of a metal strip (2), preferably made of an aluminum alloy, which is transportable in a strip direction (R) at a strip speed, wherein the plant (1) comprises: a solution annealing device (10) configured to heat the metal strip (2) to a first temperature (T1), preferably in the range of 350 °C to 650 °C, preferably up to 600 °C, particularly preferably up to 585 °C; a quenching device (20) arranged downstream of the solution annealing device (10) in the strip direction (R) and configured to cool the metal strip (2) to a second temperature (T2), preferably in the range of 70 °C to 250 °C, by applying a coolant;and a pre-aging device (30) arranged downstream of the quenching device (20) in the direction of strip travel (R) and configured to heat the metal strip (2) to a third temperature (T3), preferably in the range of 100 °C to 350 °C; wherein the solution annealing device (10), the quenching device (20) and the pre-aging device (30) are arranged in a common, continuous production line; and the pre-aging device (30) is designed as an electric rapid heating device, preferably an induction heating device.

2. Annex (1) according to claim 1, characterized by the fact that the system (1) has a blow-off device (40) which is arranged and configured between the quenching device (20) and the pre-aging device (30) to blow the coolant off the metal strip (2) with a high-pressure gas, preferably a high-pressure air stream, from one or more blow-off nozzles (41).

3. Annex (1) according to claim 2, characterized by the fact that the blow-off device (40) has one or more, preferably two, pairs of blow-off nozzles (41) arranged one behind the other, each pair of blow-off nozzles (41) comprising an upper blow-off nozzle (41) for treating the top of the metal strip (2) and a lower blow-off nozzle (41) for treating the underside of the metal strip (2).

4. Annex (1) according to any of the preceding claims, characterized by the fact that the system (1) has one or more protective rollers (50) arranged between the quenching device (20) and the pre-aging device (30), which are in contact with the metal strip (2) at least temporarily, wherein the one or more protective rollers (50) are preferably rubberized, wherein the circumferential speed of the one or more protective rollers (50) is preferably adapted to the strip running speed.

5. Annex (1) according to any of the preceding claims, characterized by the fact thatthe belt guidance between the quenching device (20) and the pre-aging device (30) is carried out at least sectionally at an upward angle (α), preferably 0° < α <= 5°.

6. Annex (1) according to claims 4 and 5, characterized by the fact that at least one of the protective rollers (50) achieves a deflection of the metal band (2) from the horizontal position into the upward position.

7. Annex (1) according to any of the preceding claims, characterized by the fact that A mechanical splash guard (32) made of an electrically non-conductive material, preferably Plexiglas or epoxy resin, is arranged between the quenching device (20) and the pre-aging device (30).

8. Annex (1) according to any of the preceding claims, characterized by the fact thatthe system (1) comprises a drying device (90) or a combined drying and pre-aging device (30') comprising a drying section and a pre-aging section, wherein the drying device (90) or the drying section of the combined drying and pre-aging device (30') is preferably configured to dry the metal strip (2) at a temperature in the range of 100 °C to 250 °C, preferably from 120 °C to 200 °C, particularly preferably from 130 °C to 170 °C.

9. A method for the heat treatment of a metal strip (2), preferably made of an aluminum alloy, which is transported in a strip direction (R) at a strip speed, wherein the method comprises: heating the metal strip (2) to a first temperature (T1), preferably in the range of 350 °C to 650 °C, by means of a solution annealing device; then cooling the metal strip (2) by applying a coolant to a second temperature (T2), preferably in the range of 70 °C to 250 °C, by means of a quenching device (20); and then heating the metal strip (2) to a third temperature (T3), preferably in the range of 100 °C to 350 °C, by means of a pre-aging device (30); wherein the heating of the metal strip (2) to the third temperature (T3) in the pre-aging device (30) is carried out by means of an electric rapid heating device, preferably an induction heating device.

10. Method according to claim 9, characterized by the fact thatA blow-off device (40) is arranged between the quenching device (20) and the pre-aging device (30), which blows coolant off the metal strip (2) with a high-pressure gas, preferably a high-pressure air stream, from one or more blow-off nozzles (41).

11. Method according to claim 9 or 10, characterized by the fact that one or more protective rollers (50) are arranged between the quenching device (20) and the pre-aging device (30), and are in contact with the metal strip (2) at least temporarily, wherein the one or more protective rollers (50) are preferably rubberized, and wherein the circumferential speed of the one or more protective rollers (50) is preferably adapted to the strip running speed.

12. Method according to any one of claims 9 to 11, characterized by the fact thatthe metal band (2) between the quenching device (20) and the pre-aging device (30) is guided at least section by section at an upward angle (α), preferably 0° < α <= 5°.

13. Method according to claims 11 and 12, characterized by the fact that the metal band (2) is deflected from the horizontal position into the upward position by at least one of the protective rollers (50).

14. Method according to any one of claims 9 to 13, characterized by the fact that the material of the metal strip (2) is an aluminum alloy whose main alloying elements are magnesium and silicon.

15. Method according to any one of claims 9 to 13, characterized by the fact that the material of the metal strip (2) is an aluminum alloy whose main alloying element is copper.

16. Method according to any one of claims 9 to 13, characterized by the fact that the material of the metal strip (2) is an aluminum alloy whose main alloying element is zinc.

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