EP2603337B1 - Method for producing rolling stock by means of a combined continuous casting and rolling system, control device for a combined continuous casting and rolling system, and combined continuous casting and rolling system - Google Patents

Description

The invention relates to a method for producing in its longitudinal direction thick profiled metal strip by means of a Gießwalzverbundanlage, comprising a casting device for casting metal to rolling and at least one rolling stand comprehensive rolling mill for hot working of the metal, wherein the Gießwalzverbundanlage is operated such that the rolling between the casting device and the rolling train extends continuously, wherein the rolling mill is continuously fed to rolling, wherein the rolling train a desired thickness profile is predetermined, according to which the rolling mill rolls the rolling stock.

The invention relates to the technical field of rolling of rolling stock, in particular of metal strip, in particular so-called "tailored blanks", i. Walzgut with desired thickness profile in the longitudinal direction of the rolling stock. If the rolling stock is a metal strip, such a metal strip is also referred to as a longitudinally profiled metal strip. The associated process is also known as flexible rolling. Flexible rolling is now used only in the cold rolling area for various reasons explained below. The products produced by these methods are used, for example, in the automotive industry to increase the safety of the vehicle occupants while minimizing the weight of the automobile.

From the publication DE10041280A1 a method for flexible cold rolling of metal strip is known.

From the WO 00/13820 For example, there is known a method for producing metal strips by a hot rolling method, the thickness of which continuously changes in the longitudinal direction. This variable thickness is adjusted by means of a variable casting roll gap and the cooling of the casting rolls. Disadvantage of this solution It is that thickness settings by means of casting rollers are inaccurate and difficult to control. Furthermore, only certain thickness profiles can be produced. This limits the flexibility of the system.

Conventional hot rolling mills today do not produce tailored blanks. Because the achievable minimum hot strip thicknesses are usually in the range of 1.2 to 1.5 millimeters, which is not sufficient for tailored blanks, which often require minimum thicknesses of 0.6 mm. Therefore, the required thickness range can be covered only insufficiently by conventional hot rolling mills for tailored blanks.

The US 2009/0139290 A1 discloses a cast-rolling composite plant comprising a casting plant and a hot rolling plant for producing a metal strip in a certain desired thickness. A method for producing a metal strip, which is intended to roll in the longitudinal direction to at least two different nominal thicknesses, the D1 is not apparent. Furthermore, it can not be deduced from D1 that casting of the metal (by means of the casting installation) takes place with a thickness profile in the longitudinal direction, so that the rolling stock already has varying thicknesses in the longitudinal direction when entering the rolling line, whereby this thickness pre-profile produced by the casting device is subsequently separated from the latter at least one rolling stand of the rolling train is rolled in such a way that the desired thickness profile is obtained in the longitudinal direction.

The WO 00/21695 A1 describes a method for producing a metal strip having regions of different thicknesses. In this case, a rolling mill is fed with a uniformly thick metal strip which has differently tempered regions in the direction of its strip longitudinal direction in order to produce a strip having different thicknesses in the longitudinal direction during rolling. The D2 thus shows no method for producing a thickness-profiled in its longitudinal metal strip by means of a Gießwalzverbundanlage.

The object of the present invention is to provide a method by means of which longitudinally profiled rolling stock can be produced significantly more favorably than with conventional processes.

The procedural part is achieved by a method for producing thickness-profiled metal strip in its longitudinal direction, by means of a Gießwalzverbundanlage comprising a casting device for casting metal to rolling and at least one rolling stand comprehensive rolling mill for hot working of the rolling stock, wherein the Gießwalzverbundanlage is operated such that the rolling stock extends continuously between the casting device and the rolling train, rolling stock being fed continuously to the rolling train, the rolling train being given a desired thickness profile according to which the rolling train rolls the rolling stock, the target thickness profile being at least two different target values. Thicknesses for different sections in the longitudinal direction of the thick-profiled metal strip, and that the desired thickness profile is formed such that the first and / or the second target thickness is set at least twice, wherein the Gießwalzverbundanl age is further operated such that an inlet speed of the rolling stock in the rolling stand is set smaller than 7 meters / second, in particular less than 5 meters / second.

A casting of the metal is carried out with a thickness profile in the longitudinal direction, so that the rolling stock already has varying thicknesses in the longitudinal direction when entering the rolling train, said thickness pre-profile produced by the casting device is then rolled by the at least one rolling stand of the rolling train such that the target Thickness profile is obtained in the longitudinal direction.

Under rolling material is in this case understood in particular a metal strip, but the rolling stock can alternatively be a long product such as wire, steel bars or profiles made of steel or from a Be non-ferrous metal such as aluminum or magnesium. The terms "metal strip" and "hot strip" are further used in the text as synonyms for "rolling stock", so that the subject invention is not limited only to band-shaped products.

The use of a Gießwalzverbundanlage whose aggregates are coupled by the one-piece rolling, allows the production of longitudinally profiled hot strip already during hot rolling. Because of the Gießwalzverbunds usually the speed of the belt at the output of the hot rolling mill is determined essentially by the casting speed and the reduction made by means of the plant thickness reduction. Due to this coupling maximum strip speeds are achieved in the rolling mill, which are significantly below the usual belt speeds of 10 to 20 meters / second in conventional, non-coupled hot rolling mills.

In addition, the thickness range required for "tailored blanks" can be easily covered, in particular in thin strip casting or thin slab casting.

Casting devices which can be used are any casting installations which are suitable for casting roll composite systems.

Thus, it becomes possible to introduce a longitudinal profile into the hot strip in an economical manner by means of a roll stand.
As a result, a flexible cold rolling step can be completely eliminated. Thus, an entire plant part, namely the cold rolling mill for the production of longitudinally profiled rolling, eliminated. This leads to significant savings in investment costs and operating costs.

As a course of thickness in the longitudinal direction, any thickness profiles can be specified, depending on what is desired by the customers of the product produced. In particular, periodic Thickness profiles in the longitudinal direction can be produced very efficiently in this way.

In an advantageous embodiment of the method, in addition to the at least two different setpoint thicknesses, associated setpoint rolling forces and / or setpoint roll gap openings are predetermined. As a result, the accuracy for the production of a longitudinally profiled rolling stock is further increased.

In a preferred embodiment, the thickness profile comprises repetitive, in particular periodically repeating, changes in thickness in the longitudinal direction of the thickness-profiled metal strip. As a result, effectively large numbers of metal sheets profiled in the longitudinal direction can be produced, which, for example, are cut directly out of the rolling stock after rolling.

In a preferred embodiment of the method according to the invention, a strip store, in particular a belt loop, is present between the casting device and the rolling train, with which mass flow fluctuations caused by the predetermined course of thickness are compensated in the cast roll composite system. This is particularly easy and effective in Dünnbandgießwalzverbundanlagen possible. Because due to the small diameter of the cast metal strip during strip casting, the cast strip already has sufficient deformability, which allows, for example, between the rolling stand and casting device formed by a gravity belt loop. This can be used as a strip storage between casting and rolling mill. A strip accumulator is therefore very advantageous since the mass flow fluctuations in the casting rolling mill, in particular in the rolling mill, can be compensated for as a result of the changes in thickness in the longitudinal direction of the metal strip. This in turn makes it possible, for example, to avoid ligament tears.

For the tape storage can be designed in particular as a tape storage device which is operated such that caused by the predetermined thickness curve mass flow fluctuations in the Gießwalzverbundanlage be compensated.

In a further advantageous variant of the invention, the casting device is operated in such a way that by means of the casting device a predetermined actual thickness profile of the rolling stock coordinated with the desired thickness profile is produced, which the rolling stock has before entering the rolling train. As a result, the at least one roll stand is supported in the longitudinal profiling of the rolling stock by the casting device. In particular, high rolling forces can thereby be avoided and unwanted processing speed deviations between casting device and rolling train can be reduced. As a result, the corresponding division of the setting of the thickness profile of the casting device and rolling train, it is possible that the rolling stand is always operated so that it does not encounter plant technical limits or technological limits in the setting of the desired thickness course. Plant engineering limits are, for example, the setting position and / or setting speed of the work rolls, technological limits are, for example, thickness decreases, which would indeed be required to set the desired thickness profile, but to intolerable deviations, for. lead in the flatness of the rolling stock. This can be avoided if the longitudinal profiling of the rolling stock is divided between the casting device and the rolling train.

In a further advantageous embodiment of the invention, the rolling mill is followed by a thickness measuring device in the mass flow direction, by means of which the rolled thickness of the thick-profiled metal strip is detected, wherein at least one actuator for the rolling train is adjusted as a function of the detected thickness and the predetermined thickness profile thick profiled metal strip. This makes it possible to make a comparison between the desired target thickness for a section behind the roll stand and the actually present actual thickness for this section. outgoing of which an improved adjustment of the actuators and / or a model adaptation can be made, which for future sections to be rolled closer the actual actual thickness behind the rolling mill of the desired target thickness behind the rolling mill further.

Further, it is advantageous that the rolling mill in the mass flow direction is a flatness measuring device downstream, by means of which the flatness of the thickness profiled metal strip is detected, wherein at least one actuator, in particular a bending cylinder is set for the rolling train in dependence on the detected flatness and a predetermined thickness profile. In this way it can be ensured that, on the one hand, the desired thickness profile is set and, on the other hand, the requirements for the rolling stock with regard to flatness are met.

In a preferred embodiment of the method according to the invention, the course of thickness is set with a rolling train which comprises a rolling stand which has a set of work rolls having a diameter of less than 800 millimeters, in particular 200 millimeters to 600 millimeters.

In particular, it is advantageous that the entry speed is set in such a way and the rolling stand is designed such that a ratio of an entry speed of the rolling stock into the rolling stand to a maximum setting speed of the work rolls of the rolling stand for influencing the thickness of the rolling stock is less than 3500, in particular less than 2000, in particular between 200 and 1500, is. Preferably, the above ratio is maintained for all operated rolling mills of a rolling train, as long as the rolling train comprises more than a single stand. As a rule, the entry speed can be influenced or controlled by means of the casting speed. By using the work rolls with a diameter of less than 800mm in combination with the mentioned ratio of inlet speed At maximum setting speed of the roll stand, it is possible to set thickness gradients which enable substantially all the required thickness gradients for the production of longitudinally profiled rolled stock. This makes it possible to realize almost all thickness profiles desired by the customer during hot rolling. In particular, while maintaining the above ratio of inlet velocity to maximum Anstellgeschwindigkeit sufficient dynamics for the rolling stand for processing the rolling stock in the desired manner. Under Dickengradient the change in thickness per unit length of the rolling, ie in the longitudinal direction of the rolling, understood. Anstellgeschwindigkeit is understood to mean the hydraulic setting speed for setting the work rolls under load.

The inventive method can be used particularly advantageously for cast roll mills in which a two-roll caster or a belt caster, also referred to as direct strip casting, is used. Because these casting facilities are Dünnbandgießeinrichtungen. The rolling stock produced by the casting device, in particular metal strip, is usually already relatively thin, in particular this has a thickness of less than 3 mm. On the one hand, this makes it possible to produce final thicknesses in the range of 0.7 mm and below, while simultaneously producing comparatively low entry speeds into the rolling train. In particular, two-roll casting devices can be considered as casting devices, in which the two rolls are arranged in a vertical plane, ie the metal is cast horizontally. These systems can be used, for example, for aluminum, magnesium, zinc, etc., ie for "soft" metals. Furthermore, two roll casters may also be used in which the rolls are arranged in a horizontal plane, ie the metal is cast vertically. This is for example common for carbon steels and other steels.

It can be provided a control and / or regulating device for a Gießwalzverbundanlage for producing longitudinally thick profiled rolling stock, with a machine-readable program code, which comprises control commands, which the control and / or regulating device for performing the method according to one of claims 1 to 11 cause. In particular, the control and / or regulating device may comprise a plurality of modules, which are designed to implement the individual method steps of the embodiments of the method according to the invention in a machine-readable manner for the control and / or regulating device, so that these are controlled by the control and / or Control device can be arranged.

Furthermore, a Gießwalzverbundlage be provided for producing longitudinally profiled in thickness rolling stock, wherein the rolling stock in the stationary operation of the Gießwalzverbundanlage continuously from the casting device to a rolling mill comprising at least one rolling mill, with said control means, wherein the control means with the at least one rolling mill is actively connected. This provides a device with which longitudinally profiled rolling stock can be produced during hot rolling.

The mill train may comprise a mill stand comprising a set of work rolls having a diameter of less than 800 millimeters, in particular 200 millimeters to 600 millimeters, the mill stand being designed and operated in such a way that a ratio of an entry speed of the rolling stock to a rolling mill is Anstellgeschwindigkeit of the work rolls of the rolling stand for thickness control of the rolling stock is less than 3500, in particular less than 2000, in particular between 200 and 1500, is. If the Gießwalzverbundanlage has a rolling train with more than one rolling mill, then the above ratio is preferably maintained for each rolling mill. As a result, a device is provided, by means of which almost all of Customer desired thickness profiles can be realized during hot rolling, since corresponding Dickengradienten are rollable.

Another advantage is that in addition the casting device is operatively connected to the control and / or regulating device. This makes it possible to divide the thickness profile and thus the load of the individual units for producing the desired target thickness for a section in expediently between the casting device and rolling train. About a Walzgut- or tape tracking then cast in accordance with the specifications of the control and / or regulating device section time and place correctly processed by the mill train such that the portion after the rolling line has the desired desired thickness as possible. This avoids that, for example, individual actuators of the rolling train for producing the desired thickness curve run to their limits or technological problems, such as flatness errors, due to, for example. To high thickness decreases in the rolling stand, occur.

It is also advantageous that the casting device is designed as Zweirollengießeinrichtung or as Umlaufbandgießeinrichtung. The advantages arise according to the above statements on the corresponding method claim.

FIG 1

eine schematische Darstellung einer Gießwalzverbundanlage mit einer Umlaufbandgießeinrichtung,

FIG 2

eine schematische Darstellung einer Gießwalzverbundanlage mit einer vertikal gießenden Zweirollengießeinrichtung,

FIG 3

eine schematische Darstellung einer Gießwalzverbundanlage mit einer horizontal gießenden Zweirollengießeinrichtung,

FIG 4

ein Ablaufdiagramm zur schematischen Darstellung einer Ausführungsform des Verfahrens.

Further advantages of the invention will become apparent from the embodiments, which are explained in more detail with reference to the following schematic drawings. Show it:

FIG. 1

a schematic representation of a Gießwalzverbundanlage with a Umlaufbandgießeinrichtung,

FIG. 2

a schematic representation of a Gießwalzverbundanlage with a vertically cast Zweirollengießeinrichtung,

FIG. 3

a schematic representation of a Gießwalzverbundanlage with a horizontally cast Zweirollengießeinrichtung,

FIG. 4

a flowchart for schematically illustrating an embodiment of the method.

FIG. 1 shows a Gießwalzverbundanlage comprising a Umlaufbandgießeinrichtung 1 'and a "direct strip casting" device, with which liquid metal M is cast on a revolving cast strip. In this case, the metal solidifies and there is a thin metal strip B as rolling, which is weiterverarbeitbar in the Gießwalzverbundanlage.

The continuous rolling system further comprises a rolling mill 2. The rolling mill 2 may have a rolling stand or even several rolling stands. The rolling train 2 is used for hot forming of the metal strip B. In particular, by means of this, the metal strip B is rolled to its final thickness.

The metal strip B extends continuously from the Umlaufbandgießeinrichtung 1 'to the rolling line 2. By the metal strip B are usually, i. in stationary operation of the Gießwalzverbundanlage, all units of the Gießwalzverbundanlage coupled to each other via the metal strip B.

Between the rolling train 2 and the Umlaufbandgießeinrichtung 1 ', a tape storage S' is arranged. The tape storage S 'is formed as a pair of S-rollers. The rotation of the pair of rollers about a pivot point located between the rollers, the tape length, which is guided over the rollers change. This can provide a tape storage volume.

Downstream of the rolling train 2 in the mass flow direction, a thickness measuring device 3 and a flatness measuring device 4 are provided. These can be configured as desired. Corresponding devices are sufficiently known to the person skilled in the art. Possibly. These may also be arranged in the direction of mass flow in front of the rolling train 2, so that the at least one rolling stand of the rolling train 2 can be operated in a pilot-controlled manner, ie the measured portion, as well Band section called, still passes through the rolling mill. As a result, this band section can still be influenced in the desired manner.

The flatness measuring device 4 and the thickness measuring device 3 are operatively connected to a control and / or regulating device 10 which controls or regulates the rolling train 2 such that the desired thickness profile is generated in the longitudinal direction of the metal strip B.

The recorded data for flatness and thickness are fed to the control and / or regulating device 10. Based on these data and on the basis of the predetermined desired thickness profile, the rolling train 2 is operated.

The control and / or regulating device 10 is upgraded by means of machine-readable program codes 12 to operate the rolling train 2 according to an embodiment of the method according to the invention. The machine-readable program code 12 is stored, for example, by means of a storage medium 11 on the control and / or regulating device 10. Furthermore, by means of the control and / or regulating device 10 to be rolled target thickness profiles for the metal strip B can be specified.

In operation, the lead-in speed V of the metal strip B is set in the rolling stand such that the entry speed of the metal strip B of 5 meters / second is not exceeded for any of the rolling stands covered by the rolling line 2. This can be achieved by a corresponding adjustment of the casting speed.
Furthermore, for the production of the thickness profiles in the longitudinal direction of the metal strip B, work rolls are used which have a diameter D of 500 millimeters. Due to the reduced diameter D of the work rolls compared to the commonly used work rolls during hot rolling - these often have a diameter of about 1000mm -, the rolling forces can be increased to the metal strip B, whereby higher thickness decreases can be achieved. At the same time be rolled higher density gradients. Furthermore, the work rolls can be set to influence the thickness at a setting speed of at most 4 millimeters / second.

This achieves an exemplary maximum ratio of inlet velocity V to setting speed of 1250, which is very well suited for thickness profiling of the metal strip B in the longitudinal direction.

Due to the thickness profiling in the longitudinal direction of the metal strip B, fluctuations of the entry speed V of the metal strip B into the rolling train or into a rolling stand usually occur. These fluctuations are compensated by means of the band memory S ', so that as far as possible a constant tension for the metal strip B is realized during the flexible hot rolling.

FIG. 2 shows a Gießnalzverbundanlage comprising a Zweiroll Casting 1 for the vertical casting of liquid metal M. Further, the casting rolling mill comprises a rolling mill 2, in which the cast metal is rolled to its final thickness. Analogous to FIG. 1 For example, the rolling train may comprise a rolling stand or a plurality of rolling stands.

The metal strip B cast by the twin roll caster 1 forms a loop S due to gravity and then enters a rolling train 2 comprising at least one rolling stand.

In mass flow direction behind the rolling train 2 and the roll stand is analogous to the under FIG. 1 described Gießwalzverbundanlage arranged a thickness measuring device for measuring the thickness of the emerging from the rolling train 2 metal strip B.

Furthermore, a flatness measuring device 4 is also arranged downstream of the rolling train 2 in the direction of mass flow. The thickness measuring device 3 and the flatness measuring device 4 are with a control and / or regulating device 10 operatively connected to which the detected data are supplied.

The control and / or regulating device 10 is in accordance with the in FIG. 1 made statements to induce an embodiment of the method according to the invention. In the present case, the control and / or regulating device 10 is operatively connected to the rolling train 2 on the one hand and to the casting device 1 on the other hand.

The control and / or regulating device 10 controls the setting of the desired thickness profile in the longitudinal direction for the metal strip B across, that is. the control and / or regulating device 10 already causes a casting of the liquid metal M with a corresponding thickness profile in the longitudinal direction based on the desired desired thickness profile, so that the metal strip B already has varying thicknesses in the longitudinal direction when entering the rolling train 2. This thickness pre-profile produced by the casting device 1 is subsequently rolled by the at least one rolling stand of the rolling train 2 such that the desired nominal thickness profile is obtained in the longitudinal direction. In this way, the required load for the desired thickness profiling between the units can be divided so that the rolling train 2 does not approach the plant limits in rolling the longitudinal profile of the metal strip B.

Further, in addition to the thickness pre-profile, the casting speed of the two-roll caster 1 is controlled such that the ratio of the lead-in speed V of the metal strip B to the rolling stand and the setting speed of the work rolls to influence the thickness of the rolling stand is less than 2,000. For this purpose, a rolling mill is used, which has a pitch of 3 millimeters / second and a casting speed of 2 meters / second set. This results in a ratio of about 670, with which it is possible, without reaching plant engineering limits, desired thickness profiles in the longitudinal direction in the desired Way to produce. Particularly advantageous this can be combined with work rolls with diameters smaller than 800 millimeters.

FIG. 3 shows a Gießnalzverbundanlage comprising a Zweiroll Casting 1 for horizontal casting of liquid metal M. In contrast to FIG. 2 the casting rolls are arranged here so that the metal can be cast horizontally and not vertically. Furthermore, forms in the system according to FIG. 3 , usually no belt loop of the potted metal, so that - as in FIG. 1 - Preferably, a strip storage device between the casting device 1 and rolling mill 2 is provided.

One reason why horizontal and not vertical shedding is due to the tensile strength of the metal to be cast. While in a plant according to FIG. 2 it comes to a design of a sling whose own weight must be borne by the band, this load of the band in a system according to FIG. 3 be avoided. This is therefore usually to be used for the casting of such metal and alloys whose tensile strength is too low to the weight of a sling, as in FIG. 2 shown to wear. Examples of such metals include magnesium, zinc or aluminum.

In addition, the apply for FIG. 2 made statements essentially analogous to FIG. 3 , In particular, there are no substantial differences from the embodiment for the rolling train, the flatness measuring device or the thickness measuring device FIG. 2 in front. The statements too FIG. 2 can easily go up for these parts FIG. 3 be transmitted.

In particular, the rolling operation is usually independent of whether the metal is cast horizontally or vertically. It is only on the possibly present changed casting speeds, material strengths, etc. take into account and adjust the rolling operation accordingly.

FIG. 4 shows an exemplary flowchart for an embodiment of the method according to the invention. In the flowchart, it is assumed that the Gießwalzverbundanlage is in a steady state operation, wherein as casting a Zweirollengießeinrichtung according to FIG. 2 is used.

In a method step 101, a desired thickness profile in the longitudinal direction of the metal strip B is specified for the hot strip to be rolled. This gives, for example, a repetitive periodic thickness profile for the metal strip.

In a method step 102, a manipulated variable for the caster and the rolling train is determined based on the predetermined thickness profile from method step 101. In particular, a thickness profile to be provided by the casting device is determined. As a rule, this deviates from the thickness progression to be provided by the rolling train in the longitudinal direction, since the casting rolls can only deliver a comparatively inaccurate thickness profile. However, this thickness curve significantly simplifies the machining of the metal strip B with regard to the provision of the desired thickness profile. Furthermore, a thickness profile is determined for the rolling train, which results in that the metal strip B emerges from the rolling train with an actual thickness profile in the longitudinal direction, which substantially corresponds to the desired nominal thickness profile in the longitudinal direction of the metal strip B.

The casting rolls of the casting device are controlled or regulated in such a way by means of the control and / or regulating device that the predetermined course of thickness is present before entry into the rolling train. In addition, the casting device is controlled by means of the control and / or regulating device in dependence on the maximum setting speed of the roll stand such that the entry speed is in the rolling mill below a corresponding threshold, for example. 3 meters / second. This will ensure that the ratio of belt entry speed into the rolling stand and setting speed of the work rolls for influencing the metal strip thickness is such that the desired thickness profile can also be produced. This is usually possible if the ratio of belt entry speed and setting speed for each rolling stand of the rolling train is less than 3500, in particular between 200 and 1500.

For the desired thickness profile, a plurality of operating points are provided, which are to be traversed by the rolling stand for a particular band section. These operating points give, for example, in addition to the desired thickness, a desired rolling force and a desired rolling gap for the rolling stand. These operating points are preferably determined by means of a process model.

In a method step 103, the corresponding strip section is cast in accordance with the thickness profile predetermined for the casting device.

Subsequently, the corresponding strip section enters the rolling train and is rolled according to the predetermined course of thickness in a method step 104 in such a way that the strip section has an actual thickness profile which substantially corresponds to the intended target thickness profile for this strip section.

The thickness of the metal strip B is preferably controlled, in particular with the aid of detected setting positions for the work rolls, detected rolling forces, detected thicknesses and / or detected profiles of the metal strip B.

In particular, in a method step 105, a thickness measurement and a flatness measurement are carried out. The data obtained from the measurement are supplied to the control and / or regulating device, which influences the actuators of the roll stand based on this data such that the subsequently rolled strip sections the actual thickness of the desired thickness and the actual flatness of the desired flatness is further approximated.

In a method step 106, a query is made as to whether the method should be aborted. If not, the procedure is executed until terminated.

Such a procedure is according to all types of equipment 1 to FIG. 3 feasible, but neither on the process as such nor on the types of equipment according to 1 to FIG. 3 limited.

The method can also be used for cast roll composite systems at correspondingly low rolling speeds, which, for example, uses a mold as a casting device.

Claims (11)

1. Method for producing metal strip which is thickness-profiled in its longitudinal direction, by means of a combined continuous casting and rolling system, comprising a casting device (1, 1') for casting metal to form rolling stock (B) and a roll train (2) comprising at least one roll stand for hot forming the rolling stock (B), wherein the combined continuous casting and rolling system is operated such that the rolling stock (B) extends continuously between the casting device (1, 1') and the roll train (2), wherein rolling stock (B) is continuously fed to the roll train (2), wherein a target thickness progression according to which the roll train (2) rolls the rolling stock (B) is predetermined for the roll train (2), wherein the target thickness progression has at least two different target thicknesses for different sections in the longitudinal direction of the thickness-profiled metal strip, and the target thickness progression is designed such that the first and/or the second target thickness is set at least twice, wherein the combined continuous casting and rolling system is further operated such that an infeed rate (V) of the rolling stock (B) into the roll stand is set to less than 7 metres per second, characterised in that casting of the metal takes place with a thickness profile in the longitudinal direction, such that the rolling stock (B) already has varying thicknesses in the longitudinal direction when it enters the roll train (2), wherein said thickness profile produced by the casting device (1) is then rolled over by the at least one roll stand of the roll train (2) such that the target thickness profile is obtained in the longitudinal direction.
2. Method according to claim 1, wherein
   in addition to the at least two different target thicknesses, associated target roll forces and/or target roll gap openings are predetermined.
3. Method according to claim 1 or 2, wherein
   the thickness progression comprises repeating, in particular recurring, changes in thickness in the longitudinal direction of the thickness-profiled metal strip.
4. Method according to one of the preceding claims, wherein
   a strip accumulator (S, S'), in particular a loop of strip (S) with which mass flow fluctuations caused by the predetermined thickness progression are equalised, is provided between the casting device (1, 1') and the roll train (2).
5. Method according to one of the preceding claims, wherein an infeed rate (V) of the rolling stock (B) into the roll stand is set to less than 5 metres per second, in particular between 1 metre per second and 4 metres per second.
6. Method according to one of the preceding claims, wherein the roll train (2) is followed in the mass flow direction by a thickness measuring device (3), by means of which the rolled thickness of the thickness-profiled metal strip is detected, wherein at least one final control element for the roll train (2), in particular of at least one roll stand, is set as a function of the detected thickness and the predetermined thickness progression of the thickness-profiled metal strip.
7. Method according to one of the preceding claims, wherein the roll train (2) is followed in the mass flow direction by a flatness measuring device (4), by means of which the flatness of the thickness-profiled metal strip is detected, wherein at least one final control element, in particular a bending cylinder, for the roll train (2), is set as a function of the detected flatness and a predetermined thickness progression.
8. Method according to one of the preceding claims, wherein the thickness progression is set using a roll train (2) comprising a roll stand having a set of work rolls that have a diameter (D) of less than 800 millimetres, in particular 200 to 600 millimetres.
9. Method according to claim 8, wherein
   the infeed rate is set and the roll stand designed such that a ratio of an infeed rate (V) of the rolling stock (B) into the roll stand to a maximum adjustment rate of the work rolls of the roll stand for influencing the thickness of the rolling stock (B) is less than 3500, in particular less than 2000, in particular between 200 and 1500.
10. Method according to one of the preceding claims, wherein a twin-roll casting machine (1) or a direct strip casting machine (1') is used as the casting device (1, 1').
11. Method according to one of claims 1 to 10, wherein the metal strip which is thickness-profiled in its longitudinal direction is produced with a minimum target thickness of 0.7 mm.

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