EP4015099A1 - Energy efficient production of a ferritic hot strip in a casting roll composite system - Google Patents

Abstract

The invention relates to the energy-efficient production of a ferritic hot strip (6) in a combined casting and rolling plant (1). The object of the invention is to modify the known method for producing a ferritic hot strip (6) in a combined casting and rolling plant (1) in such a way that the ferritic hot strip (6) can be produced much more energy-efficiently, but still has good metallurgical properties and has a good surface quality. This object is achieved by a method according to claim 1.

Description

field of technology

The present invention relates to the technical field of steel metallurgy, specifically the particularly energy-efficient production of a ferritic hot strip in a combined casting and rolling plant.

On the one hand, the invention relates to a method for producing a ferritic hot strip in a combined casting and rolling plant, comprising the steps of: continuous casting of a liquid steel to form a strand with a slab or thin slab cross section in a continuous casting plant; Pre-rolling the strand into an intermediate strip in a multi-stand roughing train; descaling the broad sides of the heated intermediate strip in a descaling device; Finish rolling of the descaled intermediate strip to form the hot strip in a multi-stand finishing train, with at least the last rolling pass in the finishing train taking place in the ferritic temperature range of the steel; Setting the hot strip to coiler temperature; and coiling the hot strip in a coiler.

On the other hand, the invention relates to a combined casting and rolling plant which is particularly well suited for the production of a ferritic hot strip, comprising: a continuous casting plant for continuously casting a liquid steel into a strand with a slab or thin slab cross section; a multi-stand roughing train for rough-rolling the strand into an intermediate strip; a descaling device for descaling the broad sides of the heated intermediate strip; a multi-stand finishing train for finish-rolling the descaled intermediate strip to form the hot strip, with at least the last rolling pass in the finishing train taking place in the ferritic temperature range of the steel; a cooling line to adjust the hot strip to coiler temperature; and a coiler for coiling the hot strip.

State of the art

From the unpublished application PCT/EP2020/068520 is known, a ferritic hot strip in a combined casting and rolling plant through the steps of continuously casting a strand with a slab or thin slab cross-section, pre-rolling of the strand to form an intermediate strip in a multi-stand roughing train, heating the intermediate strip to an average temperature ≥ 1070 °C, descaling the heated intermediate strip, finish-rolling the descaled intermediate strip to form a hot strip in a multi-stand finishing train, with at least the last rolling pass in the finishing train in the ferritic temperature range takes place, cooling the hot strip to coiler temperature, and coiling the hot strip in a coiler.

Although the ferritic hot strip produced has good metallurgical properties and a good surface quality, the process is energy-intensive, since the average temperature of the intermediate strip is first brought to a high temperature ≥ 1070 °C, the intermediate strip is then descaled and then the average temperature of the intermediate strip is increased in an intensive cooling step Intermediate bands is cooled to <900 °C. How the process can be changed so that the hot strip has the same good metallurgical properties and good surface quality, but the use of energy is greatly reduced, is not clear from the document.

Summary of the Invention

The object of the invention is to modify a method for producing a ferritic hot strip in a combined casting and rolling plant in such a way that the ferritic hot strip can be produced much more energy-efficiently, but still has good metallurgical properties and a good surface quality. In addition, a particularly well-suited casting-rolling compound system is to be specified.

The procedural aspect of this object is achieved by a method according to claim 1. Advantageous developments are the subject of the dependent claims.

Specifically, the solution is a method for producing a ferritic hot strip in a combined casting and rolling plant, with the steps: continuous casting of a liquid steel to form a strand with a slab or thin slab cross section in a continuous casting plant; Pre-rolling the strand into an intermediate strip in a multi-stand roughing train; Heating the broadsides of the intermediate strip by one or preferably more inductive surface heating modules to a surface temperature ≥ 1000 ° C, preferably ≥ 1050 ° C, wherein the surface heating module is operated with an alternating current with a first frequency f1 and for the first frequency f1 applies: f1 ≥ 20 kHz, preferably f1 ≥ 50 kHz, particularly preferably f1 ≥ 100 kHz; descaling the broad sides of the heated intermediate strip in a descaling device; Finish rolling of the descaled intermediate strip into the hot strip in a multi-stand finishing train, where the descaled intermediate strip enters a first stand of the finishing train after descaling without further cooling at an average temperature of 775 - 900 °C and at least the last rolling pass in the finishing train takes place in the ferritic temperature range of the steel; Setting the hot strip to coiler temperature; and coiling the hot strip in a coiler.

The mean temperature (also known as average temperature) is understood to mean that temperature which corresponds to the average temperature of the different layers of the intermediate strip in the thickness direction. It is therefore not generally the temperature that the intermediate strip has in the middle (i.e. in the central region) in the thickness direction.

When the hot strip is adjusted to the coiler temperature, the hot strip is typically thermally insulated in the area between the last stand of the finishing train and the coiler, so that the average temperature of the hot strip drops only slightly. As a result, a high coiling temperature is achieved without actively heating or reheating the hot strip. As an alternative to this, the hot strip can either be actively cooled or even heated up by a heating device. A combination of a heating device after the last stand of the finishing mill and a cooling section for actively cooling the hot strip before coiling is also conceivable and advantageous for certain steel grades.

According to the invention, the intermediate strip is heated to a surface temperature ≧1000° C. by at least one surface heating module. Since the surface heating module or modules are operated with an alternating current with a first frequency f1 and the following applies to the first frequency f1: f1 ≥ 20 kHz, only the near-surface layers of the broadsides are heated, with the temperature of the core of the intermediate strip changing only slightly. In other words, the surface temperature on the broad sides of the intermediate strip is increased by the surface heating module or modules to a much greater extent than the average temperature of the intermediate strip. The broad sides of the hot intermediate strip are then descaled, for example using a pinch roll descaler. Immediately after descaling, ie without further cooling, the descaled intermediate strip enters the first stand of the finishing train at an average temperature of 775 - 900 °C and is finish-rolled in the multi-stand finishing train to form the hot strip. For the direct production of a ferritic hot strip in the combined casting and rolling plant, at least the last pass in the finishing train takes place in the ferritic temperature range of the steel. Then the temperature of the ferritic hot strip adjusted to the coiling temperature and in the coiling system to bundles, engl. coils, coiled.

This results in several differences compared to the prior art: On the one hand, the inductive surface heating modules only heat the layers of the broad sides close to the surface and not all layers of the intermediate strip evenly. Since the broadsides have a surface temperature ≥ 1000 °C before descaling, descaling is very thorough, which results in a high surface quality of the hot strip. On the other hand, the descaled intermediate strip enters the first stand of the finishing mill directly at an average temperature of 775 - 900 °C without being cooled down separately in an intensive cooling step after descaling. Accordingly, energy is saved on the one hand, since only the layers close to the surface of the broad sides of the intermediate strip have to be heated to a comparatively high temperature before descaling and not the entire intermediate strip. On the other hand, the average temperature of the intermediate strip before descaling can be very low (e.g. between 875 and 990°C), which in turn is very favorable for the energy efficiency of the manufacturing process.

abgeschätzt werden, wobei µ₀ die magnetische Feldkonstante, µ_r die relative elektromagnetische Permeabilität des Stahls, f die Frequenz des Wechselstroms und κ die elektrische Leitfähigkeit angibt. Alle genannten Größen sind in SI-Einheiten einzusetzen. Da insbesondere κ aber auch µ_r stark temperaturabhängig sind, müssen diese Werte bei der aktuellen Temperatur beim Erhitzen eingesetzt werden.The ratio between the thickness s of the intermediate strip and the penetration depth d into the heated intermediate strip is preferably: s/d≦6, preferably s/d≦10, particularly preferably s/d≦14 and very particularly preferably s/d≦16 The so-called penetration depth δ (also known as the current penetration level) describes an area in the intermediate band in which the current density has fallen to 37 percent compared to the outer edge of the broadsides. In the area of the penetration depth, 86 percent of the induced energy is converted into heat, only 14 percent heat up deeper areas. In concrete terms, this means that, for example, with an intermediate strip thickness of 24 mm, the penetration depth d may be a maximum of 4 mm for s/ d ≤ 6. The penetration depth can be determined by the formula $$\delta =\frac{1}{\sqrt{{\mathit{<figure-callout\; id="0"\; label="\pi \mu "\; filenames="imgf0002.png"\; state="\{\{state\}\}">\pi \mu </figure-callout>}}_0{\mathit{\mu }}_{\mathrm{right}}\mathit{f\kappa }}}$$

where µ ₀ is the magnetic field constant, µ _r is the relative electromagnetic permeability of the steel, f is the frequency of the alternating current and κ is the electrical conductivity. All quantities mentioned are to be used in SI units. Since κ in particular, but also µ _r , are strongly temperature-dependent, these values must be used at the current temperature when heating.

An inductive surface heating module preferably heats the intermediate strip by transverse field heating. However, it is also possible that heating through Longitudinal field heating takes place. With transverse field heating, it is advantageous for a first inductor to heat the upper broadside of the intermediate strip and a second inductor to heat the lower broadside of the intermediate strip.

It is advantageous to set or keep constant the so-called coupling gap, which is the vertical distance between an upper inductor and an upper broad side of the intermediate strip, as a function of the intermediate strip thickness. The adjustment is made e.g. by a linear motor.

For thorough descaling of the intermediate strip in the width direction, it is advantageous for each broad side of the intermediate strip to be descaled by at least one row, each with a plurality of spray nozzles. The spray nozzles in a row are either stationary or arranged on rotating rotors.

A good descaling effect is achieved if the descaling is carried out using a liquid descaling agent, for example water, with the descaling agent being applied to the spray nozzles at a pressure of 450 bar>p>100 bar.

In order to keep the descaling agent in the descaling device, it is advantageous if, in the material flow direction, a pair of driver rollers ( pinch rolls) is arranged in front of the first row and behind the last row of spray nozzles.

Depending on the steel grade, the operating mode (endless, semi-endless or batch operation) or the casting speed, it can be advantageous for the average temperature of the intermediate strip to be increased in an induction furnace using several inductive through-heating modules before the broadsides are heated. The average temperature of the intermediate band is increased to about the same extent as the surface temperature by the heating module or modules. It is advantageous here if the inductive surface heating modules are operated at a first frequency f1 and the inductive through-heating modules at a second frequency f2, where: f1>f2, preferably f1≧2*f2, particularly preferably f1≧5*f2.

To adjust the entry temperature of the descaled intermediate strip into the finishing train, it is advantageous if the surface temperature T _actual of the partially finish-rolled intermediate strip is measured by a pyrometer between the first and second or between the second and third finishing stand of the finishing train, a temperature controller taking into account T _is dependent a set surface temperature T _set outputs a manipulated variable to at least one, preferably to several, inductive heating modules, and the heating modules heat the intermediate strip to such an extent that the measured surface temperature T _actual corresponds as closely as possible to the set surface temperature T _set .

This method is based on the finding that the temperature of the heated and descaled intermediate strip before the finishing train can only be measured imprecisely and that the temperature measurement in one of the intermediate stand areas of the first three stands is much more accurate. The inductive through-heating modules are controlled by a temperature controller depending on the measured actual temperature, taking into account the target temperature, so that the actual temperature corresponds as closely as possible to the target temperature.

The device-related aspect of the technical task is solved by a combined casting and rolling system according to claim 13. Advantageous developments are the subject of the dependent claims.

• eine Stranggießanlage zum Stranggießen eines flüssigen Stahls zu einem Strang mit Brammen- oder Dünnbrammenquerschnitt;
• eine mehrgerüstige Vorstraße zum Vorwalzen des Strangs zu einem Zwischenband;
• ein oder mehrere induktive Oberflächenheizmodule zum Erhitzen der Breitseiten des Zwischenbands auf eine Oberflächentemperatur ≥ 1000 °C wobei ein Oberflächenheizmodul mit einem Wechselstrom mit einer ersten Frequenz f1 betrieben wird und für die erste Frequenz f1 gilt: f1 ≥ 20 kHz, vorzugsweise f1 ≥ 50 kHz, besonders bevorzugt f1 ≥ 100 kHz;
• eine Entzunderungseinrichtung zum Entzundern der Breitseiten des erhitzten Zwischenbands;
• eine mehrgerüstige Fertigstraße zum Fertigwalzen des entzunderten Zwischenbands zu dem Warmband, wobei das entzunderte Zwischenband nach dem Entzundern ohne weitere Abkühlung mit einer mittleren Temperatur von 775 - 900 °C in ein erstes Gerüst der Fertigstraße eintritt und zumindest der letzte Walzstich in der Fertigstraße im ferritischen Temperaturbereich des Stahls erfolgt;
• eine Kühlstrecke zur Einstellung des Warmbands auf Haspeltemperatur; und
• eine Haspelanlage zum Aufwickeln des Warmbands.

In concrete terms, the solution is provided by a combined casting and rolling plant for the production of a ferritic hot strip, in particular for carrying out the method according to one of the preceding claims, having:

• a continuous casting plant for continuously casting a liquid steel into a strand with a slab or thin slab cross section;
• a multi-stand roughing train for rough-rolling the strand into an intermediate strip;
• one or more inductive surface heating modules for heating the broadsides of the intermediate strip to a surface temperature ≥ 1000 °C, wherein a surface heating module is operated with an alternating current with a first frequency f1 and the following applies to the first frequency f1: f1 ≥ 20 kHz, preferably f1 ≥ 50 kHz, particularly preferably f1 ≥ 100 kHz;
• a descaling device for descaling the broad sides of the heated intermediate strip;
• a multi-stand finishing train for finish-rolling the descaled intermediate strip to form the hot strip, the descaled intermediate strip after descaling without further cooling entering a first stand of the finishing train at an average temperature of 775 - 900 °C and at least the last rolling pass in the finishing train in the ferritic temperature range of the steel is done;
• a cooling line to adjust the hot strip to coiler temperature; and
• a coiler for coiling the hot strip.

An induction furnace with a plurality of inductive through-heating modules is preferably arranged in the material flow direction between the roughing train and the inductive surface heating modules, with the induction furnace increasing the average temperature of the intermediate strip.

It is further preferred that a pyrometer for measuring the surface temperature T _actual of the partially finish-rolled intermediate strip is arranged between the first and the second or between the second and the third finishing stand of the finishing train, the pyrometer with a temperature controller and the temperature controller with at least one inductive heating module in terms of signaling are connected, the temperature controller can output a manipulated variable to at least one inductive heating module, taking into account T _actual as a function of a target surface temperature T _setpoint , with the heating modules being able to heat the intermediate strip to such an extent that the measured surface temperature T _{actual is} as close as possible to the target surface temperature T _should correspond.

Fig 1

eine schematische Darstellung einer erfindungsgemäßen Gieß-Walz-Verbundanlage zur Durchführung des erfindungsgemäßen Verfahrens,

Fig 2

ein Temperaturprofil für das erfindungsgemäße Verfahren, und

Fig 3

ein Dickenprofil für das erfindungsgemäße Verfahren.

The properties, features and advantages of this invention described above, and the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of an exemplary embodiment, which will be explained in more detail in connection with the drawings. show:

figure 1

a schematic representation of a casting-rolling compound plant according to the invention for carrying out the method according to the invention,

figure 2

a temperature profile for the method according to the invention, and

figure 3

a thickness profile for the method according to the invention.

Description of the embodiments

In the casting-rolling compound plant 1 of figure 1 becomes liquid steel with the following chemical composition in the continuous casting plant 2 <i>Table 1: Steel chemical composition</i> element weight % C <0.004 Mn < 0.2 P < 0.01 Ti+Nb 0.03 feet rest

continuously cast to form a strand 3 with a slab cross section. The strand 3 leaves the continuous caster 2 with a thickness of 90 mm and a speed of 6 m/min. The partially solidified strand 3 is preferably subjected to a soft core or a liquid core reduction (LCR) in the curved strand guide. This reduces the thickness of the strand and improves its internal quality. The strand 3 enters the three-stand roughing train 5 uncut and is reduced there to an intermediate strip 4 with a thickness of 12.4 mm. The last pass in stand R3 of roughing train 5 takes place in the austenitic temperature range at a final rolling temperature of 1050°C. The average temperature of the intermediate strip 4 is then increased from 900° C. to 950° C. by six through-heating modules of an induction furnace IH. Following this, the surface temperature of the broad sides of the through-heated intermediate strip 4 is heated to 1070° C. by two surface heating modules 7 . The surface heating modules are operated at a frequency of 50 kHz and heat the intermediate strip by transverse field heating. Due to the heating of the broadsides, the mean temperature of the intermediate strip rises to 960°C. After heating, the broad sides of the intermediate strip 4 are descaled in a descaling device D, specifically a so-called pinch roll descaler . The average temperature of the intermediate strip drops to 850 °C. After descaling, the descaled intermediate strip 3 enters the five-stand finishing train 8 and is finish-rolled there in 5 passes to form a hot strip 6 with a thickness of 1.7 mm. Since the last rolling pass in stand F5 takes place at an average temperature of 760°C, a hot strip with a ferritic structure is present after the last rolling pass at the latest. Preferably, the last three rolling passes in the roll stands F3, F4 and F5 (particularly preferably all rolling passes in) of the finishing train 8 are carried out using roll gap lubrication. A mineral oil is sprayed between the work rolls of the finishing stand and the rolling stock, which reduces the coefficient of friction in the roll gap to a value µ < 0.15. This prevents shear bands, which lead to the development of an undesirable GOSS texture, from forming in the finish-rolled hot strip. The hot strip 6 leaves the finishing train 8 with a surface temperature of 760°C. In order to achieve a high winding temperature, the hot strip is not actively cooled in the region of the cooling section 9 shown in dashed lines, but is thermally insulated by insulating panels 14 . The winding temperature is 700°C. Shortly before the bundle has reached its target weight, the endless hot strip is cut crosswise by the shears 10 and that winding on another (in figure 1 not shown) winding device continued, the ferrite in the hot strip 6 at least partially forms a {1 1 1} texture. The average temperatures in the individual aggregates of the combined casting and rolling plant 1 result from either figure 2 or the following table: Temperature [°C] CCM Out 1200 R1 1150 R2 1100 R3 1050 IH In 900 IH Out 950 SHM In 950 SHM Out 1070 D 850 F1 840 F2 820 F3 800 F4 780 F5 760 DC 700

Table 2: Temperature control

The reduction rates in the individual stands R1... R3 and F1... F5 and the thicknesses of the thin slab 2, the intermediate strip 4 and the hot strip 6 result from either figure 3 or the following table: <i>Table 3: Thicknesses and reduction rates</i> Thickness [mm] Reduction rates [%] CCM Out 90.0 R1 in 90.0 50 R1 Out 45.0 R2 In 45.0 50 R2 out 22.5 R3 in 22.5 45 R3 out 12.4 IH In 12.4 IH Out 12.4 SHM In 12.4 SHM Out 12.4 D 12.4 F1 in 12.4 45 F1 Out 6.8 F2 in 6.8 40 F2 Out 4.1 F3 in 4.1 35 F3 Out 2.7 F4 In 2.7 25 F4 Out 2.0 F5 in 2.0 15 F5 Out 1.7 DC 1.7

In order to ensure the continuous operation of the combined casting and rolling plant 1, the hot strip 6 is cut directly in front of the winding devices and wound up alternately by at least two winding devices DC.

By using the method according to the invention in the combined casting and rolling plant 1, the coiled hot strip 6 has good deep-drawing properties, without the hot strip 6 having to be cold-rolled or annealed after the hot-rolling.

Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Reference List

1

Casting-rolling compound plant

2

continuous caster

3

strand

4

intermediate band

5

fore road

6

hot strip or finished strip

7

surface heating module

8th

finishing line

9

cooling line

10

scissors

14

insulating panel

15 DC

reel system

D

descaling device

F1...F5

First to fifth stands of the finishing train

IH

induction furnace

In

Input of an aggregate

Out

output of an aggregate

R1...R3

First to third stands of the roughing mill

tis

actual surface temperature

Tset

target surface temperature

Claims (15)

Method for producing a ferritic hot strip (6) in a combined casting and rolling plant (1), comprising the steps: continuous casting of liquid steel to form a strand (3) with a slab or thin slab cross section in a continuous casting plant (2, CCM); Pre-rolling the strand (3) to form an intermediate strip (4) in a multi-stand roughing train (5); Heating of the broad sides of the intermediate strip (4) by one or preferably several inductive surface heating modules (7) to a surface temperature ≥ 1000 ° C, preferably ≥ 1050 ° C, wherein a surface heating module (7) is operated with an alternating current with a first frequency f1 and for the first frequency f1 applies: f1≧20 kHz, preferably f1≧50 kHz, particularly preferably f1≧100 kHz; Descaling the broad sides of the heated intermediate strip (4) in a descaling device (D); Finish rolling of the descaled intermediate strip (4) to form the hot strip (6) in a multi-stand finishing train (8), the descaled intermediate strip (4) after descaling without further cooling being fed into a first stand (F1 ) enters the finishing train (8) and at least the last pass (F5) in the finishing train takes place in the ferritic temperature range of the steel; Setting the hot strip (6) to the coiler temperature; and Coiling of the hot strip (6) in a coiler (15, DC). Method according to Claim 1, characterized in that the ratio between the thickness s of the intermediate strip (4) and the penetration depth d into the heated intermediate strip (4) is: s/d ≤ 6, preferably s/d ≤ 10, particularly preferably s / d ≤ 14 and very particularly preferably s/ d ≤ 16. Method according to Claim 1 or 2, characterized in that an inductive surface heating module (7) heats the intermediate strip (4) by transverse field heating. Method according to Claim 3, characterized in that a first inductor heats the upper broad side of the intermediate strip (4) and a second inductor heats the lower broad side of the intermediate strip (4). Method according to Claim 4, characterized in that the vertical distance between the first inductor and the upper broad side is kept constant as a function of the intermediate strip thickness. Method according to one of the preceding claims, characterized in that each broad side of the intermediate strip (4) is descaled in the descaling device (D) by at least one row each having a plurality of spray nozzles. Method according to Claim 6, characterized in that the spray nozzles in a row are arranged either stationary or on rotating rotors. Method according to Claim 6 or 7, characterized in that the descaling is carried out using a liquid descaling agent, for example water, the descaling agent being applied to the spray nozzles at a pressure of 450 bar > p > 100 bar. Method according to one of Claims 6 to 8, characterized in that in the direction of material flow before the first row and behind the last row of spray nozzles there is a pair of driver rollers set against the intermediate belt (4), so that the descaling agent cannot leave the descaling device. Method according to one of the preceding claims, characterized in that before the broad sides of the intermediate strip are heated, the average temperature of the intermediate strip is increased in an induction furnace (IH) by a plurality of inductive through-heating modules, the average temperature being increased to approximately the same extent as the surface temperature of the intermediate bands. Method according to Claim 10, characterized in that the inductive surface heating modules are operated at a first frequency f1 and the inductive heat-through modules are operated at a second frequency f2, where: f1 > f2, preferably f1 ≥ 2*f2, particularly preferably f1 ≥ 5*f2 . Method according to Claim 10 or 11, characterized in that the surface temperature T _actual of the partially finish-rolled intermediate strip (4) between the first (F1) and the second (F2) or between the second (F2) and the third finishing stand (F3) of the finishing train (8) is measured by a pyrometer, a temperature controller, taking into account T _actual as a function of a target surface temperature T _target , outputs a manipulated variable to at least one, preferably to several, inductive heating modules, and the heating modules heat the intermediate strip to such an extent that the measured Surface temperature T _actual corresponds to the target surface temperature T _target as far as possible. Casting-rolling compound plant (1) for the production of a ferritic hot strip (6), in particular for carrying out the method according to one of the preceding claims, having: a continuous casting plant (2, CCM) for continuously casting a liquid steel into a strand (3) with a slab or thin slab cross section; a multi-stand roughing train (5) for rough-rolling the strand (3) into an intermediate strip (4); one or more inductive surface heating modules (7) for heating the broad sides of the intermediate strip (4) to a surface temperature ≥ 1000 °C, wherein a surface heating module (7) is operated with an alternating current with a first frequency f1 and the first frequency f1 is: f1 ≥ 20 kHz, preferably f1 ≥ 50 kHz, particularly preferably f1 ≥ 100 kHz; a descaling device (D) for descaling the broad sides of the heated intermediate strip (4); a multi-stand finishing train (8) for finish-rolling the descaled intermediate strip (4) into the hot strip (6), the descaled intermediate strip (4) after descaling without further cooling being fed into a first stand (F1 ) enters the finishing train (8) and at least the last pass (F5) in the finishing train (8) takes place in the ferritic temperature range of the steel; a cooling section (9) for adjusting the hot strip (6) to coiler temperature; and a coiler (15, DC) for coiling the hot strip (6). Casting-rolling compound system according to Claim 13, characterized in that an induction furnace (IH) with a plurality of inductive through-heating modules is arranged in the direction of material flow between the roughing train (5) and the inductive surface heating modules (7), the induction furnace (IH) measuring the average temperature of the Intermediate bands increased. Casting-rolling compound plant according to claim 13 or 14, characterized in that between the first (F1) and the second (F2) or between the second (F2) and the third finishing stand (F3) of the finishing train (8) a pyrometer for measuring the surface temperature T _actual of the partially finish-rolled intermediate strip (4), the pyrometer is connected to a temperature controller and the temperature controller is connected to at least one inductive through-heating module, the temperature controller, taking into account T _actual as a function of a target surface temperature T _{setpoint ,} a control variable at least can output an inductive heating module, the heating modules being able to heat the intermediate strip to such an extent that the measured surface temperature T _actual corresponds as closely as possible to the target surface temperature T _target .

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