EP3628416A1 - Process and system for continuously casting a metal product - Google Patents

Abstract

The invention relates to a method and a system (10) for the continuous casting of a metallic product. The continuous casting installation (10) comprises a mold (12), a supporting strand guide (13) adjoining the mold (12), along which a strand (S) emerging from the mold (12) in particular vertically downwards in a conveying direction (F ) can be transported, and a further strand guide (19) adjoining the supporting strand guide (13) with a straightening area (I) through which the strand (S) can be deflected in the horizontal direction. A radar measuring device (16) measures a thickness of the strand (S) at a measuring position (18) located directly at the end (15) of the supporting strand guide (13). The measured strand thickness can be compared with a first predetermined comparison value by means of a control device (20) with a computing unit (21) connected to the radar measuring device (16) for signaling purposes. If the measured strand thickness is greater than the first predetermined comparison value, a control signal is generated with which at least one casting parameter is changed such that the bottom tip of the strand (S) moves in the direction of the mold (12).

Description

The invention relates to a method for the continuous casting of a metallic product according to the preamble of claim 1, and a continuous caster according to the preamble of claim 10.

In the manufacture of metallic products in a continuous caster, the liquid metal is continuously poured into a mold, a first strand shell being formed there. As a rule, the strand emerges downward from the mold, the strand then being transported along a supporting strand guide. After exiting the supporting strand guide, the strand is then moved along another strand guide with a straightening area through which the strand is deflected in the horizontal direction. Subsequent to this, further processing stations for the strand, or partial products formed therefrom, can be provided along the strand guide, for example in the form of rolling mills through which the strand is passed.

In the continuous casting process, it is very important that the strand completely harden or solidify within the supporting strand guide in order to prevent the liquid metal core from breaking out and to enable the strand to be further processed. For this purpose, the cooling capacity in the area of the supporting strand guide and the casting speed are set such that the bottom tip of the strand is always in front of or upstream of the last pair of support rollers at the end of the supporting strand guide in an optimal operating sequence.

If, during the continuous casting process, for example as a result of an excessively high casting speed, the bottom of the strand lies behind or downstream of the last support roller pair of the supporting strand guide and thus "migrated" out of the supporting strand guide, the problem arises that the strand bulge, because the hydrostatic pressure of the liquid melt is now missing a counter pressure by a pair of support rollers. As a result, during the movement of the strand in a non-area of the strand guide which does not contribute to the support of the strand and - seen in a conveying direction of the strand - downstream of the supporting strand guide, bulges can develop due to an increase in the thickness of the strand.

According to the state of the art it is over DE 1 558 345 A is known to sense or scan bumps in unsupported areas of metal strands in the continuous casting process, namely by using mechanical sensors with rotatable and heat-resistant wheels that roll on the broad sides of the moving strand. Because these mechanical sensors can be moved back and forth in a direction perpendicular to the direction of conveyance of the strand, dents can be sensed which form on at least one broad side of the strand when the strand is bulged. In this case it can be provided to change the casting speed or to adjust the amount of water that is sprayed onto the moving strand in the region of the supporting strand guide.

The measuring principle according to DE 1 558 345 A , with which bulges or an increase in thickness is mechanically determined with a contacting measuring roller on the surface of a moving strand after it emerges from a supporting strand guide, is subject to various disadvantages, e.g. wear of the wheels of the mechanical sensors due to the high temperatures of the strand . Furthermore, measurement errors can result if these wheels do not roll cleanly on the broad sides of the strand.

It is also known from the prior art to carry out a thickness measurement of the strand by using laser beams. However, such an optical method is subject to the disadvantage that water vapor, which can form in the measurement environment due to the cooling of the strand with water, then the laser beams are either blocked or at least deflected, which leads to falsified measurement results. Furthermore, the use of laser beams is also subject to the disadvantage of possible contamination of the aperture.

• eine Überhitzung, die im tatsächlichen Gießprozess höher ist als dem mathematisch-physikalischen Modell zugeführt wurde,
• zu große Maulweiten der Segmente der stützenden Strangführung, die im tatsächlichen Gießprozess höher sind als dem mathematisch-physikalischen Modell zugeführt wurde,
• reduzierte Sekundärkühlung, die im tatsächlichen Gießprozess geringer ist als dem mathematisch-physikalischen Modell zugeführt wurde,
• geänderte chemische Zusammensetzung des Werkstoffs, aus dem der Strang vergossen wird, wobei diese geänderte chemischen Zusammensetzung dem mathematisch-physikalischen Modell nicht zugeführt wurde, und/oder
• Modellfehler in dem mathematisch-physikalischen Modell.

In the continuous casting process, the position of the bottom of the strand is usually monitored using mathematical-physical models. Nevertheless, there are reasons why the swamp tip leaves the area of the supporting strand guide or runs out of it. These reasons can be:

• overheating, which is higher in the actual casting process than the mathematical-physical model,
• excessively large jaw widths of the segments of the supporting strand guide, which are higher in the actual casting process than was supplied to the mathematical-physical model,
• reduced secondary cooling, which is less in the actual casting process than was supplied to the mathematical-physical model,
• changed chemical composition of the material from which the strand is cast, this changed chemical composition not being added to the mathematical-physical model, and / or
• Model errors in the mathematical-physical model.

The invention has for its object to optimize the continuous casting of a metallic product in terms of quality improvement and at the same time to increase operational reliability.

This object is achieved by a method according to claim 1 and by a continuous caster with the features of claim 10. Advantageous developments of the invention are defined in the dependent claims.

A method according to the present invention is used to manufacture a metallic product. In this case, in a continuous casting installation, a strand of the metallic product continuously emerges from a mold, in particular vertically downward, and is then transported along a supporting strand guide in a conveying direction, the strand being deflected in a directional area in the horizontal direction. In this method, in step (i) a thickness of the strand is measured by a radar measuring device at a measuring position where the strand immediately leaves the supporting strand guide, and then in step (ii) the measured strand thickness is compared with a first predetermined comparison value . Then, in a step (iii), if the measured strand thickness is greater than the first predetermined comparison value, at least one casting parameter is changed such that the bottom tip of the strand moves in the direction of the mold.

In the same way, the invention provides a continuous caster for producing a metallic product. Such a system comprises a mold and a supporting strand guide adjoining the mold, along which a strand emerging from the mold in particular vertically downwards can be transported in a conveying direction. Following the supporting strand guide, another strand guide is provided with a straightening area through which the strand can be deflected in the horizontal direction. Furthermore, a radar measuring device, with which a thickness of the strand can be measured at a measuring position located directly at the end of the supporting strand guide, and a control device, which is connected to the radar measuring device for signaling purposes, are provided with a computing unit with which the measured strand thickness can be measured with a first predetermined comparison value can be compared. In terms of programming, the control device is set up in such a way that if the measured strand thickness is greater than the first predetermined comparison value, a control signal can then be used to change at least one casting parameter in such a way that the bottom tip of the strand moves in the direction of the mold.

The invention is based on the essential finding that the measurement of a thickness of the strand at a measuring position where the strand immediately leaves the supporting strand guide is carried out using radar technology. For this purpose, a radar measuring device is arranged directly at the end of the supporting strand guide, namely where the strand exits the supporting strand guide. Compared to the above-mentioned measurement methods according to the prior art, radar measurement technology has the advantages that temperature radiation in the near IR range, which emanates from the hot line, does not influence the radar measurement, and that water vapor that arises from the Strand cooling using water occurs without the measurement being distorted from the radar beams to the strand. In addition, a radar measurement is insensitive to soiling compared to an optical measurement using a laser and a mechanical measurement using a touching measuring roller.

With regard to the positioning of the radar measuring device in the continuous casting installation, it is recommended that a relatively large distance from the hot strand be maintained. This is possible thanks to the contactless radar measurement. Such a sufficiently large distance between the radar measuring device and the hot strand ensures good protection of the radar electronics against the radiation heat emanating from the strand.

The radar measuring device is arranged relative to the supporting strand guide and the strand emerging therefrom in such a way that the radar beams or waves are directed essentially perpendicularly to a surface of the strand, namely on its broad side (s). In this way, the radar beams are directed or transmitted perpendicularly to the surface of at least one broad side of the strand by the radar measuring device.

In an advantageous development of the invention, starting from the radar measuring device, the radar beams are directed vertically from both sides of the strand onto its broad sides. This ensures a uniform and complete measurement of the thickness of the strand immediately after it has left the supporting strand guide, in conjunction with a detection of possible "bumps" on the surfaces of the broad sides. Such monitoring of the string from both sides can be achieved in that the radar measuring device has separate transmitting / receiving modules which are arranged on both sides of the broad sides of the string and emit their radar beams or waves essentially perpendicularly to the broad sides of the string . In addition and / or as an alternative to this, the radar measuring device can also have separate parabolic elements which are arranged on both sides of the broad sides of the strand and which align the radar beams essentially perpendicularly to the broad sides of the strand. By such a deflection of the radar beams by means of the parabolic elements, the actual radar measuring device, with its sensitive transmitter / receiver unit, can be positioned at a sufficient distance from the hot strand and related components of the continuous casting installation.

A further improved protection of the radar measuring device against the high temperatures of the string can be achieved by thermal insulation layers in which the radar measuring device is encapsulated. This is possible because radar beams penetrate such dielectric materials in the form of thermal insulation layers.

An important feature of the method according to the invention, and in the same way of a control device of the continuous casting installation according to the invention, is that in the event that the strand thickness measured by the radar measuring device is greater than the first predetermined comparison value, then at least one casting parameter in is changed in such a way that the sump tip of the strand moves in the direction of the mold.

This means that by appropriately changing at least one casting parameter, the bottom of the sump - as seen in the direction of conveyance of the strand - is shifted upstream and thereby "migrates" back into the supporting strand guide. The said change of at least one casting parameter expediently consists in that the casting speed is reduced, but is not set lower than a minimum casting speed at which the bottom tip of the strand is below LiquidCoreReduction (LCR) segments of the supported strand guide. Additionally and / or alternatively, in the course of changing at least one casting parameter, the cooling capacity in the area of the supporting strand guide can also be increased.

For the purposes of the present invention, the first predetermined comparison value with which the strand thickness measured by the radar measuring device is compared in step (ii) is a distance between the last two support rollers at the end of the supporting strand guide, i.e. at their exit area, where the moving strand leaves the supporting strand guide. In this regard, it should be pointed out separately that with this spacing of the two last support rollers from one another, their deflection is also taken into account, which can occur when the strand is passed between these opposite support rollers.

As explained above, depending on the strand thickness measured by the radar measuring device and in the event that this strand thickness is greater than the first predetermined comparison value (= distance between the last two support rollers at the end of the supporting strand guide), the casting speed can then be reduced will. In this regard, it should be emphasized that a reduction in the casting speed has an immediate effect on the entire length of the strand, and thus also on the position of the bottom tip of the strand, which is hereby shifted upstream, ie counter to the conveying direction of the strand, in the direction of the mold.

It is achieved with the present invention that the thickness of the strand after it has left the supporting strand guide is measured exactly by means of a radar measurement. In this way, possible bulges of the strand when it emerges from the supporting strand guide can be recognized precisely and reliably, in connection with the initiation of an immediate "countermeasure", preferably in the form of a reduction in the casting speed.

Fig. 1

eine schematisch vereinfachte Seitenansicht einer erfindungsgemäßen Stranggießanlage,

Fig. 2a

eine Seitenansicht einer stützenden Strangführung, die Teil der Stranggießanlage von Fig. 1 ist, in Verbindung mit einer Radar-Messeinrichtung nach einer Ausführungsform der Erfindung,

Fig. 2b

eine Querschnittsansicht des Strangs an der Messposition der Stranggießanlage von Fig. 1, in Verbindung mit einer Radar-Messeinrichtung nach einer weiteren Ausführungsform der Erfindung,

Fig. 3, 4

jeweils schematisch vereinfachte Seitenansichten von verschiedene Betriebstellungen einer stützenden Strangführung, die Teil der Stranggießanlage von Fig. 1 ist, und

Fig. 5

ein Flussdiagramm zur Erläuterung des Ablaufs eines erfindungsgemäßen Verfahrens, das z.B. mit einer Stranggießanlage von Fig. 1 durchgeführt werden kann.

Embodiments of the invention are described in detail below with reference to a schematically simplified drawing. Show it:

Fig. 1

2 shows a schematically simplified side view of a continuous casting installation according to the invention,

Fig. 2a

a side view of a supporting strand guide, which is part of the continuous caster of Fig. 1 is in connection with a radar measuring device according to an embodiment of the invention,

Fig. 2b

a cross-sectional view of the strand at the measuring position of the continuous caster of Fig. 1 , in connection with a radar measuring device according to a further embodiment of the invention,

3, 4

each schematically simplified side views of various operating positions of a supporting strand guide, which is part of the continuous caster of Fig. 1 is and

Fig. 5

a flowchart to explain the sequence of a method according to the invention, for example, with a continuous caster of Fig. 1 can be carried out.

Below are with reference to the 1 to 5 preferred embodiments of a continuous caster 10 according to the invention and a corresponding method for producing a metallic product are explained. The same features in the drawing are each with the same reference numerals Mistake. At this point, it is pointed out separately that the drawing is only simplified and in particular is shown without a scale.

The continuous casting installation 10 according to the invention comprises a mold 12, which is followed by a supporting strand guide 13 with a total of four segments 13.1-13.4. According to the representations in Fig. 3 respectively. Fig. 4 liquid metal is poured into the mold 12 in the area of a melt inlet 6, in which case a strand S with an initially still liquid core 7 enters the supporting strand guide 13 from the mold 12 downwards. In the segments 13.1 - 13.4 of the supporting strand guide 13, oppositely arranged pairs of support rollers 14, 14 'are arranged, between which the strand is moved in the conveying direction F. These support roller pairs 14, 14 'are each acted upon by position-controlled or position-controlled hydraulic cylinders, not shown, so that they overcome the hydrostatic pressures of the melt 8 and can thereby cause a local reduction in thickness in the strand. This applies in particular to the first two segments 13.1, 13.2 of the supporting strand guide 13, where the strand S with its liquid core 7 can be reduced in thickness by compressing the segments, which is also referred to as LiquidCoreReduction (= LCR).

At one end 15 of the supporting strand guide 13, ie where the strand S emerges from the supporting strand guide 13 in the conveying direction F, there is a last pair of support rollers 14L, 14L '(cf. Fig. 3 , Fig. 4 ) intended. It is of great importance for the continuous casting process that the strand has already completely solidified before it passes through this last pair of support rollers 14L, 14L at the end 15 of the supporting strand guide 13. This is ensured by the fact that a sump tip SP of the strand S is still located within the supporting strand guide 13, as is shown in FIG Fig. 4 is illustrated. This then effectively prevents bulging of the strand S following the supporting strand guide 13, also referred to as “whale formation”.

According to the side view of FIG Fig. 1 , Another strand guide 19 with a straightening area I, in which the strand S is deflected by bending rollers 22 in the horizontal direction. Following the straightening area I, a pair of scissors 23 is arranged in the strand guide 19, followed by at least one rolling mill 24 and a furnace 26 arranged in front of it.

Furthermore, the continuous caster 10 comprises a radar measuring device 16, with which a thickness of the strand S is measured at a measuring position 18, namely directly where the strand from the supporting strand guide 13 after passing through the last pair of support rollers 14L, 14L ' exit. This measurement position 18 is indicated by an arrow in the Fig. 1 illustrated.

In one embodiment of the radar measuring device 16, according to the side view Fig. 2a - Radar beams directed essentially perpendicular to the two broad sides of the strand S. For this purpose, the radar measuring device 16 has separate transmitting / receiving modules 16.1, 16.2, which are each arranged on both sides of the broad sides of the strand S and with which radar beams are then directed perpendicularly to the surface of a broad side of the strand. In this regard, it is pointed out that the distance between these transmitting / receiving modules 16.1, 16.2 from the supporting strand guide 13 and the hot strand S guided therein is sufficiently large that these modules are not damaged by the thermal radiation emanating from the strand S.

In a further embodiment of the radar measuring device 16 according to FIG Fig. 2b separate parabolic elements 17.1, 17.2 are provided, which are arranged on both sides of the broad sides B1, B2 of the strand S, in order thereby to direct the radar beams essentially perpendicularly to the broad sides B1, B2. This makes it possible to arrange the actual radar measuring device 16 in the radiation shadow, thereby ensuring a further improved protection against the heat radiation of the strand S.

The continuous casting installation 10 comprises a control device 20 with a computing unit 21, which is connected to the radar measuring device 16, the bending rollers 22 in the area of the strand guide 19 and the at least one rolling mill 24 in terms of signals Fig. 1 each symbolized by dotted lines. This ensures that on the one hand the strand thickness measured by the radar measuring device 16 is transmitted to the computing unit 21, and that the computing unit 21 on the other hand also information relating both to a distance between the bending rollers 22 and to the distance from (not shown) Work rolls of the rolling mill 24 receives. Furthermore, the arrows in the Fig. 1 are directed by the control device 20 both to the mold 20 and to the scissors 23, symbolizing that suitable control signals can be generated by the control device 20 in order to change both a casting speed in the mold 12 and the scissors 23 - if required - to operate, as explained separately below.

The invention now works as follows:
In the ongoing continuous casting process, a minimum casting speed V _{min is} determined on the basis of the current process values (chemical analysis of the material, strand thickness, cooling capacity set for the segments 13.1-13.4 of the supporting strand guide 13), at which the bottom tip SP below the two LCR segments 13.1, 13.2 lies (see illustration in Fig. 4 ). The radar measuring device 16 continuously measures a thickness of the strand S, as explained above at the measuring position 18, ie immediately where the strand S emerges from the end 15 of the supporting strand guide 13. This corresponds to a step (i) of a method according to the present invention, the measured strand thickness being transmitted to the computing unit 21 of the control device 20. Following this, namely in a step (ii) of the method according to the invention, the measured strand thickness is compared with a first Predetermined comparison value compared, which corresponds to a distance between the two last support rollers 14L, 14L 'to each other.

If it should then be determined in a step (iii) of the method according to the invention by the computing unit 21 that the strand thickness of the strand S measured with the radar measuring device 16 is greater than the first predetermined comparison value (= distance of the two last support rollers 14L, 14L 'from one another ), there is a risk that the sump tip SP of the strand S is either already outside (or below, seen in the conveying direction F of the strand S) of the supporting strand guide 13, as in FIG Fig. 3 is illustrated, or at least there is a tendency for the sump tip SP to shift there. In this case, the control device 20 immediately generates a control signal with which, for example, the casting speed is set to a reduced value V _red . It should be noted here that the reduced casting speed V _red always remains greater than the minimum casting speed V _min explained above. By observing this condition, it is achieved that the sump tip SP of the strand S does not move too far “upward”, ie reaches the area of the two LCR segments 13.1, 13.2.

After the casting speed has been set to the reduced value V _red , a query is carried out in the computing unit 21 for the further course of the continuous casting process as to whether the strand thickness measured by the radar measuring device 16 in step (i) is less than a predetermined second comparison value , which corresponds to a distance from bending rollers 22 arranged opposite one another. If a "No" is determined with this query, which means that the strand thickening of the strand S can no longer be transported through the bending rollers 22, the control device 20 outputs a control signal for an immediate stop of casting in order to further damage the strand guide 19 to avoid the continuous caster 12.

Otherwise, a further query is made in the computing unit 21 as to whether the strand thickness measured by the radar measuring device 16 in step (i) is smaller than a predetermined third comparison value, which corresponds to a distance from opposing work rolls in the rolling mill 24. If a "No" is determined in this query, this means that the existing strand thickening in the rolling mill 24 cannot be brought to a desired final dimension. Therefore, the control device 20 then generates a control signal for the scissors 23, by means of which the thickened section of the strand S is separated from the strand guide 19 and shredded accordingly.

The above-mentioned step sequences for the method according to the invention are also in the flow chart of Fig. 5 shown accordingly.

Reference list

6

Melt inlet

7

liquid core

8th

melt

10th

Continuous caster

11

metallic product

12th

Mold

13

supporting strand guide

13.1-13.4

Segments (the supporting strand guide 14)

14, 14 '

Role pairs (of a respective segment 14.1-14.4)

15

End (of the supporting strand guide 13)

16

Radar measuring device

16.1, 16.2

Transmit / receive modules (of the radar measuring device 16)

17.1, 17.2

Parabolic elements (of the radar measuring device 16)

18th

Measuring position

19th

Strand guide (not supported)

20th

Control device

21

Arithmetic unit

22

Bending rolls

23

scissors

24th

Rolling mill

26

oven

B1, B2

Broadsides (of strand S)

F

Direction of conveyance

I.

Straightening range

S

strand

SP

Swamp tip

V _red

reduced casting speed

V _min

minimal casting speed

Claims (16)

Process for the continuous casting of a metallic product (11), in which in a continuous casting installation (10) a strand (S) of the metallic product (11) emerges continuously from a mold (12), in particular vertically downward and then along a supporting strand guide (13) is transported in a conveying direction (F), the strand (S) being deflected in a directional region (I) in the horizontal direction, characterized by (i) measuring a thickness of the strand (S) by a radar measuring device (16) at a measuring position (18) where the strand (S) immediately leaves the supporting strand guide (13), (ii) comparing the measured strand thickness with a first predetermined comparison value, and (iii) if the measured strand thickness is greater than the first predetermined comparison value: changing at least one casting parameter such that the bottom tip (SP) of the strand (S) moves in the direction of the mold (12). A method according to claim 1, characterized in that the casting speed is reduced in step (iii). Method according to claim 2, characterized in that a minimum casting speed (V _min ) is determined on the basis of current process values for the current casting process, at which the bottom tip (SP) of the strand (S) below LCR segments (13.1, 13.2) of the supporting strand guide (13), the reduced casting speed (V _red ) being chosen to be greater than the minimum casting speed (V _min ). Method according to one of the preceding claims, characterized in that the first predetermined comparison value corresponds to a distance between the two last support rollers (14L, 14L ') at the end (15) of the supporting strand guide (13). Method according to one of the preceding claims, characterized in that in step (iii) the cooling capacity in the region of the supporting strand guide (13) is increased. Method according to one of the preceding claims, characterized in that the strand thickness measured in step (i) is compared with a second predetermined comparison value, wherein if the measured strand thickness is greater than the second predetermined comparison value, the casting process is then terminated. A method according to claim 6, characterized in that the second predetermined comparison value corresponds to a distance from bending rollers (22) of the further strand guide (19), which are arranged opposite one another in particular in the straightening area (I). Method according to one of the preceding claims, characterized in that the strand thickness measured in step (i) is compared with a third predetermined comparison value, wherein if the measured strand thickness is greater than the third predetermined comparison value, then a region of the strand (S), the strand thickness of which is greater than the third predetermined comparison value, from which the strand guide is separated using scissors (22). A method according to claim 8, characterized in that the third predetermined comparison value a distance from work rolls in a rolling mill (24) in which the solidified strand (S) is further processed. Continuous casting plant (10) for producing a metallic product (11), comprising a mold (12), and a supporting strand guide (13) adjoining the mold (12), along which a strand (S) emerging from the mold (12) in particular vertically downwards can be transported in a conveying direction (F), a further strand guide (19) adjoining the supporting strand guide (13) with a straightening area (I) through which the strand (S) can be deflected in the horizontal direction,
marked by a radar measuring device (16) with which a thickness of the strand (S) can be measured at a measuring position (18) located directly at the end (15) of the supporting strand guide (13), a control device (20), which is connected to the radar measuring device (16) for signaling purposes, with a computing unit (21) with which the measured strand thickness can be compared with a first predetermined comparison value, the control device (20) being set up in terms of programming such that if the measured strand thickness is greater than the first predetermined comparison value, then a control signal can be generated with which at least one casting parameter is changed such that the bottom tip (SP) of the strand (S) moves in the direction of the mold (12). Continuous casting plant (10) according to claim 10, characterized in that the casting speed for the strand (S) is reduced by the generated control signal. Continuous casting plant (10) according to claim 10 or 11, characterized in that the casting speed for the strand (S) is reduced by the generated control signal. Continuous casting installation (10) according to one of Claims 10 to 12, characterized in that the radar measuring device (16) is set up in such a way that radar beams are directed perpendicularly onto the broad sides (B1, B2) of the strand (S) from both sides. Continuous casting installation (10) according to claim 13, characterized in that the radar measuring device (16) comprises separate transmitting / receiving modules (16.1, 16.2) which are arranged on both sides of the broad sides (B1, B2) of the strand (S). Continuous casting installation (10) according to claim 12 or 13, characterized in that the radar measuring device (16) comprises separate parabolic elements (17.1, 17.2) which are arranged on both sides of the broad sides (B1, B2) of the strand (S). Continuous casting installation (10) according to one of claims 10 to 15, characterized in that in the further strand guide (19) a pair of scissors (23) is arranged, which is connected to the control device (20) for signaling purposes, the scissors (23) being connected by the Control device (20) can be controlled in the event that the strand thickness measured with the radar measuring device (16) is greater than a distance from work rolls in a rolling mill (24) which - seen in the conveying direction (F) of the strand (S) - Is arranged downstream of the scissors (23).

Images