AU624831B2

AU624831B2 - Continuous production of steel strip and sheet based on continuous casting

Info

Publication number: AU624831B2
Application number: AU36862/89A
Authority: AU
Inventors: Giovanni Arvedi; Klaus Bruckner; Giovanni Gosio; Peter Meyer; Fritz-Peter Pleschiutschnigg; Werner Rahmfeld; Ulrich Siegers; Ernst Windhaus
Original assignee: Mannesmann AG
Current assignee: Individual
Priority date: 1988-05-26
Filing date: 1989-05-23
Publication date: 1992-06-25
Anticipated expiration: 2009-05-23
Also published as: EP0415987B1; FI92161C; IT1224318B; DK279290A; IT8820752A0; DK171539B1; DE58903052D1; BG51443A3; KR950014488B1; AU3686289A; EP0415987B2; KR900701437A; DE3840812A1; FI904757A0; EP0415987A1; TR25630A; ZA893835B; WO1989011363A1; FI92161B; DK279290D0

Description

12 OPI DATE 12/12/89 AOJP DATE 25/01/90 APPLN. 10 36862 89 PCI NUMBER PCT/DE89/00332 PcI? INTERNATIONALE ANMELDUNG VEROFFENTLICH'I NACI- VLM vrKiK1u uDrE% LiE INTERNATIONALE ZUSAMMENARBEIT AUF DEM GEBIET DES PATENTWESENS (PCT) (51) Internationale Patentkiassifikation 4 (11) Internationale "er6ffentlichungsnummer: WO 89/11t363 B22D 11/12, B21B 1/46 Al, (43) Inenoaeu gsda m 0 oebr18(01.9 (21) Internationales Aktenzeichen: PCT/DE89/00332 Luisenstrale 114, D-4 100 Duisburg 17 PLESCHI- UTSCHNIGG, Fritz-Peter [DE/DE]; Reiserweg 65, D-4100 (22) Intemnationales Anmeldedatum: 23. Mai 1989 (23.05.89) Duist~urg 29 RAHMFELD, Werner [DE/DE]; Stockweg (30)Prioitltsdaen:32, D-4330 M0lheim/Ruhr (DE).

20752 A/88 26. Mai 1988 (26.05.88) IT (74) Anwailte: MEISSNER, Peter, E. usw. Herbertstrate 22, PCT/DE88/00629 10. Oktober 1988 (10.10.88) WO D-1000 Berlin 33 (DE).

(34) Lander ftr die die regionale oder intern ationale Anmeldung eingereichr (81) Bestimmungsstaaten: AT (europtiisches Patent), AU, BB, worden ist: DE usw. BE (europ~isches Patent), BF (QAPI Patent), BG, BJ P 38 40 812.0 30. November 1988 (30.11.88) DE (QAPI Patent), BR, CF (OAPI Patent), CG (QAP1 Patent), CH (europtiisches Patent), CM (OAPI Patent), DE (71) Anmelder (fr alle Bestimmungssfaten ausser US): MAN- (europiiisches Patent), DK, Fl, FR (europiiisches Pa- N ESMANN AG (DE/DE]; Mannesmannufer 2, D-4000 tent), GA (QAPI Patent), GB (europifisches Patent), Diisseldorf I HU, IT (europtiisches Patent), JP, KP, KR, LK, LU (europ!1isches Patent), MC, MG, ML (QAPI Patent), MR (71X72)Anmelderund Erfinder: ARVEDI, Giovanni [IT/IT]; (OAPI Patent), MW, NL (europtlisches Patent), NO, Via Mercatello, 26, 1-25100 Cremona RO, SD, SE (europaisches Patent), SN (OAPI Patent), SU, TD (OAPI Patent), TG (QAPI Patent), US.

(72) Erfinder;und Erfinder/Anmelder (nurflir US): GOSTO, Giovanni [IT/IT; Veroffentlicht Via Cocchetti, 29 1-25038 Rovato (IT. SLEGERS, Ul- Mit internationalein Recherchenberich.

rich [DE/DEl; Wozogenstraae 21, D-1000 Berlin 37 BROCKNER, Klaus [DE/DE]; Am Mihlenbusch D-5657 Haan MEYER, Peter [DE/DE); Buchenstrage 29, D-4 100 Duisburg 74 WINDHAUS, Ernst [DE/DE]; 62 483 51 (54)Title: PROCESS FOR CONTINUOUS PRODUCTION OF STEZ3L STRIP OR STEEL SHEET FROM FLAT PRO- DUCTS MADE BY THE CIRCULAR-ARC TYPE CONTINUOUS CASTING PROCESS (54)Bezeichnung: VERFAHREN ZUR KONTINUIERLICHEN HERSTELLUNG VON BANDSTAHL ODER STAHL- BLECH AUS NACH DEM BOGENSTRANGGIESSVERFAHREN HERGESTELLTEN FLACHPRO-

DUKTEN

(57) Abstract5 ,7 In a process for continuous production of steel strip or steel sheet, the flat product from the circular arc-type continuous casting plant is deformed, inductively reheated and further deformed in at least one deformation stage at roll speeds corresponding to the relevant reduction in roll pass. The invention also concerns a plant for implementing the process.

(57) Zusammenfassung Die Erf indung betrifft emn Verfahren zur kontinuierlichen Herstellung von Bandstahl oder Stahlblech, wobei zunkchst das Flachprodukt, das aus der Bogen st ranggielanlIage kommt, verformt wird, dann schlie~t emn induktives Wiederaufheizen an Urad anschliegend erfolgt eine weitere Verformung in mindestens einer Verformungstufe bei Walzgeschwindigkeiten entsprechend der jeweiligen Stichabnahme. Die Erfindung betrifft dartiber hinaus auch eine Anlage zur Durchfiihrung des Verfahrens.

Method and equipment for continuous manufacture of steel strip or steel sheet according to the continuous casting process The present invention relates to a method for continuous manufacture of steel strip or steel sheet according to the circular-arc continuous casting process with horizontal direction of run-out of the manufactured flat products.

In the steel industry, whether because of a general tendency, or with the objective of overcoming crises which, in recent years have confronted the operators of antiquated plants, there is an urgent necessity to decrease investment and operating costs, with the simultaneous improvement of product quality and augmentation of flexibility in relation to the quantity mass-produced articles, namely the so-called "coils" and steel sheets. Along with the modernisation of existing steel works and the planning and implementation of new steel works with the aid of new technological concepts and equipment, there is also striving for increased productivity and economical advantage with simultaneous improvement of product quality as well as greater degrees of freedom in the "size of article" manufactured as the end product for the purpose of achieving the optimal distribution range for the possibilities of application.

One of the new technologies, which is being actively developed at the present time, with respect to the actual demands made on steel production, relates to the processing stages between the melting of the steel and the spooling of steel strip in the form of rolls or "coils", and the stacking of steel sheet, and this encompasses the casting of thin plate slabs with thickness close to that of the final dimension, which can then be processed, with very few subsequent passes or deforming stages, to yield the desired end product. This has led to very noteworthy improvements in the continuous strip casting technique, especially in relation to the construction of the ingot moulds, as well as the corresponding dip casting, and also to improvements in the construction of the roller stands and rolling train, with the 42i T 2 Iv I 2 objective of achieving the desired deformation with the leant possible number of passes.

There are plants for the manufacture of steel strip, even though they are designated as "pilot plants", which have become known in which thin plate slabs, having a thickness of approximately millimetres, are produced by the continuous strip casting process, in contrast to the conventional slab ingots with thicknesses in the range from 150 to 320 millimetres. In this connection, these thin plate slabs pass through the successive rolling-/processing-stages in various different ways; the end product being steel strip having a thickness of only a few millimetres. It has been proposed that the actual cast plate slabs, immediately after intermediate heating in a furnace, should be rolled out, for example in a tandem train with six roller stands. Because the casting speed cannot be much faster than approximately 5 metres/minute, the resultant rolling speed at the last roller stand of the rolling train is too slow to maintain the required final rolling temperature of at least 865 oC. This means that the strip, between successive rolling stages, undergoes excessive cooling, because the speed of entry into the rolling train is identical with the casting speed.

Digressions have therefore been made from this method because, even with heat-conserving protective devices and heated rollers, the problem cannot be solved economically, owing to the fact that such measures result in substantial increases in investment and operating costs.

Another proposed solution provides for cutting-off the strip upstream of a heating furnace in which the heat treatment (equalisation of temperature) of the strip is undertaken over its complete cross-section. Said furnace can be a gas-heated roller furnace in which the temperature can be adjusted to approximately 1100 'C at the point of exit from the furnace, independently of the casting speed being taken into consideration, thus providing the optimal temperature for the subsequent rolling process. The strip is cut into standard lengths which, for a specified coil TrA 0 3 weight, can be approximately 50 metres for example. This requires a corresponding furnace length of approximately 150 metres when the necessary buffering effect is taken into account.

When the rolling train is uncoupled from the actual casting procedure, the rolling out of the thin plate slabs, or "strip precursors", can be carried out at higher speeds and therefore there need not be any anxiety about the temperature falling below the lowest admissible temperature for the final rolling stage.

Associated with the excessive length of the furnace which is approximately three times that of the cut-off strip lengths there is also a very substantial increase in plant investment costs for the furnace which occupies a much greater amount of space than most steel works can allocate for this purpose.

In addition to this, the dimensions of the plant, and therewith of the furnace, set limits to the length of the successive strips to be handled and as a result, to the final weight of the rolledup material which, in its turn, limits the amount of freedom for exploitation in relation to the fabrication of coils having the greatest possible diameter. Correspondingly, in plants of this type, the opportunity does not present itself to make use of still thinner caste plate slabs, even though this might become possible because of further developments of the continuous strip casting process. If an initial thickness of 25 millimetres is assumed as has been done hypothetically already instead of 50 millimetres, then it would be necessary to cut the strip up into lengths of approximately 100 metres in order to achieve the same final weight of the rolled-up material. This would necessitate the heat-treatment furnace having a length of the order of magnitude of approximately 300 metres, but this state of affairs could not be arrived at practically and economically.

The objective of the present invention is the creation of a method of the type referred to initially as well as of an appropriate plant for implementation of this method, with which continuous steel strip can be manufactured from a flat product

PIA~N

4 derived from a circular-arc continuous strip casting process, without the drawback of the afore-mentioned disadvantages.

In particular, cutting-off the strip between the casting process and at least the first rolling operation is to be avoided, where the insertion of the cast strip into the first roller stand takes places at the same speed as that at which the material to be rolled leaves the circular-arc portion of the strip casting plant. The method is therefore to be carried out "in lire" with practically unlimited flexibility, so that it will be possible to manufacture coils of any arbitrarily desired weight and desired length, or else to manufacture sheet, without the need for alteration to the dimensional parameters of the plant, because the cutting-off of the rolled-out strips is undertaken at least after the first rolling procedure or after carrying out all the operational steps immediately before the spooling- or stacking-device.

This objective is achieved with the use of a method which ij characterised by the following operational steps: a) deforming of the flat product after solidification throughout of the strip in a first deforming stage at temperatures higher than 1100 °C, b) inductive re-heating to a temperature of approximately 1100 with ;he best possible temperature equalisation over the complete cross-section of the flat product, c) deforming of the flat product in at least one additional deforming stage at rolling rates appropriate to the relevant reduction in thickness per pass.

In the development of the method, it is proposed that the strip should be spooled between the first and the successive deforming stage. The rolled-out strip can be spooled, depending upon the desired weight of the roll, following on the deforming of the

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flat product or after the cutting-off of the rolled-out strip, following on the deforming of the flat product, into prescribed lengths for stacking up into packets of steel sheets, optionally after cooling and straightening. Thus, the flat product is firstof-all picked up in a first roller stand at the initial speed of the product coming from the circular-arc continuous casting process and it then passes th:ough the successive rolling stages at speeds which are appropriate to the deformation in the individual reduction in thickness per pass. The rolled-out strip obtained in this manner is subsequently either spooled and, after the desired coil weight has been reached, it is cut-off or else the strip is subdivided into desired lengths and stacked up as sheets. A fundamental aspect of the present invention is the inductive re-heating of the flat product, after de-scaling, to temperatures of approximately 1100 °C with the best possible equalisation of temperature because in this way it is possible to counteract too much cooling of the strip in a favourable manner.

an embodiment In a furthor dovcl-zment of the invention, provision is made for one or more stages of the inductive intermediate re-heating of the flat product to be effected between the deforming stages referred to. Too much cooling of the rolled material is counteracted between these intermediate re-heatings, so that the required rolling temperature can be adjusted in such a manner that, in the final deforming stage, the temperature does not fall below the admissible lower limit of 860 °C.

h -lhe pCe-er-ec\ oabod' mern oeC According kto anoth-r przpzoal for the invention, the following additional steps are provided: adjustment of the deforming stages after the run-through of a starting-up billet which is provided by the casting process; cutting-off the starting-up billet immediately before the spooling of the strip or before the stacking of the sheets; i eN

TOL

i" 6 differentiated heat regulation in successive stages/zones after the run-through of the starting-up billet.

The starting-up billet, after the run-through the roller stand, can be cut off with the same equipment which is already present anyway for subdivision of the rolled strips, or else it can be cut off by an additional cutting device following the first deforming stage.

The plant for implementation of the method in accordance with the present invention is characterised by the following named plant components arranged in the sequence indicated: a) an ingot mould for continuous casting of flat products with a following guiding framework in the form of a circular arc, b) a first deforming device for deforming of the flat products in the guiding framework and/or immediately following it, c) a device for inductive heating and for temperature equalisation over the entire cross-section of the flat product, d) at least one additional roller stand and e) a cutting-off device.

The cutting-off device can be located after the first deforming device and, between the first deforming device and the additional deforming device, there can be a device, located before the cutting-off device, for spooling and un-spooling the flat product. Preferably, the device for spooling and un-spooling the flat product is located after the device for inductive heating and before the additional deforming device.

As an alternative in accordance with the present invention for this plant there is either a device for cutting-off the rolled Sstrip and at least one winch for spooling located downstream, ori r

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7 else a device for cutting-off the rolled strip, a cooling device, a straightening machine and a device for stacking the cut-off sheets.

In a furtherev=evlepme of the invention, the plant additionally includes at least one device for inductive heating for intermediate heating between the additional roller stands.

It is most favourable for each of these devices to be provided with heating stages which can be regulated separately.

In accordance with one configuration of the invention, the plant is additionally provided with devices for adjustment of the runthrough cross-section between the rollers of the first deforming device and the subsequent roller stands, in order to make possible the run-through of the starting-up billet located at the leading edge of cast billet and, immediately following its runthrough, to adjust the cross-section back again to the normal run-through value. There are devices for the successive regulation of the individual heating stages of the furnace immediately after the run-through of the starting-up billet, in which case the device for cutting-off the starting-up billet is the same as that which is also utilised for cutting the rolled strip, namely the cutting-off device located in the end section of the plant.

embodi'et According to another )eVX l for the invention, the device utilised for cutting-off the starting-up billet is the one coming after the first deforming stage.

An example of embodiment of the invention will now be described in greater detail with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic representation of part of the plant in accordance with the present invention, ~NT I

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8 Fig. 2 is a diagram showing a graph of the temperature changes in the steel strip during the rolling process and Fig. 3 is a modified form of embodiment of the invention.

Fig. 1 is a rough diagrammatic representation of the production plant in accordance with the present invention used as the basis for the description of the method. Starting from an ingot mould 1, the flat product 2 is obtained. The flat product 2 which is conveyed on conventional support rollers passes fromn the original vertical direction through the circular arc into the horizontal direction. After solidification throughout its mass, namely at the end of the circular-arc pathway, the flat product, in accordance with the present invention, passes through a first deforming stage 3 in which its thickness is reduced, for example, to a maximum of 25 millimetres. The deforming stage 3 can comprise one or several rolling devices, preferably in a fourhigh stand arrangement.

A furnace 5 is provided for temperature equalisation and this furnace is furnished with inductive heating equipment. In this furnace 5, temperature equalisation is effected throughout the entire cross-section of the flat product 2, so that said product arrives at the first roller stand 6 of the additional deforming devices at a high-enough temperature.

If too low a run-in speed, corresponding to that at the exit from the circular-arc pathway, leads to a substantial decrease in temperature which results in an insufficiently-high deforming temperature at the second roller stand 7 of the additional deforming device then, if necessary, additional intermediate heating can be provided in the form of an induction furnace 8 between the roller stands 6 and 7. This furnace 8 can be shorter than the preceding furnace 5. However, the second induction furnace 8 is only necessary if the furnace 5 is not adequate to establish the appropriate temperature gradient along the entire 0 length of the additional deforming equipment, which consists of I <'r r 22 9 the three roller stands 6, 7 and 9, during the deforming operations, in such a manner that, at the time of run-in to the last roller stand 9, the temperature lies within the range of an order of magnitude which is adequate for good deforming. At the point of exit from the last roller stand 9, the flat product 2, which has now become the rolled strip will have the desired thickness.

The method finishes with either the spooling of the rolled strip 2' on the winch 11 after it has been cut-off at 10 when the desired weight for the "coil" has been reached, or else the strip 2' is cut into desired lengths with subsequent stacking of the sheets by a stacking device at 14 as shown diagrammatically in Fig. 2.

Without the need for additional cutting-off devices, the equipment 10 for cutting-off the strip at the commencement of the working cycle can also be utilised for cutting-off the startingup billet (not depicted here) which, after the run-through in the switched-off induction furnace 5 and the successive roller stands 6, 7 and 9 of the deforming equipment as well as the optionally provided, and likewise switched-off intermediate heating device 8 can be separated and removed. Appropriate adjustment devices are provided with which the normal deforming gap between rollers can be re-established after the starting-up billet has passed through. Furthermore, the heating equipment 5 preferably comprises independent heating zones, so that, starting from the switched-off condition of the furnace, the furnace zones through which the starting-up billet is currently passing can be successively switched-on for the re-heating process.

Fig. 2 is a diagrammatic representation of the individual portions of a plant in accordance with Fig. 1 (with the same reference numbers) showing the temperature gradient of the flat product 2 up to the exit of the strip 2' from the final roller stand 9. A Table is presented below the graph, corresponding to certain portions of the plant and the associated portions of the metal strip which gives the speeds of travel and the oorresponding thicknesses of the rolled strip. It is understandable that, for different thicknesses and speeds, the temperature gradient would also be different.

It can be seen from Fig. 2 that the flat product 2, derived from the casting-rolling process, when leaving the first deforming stage 3, has a temperature of 1075 0 C which falls to 1049 0 C on the way to the de-scaling device 4. The temperature then falls abruptly to 969 0 C because of the water jets under pressure used for the de-scaling followed by gradual cooling to 934 0 C by the time the furnace 5 is reached.

In the inductive heating furnace 5, the temperature increases to 1134 with temperature equalisation throughout the entire cross-section of the flat product. This falls to a temperature of 1154 0 C by the time the roller stand 6 is reached and decreases further to 1063 0 C, owing to contact with the rollers in the stand, at the point of exit from them. In the case illustrated, the partly-rolled strip falls to a temperature of 1020 'C by the time it reaches the intermediate induction furnace 8 in which it is re-heated to 1120 0 C. At the point of take up by the second roller stand 7, the temperature of the strip has fallen to 1090 0 C and, at the point of entry into the third and final roller stand 9, the temperature is only 988 0 C. This temperature is high enough for the final rolling stage and, when the temperature has fallen still further to 953 0 C at the point of exit from said roller stand 9, the rolled strip 2' cools down still more and is cut into desired lengths at 10 and stacked at 14 or else spooled as depicted at 11 in Fig. 1.

With regard to the speed of travel, in the example of embodiment depicted, this is 0.08 metres/second or 4.8 metres/minute on leaving the first deforming stage 3. This corresponds to the intake speed on entry into the roller stand 6 at the start of the additional rolling equipment, where the thickness of the flat product is still 25 millimetres, but it is there decreased from 11 to 12.3 millimetres. The intake speed on entry into the roller stand 7 is 10.2 metres/minute, where the thickness of the flat product is reduced to 6.2 millimetres. In the final roller stand 9, the intake speed is 19.8 metres/minute, and the strip leaves the final roller stand at a speed of 30.6 metres/minute with a finished thickness of 4.05 millimetres.

From the foregoing description of an example of embodiment, which, in principle, can be transformed to handle any other strip cross-section, it is apparent that the re-heating operation which precedes the first roller stand of the additional rolling equipment, and the optional intermediate re-heating operation, which takes place between this first and subsequent roller stands, can be adjusted in such a manner that a re-heating of the flat product or rolled strip to a temperature of approximately 1100 °C takes place and the temperature can be kept at such a level that the final rolling temperature in the final rolling stand does not fall below the admissible lower limit of 860 °C.

In the modified form of embodiment depicted in Fig. 3, a spooling and un-spooling device 12 is utilised. As shown in the drawing, in this case the spooling and un-spooling device is installed downstream of the induction furnace 5. This arrangement is complemented by the de-scaling device 4. The spooling and un-spooling device 12 has flat material wound onto it until the desired coil size is reached. After the spooled strip has been transferred to the un-spooling location (shown at the right of 12 in the drawing), the flat material is forwarded for further processing to the additional deforming equipment which consists of one or more roller stands 6, 7 and 9. If necessary, there can be an additional induction furnace 8 installed between the roller stands of the additional deforming equipment. The finished roll is produced at 11, for example on a down-coiler.

Naturally, all the parameters of the production plant can be mutually influenced by the appropriate adjustment of the casting speed, the rolling speeds and the extent of deformatioi required.

'Aii i i Ik 12 The foregoing description of the invention elaborates upon the method as well as the production plant required for its implementation, which comprises continuous casting and final rolling of the starting product with low expenditure of energy and at low installation cost. It has been established that the heating capacity required for the inductive re-heating does not exceed the upper limit of approximately 8 MW which, for a steel-works of a corresponding order of magnitude, can be regarded as fundamentally economical.

The described and illustrated concept of the method proposed by the invention and 'he production plant required for its implementation can be varied within the limits of the objective set for the invention and, in particular, the re-heating device located before the rolling train or between the roller stands can be replaced by other than the induction furnaces referred to and thus, for example, furnaces operated with laser techniques, irradiation furnaces, and so forth, can be utilised.

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Claims

1. A method for continuous manufacture of steel strip of steel sheet according to the circular-arc continuous casting process with horizontal direction of run-out of manufactured flat product, which is characterised by the following phases: a) deforming of the flat product after solidification throughout of the strip, in a first deforming stage at temperatures higher than 1100 0 C, b) inductive re-heating to a temperature of approximately 1100 0 C with the best possible temperature equalisation over the complete cross-section of the flat product, c) deforming of the flat product in at least one additional deforming stage at rolling rates appropriate to the relevant reduction in thickness per pass.

2. The method according to claim 1, characterised in that there is spooling of the strip between the first and successive deforming procedures.

3. The method according to claim 1, characterised in that the rolled-out strip is spooled, depending upon the desired weight of the roll, following on the deforming of the flat product.

4. The method according to claim 1, characterised in that, following the deforming of the flat product, the .rolled-out strip is cut-off into prescribed lengths and stacked in packets of steel sheets.

The method according to claims 1 to 4, characterised in that there is/are one, or more, stage(s) of intermediate inductive re-heating of the flat product between additional deforming stages.

6. The method according to any one of the preceding claims, inclusive of the following additional stages: adjustment of the deforming stages after the run-through of a starting-up billet which is provided by the casting process; Nf 1 14 cutting-off the starting-up billet immediately before the spooling of the strip or before the stacking of the sheets; differentiated heat regulation in successive stages/zones after the run-through of the starting-up billet.

7. A plant for implementation of the method according to claim 1, characterized in that the following named plant components are arranged in the sequence indicated: a) an ingot mould for continuous casting of flat products with a following guiding framework in the form of a circular arc, b) a first deforming device for deforming of the flat products in the guiding framework and/or immediately following it, c) a device for inductive heating and for temperature equalisation over the entire cross-section of the flat product, d) at least one additional roller stand, and e) a cutting-off device.

8. The plant according to claim 7, characterized in that the cutting-off device is located after the first deforming device.

9. The plant according to claims 7 and 8, characterized in that, between the first deforming device and the additional deforming device there is a device located before the cutting-off device for spooling and un-spooling the flat product.

The plant according to claim 9, characterised in that the device for spooling and un-spooling the flat product is located after the device for inductive heating and before the additional deforming device.

11. The plant according to claim 7, characterised in that there is a device for cutting-off the rolled strip and at least one winch for spooling the strip. .1 I,.

12. The plant according to claim 7, characterized in that there is a device for cutting-off the rolled strip, a cooling device, a straightening roller and a device for stacking the cut-off sheets located at the end of said plant.

13. The plant according to claim 7, characterised in that there is at least one additional inductive heating device for intermediate heating provided between th additional roller stands.

14. The plant according to claim 13, characterized in that each device for inductive heating has separate regulation of the individual heating stages.

The plant according to claim 11, characterized in S"that it is provided with ::an additional device for adjustment of the run-through cross-section between the rollers of the deforming device and the subsequent roller stands to make possible the run-through of the starting-up billet located at the leading edge of cast billet and, immediately following its run-through, to adjust the cross-section back :..*:again to the normal run-through value for the deforming operations devices for successive regulation of the individual heating stages of the inductive heating device immediately after the run-through of the starting-up billet and a device also utilised for cutting-off the starting-up billet from the rolled strip.

16. The plant according to claim 8, characterised in that the device is utilised for cutting-off the starting-up billet. DATED THIS 12th DAY OF March 1992 MANNESMANN AG AND GIOVANNI ARVEDI By Their Patent Attorneys GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia RR4 ~i