Patent ID: 12246365

DETAILED DESCRIPTION

The combined casting and rolling installation10comprises for example a continuous casting installation25, a first to third severing device31,32,55, an intermediate heating system35, a descaler40, a finishing rolling mill train45, a cooling device50, a winding device60, a first transporting device65, a quenching device70, a second transporting device75, a discharging device76and a rough-rolled strip piece storage unit80.

The continuous casting installation25is configured for example in the form of a bow-type continuous casting installation. Another configuration of the continuous casting installation25is also conceivable. During operation of the combined casting and rolling installation10, the continuous casting installation25is filled with a metallic melt90by means of a ladle85. The metallic melt90may be produced for example by means of a converter, for example an electric arc furnace, or in a Linz-Donawitz process. The metallic melt90may comprise for example steel. The temperatures specified below are based in each case on the fact that the combined casting and rolling installation10is fed with steel as material. The metallic melt90may also comprise predominantly a non-ferrous material.

In the continuous casting installation25, the metallic melt90is solidified to form a hot billet95. It is particularly advantageous here if the continuous casting installation25casts the hot billet95in a continuous strip mode (also called endless strip production). In a conveying direction of the hot billet95, the rough-rolling mill train30is arranged downstream of the continuous casting installation25and follows directly after the continuous casting installation25in the embodiment.

The rough-rolling mill train30may comprise one or more rough-rolling stands100which are arranged in succession in the conveying direction of the hot billet95. The number of rough-rolling stands100is essentially freely selectable and is essentially dependent on a format of the hot billet95. The rough-rolling mill train30is configured to roll the hot billet95, which is hot during supply into the rough-rolling mill train30, to form a rough-rolled strip105. During supply of the hot billet95into the rough-rolling mill train30, the hot billet95has a temperature of 1100° C. to 1200° C., for example. The rough-rolling mill train30rolls the hot billet95into the rough-rolled strip105. Upon leaving the rough-rolling mill train30, the rough-rolled strip105may have a thickness d of 6 mm to 45 mm and a first temperature T1of 1050° C. to 1200° C. In the embodiment, the rough-rolled strip105has the thickness d of 40 mm as an example.

The first and second severing devices31,32are arranged downstream of the rough-rolling mill train30with respect to the conveying direction of the hot billet95which is rolled to form the rough-rolled strip105. In this case, the first severing device31may be arranged directly downstream of the rough-rolling mill train30between the first severing device31and the second severing device32. The second severing device32is arranged downstream of the discharging device76with respect to the conveying direction of the rough-rolled strip105. It is also possible to dispense with the second severing device32. The first and/or second severing device(s)31,32may be configured for example in the form of drum shears or in the form of pendulum shears.

The intermediate heating system35may be arranged between the second severing device32and the finishing rolling mill train45. The intermediate heating system35may be configured for example in the form of an induction furnace. Another configuration of the intermediate heating system35would also be conceivable. The intermediate heating system35is arranged upstream of the finishing rolling mill train45and of the descaler40with respect to the conveying direction of the rough-rolled strip105. The descaler40is arranged directly upstream of the finishing rolling mill train45and directly downstream of the intermediate heating system35.

The finishing rolling mill train45may comprise one or more finishing rolling stands155. By way of example, in the embodiment, provision is made for five finishing rolling stands155which are arranged in succession with respect to the conveying device of the rough-rolled strip105. The finishing rolling mill train45is configured to roll the rough-rolled strip105in the conveying direction of the rough-rolled strip105to form a finish-rolled strip190, for example to form a metal sheet having a final thickness of 0.5 mm to 12.5 mm upon leaving the finishing rolling mill train45.

With respect to the conveying direction of the finish-rolled strip190, the finishing rolling mill train45is adjoined by the cooling device50. The third severing device55is arranged on a side, facing away from the finishing rolling mill train45, of the cooling device50. The third severing device55may be configured for example in the form of drum shears or crank shears. The winding device60may be arranged downstream of the third severing device55.

The first transporting device65begins at the discharging device76and is preferably configured in the form of a first roller table. Less preferably, the first transporting device65could also be realized by a lifting apparatus (aerial device, for example a crane). The first transporting device65ends at the quenching device70.

By way of example, in the embodiment, the quenching device70comprises a quenching tank160and a lifting device170. The quenching tank160can be filled with a cooling liquid165, for example water. In addition, an additive may be mixed with the cooling liquid165in order to reduce for example corrosive properties of the cooling liquid165. The lifting device170can be moved between a first position and a second position. In the first position, a loading region of the lifting device170is arranged completely outside of the quenching tank160. In the second position, the lifting region of the lifting device170is at least partially lowered in the quenching tank160.

The second transporting device75is arranged on a side, facing away from the first transporting device65, of the quenching device70. The second transporting device75may be configured for example in the form of a second roller table. It is for example also possible for the second transporting device75to comprise a crane, a forklift or similar. The second transporting device75connects the quenching device70to the rough-rolled strip piece storage unit80.

The combined casting and rolling installation10may also comprise a control unit110. The control unit110comprises for example a control device115and a data memory120connected to the control device115, and also an interface125connected to the control device115. A predefined minimum casting rate may be stored in the data memory120. A control program for controlling the combined casting and rolling installation10may also be stored in the data memory120.

Furthermore, the combined casting and rolling installation10may comprise at least one sensor130, wherein the sensor130is connected to the interface125by means of a first data connection135. It is also possible at least for the first severing device31to be connected to the interface125via a second data connection140and the second severing device32to be connected to the interface125via a third data connection145. The quenching device70may be connected to the interface125by means of a fourth data connection150. It is also possible for the intermediate heating system35, the descaler40, the finishing rolling mill train45and the cooling device50to be connected to the interface120by means of an assigned fifth to eighth data connection145,146,147,148,149. The data connection135,140,145,146,147,148,149,150may be for example part of an industrial network. For example, the industrial network may be operated in accordance with an EtherCAT standard.

FIG.2shows a flow diagram of a method for operating the combined casting and rolling installation10shown inFIG.1.FIG.3shows a cross section through a rough-rolled strip piece185.FIG.4shows a temperature-time graph of a rough-rolled strip piece185during the method.FIG.5shows a graph concerning a composition of the rough-rolled strip piece185over the thickness d of the rough-rolled strip piece185in a center193in a transverse direction of the rough-rolled strip piece185after an eighth method step240.

During operation of the combined casting and rolling installation10, in a first method step205, a mold (not illustrated inFIG.1) of the continuous casting installation25is closed by means of a dummy bar head and sealed by additional sealing material. A distributor of the continuous casting installation25is filled with the metallic melt90by means of the ladle85. In order to begin the continuous casting process, a plug is removed from a casting tube of the continuous casting installation25. Preferably, the metallic melt90is for example steel, for example an X70 grade steel. The metallic melt90may also comprise another material.

At the beginning of the continuous casting process, the metallic melt90in the mold flows around the dummy bar head and solidifies by cooling on the dummy bar head. The dummy bar head is slowly drawn out of the mold of the continuous casting installation25in the direction of the rough-rolling mill train30. In the conveying direction, downstream of the dummy bar head, the metallic melt90in the mold cools at its contact surface with respect to the mold and forms a shell of the hot billet95. The shell encloses a still liquid core191and retains the liquid core191. The hot billet95leaves the mold at the mold outlet at a local casting rate, which is assigned to a region of the hot billet95. At the mold outlet, a thickness d of the hot billet95may for example be 120 mm. The first sub-portion of the hot billet95, said first sub-portion adjoining the dummy bar head, may also be referred to as a start-up billet.

In the continuous casting installation25, the hot billet95is cooled further on the way to the rough-rolling mill train30, such that the hot billet95solidifies from the outside toward the inside. By way of example, in the embodiment, the continuous casting installation25is configured in the form of a bow-type continuous casting installation, such that as a result of a deflection of the hot billet95through substantially 90° from the vertical, the hot billet95is supplied so as to run substantially in the horizontal into the rough-rolling mill train30.

In a second method step210, the local casting rate may be ascertained for example by means of the sensor130, wherein the sensor130provides a rate signal, assigned to the local casting rate, to the interface125via the first data connection135. The interface125captures the rate signal and, for its part, provides the rate signal to the control device115. The hot billet95is introduced into the rough-rolling mill train30at the assigned local casting rate.

As the duration of the continuous casting process increases, the plug may be opened further, such that by means of a stabilization of the continuous casting of the hot billet95, the local casting rate is greater than at the beginning of the continuous casting process.

In the third method step215, the dummy bar head and the hot billet95are guided through the rough-rolling mill train30. The rough-rolling mill train30preferably reduces the thickness d of the hot billet95from for example 100 mm to 400 mm to 6 mm to 45 mm to form the rough-rolled strip105.

In a fourth method step220, the control device115assigns the local casting rate of the hot billet95to a rough-rolled strip position of the rough-rolled strip105. On the basis of the rough-rolled strip position and the local casting rate, the control device115also ascertains a first sub-portion175of the rough-rolled strip105, the local casting rate of which undershoots the predefined minimum casting rate, and a second sub-portion180, the local casting rate of which exceeds the predefined minimum casting rate.

Usually, the first sub-portion175adjoins the dummy bar head and may also be referred to as a start-up billet. The second sub-portion180adjoins the first sub-portion175on a side facing away from the dummy bar head with respect to the conveying direction of the rough-rolled strip105.

The first sub-portion175has a microstructure which, on account of the slow continuous casting process and the low local casting rate, cannot be finish-rolled. Due to the low casting rate, the first sub-portion175is also cooled to such an extent that it is not suitable for hot rolling. As a result of the casting of the second sub-portion180above the minimum casting rate, the temperature of the second sub-portion180on the outlet side of the rough-rolling mill train30is significantly higher than that of the first sub-portion175, and hot rolling is possible as a result.

The control device115separates the first sub-portion175into at least one, usually a plurality of rough-rolled strip pieces185. This may be necessary if, in the conveying direction of the rough-rolled strip105, the first sub-portion175is longer than a distance of the first severing device31from the second severing device32or a length of the discharging device76.

In a fifth method step225, the control device115actuates the first severing device31via the second data connection140in such a way that the first sub-portion175is cut up into at least one or a plurality of rough-rolled strip pieces185. The control device115also actuates the discharging device76in such way that the discharging device76supplies the rough-rolled strip piece185to the first transporting device65, such that the rough-rolled strip piece185is not supplied to the intermediate heating system35.

In a sixth method step230, the first transporting device65transports the rough-rolled strip piece185to the quenching device70and supplies it to the quenching device70. In this case, the rough-rolled strip piece185has a substantially identical first temperature T1over its thickness d (seeFIG.4). The severed rough-rolled strip piece185is transported for example to the lifting region of the lifting device170.

In a seventh method step235which follows the sixth method step230, the control device115controls the quenching. In this case, the still hot rough-rolled strip piece185is lowered into the quenching tank160and quenched. The rough-rolled strip piece185remains in the cooling liquid165for a predefined first time interval t1for quenching purposes. In order to ensure particularly rapid quenching in the quenching tank160, a forced flow of the cooling liquid165may additionally be effected around the rough-rolled strip piece185. As a result, a particularly high quenching rate of at least 30° C. per second is set. The rough-rolled strip piece185is cooled from the outside to the inside.

FIG.4illustrates a first to tenth graph305to314, wherein each graph305to314illustrates a temperature of the rough-rolled strip piece185in the center193of the rough-rolled strip piece185at a determined thickness position of the rough-rolled strip piece185over the course of the method. A thickness distance of the graphs305to314is for example 2 mm. Thus, for example the first graph305shows the temperature profile over the course of the method at a thickness of 0 mm, that is to say on an external surface of the rough-rolled strip piece185, and the tenth graph314at a thickness of 20 mm.

After the predefined first time interval t1has expired, the rough-rolled strip piece185is lifted completely out of the quenching tank160. The predefined first time interval t1is in this case selected in such a way that the core191has substantially a temperature of above 600° C. to 800° C. at the end of the first time interval t1.

In an eighth method step240, the rough-rolled strip piece185remains outside of the quenching tank160for a predefined second time interval t2. During this time, the core191heats the outer layer192, such that recrystallization occurs in the outer layer192and a proportion of martensite in the outer layer192is reduced as a result. In this case, austenite forms in the outer layer192. Within the second time interval t2, the outer layer192is heated to a temperature of 400° C. to 600° C., in particular 400° C. to 450° C., by the heat of the core191. An additional supply of heat to the rough-rolled strip piece185can be dispensed with.

After the predefined second time interval t2has expired, in a ninth method step245, the rough-rolled strip piece185is again lowered into the quenching tank160and quenched. The rough-rolled strip piece185remains in the cooling liquid165for a predefined third time interval t3for quenching purposes. The third time interval t3may be shorter than the first and/or the second time interval t1, t2. The forced flow-around may additionally be activated again, such that the quenching rate in the quenching tank160is particularly high.

The seventh to ninth method steps235,240,245may be repeated multiple times until the core191has also been cooled below a predefined temperature, for example 400° C. (seeFIG.5). After the eighth method step240, the substantially d/4 thick outer layer192of the rough-rolled strip piece185comprises predominantly a proportion PA of martensite410phase with a lower proportion PA of ferrite405and pearlite415phases. In the core191, the rough-rolled strip piece185comprises for example substantially the phase proportions PA ferrite405and pearlite415. The proportion PA of bainite420phase is for example below 1%. The proportion PA of martensite410phase decreases from the outside toward the inside.

On conclusion of the quenching operation, the hardened rough-rolled strip piece185is transferred from the quenching device70to the second transporting device75, wherein, in a tenth method step250, the second transporting device75transports the rough-rolled strip piece185into the rough-rolled strip piece storage unit80. A plurality of rough-rolled strip pieces185may be stacked one on top of the other in the rough-rolled strip piece storage unit80, such that the rough-rolled strip pieces185lie against one another in an areal manner Core residual heat of the core191of each rough-rolled strip piece brings about a further heat treatment and recovery process of the outer layer192. The rough-rolled strip pieces185are stored in the stack in the rough-rolled strip piece storage unit80for a predefined fourth time interval. After the predefined time interval has expired, the rough-rolled strip pieces stored in the stack may be removed from the stack in order to store them individually at a spacing from one another. The fourth time interval may be 10 min to 6 h.

The rough-rolled strip pieces185are stored in the rough-rolled strip piece storage unit80for at least 12 hours, preferably 24 hours, such that the hardened rough-rolled strip piece185cools to ambient temperature in a fourth time interval t4. After the storage of the rough-rolled piece185in the rough-rolled strip piece storage unit80, the rough-rolled strip piece185may be further processed, for example to form a wear plate. After storage in the rough-rolled strip piece storage unit80, the rough-rolled strip piece185may subsequently be correspondingly cut to length and customized.

After the first sub-portion175has been separated out by means of the cutting-up into the rough-rolled strip piece185upstream of the intermediate heating system35, in an eleventh method step255, the second sub-portion180which follows the first sub-portion175and the local casting rate of which is higher than the predefined minimum casting rate is guided through the first and second severing devices31,32and supplied to the intermediate heating system35. The second sub-portion180is supplied continuously to the intermediate heating system35in the eleventh method step255. The intermediate heating system35heats the second sub-portion180of the rough-rolled strip105from approximately 900° C. to a predefined finishing rolling temperature of 1100° C. to 1200° C. Scale can be removed from a surface of the second sub-portion180in the descaler40connected downstream of the intermediate heating system35. For example, the scale may be washed off. The finishing rolling mill train45rolls, by means of the finishing rolling stands155, the second sub-portion180from for example 6 to 45 mm to form a finish-rolled strip190which has for example a thickness of 0.5 mm to 12.5 mm upon leaving the finishing rolling mill train45.

In a twelfth method step260which follows the eleventh method step255, after leaving the finishing rolling mill train45, the finish-rolled strip190is guided through the cooling device50. The cooling device50cools the finish-rolled strip190from a temperature of approximately 800° C. to 950° C. to a temperature of below 170° C. at a cooling rate of more than 10° C. per second. The finish-rolled strip190is connected to the second sub-portion180of the rough-rolled strip105and to the hot billet95.

In a thirteenth method step265, at the end of the combined casting and rolling installation10, the winding device60winds up the finish-rolled strip190to form a coil195. The winding-up to form the coil195may be effected on a reel or a mandrel. A mandrel-less winding-up operation is also conceivable.

When the coil195has been completely wound, in a fourteenth method step270, the third severing device55severs the wound-up finish-rolled strip190on the coil195from the finish-rolled strip190running through the cooling device50. The wound-up finish-rolled strip190on the coil195may be transported away to a finished-product storage unit (not illustrated) and cooled further to ambient temperature there.

The finishing rolling mill train45may roll the second sub-portion180of the rough-rolled strip105to form the finish-rolled strip190in parallel with the quenching device70. It is also possible for the finishing rolling mill train45to be idled for a short period, but an operating temperature is maintained in this state of the finishing rolling mill train45so that after the rough-rolled strip pieces185have been separated out, it is possible to begin with the rolling of the second sub-portion180by means of the finishing rolling mill train45.

FIG.6shows a temperature-time graph of the rough-rolled strip piece185during a development of the method described inFIG.2.FIG.7shows a graph concerning a composition of the rough-rolled strip piece185over the thickness d of the rough-rolled strip piece185in the center193in the transverse direction of the rough-rolled strip piece185after the ninth method step245with complete full hardening of the rough-rolled strip piece185.

In a development of the method described inFIG.2, the eighth and ninth method steps240,245are dispensed with, and in the seventh method step230the rough-rolled strip piece185remains in the quenching tank160until the rough-rolled strip piece185has been fully hardened and has been cooled in the core191to for example below 200° C. (seeFIG.6). As a result, over the thickness d, the rough-rolled strip piece185(seeFIG.7) has a composition other than the composition of the phase proportions PA shown inFIG.5. The modification has the advantage that the method can be controlled in a particularly simple manner. The eighth and ninth method steps240,245have the advantage that composition peaks of the phase proportions PA in the rough-rolled strip piece185are avoided and the phase proportions PA are distributed more homogeneously than shown inFIG.7.

FIG.8shows a schematic illustration of a combined casting and rolling installation10according to a second embodiment.

The combined casting and rolling installation10is configured to be substantially identical to the combined casting and rolling installation10shown inFIG.1. Only the differences between the combined casting and rolling installation10according to the second embodiment shown inFIG.8and the first embodiment shown inFIG.1are discussed below. By contrast thereto, the quenching device70comprises a quenching unit200instead of the quenching tank160and the lifting device170, wherein the quenching unit200is arranged between the first transporting device65and the second transporting device75.

The combined casting and rolling installation10shown inFIG.8may be operated substantially by the method described inFIG.3. Only the differences between the method for operating the combined casting and rolling installation10shown inFIG.8and the method described inFIG.2are discussed below.

During the seventh method step235and the ninth method step245, for quenching of the rough-rolled strip piece185, the cooling liquid165is sprayed in the quenching unit200onto the rough-rolled strip piece185, and the rough-rolled strip piece185is guided at a predefined rate v, for example 1.5 m/s, through the quenching unit200and quenched in the process. The cooling liquid165may comprise water. Alternatively, it is also possible for liquid nitrogen as cooling liquid165to be sprayed in the quenching unit200onto the rough-rolled strip piece185. The rough-rolled strip piece185is guided at the predefined rate v through the quenching unit200from the first transporting device65in the direction of the second transporting device75. The cooling liquid165cools the rough-rolled strip piece185within the first time interval t1. In the second time interval t2, in the eighth method step240, the rough-rolled strip piece185may remain at the beginning of the second transporting device75. In the second time interval t2, the core191of the rough-rolled strip piece185heats the outer layer192.

After the predefined second time interval t2has expired, in the ninth method step245, the rough-rolled strip piece185is again guided through the quenching unit200for example from the second transporting device75in the direction of the first transporting device65. In this case, the quenching unit200once again sprays cooling liquid165onto the already quenched rough-rolled strip piece185, the outer layer192of which has been reheated, and the rough-rolled strip piece185is quenched again. In the embodiment, the seventh to ninth method steps230to240are repeated until the core191of the rough-rolled strip piece185has been cooled below a temperature of 400° C. to 450° C. The rough-rolled strip piece185is then transported from the quenching unit200to the rough-rolled strip piece storage unit80via the second transporting device75.

The use of the quenching unit200for quenching the rough-rolled strip piece185has the advantage that the cooling liquid165having a particularly low temperature, in particular even liquid nitrogen, can be sprayed onto the rough-rolled strip piece185, such that a particularly high quenching rate of the rough-rolled strip piece185can be ensured.

FIG.9shows a schematic illustration of a combined casting and rolling installation10according to a third embodiment.

The combined casting and rolling installation10is configured to be substantially identical to the combined casting and rolling installation10shown inFIG.1. Only the differences between the combined casting and rolling installation10according to the third embodiment shown inFIG.9and the first embodiment shown inFIG.1are discussed below.

Instead of the discharging device76, the quenching device70is arranged between the first severing device31and the second severing device32. By contrast toFIG.1, the quenching device70comprises for example the quenching unit200described inFIG.8instead of the quenching tank160and the lifting device170.

With respect to the conveying direction of the finished strip190, the discharging device76is arranged downstream of the cooling section50, and thus also of the finishing rolling mill train45, and upstream of the third severing device55.

The first transporting device65extends through the intermediate heating system35, the descaler40, the cooling device50and comprises the finishing rolling mill train45configured. In addition, the first transporting device65comprises a roller table510which connects the outlet side of the rough-rolling mill train30to the quenching device70. In the embodiment shown inFIG.9, the second transporting device75connects for example the discharging device76to the rough-rolled strip piece storage unit80.

The finishing rolling mill train45has a first operating state and a second operating state. In the first operating state, the finishing rolling stands155are open and form a kind of roller table. In the second operating state, the finishing rolling mill train is connected in a rolling mode in order to roll the finish-rolled strip190.

The combined casting and rolling installation10shown inFIG.9may be operated substantially by the method described inFIG.2. Only the differences between the method for operating the combined casting and rolling installation10shown inFIG.9and the method described inFIG.2are discussed below.

Since the quenching device70adjoins the first severing device31, the sixth method step230is integrated in the transport of the preliminary strip105.

In the seventh method step235, the quenching unit200is activated by the control device115, such that the rough-rolled strip piece185is sprayed with the cooling liquid and quenched by the quenching unit200. In order to quench the rough-rolled strip piece185over the entire length, the intermediate heating system35may be spaced apart from the quenching device70to such an extent that the rough-rolled strip piece185is outside of the intermediate heating system35in the seventh method step235.

The eighth method step240is carried out in that the quenched rough-rolled strip piece185is transported through the intermediate heating system35in the direction of the cooling device50by means of the first transporting device65. In this case, the control device115deactivates the descaler40, to the effect that no descaling takes place. The intermediate heating system35can be activated and can assist the heat treatment process and recovery process in the outer layer192.

In the eighth method step240, the control device115actuates the finishing rolling mill train45in such a way that the finishing rolling mill train45is switched to the first operating state. The recovery and heat treatment process continues during the transport of the rough-rolled strip piece185through the finishing rolling mill train45. The transport from the quenching device70to the cooling device50lasts for the second time interval t2described inFIG.2.

In the ninth method step245, the control device115activates the cooling device50and the cooling device50quenches the rough-rolled strip piece185for the third time interval t3.

In the tenth method step250, the hardened rough-rolled strip piece185is transported from the cooling device50to the discharging device76. The discharging device76discharges the rough-rolled strip piece185and transfers it to the second transporting device75. The second transporting device75transports the rough-rolled strip piece185to the rough-rolled strip piece storage unit80.

In the eleventh method step255, the control device115deactivates the quenching device70and the first severing device31. The second sub-portion180of the rough-rolled strip105is transported in unmachined form through the first and second severing devices31,32and the quenching device70. In the eleventh method step255, the control device115also activates the intermediate heating system35and the descaler40, such that the second sub-portion180is heated by the intermediate heating system35and descaled by the descaler40. In the eleventh method step255, the control device120controls the finishing rolling mill train45in the second operating state, such that the finishing rolling mill train45rolls the second sub-portion180to form the finish-rolled strip190.

In the twelfth method step260, the cooling device50is activated and cools the finished strip190.

In the thirteenth method step265, the finish-rolled strip190is guided through the discharging device76to the winding device60and wound up on the coil195.

FIG.10shows a schematic illustration of a combined casting and rolling installation10according to a fourth embodiment.

The combined casting and rolling installation10is configured to be substantially identical to the combined casting and rolling installation10shown inFIG.9. Only the differences between the combined casting and rolling installation10according to the fourth embodiment shown inFIG.10and the third embodiment shown inFIG.9are discussed below.

By contrast toFIG.9, a deflection device500is arranged on the outlet side of the second severing device55. The deflection device500adjoins the discharging device76in a straight line of the conveying direction of the finish-rolled strip190in the cooling device. The winding device60is arranged offset with respect to the straight line of the conveying direction of the finish-rolled strip190in the cooling device50.

The combined casting and rolling installation10shown inFIG.10may be operated substantially by the method described inFIG.9. The refinement shown inFIG.10has the advantage that the rough-rolled strip piece185can be transported in a rectilinear manner, and the easily deflectable finish-rolled strip190can be deflected by the deflection device500, which comprises for example a deflection roll, to the winding device60in the thirteenth method step265.

FIG.11shows a schematic illustration of a combined casting and rolling installation10according to a fifth embodiment.

The combined casting and rolling installation10is configured to be substantially identical to the combined casting and rolling installation10shown inFIG.9. Only the differences between the combined casting and rolling installation10according to the fifth embodiment shown inFIG.11and the third embodiment shown inFIG.9are discussed below.

The quenching device70and the cooling device50are of integrated configuration. On the output side of the cooling device50, a third transporting device505connects the discharging device76to the cooling device50. A roller table510is arranged between the first severing device31and the second severing device32in order to transport the rough-rolled strip105or the rough-rolled strip piece185between the first severing device31and the second severing device32. The roller table510is part of the first transporting device65.

The combined casting and rolling installation10shown inFIG.11may be operated substantially by the method described inFIG.9. Only the differences between the method for operating the combined casting and rolling installation10shown inFIG.11and the method described inFIG.9are discussed below.

In the sixth method step230, the control device115may deactivate the descaler40. It is also possible for the descaler40to be activated. The intermediate heating system35may be activated or deactivated by the control device115. The control device115also switches the finishing rolling mill train45to the first operating state.

In the sixth method step230, the roller table510transports the rough-rolled strip piece185from the first severing device31to the second severing device32and into the intermediate heating system35. From the intermediate heating system35, the hot rough-rolled strip piece185is transported through the descaler40into the finishing rolling mill train45, which, for its part, transports the rough-rolled strip piece into the integrated cooling and quenching device50,70.

In the seventh to ninth method steps235,240,245, the cooling and quenching device50,70which is of elongate form in the conveying direction of the finish-rolled strip190makes it possible for the rough-rolled strip piece185to remain in the integrated cooling and quenching device50,70, wherein, in the eighth method step240, the control device120deactivates the cooling and quenching device50,70and the rough-rolled strip piece185undergoes no cooling by cooling liquid. As a result, the recovery and heat treatment process is carried out in the cooling and quenching device50,70.

The embodiment shown inFIG.11has the advantage that the combined casting and rolling installation10is configured in a particularly simple and cost-effective manner, and the additional installation space requirement is kept low.

In addition, with regard to the embodiment of the combined casting and rolling installation10shown inFIGS.1and7to11, a tempering section may also be provided between the quenching device70and the second transporting device75, in order to temper the rough-rolled strip piece185again after the rough-rolled strip piece185has been quenched.

The combined casting and rolling installation10shown in the figures, and the method for operating the combined casting and rolling installation10, ensures that the rough-rolled strip piece185does not need to be scrapped, but rather can be further processed by way of the quenching to form, for example, wear-resistant plates.

LIST OF REFERENCE DESIGNATIONS

10Combined casting and rolling installation25Continuous casting installation30Rough-rolling mill train31First severing device32Second severing device35Intermediate heating system40Descaler45Finishing rolling mill train50Cooling device55Third severing device60Winding device65First transporting device70Quenching device75Second transporting device76Separating-out device80Rough-rolled strip piece storage unit85Ladle90Metallic melt95Hot billet100Rough-rolling stand105Rough-rolled strip110Control unit115Control device120Data memory125Interface130Sensor135First data connection140Second data connection145Third data connection150Fourth data connection155Finishing rolling stand160Quenching tank165Cooling liquid170Lifting device175First sub-portion180Second sub-portion185Rough-rolled strip piece190Finish-rolled strip191Core193Center192Outer layer195Coil200Quenching stand205First method step210Second method step215Third method step220Fourth method step225Fifth method step230Sixth method step235Seventh method step240Eighth method step245Ninth method step250Tenth method step255Eleventh method step260Twelfth method step265Thirteenth method step270Fourteenth method step305First graph306Second graph307Third graph308Fourth graph309Fifth graph310Sixth graph311Seventh graph312Eighth graph313Ninth graph314Tenth graph405Ferrite410Martensite415Pearlite420Bainite500Deflection device505Third transporting device510Roller tableti i-th time interval