Transportation device, raising device, rolling facility, transportation method, and temperature raising method

Abstract

A transportation device for transporting a slab between a rolling line and an outside of the rolling line, the rolling line being between a continuous casting machine 12 and a rough rolling mill 70, includes a first slab transportation device 42 and a second slab transportation device 46 that are disposed between the outside of the rolling line and a position between the continuous casting machine 12 and an inline raising device 501 disposed on the rolling line and are configured to be capable of transporting a slab from the rolling line toward the outside of the rolling line. The transportation device includes also a transportation heating furnace 630 that is disposed between the outside of the rolling line and a position between the first slab transportation device 42 and the second slab transportation device 46 and the inline raising device 501 and is configured to be capable of transporting a slab from the outside of the rolling line toward the rolling line.

Description

TRANSPORTATION DEVICE, RAISING DEVICE, ROLLING FACILITY, TRANSPORTATION METHOD, AND TEMPERATURE RAISING METHOD

[0001] The present invention relates to a transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method for a cast piece.

[0002] A continuous casting rolling device is described in Patent Document 1 as one example of a continuous casting rolling device and a continuous casting rolling method that can complement the temperature lowering of a cast piece at the time of abnormal operation and prevent the lowering of the recovery of the cast piece. This continuous casting rolling device includes a continuous casting machine, a cutting machine that is located on the exit side of the continuous casting machine and cuts an internal cast piece manufactured by the continuous casting machine, a rolling mill that presses the cast piece and is disposed on the downstream in the movement direction of the internal cast piece relative to the continuous casting machine, a tunnel furnace that is disposed between the cutting machine and the rolling mill and heats up the cast piece located on a main path of the internal cast piece transported from the continuous casting machine to the rolling mill, and a load adjustment unit that is disposed adjacent to the tunnel furnace, causes the cast piece on the main path to leave the main path from the exit side of the tunnel furnace, and draws the cast piece onto the main path from the entry side of the tunnel furnace.

[0003] [PTL 1] JP-2021-501056-A

[0004] For example, there is a technique described in Patent Document 1 as a conventional technique to raise the temperature of a cast piece by IH between a continuous casting machine and a rough rolling mill.

[0005] In the technique described in this Patent Document 1, it is described that a cast piece is drawn out to an auxiliary path from the exit side of the tunnel furnace disposed on the main path between the continuous casting machine and the rolling mill, and the cast piece is returned to the entry side of the tunnel furnace on the main path after the temperature of the cast piece is raised by a reheater disposed on the auxiliary path.

[0006] However, in the technique of the above-described Patent Document 1, the timing of the carrying-in of a cast piece needs to be adjusted in order to avoid interference with a cast piece in casting when the cast piece is returned from the auxiliary path to the entry side of the tunnel furnace on the main path.

[0007] In particular, in the case of manufacturing a product that requires surface treatment like an outer strip of automobile steel strips, cast pieces are all once transported to an offline area and the treatment is executed. However, there are matters about reheating-up against a temperature drop in this treatment and so forth. Therefore, there is a problem that it is difficult to efficiently return a large amount of cast piece to the rolling line.

[0008] It is also conceivable that the production by the continuous casting machine is suspended in order to return a large amount of cast piece. However, this lowers the production efficiency, and therefore a new technique is required.

[0009] The present invention provides a transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method that allow efficient transportation of a cast piece from an offline area to a rolling line without suspending production by a continuous casting machine.Means for Solving the Problem

[0010] The present invention includes a plurality of means for solving the above-described problem. To cite one example thereof, there is provided a transportation device for transporting a cast piece between a rolling line and an outside of the rolling line, the rolling line being between a continuous casting machine and a rough rolling mill. The transportation device includes a first transportation device that is disposed between the outside of the rolling line and a position between the continuous casting machine and a first raising device disposed on the rolling line, and is configured to be capable of transporting the cast piece from the rolling line toward the outside of the rolling line. The transportation device includes also a second transportation device that is disposed between the outside of the rolling line and a position between the first transportation device and the first raising device, and is configured to be capable of transporting the cast piece from the outside of the rolling line toward the rolling line.Advantages of the Invention

[0011] According to the present invention, the cast piece can be efficiently transported from an offline area to the rolling line without suspending production by the continuous casting machine. Problems, configurations, and effects other than the above-described ones will be made apparent by the following description of embodiments.

[0012] FIG. 1 is a diagram illustrating the outline of a rolling facility including a transportation device of a first embodiment. FIG. 2 is a diagram illustrating a state of an IH device in a raising device including the transportation device of the first embodiment when viewed from a lateral side of a transportation direction. FIG. 3 is a diagram illustrating one example of the flow of transportation of slabs in the transportation device of the first embodiment. FIG. 4 is a diagram illustrating the outline of a rolling facility including a transportation device of a second embodiment. FIG. 5 is a diagram illustrating one example of the flow of transportation of the slabs in the transportation device of the second embodiment. FIG. 6 is a diagram illustrating another example of the flow of transportation of the slabs in the transportation device of the second embodiment. FIG. 7 is a diagram illustrating the outline of a rolling facility including a transportation device of a third embodiment. FIG. 8 is a diagram illustrating one example of the flow of transportation of the slabs in the transportation device of the third embodiment. FIG. 9 is a diagram illustrating another example of the flow of transportation of the slabs in the transportation device of the third embodiment. FIG. 10 is a diagram illustrating the outline of a rolling facility including a transportation device of a fourth embodiment. FIG. 11 is a diagram illustrating one example of the flow of transportation of the slabs in the transportation device of the fourth embodiment. FIG. 12 is a diagram illustrating another example of the flow of transportation of the slabs in the transportation device of the fourth embodiment. FIG. 13 is a diagram illustrating the outline of a rolling facility including a transportation device of a fifth embodiment. FIG. 14 is a diagram illustrating one example of the flow of transportation of the slabs in the transportation device of the fifth embodiment. FIG. 15 is a diagram illustrating another example of the flow of transportation of the slabs in the transportation device of the fifth embodiment. FIG. 16 is a diagram illustrating another example of the flow of transportation of the slabs in the transportation device of the fifth embodiment. FIG. 17 is a diagram illustrating the outline of a rolling facility including a transportation device of a sixth embodiment.Modes for Carrying Out the Invention

[0013] Embodiments of a transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method according to the present invention will be described below with use of the drawings. Note that, in the drawings used in the present specification, the same or corresponding constituent elements are given the same or similar numerals, and repeated description is omitted regarding these constituent elements in some cases.

[0014] <First Embodiment> A first embodiment of the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the present invention will be described with use of FIGs. 1 to 3.

[0015] First, the overall configuration of a rolling facility including a transportation device and a raising device will be described with use of FIG. 1. FIG. 1 is a diagram illustrating the outline configuration of the rolling facility of the present embodiment.

[0016] The rolling facility in FIG. 1 includes a ladle turret 10, a continuous casting machine 12, a torch cutting machine 14, an IH device entry-side thermometer 210, an inline raising device 501, a first slab transportation device 42, a second slab transportation device 46, a third slab transportation device 48, a storage yard 50 for rejected slab, a scale breaker 60, a surface inspection device 701, a rough rolling mill 70, a finishing rolling mill 75, a run out table 80, a down coiler 85, a transportation controller 90, an output power controller 91, and so forth.

[0017] Among them, the transportation device for transporting a slab between the storage yard 50 for rejected slab and a rolling line between the continuous casting machine 12 and the rough rolling mill 70 is composed of the first slab transportation device 42, the second slab transportation device 46, a transportation heating furnace 630, and the transportation controller 90. Furthermore, the raising device is composed of the above-described transportation device, the inline raising device 501 disposed on the rolling line, the IH device entry-side thermometer 210, and the output power controller 91.

[0018] The continuous casting machine 12 has a first strand 401 and a second strand 402. In the present embodiment, the same line as the line on which the inline raising device 501 is disposed is defined as the first strand 401, and the other line different from the first strand 401 is defined as the second strand 402.

[0019] As illustrated by an arrow in FIG. 1, a slab on the second strand 402 is transported to the first strand 401 by the first slab transportation device 42, and thereafter is transported in the direction toward the rough rolling mill 70 and so forth.

[0020] Note that, although the configuration of two strands is illustrated in FIG. 1, the present invention is established even with one strand, including embodiments to be described later.

[0021] Moreover, in the present specification, the longitudinal direction of a slab with a substantially rectangular parallelepiped shape is regarded as the direction that corresponds with the rolling direction, and the transverse direction is regarded as the direction perpendicular to the rolling direction.

[0022] A strand thermometer 403 is a thermometer that measures the temperature of slabs transported on the first strand 401 and the second strand 402.

[0023] Although being omitted for convenience of illustration, a ladle is mounted on the ladle turret 10, and molten steel is poured from this ladle into a tundish. The tundish has two exits and molten steel is poured from this exit into each of molds of both the first strand 401 and the second strand 402.

[0024] Since the continuous casting machine 12 has the two strands, slabs are cast on two rows and are split into slabs with a desired length by the torch cutting machine 14 present on the exit side of the continuous casting machine 12.

[0025] The IH device entry-side thermometer 210 is a thermometer that is disposed on the upstream side of the inline raising device 501 in the transportation direction of the slab, and measures either one or more of, preferably both of, the temperature distribution in the longitudinal direction and the temperatures of both side end parts of the slab in the width direction, regarding the slab to be transported into the inline raising device 501.

[0026] The inline raising device 501 is disposed on the line between the first strand 401 in the continuous casting machine 12 and the rough rolling mill 70, and has a third soaking device 34, a first IH slab heater 20, a thermometer 201 in the first IH device, a second soaking device 32, a second IH slab heater 22, a thermometer 203 in the second IH device, a first soaking device 30, and so forth. This inline raising device 501 is disposed on the same line as the first strand 401 of the continuous casting machine 12.

[0027] Desired heating-up of a slab transported from the continuous casting machine 12 in the direction toward the rough rolling mill 70 is executed by at least the first IH slab heater 20 or the second IH slab heater 22, and thereafter the slab is transported to the third soaking device 34, the second soaking device 32, or the first soaking device 30. In these first soaking device 30, second soaking device 32, and third soaking device 34, homogenization of the temperature distribution in a section of the slab and adjustment of the rolling timing are executed while heat dissipation from the slab is suppressed.

[0028] The third soaking device 34 is a soaking device that is disposed on the slab entry side of the first IH slab heater 20 and employs heat retained by the slab as a heat source. The second soaking device 32 is a soaking device that is disposed on the slab exit side of the first IH slab heater 20 and on the slab entry side of the second IH slab heater 22, and employs heat retained by the slab as a heat source. The first soaking device 30 is a soaking device that is disposed on the slab exit side of the second IH slab heater 22, and employs heat retained by the slab as a heat source.

[0029] When a slab is inserted into the first IH slab heater 20, each IH means with which the first IH slab heater 20 is equipped is adjusted in such a manner that the deviation of the temperature distribution of the slab in the longitudinal direction becomes small on the basis of the temperature distribution measured by the IH device entry-side thermometer 210 or the like. Furthermore, adjustment is executed to cause the slab to have a desired temperature gradient, including the case of a temperature gradient having been generated from the top end side of the slab toward the tail end side at the timing when the slab is transported.

[0030] Here, the two IH slab heaters, which are the first IH slab heater 20 and the second IH slab heater 22, are disposed in the inline raising device 501 in consideration of the fact that slabs corresponding to the two strands need to be heated up and the fact that the amount of temperature drop is large in the slab with a low casting velocity.

[0031] Note that, although the configuration in which the inline raising device 501 has the three soaking devices, the two IH slab heaters, and the two thermometers is illustrated, none of the numbers is limited to the exemplified number. For example, the number of IH slab heaters is not limited to two, i.e. the first IH slab heater 20 and the second IH slab heater 22, and may be one or three or more. The number necessary for heating-up of produced slabs is employed.

[0032] Details of the first IH slab heater 20 and the second IH slab heater 22 will be described with use of FIG. 2. FIG. 2 is a diagram illustrating the configuration of the first IH slab heater 20 and the second IH slab heater 22.

[0033] As illustrated in FIG. 2, the first IH slab heater 20 and the second IH slab heater 22 have one or more slab width end part heaters 120 that raise the temperature of an end part of a slab S in the width direction, one or more slab whole area heaters 128 that raise the temperature of the section of the slab S, and one or more table rollers 116.

[0034] As above, the first IH slab heater 20 and the second IH slab heater 22 can allow equalization of the temperature in the section while causing reciprocation (oscillation) in which a slab is moved back and forth in the direction to be rolled to allow homogenization of a temperature rise in the longitudinal direction of the slab. FIG. 2 shows a case where one or more slab width end part heater 120 for heating the widthwise ends of the slab S are arranged between one or more slab whole area heater 128 for heating the cross section of the slab S. However, the present invention also includes a case where the slab width end part heater 120 are arranged on the exit or entry side of one or more slab whole area heater 128 to heat the slab width end.

[0035] Referring back to FIG. 1, the above-described first soaking device 30, second soaking device 32, and third soaking device 34 can employ a configuration in which the escape of heat from a slab disposed inside the soaking device is suppressed and equalization of the temperature inside the slab is promoted, by surrounding the slab by a panel formed of a reflective plate and a heat insulator. It is also possible to employ a structure obtained by combining a heat insulator like a fire-resistant object and an iron shell outside the heat insulator, without disposing the reflective plate. Furthermore, disposing heating means inside the soaking device to raise the temperature in the soaking device by using the heating means at the start of operation is also effective for shortening of the time for the temperature rise. Gas heating-up may be used for the heating means inside the soaking device. However, using an electrical heater can suppress direct CO2emission.

[0036] In some cases, the movement velocity of a slab becomes low when the temperature gradient of the slab at the time of insertion of the slab into the first IH slab heater 20 is adjusted. On that occasion, the third soaking device 34 among these soaking devices acts to prevent the lowering of the temperature of the slab.

[0037] The first soaking device 30 is used for the purposes of prevention of a temperature drop in the heat equalization process after IH of a slab in the first IH slab heater 20 or the second IH slab heater 22 and prevention of a temperature drop when the timing of supply of a slab to the side of the rough rolling mill 70 is adjusted.

[0038] These first soaking device 30, second soaking device 32, and third soaking device 34 can also be configured to allow equalization of the temperature in the section while causing reciprocation (oscillation) in which a slab is moved back and forth in the direction to be rolled to allow homogenization of a temperature rise in the longitudinal direction of the slab.

[0039] The thermometer 201 in the first IH device is disposed in the first IH slab heater 20 and, for example, is configured to measure the surface temperature of a slab in the first IH slab heater 20.

[0040] The thermometer 203 in the second IH device is disposed in the second IH slab heater 22 and, for example, is configured to measure the surface temperature of a slab in the second IH slab heater 22.

[0041] The first slab transportation device 42 is disposed to connect the downstream side of the first strand 401 and the downstream side of the second strand 402, and is configured to be capable of transporting and moving a slab from the rolling line on which the inline raising device 501 is disposed toward the line on which the second strand 402 is disposed. In addition, the first slab transportation device 42 is configured to be capable of transporting and moving a slab from the line on which the second strand 402 is disposed toward the rolling line on which the inline raising device 501 is disposed.

[0042] The second slab transportation device 46 is configured to connect the downstream side of the second strand 402 and the storage yard 50 for rejected slab, and allow movement of a slab between them.

[0043] These first slab transportation device 42 and second slab transportation device 46 configure a first transportation device that is disposed between the storage yard 50 for rejected slab and a position between the continuous casting machine 12 and the inline raising device 501 disposed on the rolling line, and is configured to be capable of transporting a slab from the rolling line toward the storage yard 50 for rejected slab. Moreover, preferably, these first slab transportation device 42 and second slab transportation device 46 serve as an execution entity of a first transportation step of transporting a slab, from the rolling line toward the storage yard 50 for rejected slab, between the storage yard 50 for rejected slab and a position between the continuous casting machine 12 and the inline raising device 501 disposed on the rolling line.

[0044] The third slab transportation device 48 is disposed between the storage yard 50 for rejected slab in which slabs are stored and the rolling line between the surface inspection device 701 and the rough rolling mill 70, and is used for returning a slab to the storage yard 50 for rejected slab when the slab has surface quality with which rolling is impossible as the result of surface inspection in the surface inspection device 701 after removal of scales from the surface of the slab in the scale breaker 60.

[0045] The transportation heating furnace 630 is a device that is disposed on the downstream side of the first slab transportation device 42 and the second slab transportation device 46, and in a position between a line on the upstream side of the inline raising device 501 and the storage yard 50 for rejected slab, and that is configured to be capable of transporting a slab from the storage yard 50 for rejected slab toward the rolling line. Preferably, this transportation heating furnace 630 serves as an execution entity of a second transportation step of transporting a slab, from the storage yard 50 for rejected slab toward the rolling line, between the storage yard 50 for rejected slab and a position between the transportation position in the first transportation step and the inline raising device 501.

[0046] This transportation heating furnace 630 is formed of a heating furnace having a configuration that transports the slab in the width direction. A large quantity of electricity or combustion gas is required for the temperature rise. Therefore, a heating system by electricity is considered as the transportation heating furnace 630 in a region where the electric bill is comparatively inexpensive and a region where electricity generated with low CO2emission can be used. In contrast, a gas heating system is considered as the transportation heating furnace 630 when a combustion gas for RF can be easily obtained or when the electric bill is expensive.

[0047] A thermometer 205 in the storage yard is a thermometer that is disposed in the storage yard 50 for rejected slab and measures the surface temperature of a slab in the storage yard 50 for rejected slab.

[0048] A scarfing device 600 is a device that is disposed in the storage yard 50 for rejected slab and executes treatment of the surface of a slab transported to the storage yard 50 for rejected slab. For example, the scarfing device 600 is a device for executing scarfing to remove surface defects of a steel strip by oxygen and acetylene or the like at any one or more places of the top surface, bottom surface, left side surface, and right side surface of a slab.

[0049] In the present embodiment, the case in which the outside of the rolling line is the storage yard 50 for rejected slab is illustrated. However, the outside of the rolling line is not limited to the storage yard 50 for rejected slab.

[0050] The transportation controller 90 predicts the average temperature of a slab and the temperature of the center of the slab on the basis of the measurement result of the temperature of the slab by any one or more of the above-described strand thermometer 403, thermometer 201 in the first IH device, thermometer 203 in the second IH device, and thermometer 205 in the storage yard, and decides the transportation destination of the slab on the basis of the measured surface temperature and the predicted inside temperature. Moreover, the transportation controller 90 decides the transportation velocity of a slab in addition to the transportation direction in each device in the raising device regarding the slab, and controls the velocity.

[0051] In the present specification, including the present embodiment, the transportation controller 90 executes control in such a manner that a slab in the storage yard 50 for rejected slab or a slab in the storage yard 50 for rejected slab after surface treatment in the scarfing device 600 arrives at the rolling line by using the transportation heating furnace 630, when the slab transported from the continuous casting machine 12 does not exist in a path for transporting the slab outside the rolling line to the rolling line by using the transportation heating furnace 630 (the second transportation device) between the continuous casting machine 12 and the inline raising device 501, that is, at the timing when slabs do not interfere with each other and the production efficiency is maximized.

[0052] Furthermore, the transportation controller 90 can execute control to cause a slab in the storage yard 50 for rejected slab to arrive at the rolling line by using the transportation heating furnace 630, after switching the transportation direction of a slab, which has been cast by the continuous casting machine 12, in such a manner that the slab is transported to the storage yard 50 for rejected slab by using the first slab transportation device 42 and the second slab transportation device 46.

[0053] Moreover, the transportation controller 90 can execute control to transport the slab cast by the continuous casting machine 12 to the rough rolling mill 70 after stopping the control to transport the slab in the storage yard 50 for rejected slab to the rolling line by using the transportation heating furnace 630.

[0054] The output power controller 91 adjusts the output power of the inline raising device 501 on the basis of the temperature distribution of the slab in the longitudinal direction measured by the IH device entry-side thermometer 210 or the temperatures of both side end parts of the slab in the width direction.

[0055] This output power controller 91 can adjust the output power of the inline raising device 501 in such a manner that the temperature of the upstream side in the rolling line of the slab becomes higher than that of the downstream side. Furthermore, the output power controller 91 can adjust the output power of the inline raising device 501 in such a manner that the difference between the temperatures of both side end parts measured by the IH device entry-side thermometer 210 becomes small.

[0056] Preferably, this output power controller 91 serves as an execution entity of an output power control step of adjusting the output power of the inline raising device 501 on the basis of the temperature distribution of the slab in the longitudinal direction measured on the upstream side of the inline raising device 501 in the transportation direction of the slab, or an execution entity of an output power control step of adjusting the output power of the inline raising device 501 on the basis of the temperatures of both side end parts of the slab in the width direction measured on the upstream side of the inline raising device 501 in the transportation direction of the slab.

[0057] After heating-up by the raising device ends, in the rolling facility, first, because oxide scales are generated on the surface of the slab due to the high temperature heating-up prior to rolling, the scales on the surface are removed by the scale breaker 60 that jets high pressure water to the surface of the slab to remove the scales before the rolling. Then, the rough rolling mill 70 of one rolling mill stand executes reverse rolling, and unidirectional rolling is executed by the finishing rolling mill 75 of a plurality of rolling mill stands. Then, strip cooling is executed by the run out table 80, and the rolled metal strip is coiled up by the down coiler 85. It is also possible to dispose the rough rolling mill 70 of a plurality of rolling mill stands in the rolling facility.

[0058] In the rolling facility of the present embodiment, in the case of direct rolling, a slab produced on the first strand 401 is transported to the rolling line via the inline raising device 501 as illustrated in FIG. 1. A slab produced on the second strand 402 is transported to the rolling line via the first slab transportation device 42 and the inline raising device 501.

[0059] As above, the slabs produced on the first strand 401 and the second strand 402 alternately pass through the inline raising device 501. Thus, the temperature distribution of the slab in the longitudinal direction is measured on that occasion by the IH device entry-side thermometer 210 disposed on the entry side of the inline raising device 501, and the output power of the inline raising device 501 is adjusted. This adjustment includes, for example, adjustment of the velocity of insertion into the first IH slab heater 20 or the second IH slab heater 22 through adjustment of the output power of the table roller 116, control of whether or not to execute reciprocation after the insertion, and control of the output power of the slab width end part heater 120 and the slab whole area heater 128 in reciprocation being performed.

[0060] For example, description will be made by taking as an example the case of making the temperature difference of a slab in the width direction small.

[0061] Between offline heating-up in the transportation heating furnace 630 and inline heating-up in the inline raising device 501 and further, preferably, on the entry side of the inline heating-up on the rolling line, the temperatures of width end parts of the slab on both sides are measured by the IH device entry-side thermometer 210, and the temperature difference is grasped. Thereafter, the slab is heated up while being inserted into the first IH slab heater 20 or the second IH slab heater 22, and the slab is heated up while being reciprocated in the first IH slab heater 20 or the second IH slab heater 22 after the insertion into the first IH slab heater 20 or the second IH slab heater 22. During these heating-up processes, each of the slab width end part heaters 120 on both sides disposed in at least one of the first IH slab heater 20 and the second IH slab heater 22 is adjusted to avoid the occurrence of temperature difference between the width end parts.

[0062] During heating-up by IH, the temperature of the surface becomes high and thereafter heat is conducted to the inside. However, by comparing the surface temperatures of both sides to grasp the temperature difference and adjusting the output power so as to make the temperature difference small, the difference between both sides becomes small also regarding the temperatures of the inside near the width end parts.

[0063] Here, the temperature distribution of the slab in the width direction is measured while the temperature distribution in the longitudinal direction is measured in conjunction therewith by the IH device entry-side thermometer 210, and the output power of the slab width end part heaters 120 of the first IH slab heater 20 or the second IH slab heater 22 can be adjusted by using the temperature measurement result.

[0064] Furthermore, it is also possible to measure the temperatures of the width end parts on both sides by the thermometer 203 in the second IH device, and adjust the output power of the slab width end part heaters 120 on both sides so as to make the temperature difference between both sides small by using the measurement result.

[0065] FIG. 3 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment.

[0066] The slab produced on the first strand 401 is transported to the storage yard 50 for rejected slab via the first slab transportation device 42 and the second slab transportation device 46. The slab produced on the second strand 402 is transported to the storage yard 50 for rejected slab via the second slab transportation device 46.

[0067] When the slab requires scarfing, the surface is scarfed by the scarfing device 600 in the storage yard 50 for rejected slab. Thereafter, surface inspection after the scarfing, deburring after the scarfing, and the like are executed, and then the slab is inserted into the transportation heating furnace 630. The slab is heated up to, for example, approximately 1000°C in the transportation heating furnace 630. Thereafter, the slab is drawn out to the rolling line by a slab drawing device. Moreover, the temperature of the slab is raised to a rolling temperature by the inline raising device 501 while the temperature distribution is adjusted.

[0068] When the temperature of the slab is raised to the rolling temperature by only the heating furnace, scales are generated in the heating furnace and weight loss due to the scales becomes large. However, in the present invention, the slab exits from the furnace at a comparative low temperature, and therefore the weight loss due to the scales can be suppressed.

[0069] Note that, although FIGs. 1 and 3 illustrate the case where the scarfing device 600, the surface inspection device, the deburring device (illustration is omitted), and the transportation heating furnace 630 are disposed in the storage yard 50 for rejected slab, the present invention is not limited thereto and any positions of them fall within the scope of the present invention as long as they are disposed outside the rolling line.

[0070] Furthermore, the scope of the present invention includes also combining therewith a system in which the position of the heated-up slab is shifted every time heating-up is executed to decrease the deviation of the temperature distribution in the longitudinal direction in IH, or the like, when heating-up outside the rolling line in the transportation heating furnace 630 or inline heating-up by the inline raising device 501 is executed by the IH.

[0071] Moreover, the scope of the present invention includes also the case in which an IH slab heater is disposed between the continuous casting machine 12 and the torch cutting machine 14 to heat up a slab during casting, and the inline raising device 501 and so forth are disposed on the downstream side thereof.

[0072] Next, effects of the present embodiment will be described.

[0073] For example, even in the case of an outer strip of automobile steel strips, reduction in energy loss is enabled if direct rolling can be executed. However, ensuring of the surface quality becomes a matter when the outer strip of automobile steel strips is manufactured. A steel grade that requires surface treatment, typified by such an outer strip of automobile steel strips, is transported to an offline area, and surface treatment such as scarfing is executed, also currently.

[0074] Conventionally, there exists a rolling facility in which several reheating furnaces are disposed on the entry side and a slab at a high temperature is supplied to a rolling line while heating-up is collectively executed by the reheating furnaces. However, the reheating furnace involves high CO2emission, and production of green steel is not reached if no change is made. Therefore, improvement is required.

[0075] The transportation device for transporting a slab between the storage yard 50 for rejected slab and the rolling line between the continuous casting machine 12 and the rough rolling mill 70 according to the above-described first embodiment of the present invention includes: the first slab transportation device 42 and the second slab transportation device 46 that are disposed between the storage yard 50 for rejected slab and a position between the continuous casting machine 12 and the inline raising device 501 disposed on the rolling line, and are configured to be capable of transporting a slab from the rolling line toward the storage yard 50 for rejected slab; and the transportation heating furnace 630 that is disposed between the storage yard 50 for rejected slab and a position between the first slab transportation device 42 and the second slab transportation device 46 and the inline raising device 501, and is configured to be capable of transporting a slab from the storage yard 50 for rejected slab toward the rolling line.

[0076] This allows steel grades that do not require surface treatment to be produced in such a manner that casting, heating-up, and rolling are executed through direct sending. Thus, the amount of heating-up in the inline raising device 501 can be suppressed by using heat retained by a cast slab. Therefore, energy loss can be reduced. Furthermore, the inline raising device 501 can be effectively used also in reheating-up of a slab transported to the storage yard 50 for rejected slab. Therefore, the amount of heating-up by the heating means can be suppressed in the offline area. Thus, the amount of heating-up when the slab is returned to the rolling line can be reduced compared with conventional configurations. In addition, the slab for which surface treatment and the like have been executed can be returned from the storage yard 50 for rejected slab to the rolling line depending on the situation of production of the slab in the continuous casting machine 12. Therefore, CO2reduction and so forth can also be achieved while the production efficiency is improved.

[0077] The rolling facilities of the present embodiment and a fifth embodiment to be described later are preferably selected in the case of production performed via an offline area for a steel grade for which batch rolling is executed and repair and inspection of a slab mainly in the storage yard 50 for rejected slab are executed. In contrast, when enabling also endless rolling is required, a configuration of a fourth embodiment to be described later is a preferable candidate.

[0078] Furthermore, the transportation heating furnace 630 includes a heating furnace that transports a slab in the width direction, and therefore can simultaneously execute heating-up and transportation in an offline area. This can further improve the production efficiency.

[0079] Moreover, the transportation device further includes the transportation controller 90 that executes control to cause a slab in the storage yard 50 for rejected slab to arrive at the rolling line by using the transportation heating furnace 630 when a slab transported from the continuous casting machine 12 does not exist in a path for transporting the slab outside the rolling line to the rolling line by using the transportation heating furnace 630 (the second transportation device) between the continuous casting machine 12 and the inline raising device 501. This can implement production with ensured avoidance of interference between the production of the slab in the continuous casting machine 12 and the transportation of the slab from the storage yard 50 for rejected slab.

[0080] Furthermore, the transportation controller 90 executes control to cause a slab in the storage yard 50 for rejected slab to arrive at the rolling line by using the transportation heating furnace 630 after switching the transportation direction of a slab, which is cast by the continuous casting machine 12, in such a manner that the slab is transported to the storage yard 50 for rejected slab by using the first slab transportation device 42 and the second slab transportation device 46. This can make a configuration very suitable also for production of a steel grade for which surface treatment in the storage yard 50 for rejected slab is necessary.

[0081] Moreover, the transportation controller 90 executes control to transport the slab cast by the continuous casting machine 12 to the rough rolling mill 70 after stopping the control to transport the slab in the storage yard 50 for rejected slab to the rolling line by using the transportation heating furnace 630. This can surely avoid interference between the directly sent slab and the slab from the storage yard 50 for rejected slab.

[0082] Furthermore, in the raising device including the transportation device, the inline raising device 501 disposed on the rolling line, the IH device entry-side thermometer 210 that is disposed on the upstream side of the inline raising device 501 in the transportation direction of the slab and measures the temperature distribution of the slab in the longitudinal direction, and the output power controller 91 that adjusts the output power of the inline raising device 501 on the basis of the temperature distribution measured by the IH device entry-side thermometer 210, the output power of the inline raising device 501 can be adjusted in such a manner that variation in the temperature of the slab in the longitudinal direction measured by the IH device entry-side thermometer 210 becomes small. Conventionally, a walking beam furnace is used as a heating furnace. With this walking beam furnace, a slab is supported by a skid in the furnace. Internal water cooling is executed around the skid. Therefore, a skid mark (temperature difference) arising from the lowering of the temperature of a position corresponding to the skid is generated in the slab. There is a problem that strip thickness deviation and strip width deviation are caused when rolling is executed in the state in which the skid mark exists. In contrast, the skid mark can be reduced by making the variation in the temperature of the slab in the longitudinal direction small. Thus, rolling with small strip thickness deviation and small strip width deviation is enabled, and the rolling as a downstream process can be stably executed. Furthermore, even when a slab does not pass through the heating furnace, variation in the temperature of the slab in the longitudinal direction is caused in some cases. For example, a slab becomes stalled on a table roller during transportation of the slab, and the state in which part of the slab in the longitudinal direction is in contact with the table roller is made. Thus, a temperature difference from the part that is not in contact with the table roller is caused. Alternatively, variation in the temperature of a slab in the longitudinal direction is involved when the slab is heated up by heating means other than the heating furnace during transportation of the slag. In such a case, the variation in the temperature of the slab in the longitudinal direction can be made small.

[0083] Moreover, the output power controller 91 exerts an effect also for homogenization of the temperature of a rolled metal strip on the entry side of finishing rolling by adjusting the output power of the inline raising device 501 in such a manner that the temperature on the upstream side in the rolling line of the slab becomes higher than that on the downstream side. In the finishing rolling after rough rolling, a long time is required from threading of the top end of the rolled metal strip into the finishing rolling mill 75 to threading of the tail end of the rolled metal strip into the finishing rolling mill 75. During this time, the strip temperature of the tail end side of the rolled metal strip gradually lowers. Therefore, the threading of the tail end into the finishing rolling mill 75 occurs in the state in which the temperature thereof is low. Thus, the rolling load in the latter half is high compared with the rolling load in the former half of the rolling in some cases, and therefore setting of the rolling condition has been complicated such that distribution of the reduction rate in consideration of the rise in the rolling load is executed, adjustment of change in the strip shape in association with change in the rolling condition is executed, and so forth. The rolling condition of the finishing rolling can be made more constant by setting the temperature condition in advance in such a manner that the temperature on the upstream side in the rolling line of the slab becomes higher than that on the downstream side in consideration of the temperature drop on the latter half side of the finishing rolling and allowing homogenization of the rolling temperature of the finishing rolling from the top end to the tail end of the rolled metal strip. This can suppress change in the reduction load, and suppression of variation in the strip shape is also enabled. Thus, even rolling across the whole length can be executed.

[0084] Furthermore, in the raising device including the transportation device, the inline raising device 501 disposed on the rolling line, the IH device entry-side thermometer 210 that is disposed on the upstream side of the inline raising device 501 in the transportation direction of the slab and measures the temperatures of both side end paths of the slab in the width direction, and the output power controller 91 that adjusts the output power of the inline raising device 501 on the basis of the temperatures of both side end parts measured by the IH device entry-side thermometer 210, the output power of the inline raising device 501 is adjusted in such a manner that the difference between the temperatures of both side end parts measured by the IH device entry-side thermometer 210 becomes small. This can reduce the amount of camber to a larger extent. If width reduction or horizontal reduction is executed in the state in which a temperature difference exists between both side end parts of the slab, the higher temperature side extends to a larger extent in the longitudinal direction than the lower temperature side, and bending is caused. This bending is one of the cambers, and the camber attributed to the material side can be made small by making the difference between the temperatures of both side end parts small. Thus, it is possible to significantly reduce contrivance to make the camber attributed to the material side small through various kinds of contrivance regarding the order of loading into the heating furnace and the order of rolling, and contrivance to suppress the camber that occurs due to a side guide or the like in a width reduction device or a rolling mill. Furthermore, the temperature difference between both side end parts also occurs in some cases other than a case where heating-up is performed in the heating furnace. For example, even when there exists a condition under which a cooling difference in the vicinity of both side end parts occurs in a continuous casting machine or a condition under which a temperature difference occurs between both side end parts during transportation of a slab after continuous casting, the temperature difference between both side end parts of the slab can be made small, and thus the amount of camber can be suppressed.

[0085] Moreover, with conventional various kinds of contrivance, advanced rolling techniques are required in both the rough rolling and the finishing rolling in order to make the amount of camber small. In contrast, since the amount of camber attributed to the material side can be made small compared with conventional configurations, easy operation can be stably continued.

[0086] <Second Embodiment> A transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method according to a second embodiment of the present invention will be described with use of FIGs. 4 to 6.

[0087] The transportation device included in the rolling facility of the present embodiment illustrated in FIG. 4 includes a fifth slab transportation device 422 that is disposed between the storage yard 50 for rejected slab and a position between the first slab transportation device 42 and the second slab transportation device 46 and the inline raising device 501, and is configured to be capable of transporting a slab from the storage yard 50 for rejected slab toward the rolling line, instead of the transportation heating furnace 630 in the rolling facility illustrated in FIG. 1.

[0088] Furthermore, the transportation device further includes a first offline raising device 511 and a second offline raising device 512, which are disposed in parallel to each other between the scarfing device 600 that executes treatment of the surface of a slab in the storage yard 50 for rejected slab and the fifth slab transportation device 422.

[0089] In the present embodiment, the transportation device is composed of the first slab transportation device 42, the second slab transportation device 46, a transportation controller 90A, and the fifth slab transportation device 422. Moreover, the raising device is composed of the above-described transportation device, the inline raising device 501, the IH device entry-side thermometer 210, the first offline raising device 511, the second offline raising device 512, and an output power controller 91A.

[0090] The first offline raising device 511 includes a seventh soaking device 314, a third IH slab heater 251, a thermometer 221 in the third IH device, and a sixth soaking device 312 in this order from the side closer to the continuous casting machine 12.

[0091] The second offline raising device 512 includes a ninth soaking device 324, a fourth IH slab heater 252, a thermometer 222 in the fourth IH device, and an eighth soaking device 322 in this order from the side closer to the continuous casting machine 12.

[0092] The configurations of the third IH slab heater 251 in the first offline raising device 511 and the fourth IH slab heater 252 in the second offline raising device 512 are substantially the same as the above-described first IH slab heater 20 and second IH slab heater 22 although the slab width end part heater 120 is omitted in some cases. The configurations of the sixth soaking device 312, the seventh soaking device 314, the eighth soaking device 322, and the ninth soaking device 324 are substantially the same as the above-described first soaking device 30 and the like. The configurations of the thermometer 221 in the third IH device and the thermometer 222 in the fourth IH device are substantially the same as the above-described thermometer 201 in the first IH device.

[0093] The fifth slab transportation device 422 is disposed in parallel to the first slab transportation device 42 and the second slab transportation device 46, and can transport a slab from the storage yard 50 for rejected slab toward the rolling line. Furthermore, the fifth slab transportation device 422 is configured to transport, toward the rolling line, a slab resulting from surface treatment in the scarfing device 600 and a slab resulting from reheating-up in the first offline raising device 511 or the second offline raising device 512.

[0094] A fourth slab transportation device 420 is disposed in parallel to the fifth slab transportation device 422 and is configured to transport a slab between the scarfing device 600 and the second offline raising device 512 and the first offline raising device 511.

[0095] In the rolling facility of the present embodiment, as illustrated in FIG. 4, in the case of direct rolling, a slab produced on the second strand 402 is transported to the rolling line via the first slab transportation device 42. As above, slabs produced on the first strand 401 and the second strand 402 alternately pass through the inline raising device 501.

[0096] FIG. 5 is a diagram illustrating transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment.

[0097] Similarly to FIG. 3, the slab produced on the first strand 401 is transported to the storage yard 50 for rejected slab via the first slab transportation device 42 and the second slab transportation device 46 because the slab surface is scarfed by the scarfing device 600 for the slab that requires scarfing. The slab produced on the second strand 402 is transported to the storage yard 50 for rejected slab via the second slab transportation device 46.

[0098] After the scarfing in the scarfing device 600 in the storage yard 50 for rejected slab, surface inspection and deburring after the scarfing are executed. Thereafter, the slab is transported to the first offline raising device 511 or the second offline raising device 512 by the fourth slab transportation device 420.

[0099] Here, the temperature of the slab stored in the storage yard 50 for rejected slab has lowered. Therefore, for example, the slab is moved to the respective devices in order of the fourth IH slab heater 252, the eighth soaking device 322, the fourth IH slab heater 252, the ninth soaking device 324, the fourth IH slab heater 252, and the ninth soaking device 324. That is, heating-up in the fourth IH slab heater 252 is executed three times. Thereafter, the slab is transported to the rolling line, and is further heated up by the first IH slab heater 20 and the second IH slab heater 22. Subsequent slabs are also similarly heated up. Note that the number of times of the heating-up in the fourth IH slab heater 252 is not limited to three. The number of times is often decreased when the slab to be heated up has a comparatively high temperature. Alternatively, a larger number of times of heating-up is often executed when the heating-up requires a long time. Moreover, in some cases, a high temperature state is kept while temperature raising and soaking are repeated by the fourth IH slab heater 252, the eighth soaking device 322, and the ninth soaking device 324.

[0100] Similar transportation processing is executed also in the case of heating-up by the third IH slab heater 251.

[0101] Furthermore, in the case of heating-up by the third IH slab heater 251 or the fourth IH slab heater 252, the surface temperature becomes high comparatively fast, whereas a long time is required for the rise in the temperature of the inside of the slab. Therefore, the temperature of the slab is raised while soaking in the respective soaking devices is combined therewith.

[0102] FIG. 6 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment, and illustrates different routes from FIG. 5.

[0103] The temperature of the slab stored in the storage yard 50 for rejected slab has lowered. Therefore, as illustrated in FIG. 6, for example, the slab is moved to the respective devices in order of the fourth IH slab heater 252, the ninth soaking device 324, the fourth IH slab heater 252, the eighth soaking device 322, the fourth IH slab heater 252, the eighth soaking device 322, the third IH slab heater 251, the sixth soaking device 312, the third IH slab heater 251, the seventh soaking device 314, the third IH slab heater 251, and the seventh soaking device 314. That is, total six times of heating-up are executed in the fourth IH slab heater 252 and the third IH slab heater 251. Thereafter, the slab is transported to the rolling line, and is further heated up by the first IH slab heater 20 and the second IH slab heater 22.

[0104] The fourth slab transportation device 420 and the fifth slab transportation device 422 are used for movement between the scarfing device 600 and the first offline raising device 511 or the second offline raising device 512 and movement between the first offline raising device 511 or the second offline raising device 512 and the rolling line.

[0105] Note that, although the configuration in which the first offline raising device 511 and the second offline raising device 512 are disposed in the storage yard 50 for rejected slab has been illustrated, the places at which they are disposed are not limited to within the storage yard 50 for rejected slab and there is no particular limitation.

[0106] The other configuration and operation are substantially the same configuration and operation as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment, and details thereof are omitted.

[0107] Also in the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the second embodiment of the present invention, almost the same effects as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment are obtained.

[0108] Moreover, transportation by various paths is enabled due to further including the first offline raising device 511 and the second offline raising device 512 disposed in parallel to each other between the scarfing device 600 that executes treatment of the surface of a slab in the storage yard 50 for rejected slab and the fifth slab transportation device 422. This achieves an effect that the flexibility of usage of the raising device is enhanced and it is possible to flexibly deal with production of slabs of various steel grades.

[0109] Furthermore, the offline raising device is not limited to the two sets of the first offline raising device 511 and the second offline raising device 512. It is also possible to employ one set or three or more sets of the offline raising devices.

[0110] <Third Embodiment> A transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method according to a third embodiment of the present invention will be described with use of FIGs. 7 to 9.

[0111] In the rolling facility of the present embodiment illustrated in FIG. 7, a second transportation device that is disposed between an inline raising device 501A and the storage yard 50 for rejected slab and is configured to be capable of transporting a slab from the storage yard 50 for rejected slab toward the rolling line is composed of the fifth slab transportation device 422 and a temperature raising line raising device 502.

[0112] Furthermore, the transportation device further includes a plurality of offline raising devices, which are the first offline raising device 511 and the second offline raising device 512, disposed in parallel to each other between the scarfing device 600 that executes treatment of the surface of a slab in the storage yard 50 for rejected slab and the fifth slab transportation device 422 and the temperature raising line raising device 502.

[0113] In the present embodiment, the transportation device is composed of the first slab transportation device 42, the second slab transportation device 46, the fifth slab transportation device 422, the temperature raising line raising device 502, and a transportation controller 90B. Moreover, the raising device is composed of the above-described transportation device, the inline raising device 501A, the IH device entry-side thermometer 210, the first offline raising device 511, the second offline raising device 512, and an output power controller 91B.

[0114] The inline raising device 501A is disposed on the line between the first strand 401 in the continuous casting machine 12 and the rough rolling mill 70, and is composed of the third soaking device 34, the first IH slab heater 20, the thermometer 201 in the first IH device, the second soaking device 32, and so forth.

[0115] The temperature raising line raising device 502 is disposed on the same line as the second strand 402 of the continuous casting machine 12, and is composed of a fifth soaking device 38, the second IH slab heater 22 that transports a slab in the longitudinal direction, the thermometer 203 in the second IH device, a fourth soaking device 36, and so forth.

[0116] In the rolling facility of the present embodiment, a slab produced on the second strand 402 is heated up by the temperature raising line raising device 502, and thereafter is transported to the rolling line on the exit side of the temperature raising line raising device 502.

[0117] The first IH slab heater 20 and the second IH slab heater 22 in FIG. 7 each heat up a slab of one strand. Therefore, the slab heating capability of each of the first IH slab heater 20 and the second IH slab heater 22 can be set to a level similar to that of the first offline raising device 511 and the second offline raising device 512 of the second embodiment.

[0118] FIG. 8 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment.

[0119] Similarly to FIG. 3, the slab surface is scarfed by the scarfing device 600 for the slab that requires scarfing. Thereafter, surface inspection after the scarfing and deburring after the scarfing are executed. Then, the slab is transported to the first offline raising device 511 or the second offline raising device 512.

[0120] At this time, the temperature of the slab in the storage yard 50 for rejected slab has lowered. Therefore, for example, the slab is moved to the respective devices in order of the fourth IH slab heater 252, the ninth soaking device 324, the fourth IH slab heater 252, the eighth soaking device 322, the fourth IH slab heater 252, and the eighth soaking device 322. That is, heating-up in the fourth IH slab heater 252 is executed three times. Thereafter, the slab is further heated up by the second IH slab heater 22 and the first IH slab heater 20 or by either one of the second IH slab heater 22 or the first IH slab heater 20. Subsequent slabs are also similarly heated up. Note that the number of times of the heating-up in the fourth IH slab heater 252 is not limited to three. For example, the number of times is often decreased when the slab to be heated up has a comparatively high temperature. Alternatively, four or more times of heating-up are often executed when the heating-up requires a long time. Moreover, in some cases, a high temperature state is kept while temperature raising and soaking are repeated by the fourth IH slab heater 252, the eighth soaking device 322, and the ninth soaking device 324.

[0121] Similar transportation processing is executed also in the case of heating-up by the third IH slab heater 251.

[0122] In the case of heating-up by the third IH slab heater 251 or the fourth IH slab heater 252, the surface temperature becomes high comparatively fast, whereas a long time is required for the rise in the temperature of the inside of the slab. Therefore, the temperature of the slab is raised while soaking in the respective soaking devices is combined therewith.

[0123] FIG. 9 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment, and illustrates different routes from FIG. 8.

[0124] For example, the slab is moved to the respective devices in order of the fourth IH slab heater 252, the eighth soaking device 322, the fourth IH slab heater 252, the ninth soaking device 324, the fourth IH slab heater 252, the ninth soaking device 324, the third IH slab heater 251, the seventh soaking device 314, the third IH slab heater 251, the sixth soaking device 312, the third IH slab heater 251, and the sixth soaking device 312. That is, total six times of heating-up are executed in the fourth IH slab heater 252 and the third IH slab heater 251. Thereafter, the slab is further heated up by the second IH slab heater 22 and the first IH slab heater 20 or by either one of the second IH slab heater 22 or the first IH slab heater 20.

[0125] The fourth slab transportation device 420 and the fifth slab transportation device 422 are used for movement between the scarfing device 600 and the first offline raising device 511 or the second offline raising device 512 and movement between the first offline raising device 511 or the second offline raising device 512 and the rolling line.

[0126] The other configuration and operation are substantially the same configuration and operation as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment, and details thereof are omitted.

[0127] Also in the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the third embodiment of the present invention, almost the same effects as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment are obtained.

[0128] Furthermore, the temperature raising line raising device 502 includes the second IH slab heater 22 that transports a slab in the longitudinal direction. This can shorten the distance between the continuous casting machine 12 and the rough rolling mill 70 compared with the configuration of the second embodiment, and therefore is one of countermeasures when the installation space is limited.

[0129] Moreover, transportation by various paths is enabled due to the further including the first offline raising device 511 and the second offline raising device 512 disposed in parallel to each other between the scarfing device 600 that executes treatment of the surface of a slab in the storage yard 50 for rejected slab and the fifth slab transportation device 422 and the temperature raising line raising device 502. Thus, an effect that the flexibility of usage of the raising device is enhanced is achieved.

[0130] Furthermore, the offline raising device is not limited to the two sets of the first offline raising device 511 and the second offline raising device 512. It is also possible to employ one set or three or more sets of the offline raising devices.

[0131] <Fourth Embodiment> A transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method according to a fourth embodiment of the present invention will be described with use of FIGs. 10 to 12.

[0132] The rolling facility of the present embodiment illustrated in FIG. 10 has a configuration in which a rough rolling mill 70A is composed of a plurality of rolling mill stands, and thus unidirectional rolling is executed by this composition.

[0133] The rolling facility of the present embodiment is the same as the rolling facility of the first embodiment in the following point. The transportation heating furnace 630 is a device that transports a slab in the width direction and heats up the slab. The transportation heating furnace 630 is disposed between the storage yard 50 for rejected slab and a position between the first slab transportation device 42 and the second slab transportation device 46 and an inline raising device 501B, and is configured to be capable of transporting a slab from the storage yard 50 for rejected slab toward the rolling line.

[0134] In the present embodiment, the transportation device is composed of the first slab transportation device 42, the second slab transportation device 46, the transportation heating furnace 630, and a transportation controller 90C. Furthermore, the raising device is composed of the above-described transportation device, the inline raising device 501B, the IH device entry-side thermometer 210, and an output power controller 91C.

[0135] In the rolling facility of the present embodiment, the rough rolling mill 70A does not execute reverse rolling. Therefore, the first soaking device 30 is omitted in the inline raising device 501B, and rough rolling can be executed by the rough rolling mill 70A after a slab is heated up by the second IH slab heater 22. Heating-up in the first IH slab heater 20 and the second IH slab heater 22 is similar to that in FIG. 1 and so forth.

[0136] FIG. 10 illustrates the state in which only the first strand 401 produces a slab and direct rolling of the slab is executed.

[0137] Here, when the slab is supplied to the rolling facility while being split into optional lengths, rolled metal strips are coiled up by the down coiler 85 after rolling for each slab.

[0138] When the rough rolling mill 70A executes rolling of the top end of a slab, the tail end of the slab remains in the second IH slab heater 22 in some cases. In particular, the entry-side velocity of the rough rolling mill 70A is low. Therefore, when the temperature drop of the slab during the rough rolling is large, it is possible to continue heating-up of the slab by the second IH slab heater 22 during the rolling by the rough rolling mill 70A to suppress the temperature drop of the tail end side of the slab.

[0139] Moreover, it is also possible to execute endless rolling, in which the slab is supplied to the rolling facility without being split and rolling is executed in the state of the slab being continuous from casting to the rolling. In this case, the rolled metal strip is divided for each coil by a dividing shear 530 disposed on the entry side of the down coiler 85. In the case of the endless rolling, the first IH slab heater 20 and the second IH slab heater 22 execute heating-up during the passing of the slab in one direction.

[0140] In FIG. 11, in the rolling facility of the present embodiment, both the first strand 401 and the second strand 402 produce slabs. The slab produced on the second strand is transported to the rolling line via the first slab transportation device 42, and the slabs produced on the two strands are transported to the rolling facility after being alternately heated up by the inline raising device 501B.

[0141] FIG. 12 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment. These routes are similar to those in FIG. 3.

[0142] Here, even when the transportation heating furnace 630 is replaced by the first offline raising device 511 and the second offline raising device 512, a rolling facility similar to those of the second embodiment and the third embodiment is obtained.

[0143] The other configuration and operation are substantially the same configuration and operation as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment, and details thereof are omitted.

[0144] Also in the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the fourth embodiment of the present invention, almost the same effects as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment are obtained.

[0145] <Fifth Embodiment> A transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method according to a fifth embodiment of the present invention will be described with use of FIGs. 13 to 16.

[0146] In the rolling facility of the present embodiment illustrated in FIG. 13, a second transportation device that is disposed between the storage yard 50 for rejected slab and a position between the first slab transportation device 42 and the second slab transportation device 46 and the inline raising device 501 and is configured to be capable of transporting a slab from the storage yard 50 for rejected slab toward the rolling line is composed of a seventh slab transportation device 426 and an eighth slab transportation device 428 or composed of the transportation heating furnace 630 and the eighth slab transportation device 428.

[0147] Furthermore, the rolling facility includes a plurality of heating devices, the transportation heating furnace 630, and the first offline raising device 511, in parallel to each other between the scarfing device 600 that executes treatment of the surface of a slab in the storage yard 50 for rejected slab and the transportation device.

[0148] In the present embodiment, the transportation device is composed of the first slab transportation device 42, the second slab transportation device 46, the seventh slab transportation device 426, the eighth slab transportation device 428, the transportation heating furnace 630, and a transportation controller 90D. Moreover, the raising device is composed of the above-described transportation device, the inline raising device 501, the IH device entry-side thermometer 210, and an output power controller 91D.

[0149] A sixth slab transportation device 424 is configured to transport the slab for which surface treatment in the scarfing device 600 has been completed to the first offline raising device 511.

[0150] The seventh slab transportation device 426 is configured to transport a slab from the first offline raising device 511 to the rolling line via the transportation heating furnace 630 or the eighth slab transportation device 428.

[0151] The eighth slab transportation device 428 is configured to transport a slab from the transportation heating furnace 630 to the rolling line.

[0152] FIG. 14 illustrates transportation routes when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment.

[0153] The slabs are transported to the storage yard 50 for rejected slab by the first slab transportation device 42 and the second slab transportation device 46. The slab for which scarfing or the like has been executed is inserted into the transportation heating furnace 630. The slab is heated up to, for example, approximately 1000°C in the transportation heating furnace 630. Thereafter, the slab is drawn out to the rolling line, and the temperature of the slab is raised to a rolling temperature by the inline raising device 501 while the temperature distribution is adjusted.

[0154] FIG. 15 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment, and illustrates another example of FIG. 14.

[0155] The slabs are transported to the storage yard 50 for rejected slab by the first slab transportation device 42 and the second slab transportation device 46. The slab for which scarfing or the like has been executed is heated up once or a plurality of times by the third IH slab heater 251 of the first offline raising device 511. Thereafter, the slab is transported to the rolling line, and the temperature of the slab is raised to the rolling temperature by the inline raising device 501 while the temperature distribution is adjusted.

[0156] FIG. 16 illustrates transportation routes of slabs when slabs produced by the continuous casting machine 12 are transported to the storage yard 50 for rejected slab in the rolling facility of the present embodiment, and illustrates another example of FIGs. 14 and 15.

[0157] The slabs are transported to the storage yard 50 for rejected slab by the first slab transportation device 42 and the second slab transportation device 46. The slab for which scarfing or the like has been executed is heated up once or a plurality of times by the third IH slab heater 251 of the first offline raising device 511. Thereafter, the slab is inserted into the transportation heating furnace 630, and is transported to the rolling line. Then, the temperature of the slab is raised to the rolling temperature by the inline raising device 501 while the temperature distribution is adjusted.

[0158] Here, it is also possible to select a route on which a slab is first heated up by the transportation heating furnace 630 in an offline area and then is heated up by the second IH slab heater 22 or a route other than the routes illustrated in FIG. 16.

[0159] The other configuration and operation are substantially the same configuration and operation as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment, and details thereof are omitted.

[0160] Also in the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the fifth embodiment of the present invention, almost the same effects as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described first embodiment are obtained.

[0161] <Sixth Embodiment> A transportation device, a raising device, a rolling facility, a transportation method, and a temperature raising method according to a sixth embodiment of the present invention will be described with use of FIG. 17.

[0162] The rolling facility of the present embodiment illustrated in FIG. 17 is obtained by further disposing, in the rolling facility of the fifth embodiment, a sizing press 900 on the entry side of the rough rolling mill 70 as a reduction device that is disposed on the slab entry side of the rough rolling mill 70 and executes reduction of the slab in the width direction. Note that it is possible to employ a roll instead of the sizing press 900.

[0163] In the present embodiment, the transportation device is composed of the first slab transportation device 42, the second slab transportation device 46, the seventh slab transportation device 426, the eighth slab transportation device 428, the transportation heating furnace 630, and a transportation controller 90E. Furthermore, the raising device is composed of the above-described transportation device, the inline raising device 501, the IH device entry-side thermometer 210, and an output power controller 91E.

[0164] The sizing press 900 is a device for adjusting the slab width before rough rolling. Note that, although the sizing press 900 is disposed on the exit side of the surface inspection device 701, it may be disposed between the scale breaker 60 and the surface inspection device 701, for example. That is, it suffices for the sizing press 900 to be disposed on the entry side of the rough rolling mill 70, and the installation place thereof is not limited.

[0165] Furthermore, although the case in which the sizing press is used for width reduction of the slab is illustrated here, the same applies also to the case in which width reduction is executed by using a roll. Moreover, although the case in which the width reduction means is disposed in the rolling facility of the fifth embodiment is illustrated as an example here, the scope of the present invention includes also disposing the width reduction means in the configuration of the rolling facility of any of the first to fourth embodiments, and obtained effects are also substantially the same.

[0166] Furthermore, the rolling facility of the present embodiment has the following configuration. In at least one of the first IH slab heater 20 and the second IH slab heater 22, the slab width end part heaters 120 illustrated in FIG. 2 are disposed on both sides in the width direction of the slab. The slab width end part heaters 120 disposed on both sides in the width direction of the slab are adjusted on each of both sides. This can adjust the temperature difference in the width direction. Thus, the temperature difference of the slab in the width direction can be made small, and the camber that occurs at the time of width reduction can be suppressed.

[0167] The other configuration and operation are substantially the same configuration and operation as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described fifth embodiment, and details thereof are omitted.

[0168] Also in the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the sixth embodiment of the present invention, almost the same effects as the transportation device, the raising device, the rolling facility, the transportation method, and the temperature raising method according to the above-described fifth embodiment are obtained.

[0169] Moreover, by further including the sizing press 900 that is disposed on the slab entry side of the rough rolling mill 70 and executes reduction of the slab in the width direction, the camber attributed to the rolled metal strip side can be suppressed in rolling by a horizontal rolling mill such as the rough rolling mill 70.

[0170] <Others> Note that the present invention is not limited to the above-described embodiments and various modification examples are included therein. The above-described embodiments are described in detail in order to explain the present invention in an easy-to-understand manner and are not necessarily limited to that including all configurations described. Although the case in which the cast piece is a slab has been explained in the above description, the case where the cast piece is a billet, bloom, beam blank, or the like is also included in the present invention.

[0171] Furthermore, it is also possible to replace part of a configuration of a certain embodiment by a configuration of another embodiment. Moreover, it is also possible to add a configuration of a certain embodiment to a configuration of another embodiment. In addition, it is also possible to execute addition, deletion, or substitution of another configuration regarding part of a configuration of each embodiment.Description of Reference Characters

[0172] 10: Ladle turret 12: Continuous casting machine 14: Torch cutting machine 20: First IH slab heater (IH device) 22: Second IH slab heater (IH device) 30: First soaking device 32: Second soaking device 34: Third soaking device 36: Fourth soaking device 38: Fifth soaking device 42: First slab transportation device (first transportation device) 46: Second slab transportation device (first transportation device) 48: Third slab transportation device 50: Storage yard for rejected slab 60: Scale breaker 70, 70A: Rough rolling mill 75: Finishing rolling mill 80: Run out table 85: Down coiler 90, 90A, 90B, 90C, 90D, 90E: Transportation controller 91, 91A, 91B, 91C, 91D, 91E: Output power controller 116: Table roller 120: Slab width end part heater 128: Slab whole area heater 201: Thermometer in the first IH device 203: Thermometer in the second IH device 205: Thermometer in the storage yard 210: IH device entry-side thermometer (thermometer) 221: Thermometer in the third IH device 222: Thermometer in the fourth IH device 251: Third IH slab heater (IH device) 252: Fourth IH slab heater (IH device) 312: Sixth soaking device 314: Seventh soaking device 322: Eighth soaking device 324: Ninth soaking device 401: First strand 402: Second strand 403: Strand thermometer 420: Fourth slab transportation device 422: Fifth slab transportation device (second transportation device) 424: Sixth slab transportation device 426: Seventh slab transportation device (second transportation device) 428: Eighth slab transportation device (second transportation device) 501, 501A, 501B: Inline raising device (first raising device) 502: Temperature raising line raising device (second transportation device) 511: First offline raising device (IH device) 512: Second offline raising device (IH device, raising device) 530: Dividing shear 600: Scarfing device (surface treatment device) 630: Transportation heating furnace (second transportation device, raising device) 701: Surface inspection device 900: Sizing press (reduction device) S: Slab

Claims

1. A transportation device for transporting a cast piece between a rolling line and an outside of the rolling line, the rolling line being between a continuous casting machine and a rough rolling mill, the transportation device comprising: a first transportation device that is disposed between the outside of the rolling line and a position between the continuous casting machine and a first raising device disposed on the rolling line, and is configured to be capable of transporting the cast piece from the rolling line toward the outside of the rolling line; and a second transportation device that is disposed between the outside of the rolling line and a position between the first transportation device and the first raising device, and is configured to be capable of transporting the cast piece from the outside of the rolling line toward the rolling line.

2. The transportation device according to claim 1, further comprising: a transportation controller configured to execute control to cause the cast piece in the outside of the rolling line to arrive at the rolling line by using the second transportation device when the cast piece transported from the continuous casting machine does not exist in a path for transporting the slab outside the rolling line to the rolling line by using the second transportation device between the continuous casting machine and the first raising device.

3. The transportation device according to claim 2, wherein the transportation controller further configured to execute the control to cause the cast piece in the outside of the rolling line to arrive at the rolling line by using the second transportation device after switching a transportation direction of the cast piece cast by the continuous casting machine, the switching being performed in such a manner that the cast piece is transported to the outside of the rolling line by using the first transportation device.

4. The transportation device according to claim 3, wherein the transportation controller further configured to execute control to transport the cast piece cast by the continuous casting machine to the rough rolling mill after stopping the control to transport the cast piece in the outside of the rolling line to the rolling line by using the second transportation device.

5. The transportation device according to claim 1, wherein the second transportation device includes at least one of a heating furnace that transports the cast piece in a width direction or an IH device that transports the cast piece in a longitudinal direction.

6. The transportation device according to claim 1, further comprising: a plurality of raising devices disposed in parallel to each other between a surface treatment device that executes treatment of a surface of the cast piece in the outside of the rolling line and the second transportation device.

7. A raising device comprising: the transportation device according to any one of claims 1 to 6; the first raising device disposed on the rolling line; a thermometer that is disposed on an upstream side of the first raising device in a transportation direction of the cast piece and measures temperature distribution of the cast piece in a longitudinal direction; and an output power controller configured to adjust output power of the first raising device on a basis of the temperature distribution measured by the thermometer.

8. The raising device according to claim 7, wherein the output power controller further configured to adjust the output power of the first raising device in such a manner that a temperature on an upstream side in the rolling line of the cast piece becomes higher than a temperature on a downstream side.

9. A raising device comprising: the transportation device according to any one of claims 1 to 6; the first raising device disposed on the rolling line; a thermometer that is disposed on an upstream side of the first raising device in a transportation direction of the cast piece and measures temperatures of both side end parts of the cast piece in a width direction; and an output power controller configured to adjust output power of the first raising device on a basis of the temperatures of both side end parts measured by the thermometer.

10. The raising device according to claim 9, wherein the output power controller further configured to adjust the output power of the first raising device in such a manner that a difference between the temperatures of both side end parts measured by the thermometer becomes small.

11. A rolling facility comprising: the continuous casting machine; the raising device according to claim 7; and the rough rolling mill.

12. A rolling facility comprising: the continuous casting machine; the raising device according to claim 9; and the rough rolling mill.

13. The rolling facility according to claim 12, further comprising: a reduction device that is disposed on an entry side of the rough rolling mill, the entry side being for the cast piece, and executes reduction of the cast piece in the width direction.

14. A transportation method for a cast piece transported between a rolling line and an outside of the rolling line, the rolling line being between a continuous casting machine and a rough rolling mill, the transportation method comprising: a first transportation step of transporting the cast piece from the rolling line toward the outside of the rolling line between the outside of the rolling line and a position between the continuous casting machine and a first raising device disposed on the rolling line; and a second transportation step of transporting the cast piece from the outside of the rolling line toward the rolling line between the outside of the rolling line and a position between a transportation position in the first transportation step and the first raising device.

15. A temperature raising method comprising: the respective steps in the transportation method according to claim 14; and an output power control step of adjusting output power of the first raising device on a basis of temperature distribution of the cast piece in a longitudinal direction, the temperature distribution being measured on an upstream side of the first raising device in a transportation direction of the cast piece.

16. A temperature raising method comprising: the respective steps in the transportation method according to claim 14; and an output power control step of adjusting output power of the first raising device on a basis of temperatures of both side end parts of the cast piece in a width direction, the temperatures being measured on an upstream side of the first raising device in a transportation direction of the cast piece.

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