JP4133042B2 - Steel sheet hot rolling method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot rolling method and apparatus for finish rolling by uniforming the temperature distribution in the width direction of the roughly rolled coarse bar.
[Prior art]
As shown in FIG. 1, hot rolling of a steel plate is performed by inserting a low-temperature slab 2 into a heating furnace 1, reheating it to a predetermined temperature, and then reheating the reheated slab 2 with a rough rolling mill 3. In order to recover the temperature drop at both edges of the coarse bar 4 in the width direction by cutting the leading end of the coarse bar using a crop shear 5 This is performed by heating the section and finishing and rolling it into a predetermined hot-rolled steel sheet with a continuous finish rolling mill 7 composed of a plurality of stands, then cooling with a cooling stand 8 on a run-out table and winding it with a coiler 9. Yes.
[0002]
In addition, when endless rolling is performed in which rough bars are joined to each other before finish rolling, as shown in FIG. 2, a low-temperature slab 2 is inserted into a heating furnace 1 to obtain a predetermined The slab 2 is reheated to a temperature, rolled to a predetermined thickness by a roughing mill 3 to form a rough bar 4, wound by a coil box 10, and the tip of the rough bar unwound from the coil box In order to recover the temperature drop at both edge portions in the width direction of the coarse bar 4 by cutting with the joining shear 11 and joining the trailing end of the preceding coarse bar and the leading end of the following coarse bar with the welding device 12. The two edge portions are heated and rolled into a predetermined hot-rolled steel plate by a continuous finish rolling mill 7 composed of a plurality of stands, cooled at a cooling stand 8 on a run-out table, and wound by a coiler 9. Has been done.
[0003]
In such a hot-rolled steel sheet manufacturing process, in order to reheat the low-temperature slab in the heating furnace, the heat radiation from the heating furnace extraction and the thickness of the rolled material becomes smaller than the sheet width during rolling. A temperature drop occurs at both edges of the coarse bar during rolling. These temperature drops cause non-uniform temperature distribution in the width direction of the coarse bars, and cause non-uniform finishing temperatures.
[0004]
Therefore, if the temperature distribution in the width direction of the coarse bar becomes non-uniform, ear waves and medium elongation occur in the hot-rolled steel sheet during finish rolling, and the material properties such as the mechanical properties in the width direction of the hot-rolled steel sheet are non-uniform. The problem of becoming.
[0005]
In order to prevent such problems due to uneven temperature distribution in the width direction of the rough bar, a heating device and an edge heater are provided between the rough rolling mill and the finish rolling mill, and rough rolling is performed by the rough rolling mill. It is known to heat the roughed bar. For example, Japanese Patent Laid-Open No. 3-314216 discloses a solenoid-type induction heating device for heating a rough bar over the entire width direction between a rough rolling mill and a finish rolling mill, and both edge portions of the rough bar. It has been proposed to provide an edge heater for heating, and to heat the rough bar on the entry side of the finishing mill to a uniform temperature in the width direction by a solenoid induction heating device and an edge heater. .
[0006]
The feature of the solenoid type induction heating device used here is that the coil is wound around the plate and a magnetic field is generated in parallel with the plate. The entire surface of the plate is heated centrally, and the temperature is averaged by heat transfer. Therefore, the temperature is increased by a uniform temperature over the entire width in a state where the temperature distribution in the plate width direction is substantially constant.
[0007]
That is, in the proposed technique, in order to reduce the rolling load, the entire width direction of the coarse bar is uniformly heated with a solenoid induction heating device, and both edge portions are heated with an edge heater so that the width direction is uniform. It is intended to have a temperature distribution.
[0008]
However, as a result of the study of the material properties in the width direction of the hot-rolled steel sheet by the present inventor, the coarse bar on the finishing rolling mill entrance side is heated with an edge heater at the edge part where the temperature drop is large, and the temperature on the left and right in the width direction It has been found that even if heating is performed so as to eliminate the distribution, the material properties in the width direction of the steel sheet obtained by finish rolling are not uniform. That is, in the heating method in which the rough bar is entirely heated in the width direction between the rough rolling mill and the finish rolling mill, and both ends having a large temperature drop are heated by the edge heater, the temperature distribution on the left and right in the width direction is not corrected. In the heating method that tries to eliminate the uniformity, it is difficult to make uniform the material properties in the width direction of the hot-rolled steel sheet obtained by finish rolling. The cause was investigated through various experiments, and it was found that there was a cause during slab heating in a heating furnace. That is, since the heating furnace heats the slab in a high temperature atmosphere, the temperature distribution of the slab is inevitably asymmetrical and the temperature at the center of the slab is low. This trend does not change even when the plate thickness is reduced by rolling, so the temperature distribution of the coarse bar is asymmetric in the width direction, the center is lower than the average temperature in the width direction, and the edge portion It has been found that there is a cause in the temperature distribution that becomes higher and the edge portion has the lowest temperature.
[0009]
Therefore, the uniformity of the material characteristics in the plate width direction cannot be solved by a heating method using an edge heater or a solenoid type induction heating device.
[0010]
[Problems to be solved by the invention]
Therefore, the present invention heats the central low-temperature part and both-end edge low-temperature part of the coarse bar and eliminates the temperature distribution that is asymmetric in the width direction, and the temperature distribution over the entire width direction of the coarse bar on the finishing mill entry side. Is provided, and a hot rolling method and apparatus for producing a hot-rolled steel sheet with a high yield without causing variations in the material properties in the width direction by performing finish rolling while ensuring a temperature for obtaining the required material properties is provided. This is a problem.
[0011]
[Means for Solving the Problems]
In order to obtain a hot-rolled steel sheet with no variation in material properties in the width direction, it is necessary to uniformize the temperature distribution in the width direction of the rough bar on the entry side of the finishing mill. It is important to eliminate the unevenness of the temperature distribution in the width direction of the coarse bar due to the left-right asymmetry of the temperature distribution and the low temperature at the center of the slab. The inventor heats and raises the temperature of the central low temperature portion of the coarse bar, heats and raises the temperature drop portions at both ends of the coarse bar that occur during rough rolling, and eliminates the temperature distribution asymmetry on the left and right of the width direction. By adjusting the heating temperature rise amount, it was found that the temperature distribution in the width direction of the coarse bar can be made uniform, and that the above heating can be achieved by using a transverse induction heating device having excellent heating characteristics as the heating device. The present invention has been completed.
[0012]
The gist of the present invention is as follows.
[0015]
( 1 ) In a hot rolling method for a steel sheet, in which a slab heated in a heating furnace is roughly rolled with a roughing mill and finish-rolled with a finish rolling mill, along the rolling line between the rough rolling mill and the finish rolling mill. A transverse type induction heating device having an iron core width equal to or greater than the plate width and a transverse type mailing heating device having an iron core width narrower than the plate width are placed above or below each transverse type induction heating device so as to face each other above and below the coarse bar. Alternatively, the heating temperature rise amount is adjusted so that the temperature distribution in the width direction of the coarsely rolled coarse bar is uniformed by tilting both in the plate width direction in a plane perpendicular to the longitudinal direction of the plate. To hot-roll steel plates.
[0020]
( 2 ) The hot rolling method for a steel sheet according to the above (1), wherein both ends of the rough bar are heated with an edge heater and the temperature is additionally compensated.
[0023]
( 3 ) In a hot rolling apparatus for a steel plate comprising a heating furnace for heating a slab, a roughing mill for rough rolling the slab, and a finishing rolling mill for finish rolling the rough rolled rough bar, A transverse type induction heating apparatus capable of heating the full width of the steel sheet between the finishing rolling mill and a heating portion having a larger temperature rise than the center portion, and a transformer capable of heating a steel plate having a large temperature rising amount. Each of the berth-type induction heating devices is disposed so as to be opposed to each other up and down, and a tilting device that tilts the transverse-type induction heating device above or below or both in the plate width direction in a plane perpendicular to the longitudinal direction of the plate. A hot-rolling apparatus for steel sheets, characterized in that it is installed.
[0024]
( 4 ) The tilting device includes a shaft that supports the transverse induction heating device in a central portion of the transverse induction heating device so that the transverse induction heating device can be tilted in the plate width direction in a plane perpendicular to the longitudinal direction of the plate . The hot-rolling apparatus for steel sheets according to (3) above, wherein
[0025]
(5) the tilting device above, characterized in that it has a supporting device for tilting the plate width direction in a plane perpendicular to the longitudinal direction of the plate canti or both cantilevered a transverse-type induction heating device (3) The hot-rolling apparatus of the steel plate as described in 2.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
It is known that in order to obtain a hot-rolled steel sheet having no variation in material properties in the width direction, it is necessary to make the temperature distribution in the width direction of the rough bar on the entrance side of the finishing mill uniform. Conventionally, the temperature drop at both ends (edges) of the rough bar that occurred during rough rolling is raised by an edge heater, and the temperature distribution in the width direction of the rough bar is made uniform by eliminating the asymmetry of the left and right temperature distributions. It was thought to be.
[0031]
However, as a result of investigation by the inventor, the hot rolled steel sheet finished and rolled by eliminating the asymmetry of the temperature distribution in the width direction by heating both ends of the coarse bar with an edge heater has a variation in material characteristics in the width direction. It has been found that has occurred.
[0032]
Therefore, the present inventor conducted various experiments on the cause, and as a result, found out that there is a cause at the time of slab heating in the heating furnace.
[0033]
That is, as shown in FIG. 3, the slab is heated in the pretropical zone 13 and the heating zone 14 in the direction of the arrow from the charging side in the high temperature atmosphere of the heating furnace, and extracted to a predetermined temperature in the soaking zone 15. Has been. In the heating furnace, the slab is heated at the charging side end A in the slab width direction with a smaller heat input, and at the extraction side end B, the heat input is larger. When the extraction door is opened from the soaking zone, the heating slab has a higher temperature at the charging side end A than at the extraction side end B. For this reason, the difference of about 20 degreeC may arise in the temperature of the width direction right and left of a heating slab. Further, as shown in FIG. 4A, the heated slab 2 is surrounded by a high temperature portion 16, but it is inevitable that a low temperature portion 17 is generated at the center. And when the temperature distribution of the slab on the roughing mill entry side is measured, as shown in FIG. 4B, the center of the center line (CL) is low (1200 ° C.) with respect to the average temperature in the width direction, and the end portion (1240 ° C. and 1220 ° C.), the temperature distribution was asymmetric in the width direction.
[0034]
When a slab having such a temperature distribution is roughly rolled to form a rough bar, as shown in FIG. 5A, both ends of the rough bar are allowed to cool, and the temperature distribution of the rough bar is as shown in FIG. As shown in b), the temperature at the center of the center line is low (1033 ° C.) with respect to the average temperature in the width direction, high between the center and the end (1063 ° C. and 1049 ° C.), and at the end It became low and became M-shaped temperature distribution. When the rough bar having such a temperature distribution is finish-rolled, as shown in FIG. 5 (c), the M-shaped temperature distribution is maintained even if the plate thickness is reduced by finish rolling, the center portion is 842 ° C., and the left middle The temperature of the part was the highest (872 ° C.), and the right intermediate part temperature was 858 ° C.
[0035]
A case where an induction heating device is used as a heating device for the coarse bar and the coarse heating bar is heated by moving the induction heating device in the width direction will be described with reference to FIG.
[0036]
The temperature distribution in the width direction of the slab extracted from the heating furnace is shown in FIG. As shown in FIG. 6B, the temperature distribution in the width direction of the rough bar obtained by roughly rolling the slab having this temperature distribution was 1033 ° C. in the central low temperature portion and 1063 ° C. in the left middle portion. When this rough bar is heated by moving the induction heating device in the width direction, the overall temperature is increased by a temperature increase amount 19 indicated by oblique lines, the central portion is 1063 ° C., the left intermediate portion is 1083 ° C., and the right intermediate portion is 1069 ° C. However, also in this case, the temperature distribution in the width direction is an M-shaped temperature distribution. Therefore, when the rough bar heated across the width direction by moving the induction heating device is rolled with a finishing mill, as shown in FIG. 6C, a hot-rolled steel sheet having an M-shaped width direction temperature distribution is obtained. can get.
[0037]
As described above, the present inventor, when hot-rolling a slab heated in a heating furnace, uses a method of heating both ends of a coarse bar with an edge heater during rolling, or an induction heating device as in the past. In the method of heating the coarse bar by moving in the width direction, new knowledge was obtained that the temperature distribution in the width direction of the steel sheet after finish rolling was not uniform, contrary to the conventional way of thinking.
[0038]
And, due to the three of the central low temperature part and width direction temperature distribution asymmetry of the slab heated in the heating furnace, and the cooling of the edge part during rolling, the width direction temperature distribution of the rough bar may not be uniform. It has been clarified that this is a major cause of variations in material properties in the width direction of the steel sheet.
[0039]
Therefore, in the present invention, in order to uniformize the temperature distribution in the width direction of the rough bar on the entrance side of the finishing mill, the central low-temperature part and the low-temperature part at both ends of the rough bar are heated by a transverse induction heating apparatus. In order to eliminate the asymmetry of the temperature distribution in the width direction, the transverse type induction heating device is tilted to increase the temperature of the heating, and if necessary, the temperature at both ends is additionally compensated with an edge heater to increase the temperature. The temperature distribution in the width direction of the bar was made uniform.
[0040]
As the heating device for the coarse bar central low-temperature portion, any heating device capable of heating and heating only the central portion of the temperature rise distribution in the width direction can be used. Unlike the solenoid type induction heating device, the transverse type induction device has a characteristic capable of uniformly heating the specific portion in the width direction of the coarse bar according to the iron core width. In other words, the transverse induction heating apparatus having a narrower iron core width than the steel plate width has a feature that can heat the central portion of the steel plate in accordance with the iron core width, and is a transverse type having a wider iron core width than the steel plate width. The induction heating apparatus can heat the entire width of the steel sheet, but has a feature that can perform heating with a higher temperature rise at the end than at the center.
[0041]
Furthermore, the feature of the transverse induction heating apparatus is that the amount of temperature increase is theoretically almost inversely proportional to the gap between the iron core and the steel sheet. That is, as shown in FIG. 7, when the transverse induction heating device 20 is tilted 21 in the steel plate width direction (arrow direction), the gap (GAP) between the iron core and the steel plate of the transverse induction heating device changes and increases. The amount of heat changes. For example, FIG. 7B shows an example of the temperature rise characteristic of the transverse induction heating apparatus when the output of the transverse induction heating apparatus is 20 MW at the position indicated by the solid line in FIG. As can be seen from FIG. 7, the amount of temperature increase increases when the gap is closed, and the amount of temperature increase decreases when the gap is opened. The temperature increase amount is almost inversely proportional to the gap distance.
[0042]
Therefore, since the gap distance can be changed by tilting the transverse induction heating device, if the transverse induction heating device is tilted according to the temperature distribution in the width direction and the temperature is increased by heating, the width direction heating is performed. Since the temperature increase amount can be adjusted, the asymmetry of the temperature distribution in the plate width direction can be eliminated.
[0043]
A plurality of transverse type induction heating devices having different core widths are arranged along the rolling line, and at least one of the transverse type induction heating devices whose iron core width is narrower than the width of the coarse bar, and the iron core width is the width of the coarse bar. If at least one of the wider transverse induction heating devices is used for heating and heating, the central low temperature portion of the coarse bar and the specific width portion of the low temperature portion at both ends can be heated. The temperature distribution asymmetry can also be eliminated. In addition, as shown in FIG. 8, the transverse induction heating device 20 formed by applying the coil 23 to the iron core 22 is arranged and used at the upper and lower positions of the steel plate (coarse bar) 21, so that handling is easy. The surface of the rough bar is not wrinkled, the surface is not overheated due to its characteristics, and the distance from other equipment such as a rolling mill and a deske is not restricted.
[0044]
Hereinafter, the present invention will be described with reference to the drawings.
[0045]
In the hot rolling apparatus shown in FIG. 1, as schematically shown in FIG. 9 between the rough rolling mill and the finish rolling mill, the transverse induction heating apparatus 25 having a core width wider than the width of the coarse bar and the core width. A transverse type induction heating device 24 having a width smaller than the width of the coarse bar and two transverse type induction heating devices having different widths are arranged so as to be tiltable in the steel plate width direction, and an edge heater 8 is provided. A hot rolling apparatus was used.
[0046]
An entrance-side width direction thermometer 26 is installed on the entrance side of the two transverse induction heating apparatuses having different iron core widths, and an exit-side width direction thermometer 27 is installed on the exit side. The coarse bar 4 rolled by the coarse rolling mill is conveyed in the direction of the arrow by a table roll. The width direction temperature distribution of the coarse bar 4 is measured by the entrance side width direction thermometer 26, and the temperature rise amount of the coarse bar due to the heating of each transverse induction heating device 24, 25 is determined based on the width direction temperature distribution. Then, the transverse induction heating device is tilted so as to have a predetermined gap distance. The coarse bar is heated only at the central low temperature portion by the narrow transverse type induction heating device 24 and is heated at the entire width by the wide transverse type induction heating device 25, and the low temperature portion at both ends is heated and heated. The low temperature portions at both ends of the coarse bar are additionally heated by the edge heater 6 as necessary when the amount of temperature increase due to wide transverse induction heating is insufficient. The temperature distribution in the width direction of the coarse bar after heating is measured by the exit-side width direction thermometer 27. If the temperature distribution in the width direction measured by the exit-side width direction thermometer 27 is not uniform, the measurement data is fed back to the temperature rise control device of the transverse induction heating device, and each heating is performed by the control device. The temperature rise amount of the apparatus is changed and controlled, and the temperature distribution in the width direction of the coarse bar is made uniform.
[0047]
The temperature rise characteristics of the transverse induction heating apparatus will be described with reference to FIG.
[0048]
FIGS. 10A and 10B show the temperature rise distribution of the coarse bar due to heating by the different width transverse induction heating apparatus. (A) shows the amount of temperature increase during parallel (solid line) and tilting (dotted line) by the transverse induction heating device 24 whose iron core width is narrower than the width of the coarse bar shown in FIG. 9, and (b) in FIG. The temperature rise distributions of the amount of temperature rise at the time of parallel (solid line) and at the time of tilting (dotted line) by the transverse induction heating device 25 having a wider iron core than the width of the coarse bar shown are shown.
[0049]
As shown in FIG. 10 (a), the transverse induction heating device 24 having a narrow iron core width can increase the temperature of the center portion of the coarse bar by up to 40 ° C. corresponding to the iron core width when parallel with a gap distance of 200 mm. When tilting, the maximum temperature could be raised by 53 ° C. at the shortest gap. Since the temperature rise is due to heat transfer outside the width of the iron core, the amount of temperature rise gradually decreases, resulting in a gentle mountain-shaped temperature rise distribution.
[0050]
Further, as shown in FIG. 10 (b), the transverse induction heating device 25 having an iron core width equal to or larger than the width of the coarse bar can raise the temperature at the center of the full width of the coarse bar by 40 ° C., and at both ends of the coarse bar. When the gap is 200 mm due to the characteristics of increasing current, the temperature of about 150 mm width at both ends can be increased by about 150 ° C., and the left end is maximum when tilted so that the right gap is 250 mm and the left gap is 150 mm. The temperature could be raised by 200 ° C., and the temperature at the right end could be raised by 120 ° C.
[0051]
Therefore, as shown in FIG. 10C, the temperature distribution in the width direction of the coarse bar is made uniform by the total amount of temperature rise by the two transverse induction heating devices 24 and 25 having different widths. Furthermore, by arranging a large number of transverse-type induction heating devices having different widths along the rolling line and using them together, it becomes possible to finely adjust the temperature rise distribution state of the coarse bars.
[0052]
In addition, it is preferable that the iron core width | variety of the narrowest transverse type | formula induction heating apparatus used by this invention shall be in the range of 400-700 mm. This is because a typical minimum sheet width of a hot-rolled steel sheet is 550 to 800 mm, so that a transverse heating apparatus having a width of 100 to 150 mm narrower than this is required in order to suppress edge heating and perform center heating. Because it becomes.
[0053]
Moreover, it is preferable that the iron core width | variety of a wide transverse type | formula induction heating apparatus shall be in the range of 1000-2000 mm. This is because edge heating requires that the core width be equal to or greater than the 1000-2000 mm plate width of a normal wide hot-rolled steel plate.
[0054]
The tilting device for tilting the transverse induction heating device according to the present invention is, for example, a shaft capable of tilting the transverse induction heating device 20 suspended by the support 28 as shown in FIG. 29 and 30 elevators are arranged at the end of the transverse induction heating apparatus. When the end of the transverse induction heating device is lifted and lowered by the elevator 30, the transverse induction heating device can be tilted by rotating around the shaft 29. Further, if the shaft is fixed and mechanically or electrically rotated, it can be tilted without being cantilevered by an elevator.
[0055]
As another example, as shown in FIG. 11 (b), both ends of the transverse induction heating device 20 are held by two elevators 30, and the ends are moved up and down by the elevators 30, thereby moving the transverse type. The induction heating device can be tilted. Note that the transverse induction heating device disposed on the lower side of the plate can also be tilted by a similar mechanism.
[0060]
In addition, as the elevator 30 , for example, an elevator using a piston mechanism such as hydraulic pressure or pneumatic pressure, an elevator using a crank mechanism, an elevator using an electric motor, or the like can be used.
[0064]
【The invention's effect】
According to the hot rolling method of the present invention, the width direction temperature distribution of a rough bar having a non-uniform width direction temperature distribution before finish rolling can be made uniform, and the material such as mechanical properties in the width direction can be obtained by finish rolling. The remarkable effect that the hot rolled steel plate without the dispersion | variation in a characteristic can be obtained arises. Further, according to the hot rolling apparatus of the present invention, the transverse asymmetrical temperature distribution of the rough bar before finish rolling can be eliminated using the transverse induction heating apparatus, and the central low temperature part and the low temperature parts at both ends are selected. Since the temperature can be increased by heating, a remarkable effect is achieved that the temperature distribution in the width direction can be made uniform.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a conventional continuous hot rolling apparatus.
FIG. 2 is a diagram showing an outline of a conventional endless rolling apparatus.
FIG. 3 is a diagram illustrating that when the slab is heated in a heating furnace, the temperature in the width direction of the slab becomes asymmetric.
FIGS. 4A and 4B are diagrams for explaining the temperature distribution in the width direction of a slab reheated in a heating furnace. FIG. 4A shows that there is a low temperature portion at the center of the slab, and FIG. 4B shows that the temperature distribution in the width direction of the slab is asymmetric. It is a figure which shows that there exists a low-temperature part in the center part of the width direction.
FIG. 5 is a graph showing the temperature distribution in the width direction of a steel sheet after rough rolling and finish rolling, (a) is a rough bar, (b) is a laterally asymmetric width direction temperature distribution after rough rolling, and (c) is a finish. It is a figure which shows the left-right asymmetric width direction temperature distribution after rolling.
6A and 6B are diagrams showing a temperature distribution in the width direction when heated and hot-rolled by an induction heating device that moves a rough bar in the width direction, where FIG. 6A is a slab, and FIG. 6B is a width of the induction heating device. The coarse bar which was moved in the direction and heated, and (c) is a diagram showing the temperature distribution in the width direction of the steel sheet after finish rolling.
FIG. 7 is a diagram illustrating the relationship between the gap and the temperature rise when the transverse distance induction heating device is tilted to change the gap distance.
FIG. 8 is a diagram for explaining a transverse induction heating apparatus.
FIG. 9 is a view showing an example in which two tiltable transverse induction heating devices having different iron core widths are arranged in a rolling line.
10A and 10B are diagrams showing a temperature increase distribution of a transverse induction type heating apparatus, where FIG. 10A is a temperature increase distribution of a narrow transverse type induction heating apparatus, and FIG. 10B is a temperature increase distribution of a wide transverse type induction heating apparatus. (C) is a figure which shows the total temperature rising distribution of two transverse type | mold induction heating apparatuses.
FIG. 11 is a diagram illustrating a tilting device of a transverse induction heating device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Slab 3 Coarse rolling mill 4 Coarse bar 5 Crop shear 6 Edge heater 7 Continuous finish rolling mill 8 Cooling stand 9 Coiler 10 Coil box 11 Joining shear 12 Welding device 13 Pre-tropical zone 14 Heating zone 15 Soaking zone 16 Hot zone 17 Low temperature part 18 Cooling large 19 Temperature rise by induction heating device 20 Transverse type induction heating device 21 Tilt 22 Iron core 23 Coil 24 Transverse type induction heating device (narrow)
25 Transverse type induction heating device (wide)
26 Thermometer (incoming side)
27 Thermometer (Outside)
28 support 29 axis 30 elevator

Claims (5)

In the hot rolling method of a steel sheet, in which a slab heated in a heating furnace is roughly rolled with a roughing mill and finish-rolled with a finishing mill, the width of the sheet along the rolling line between the roughing mill and the finishing mill The above-described transverse-type induction heating device and the transverse-type mailing heating device having an iron core width narrower than the plate width are opposed to the top and bottom of the coarse bar, respectively, and above, below, or both of each transverse-type induction heating device. A steel plate characterized by adjusting the heating temperature rise so that the temperature distribution in the width direction of the coarsely rolled coarse bar is made uniform by tilting in the plate width direction in a plane perpendicular to the longitudinal direction of the plate. Hot rolling method. The hot rolling method for a steel sheet according to claim 1, wherein both ends of the coarse bar are heated by an edge heater and the temperature is additionally compensated. In a hot rolling apparatus for a steel sheet, comprising a heating furnace for heating a slab, a rough rolling machine for rough rolling the slab, and a finish rolling machine for finish rolling the rough rolled rough bar, the rough rolling mill and the finish rolling mill A transverse type induction heating device capable of heating the entire width of the steel sheet and having a higher temperature rise at the edge than at the central part, and a transverse type induction capable of heating with a large temperature rise at the central part of the steel sheet Each of the heating devices is arranged facing the top and bottom, and a tilting device is installed that tilts the transverse induction heating device above or below or both in the plate width direction in a plane perpendicular to the longitudinal direction of the plate. An apparatus for hot rolling steel sheets. The tilting device includes a shaft that supports the transverse induction heating device in a central direction of the transverse induction heating device so as to be tiltable in the plate width direction within a plane perpendicular to the longitudinal direction of the plate. The steel sheet hot rolling apparatus according to claim 3 . The steel plate according to claim 3 , wherein the tilting device includes a support device that tilts the transverse induction heating device in a plate width direction in a plane perpendicular to the longitudinal direction of the plate by cantilevering or holding both sides. Hot rolling equipment.

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