JP3428400B2 - Hot rolling equipment and hot rolling method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling facility for producing hot rolled steel strip, which is a facility between a rough rolling mill and a finish rolling mill, particularly a sheet bar stage on the entry side of the finish rolling mill. The present invention relates to a hot rolling facility characterized by the facility for induction heating.

[0002]

2. Description of the Related Art Conventionally, in the production of hot-rolled steel strip, heating has been performed at the sheet bar stage after rough rolling to make the temperature of the sheet bar uniform, so that a plate having a uniform length can be obtained. It is being appreciated. In recent years, for example, Japanese Patent Laid-Open No. 2-60
As described in Japanese Patent Publication No. 09, etc., a method is known in which a sheet bar is heated between a rough rolling mill and a finish rolling mill by using an induction heating device.

[0003]

However, for example, when the entire sheet bar is heated by the induction heating device, the induction heating coil is arranged as close to the seat bar as possible in order to suppress a decrease in heating efficiency. the induction height direction of the opening size of the heating device can the be as small as desired, in general, in the gap 200 mm approximately between induction heating coils, the heating efficiency in this case is about 50% . Furthermore, when a heat insulating material is provided between the induction heating coil and the conveyed sheet bar for coil protection, the vertical gap between the induction heating device and the sheet bar is only about 150 mm. Cannot be secured.

Therefore, when there is a warp in the leading end and the tail end of the roughly rolled sheet bar, the inner wall of the opening of the induction heating device is struck at the longitudinal end of the sheet bar to be conveyed. If the heat insulating material or the like is damaged or severe, the induction heating coil may be deformed and damaged and the induction heating may not be possible for a long time.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a hot rolling facility which improves the heating efficiency while preventing damage to the induction heating device.

[0006]

In order to solve the above-mentioned problems, the hot rolling equipment according to claim 1 or 2 of the present invention is an induction system for heating a sheet bar to the entrance side of a finish rolling mill. In a hot rolling facility provided with a heating device, a warp straightening device for straightening the warp of the sheet bar is provided on the entrance side of the induction heating device.

In the present invention, the warp of the sheet bar can be corrected before the induction heating process, the amount of warp can be reduced, the frequency of contact of the warped sheet bar with the induction heating device can be suppressed, and The vertical gap between the induction heating coil and the seat bar can be set small.

Further, the invention described in claim 2, the induction heating coil of the upper Symbol induction heating device is characterized in being arranged to seat bar periphery as around the entire circumference in the plate width direction .

In the present invention, in addition to the above-mentioned operation, the induction heating coil is arranged so as to go around the outer circumference of the sheet bar in the plate width direction to form a tunnel-shaped bar passage, and the induction heating is performed. By passing the sheet bar through the coil, the entire sheet bar can be heated.

In particular, it is effective for compensating for the temperature drop at the tip end and tail end of the seat bar. Also, claim 1 or claim
2 described in the invention, between the upper Symbol finishing mill installed coarse rolling mill and the induction heating device upstream from, taken temporarily wind the sheet bar back reeling to the standby unit and A bar joining device for joining the tail end portion of the preceding sheet bar and the tip end portion of the following sheet bar to the downstream side of the winding and rewinding device.

In the present invention, in addition to the above operation, by providing a take-up / rewinding device and a bar joining device, finish rolling in a so-called endless state is possible, and it is possible to perform batch rolling without joining sheet bars. a sheet bar longitudinal end unsteady portion without the, will be able to stable finish rolling over the material to be rolled overall length, for example, it is possible to rolling less than 1mm thin.

Here, the winding and unwinding device winds the trailing material in a coil shape to absorb a time schedule error, and by winding it in a coil shape and waiting it.
The temperature drop can be suppressed compared to the looper.

Further, in the present invention, even when the sheet bar is wound in the coil shape as described above, the inner end position and the outer end position (the tip end portion and the tail end position) are higher than the intermediate portion in temperature. Although the decrease is large, the induction heating device can compensate for the decrease in the temperature of the entire end portion of the seat bar. At this time, it is conceivable to raise the heating temperature of the heating furnace to perform temperature compensation, but this is disadvantageous in terms of generation of slag, increase in energy cost, life of the furnace, and the like.

The invention described in claim 3 is the following:
In contrast to the structure described in claim 1 or 2 , the warp correction device is characterized in that it is provided at least on the entrance side of the entrance side and the exit side of the bar joining device.

According to the present invention, the warp straightening device on the entry side of the bar joining device corrects the warp of the sheet bar rewound from the winding / rewinding device and at the same time before the sheet bar is conveyed to the induction heating device. In addition, the warp of the seat bar is corrected.

Further, when a warp straightening device is also provided on the outlet side of the bar joining device, the warp straightening process can be performed by the warp straightening device on the inlet side of the bar joining device in the endless rolling.
In the case of normal batch rolling, the warp straightening device on the outlet side of the bar joining device can perform the warp straightening process, so in both rolling operations, the warp straightening device corrects the warp before passing through the induction heating device. Then, the same operation as described above is obtained.

Next, the invention described in claim 4 is different from the structure described in any one of claims 1 to 3 in that a seat bar is provided on at least one of an inlet side and an outlet side of the warp straightening device. A warp detection device for detecting the warp is provided, and a controller for controlling the warp correction device based on a detection value of the warp detection device is provided.

In the present invention, in addition to the above operation, it is possible to properly correct the warp according to the state of the warp and grasp the correction result. Next, the invention described in claim 5 is, in the hot rolling equipment according to any one of claims 1 to 3 , a warp straightening device for straightening a warp of a sheet bar at an inlet side of the induction heating device. Provided with a warp detection device for detecting the warp of the seat bar on the entrance side of the warp correction device, only when the warp amount of the seat bar exceeds a predetermined allowable range based on the detection by the warp detection device, The hot rolling method is characterized in that a warp straightening process is performed by a warp straightening device.

In the present invention, when there is no warp or a small amount of warp, the warp straightening device is opened, so that the tip portion of the sheet bar hits the warp straightening device and a flaw is generated in the straightening portion of the warp straightening device. And the size of the flaw can be suppressed small. At the same time, for a sheet bar having a warp exceeding a predetermined allowable range, warp correction processing is realized.

Here, when a flaw having a size larger than a predetermined value occurs in the warp straightening device, the abutting flaw is transferred at the time of straightening the succeeding material, resulting in poor quality of the sheet bar. This also contributes to a reduction in the frequency of flaw transfer because the warp correction is not performed when there is no warp or the warp is small.

Next, the invention described in claim 6 is the hot rolling equipment according to any one of claims 1 to 3 , in which the warp of the sheet bar is corrected on the inlet side of the induction heating device. A warp correction device is provided, and a warp detection device that detects the warp of the seat bar is provided on the exit side of the warp correction device. When the warp amount of the seat bar is within the allowable range based on the detection by the warp detection device, the warp correction device is provided. If the warp amount of the sheet bar exceeds the allowable range without performing the correction process by the device, the conveyance of the sheet bar is once stopped, the sheet bar is returned by a predetermined amount, and the warp correction process is performed by the warp correction device. It is characterized by performing.

Also in the present invention, when the warp of a predetermined amount or more does not occur, the correction process by the warp correction device is not performed, and the same effect as in the above-mentioned claim 5 is obtained. Next, the invention described in claim 7 is, in the hot rolling equipment according to any one of claims 1 to 3 , a warp straightening device for straightening a warp of a sheet bar at an inlet side of the induction heating device. A warp detection device for detecting the warp of the seat bar is provided on the exit side of the warp correction device, and if the warp amount of the seat bar is a predetermined value or more based on the detection by the warp detection device, the induction heating is performed. The apparatus is characterized in that the apparatus is temporarily retracted from the online position and the sheet bar is passed through without being heated by the induction heating apparatus.

In the present invention, when the warp that cannot be completely corrected is not less than a predetermined value, the induction heating device is temporarily retracted, so that long-term equipment down due to damage of the induction heating device can be avoided.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an equipment row for hot rolling showing an example of this embodiment. Reference numeral 1 denotes a rough rolling mill, and reference numeral 2 denotes a finishing rolling mill. The sheet bar roughly rolled by the rough rolling mill 1 is guided to the table roller 3 and sent to the finishing rolling mill 2 side. ing.

[0025] the entry side of the finishing mill 2, the induction heating device 4 of the sheet bar heating for heating the sheet bar is arranged. The induction heating device 4 includes a bar heater 5 which is a sheet bar width direction entire heating device and an edge heater 6 which is a sheet bar width direction end heating device which are arranged along the transport direction.

The bar heater 5 has an induction heating coil 8 as shown in FIG. 2 which is a schematic diagram and FIG. 3 which is a plan view.
However, the shaft is arranged so as to circulate in the width direction around the seat bar 7, and the shaft is arranged in the conveying direction of the seat bar 7, and the seat bar 7 can pass through the space in the induction heating coil 8. The induction heating coil 8 is composed of a plurality of sets of coils divided into a plurality in the axial direction, and each coil is
Current is supplied from the high frequency power supply.

Here, FIG. 2 shows only one set of coils. Further, in FIG. 3, an arrow A indicates the direction in which the coil current flows, and an arrow B indicates the direction in which the induction current induced in the seat bar 7 flows. Although not shown, a heat insulating material that protects the induction heating coil 8 from radiant heat or the like is arranged inside the induction heating coil 8.

The edge heaters 6 arranged on the downstream side of the bar heater 5 are arranged at both ends of the seat bar 7 in the width direction, and each of them comprises a pair of upper and lower induction heating coils 8. Is a device for induction-heating the widthwise end portion of the same from above and below.

A warp straightening device 14 is arranged on the inlet side of the induction heating device 4. The warp straightening device exemplified in the present embodiment is configured by staggering the straightening rollers for warping straightening in a zigzag manner, and the gap between the upper and lower straightening rollers can be adjusted.

Reference numeral 15 is a crop shear, reference numeral 16 is a finishing scale breaker, and reference numeral 17 is an edger. Although not shown, a sensor for detecting the end position of the seat bar 7 is arranged at an appropriate position, and the processing of each of the above devices is controlled by a signal from the sensor.

Next, the operation and effects of the hot rolling equipment having the above structure will be described. The sheet bar 7 roughly rolled by the rough rolling mill 1 is guided by the table roller 3 to finish the rolling mill 2.
Be transported to the side.

During this transportation, part of the heat held by the sheet bar 7 is dissipated into the atmosphere. Especially the seat bar 7
A difference occurs in the amount of heat dissipated in the atmosphere between the widthwise end portion and the widthwise central portion, and the temperature of the seat bar 7 is lower at the widthwise end portion than at the widthwise central portion. Then, when the temperature becomes low, the material in the width direction end portion becomes defective, but the width direction end portion is heated by the edge heater 6, so that the temperature drop is compensated.

Further, although a temperature drop occurs at the leading end and the tail end of the seat bar 7, the temperature drop at the longitudinal end of the seat bar 7 is compensated by being heated by the bar heater 5. Here, for detecting the end portion of the seat bar 7, for example,
This can be achieved by providing a temperature sensor on the inlet side and performing feedback control so that the target temperature is reached based on the temperature signal from the sensor.

The temperature drop at the end portion of the sheet bar 7 causes a decrease in finishing workability due to abnormal growth of crystal grains and causes a flaw on the finishing roll. The heating by the bar heater 5 is performed when the seat bar 7 passes through the tunnel-shaped induction heating coil 8. At this time, if the tip portion of the seat bar 7 is warped, the seat bar 7 may hit the induction heating coil 8 or the heat insulating material. However, in the present embodiment, the seat bar 7 is the warp straightening device 14. Since the warp is corrected and then passes through the inside of the induction heating device 4, the amount of warpage of the seat bar 7 that passes through the inside of the induction heating device 4 is suppressed, and the seat bar 7 to the induction heating coil 8 and the like is suppressed. Can be suppressed. As a result, damage to the induction heating coil 8 and the heat insulating material, that is, damage to the equipment of the induction heating coil 8 is prevented, and stoppage of equipment is avoided.

As described above, since the heating is performed after the warp is corrected, the gap between the induction heating coil 8 and the sheet bar 7 can be made small, and the damage to the equipment can be suppressed and the deterioration of the heating efficiency can be suppressed. be able to.

Here, when compensating for the temperature drop in the induction heating device 4, it is advantageous that the sheet passing speed is slow. Therefore, in the present embodiment, the induction heating device 4 is used as much as possible in the finish rolling mill 2. By arranging them close to each other, the threading speed is reduced to the threading speed at the time of entry into the finish rolling mill 2 so that the material is passed through the induction heating device 4.

Next, a second embodiment will be described with reference to the drawings. It should be noted that, of the same equipment and the like as those of the above-described embodiment, description of those that are not changed will be omitted. The basic configuration of the present embodiment is the same equipment configuration as that of the first embodiment, but as shown in FIG. 4, the warp detection device 16 for detecting the warp of the seat bar 7 on the entry side of the warp correction device 14 is shown. Is different.

The warp detection device 16 comprises an upper warp detection device 17 and a lower warp detection device 18. The warp detection device 17 includes a swivel shaft 17a that can swivel up and down above the seat bar 7, and a rod 17b having an upper end fixed to the swivel shaft 17a extends toward the upper surface of the seat bar 7. The gap between the lower end of the rod 17b and the seat bar 7 is set small. When the sheet bar 7 has a warp, the conveyed sheet bar 7 hits the rod 17b, and the rod 17b corresponds to the warp.
It is designed to push up and turn. A rotation amount detection sensor 17c is connected to the swivel shaft 17a, and the rotation amount detection sensor 17c can supply a signal corresponding to the detected rotation amount to the warp correction controller 19.

Further, in the warp detection device 18, the center part of the plate 18a is supported by the apron of the table roller 3 so as to be vertically pivotable, and the counterweight 18b is provided at the rear end of the plate 18a. The plate 18a is tilted up and down so that the front side is slightly upward, and is balanced. Then, the plate body 18a is swung downward by hitting the plate body 18a at the end portion of the warped seat bar 7. Further, a rotation amount detection sensor 18c is connected to the turning axis of the plate 18a, and the rotation amount detection sensor 18c can supply a signal according to the detected rotation amount to the warp correction controller 19.

The warp correction controller 19 determines the warp amount based on the signals from the rotation amount detection sensors 17c and 18c, and feedback-controls the correction position of the upper correction roller so as to correct the warp amount.

At this time, if the amount of warp determined by the above determination is within the predetermined allowable value, the upper correction roller 14a is released upward to open the warp correction device 14 as shown in FIG. 4 (a). If the amount of warpage determined by the above determination exceeds the predetermined allowable value, the upper straightening roller 14a is lowered to perform straightening processing, as shown in FIG. 4 (b).

In FIG. 4, 14c is a warp straightening device 1.
4 is a guide member provided on the inlet side and can be moved up and down in synchronization with the upper correction roller 14a. In such a configuration, the warp correction device 14 is provided by disposing the warp detection device 16 on the entrance side of the warp correction device 14.
The presence or absence of warp of the seat bar 7 and the warp amount can be detected before the entry. Then, for the seat bar 7 whose warpage is small within the predetermined allowable range or has no warpage, the warp straightening device 14
Is released, the frequency with which the leading end of the seat bar 7 hits the warp straightening device 14 and scratches the straightening rollers 14a, 14b, etc. is reduced, and the warp straightening is performed only for the seat bar 7 having a predetermined warp or more. Is done.

As a result, the occurrence rate of the quality defect of the sheet bar 7 due to the transfer of the abutting flaw can be suppressed to be small, and
The seat bar 7 can pass through the inside of the induction heating device 4 while suppressing the warp, and the heating efficiency is good.

Other functions and effects are the same as those in the first embodiment. The warp detection device 16 is not limited to the above configuration, and other known devices such as a non-contact sensor using laser light or the like may be used.

Next, a third embodiment will be described with reference to the drawings. It should be noted that, of the same facilities and the like as those of the above-mentioned embodiment, those that are not changed will not be described.
The basic configuration of this embodiment is the same as the equipment configuration of the first embodiment, but as shown in FIG.
The difference is that a warp detection device 20 for detecting the warp of the seat bar 7 is provided on the exit side of the sheet 4.

Since the warp detection device 20 is the same device as that described in the second embodiment, the details thereof will be omitted, but the upper warp detection device 21 and the lower warp detection device 2 are omitted.
The rotation amount detection sensors 21c and 22c of the upper warp detection device 21 and the lower warp detection device 22 each include a signal corresponding to the detected rotation amount to the warp correction controller 19.
Can be supplied to.

Warp correction controller 19 of the present embodiment
Then, the warp amount is determined based on the signals from the rotation amount detection sensors 21c and 22c, and the correction position of the upper correction roller 14a is adjusted. That is, when it is determined that the amount of warp is within the predetermined allowable range, the upper straightening roller 14a is allowed to escape upward, and the warp straightening device 14 is opened. If it is determined that the warp amount exceeds the predetermined allowable range, a signal for stopping conveyance is supplied to the sheet bar conveyance controller (not shown), and then the upper and lower straightening rollers 14a, 14b.
The gap between them is adjusted to correspond to the thickness of the seat bar 7. Subsequently, a signal for returning the sheet bar to the controller for carrying the sheet bar (not shown) is restarted and then fed again.

In such a structure, the seat bar 7
The warp correction device 14 corrects the warp only when the warp is greater than or equal to a predetermined value. As a result, with respect to the seat bar 7 in which the warp is small within the predetermined allowable range or does not have the warp, the warp straightening device 14 is opened, and the tip end portion of the seat bar 7 hits the straightening rolls 14a, 14b of the warp straightening device 14 or the like. The frequency of occurrence of flaws is suppressed to a low level, and only the sheet bar 7 having a warp of a predetermined value or more is once returned by the reverse running process and the warp correction process is performed. Therefore, the occurrence rate of defective quality of the sheet bar 7 due to the transfer of the abutting flaw can be suppressed to be small.

Other functions and effects are the same as those in the first embodiment. The warp detection device 20 is not limited to the above configuration, and other known devices such as a non-contact sensor using laser light or the like may be used.

Further, the second embodiment and the third embodiment may be combined. That is, the warp detection device 20 detects the warp after the warp correction according to the second embodiment, and when there is a warp of a predetermined amount or more, the seat bar 7 is run backward to correct the warp again. . According to this, more reliable warp correction is possible.

Next, a fourth embodiment will be described with reference to the drawings. It should be noted that, of the same equipments as those of the above-mentioned embodiment, those that are not changed will not be described. The configuration of this embodiment is the same as that of the third embodiment, but as shown in FIG. 6, the bar heater 5 and the edge heater 6 which are the induction heating devices 4 are driven by the advancing / retreating actuator 25 such as a hydraulic cylinder device. The seat bar 7 can be moved back and forth in the plate width direction. The advancing / retreating actuator 25 operates based on a command from the advancing / retreating controller 26.

The warp detection device 16 arranged on the outgoing side of the warp correction device 14 supplies a detection signal to the advancing / retreating controller 26. The advancing / retreating controller 26 determines the warp amount based on a signal from the warp detecting device 20 arranged on the exit side of the warp correcting device, and when it determines that the warp amount is equal to or more than a predetermined value, the advancing / retreating actuator 25 retracts. A command is supplied to retract the bar heater 5 and the edge heater 6.

In this embodiment, when the warp that cannot be completely corrected even after passing through the warp correction device 14 is equal to or larger than a predetermined value, the bar heater 5 and the edge heater 6 are retracted to guide the sheet bar 7. It is prevented from hitting the heating device 4, and as a result, long-term equipment down due to damage to the equipment of the induction heating device 4 is avoided.

In this embodiment, the warp straightening device 1 is used.
The control method of No. 4 is not limited to the contents of the third embodiment, and as shown in FIG. 7, that is, as in the second embodiment, the warp detection device 16 is separately provided on the entrance side of the warp correction device 14.
Alternatively, the warp correction device 14 may be feedback-controlled based on the detection result of the warp detection device 16 on the entrance side.

Other functions and effects are similar to those of the above embodiment. The warp detection device 20 is not limited to the above configuration, and other known devices such as a non-contact sensor using laser light or the like may be used.

Next, a fifth embodiment will be described with reference to the drawings. The same equipment and the like as those in the above embodiment will be described with the same reference numerals. As shown in FIG. 8, the basic configuration of the present embodiment is the same as that of the first embodiment, but the position of the warp straightening device 14 is different, and the winding / rewinding device 28 and the bar joining device 29 are different. Differences are added.

That is, between the outgoing side of the rough rolling mill 1 and the incoming side of the induction heating device 4, in order from the rough rolling mill 1 side, the winding / unwinding device 28, the warp straightening device 14, and the bar joining device 29.
Are arranged.

The winding / unwinding device 28 is composed of a plurality of coilers 28a, winds the sheet bar 7 rolled by the rough rolling machine 1 and adjusts the feed timing of the succeeding sheet bar 7. By winding and adjusting in a coil shape, the temperature drop of the seat bar 7 can be suppressed smaller than that of the looper.

The bar joining device 29 is a device for joining the tail end of the leading sheet bar 7 and the leading end of the trailing sheet bar 7 by welding or the like, and thereby finishes the seat bar 7 in an endless state. It can be transported to the rolling mill 2 side.

In this structure, the trailing seat bar 7 is wound around the coiler and stored in a coil state, and the trailing seat bar 7 is adjusted in accordance with the timing when the tail end of the leading seat bar 7 passes through the bar joining device 29. Then, the succeeding sheet bar 7 is unwound and the trailing sheet bar 7 is fed out so that the end portions of the two sheet bars 7 are joined to each other by the bar joining device 29. By repeating this, finish rolling is performed in an endless state.

In this endless rolling, since finish rolling is performed in a state where the preceding material and the following material are connected to each other, a leading end such as batch processing (when processing is performed without connecting each sheet bar 7) Since there is no unsteady part at the edge, stable finish rolling can be realized over the entire length of the material to be rolled. In particular, the equipment enables rolling of thin products such as rolling of unsteady parts which is difficult.

Further, as the material to be rolled becomes thinner, the temperature drop becomes larger, but the temperature compensation can be surely realized by heating the entire seat bar 7 by the bar heater 5. Here, the sheet bar that has been coiled and waited
Not only a thin product, but especially the outer end portion (tip portion) and the inner end portion (tail end portion) lower in temperature than the central portion in the longitudinal direction, but the tip end and tail end of the seat bar 7 are By heating the whole at 5, the temperature drop can be compensated.

Further, in this embodiment, the warp straightening device 14 arranged on the exit side of the winding / rewinding device 28 straightens the warp of the rewound sheet bar 7 to thereby induce the induction heating device. It is possible to reduce the hit of the induction heating device 4 by the seat bar 7 passing through 4, and to set the vertical gap between the induction heating coil 8 and the seat bar 7 to be small as in the first embodiment. Yes, that is, the heating efficiency is good.

Other configurations, operations, and effects are similar to those of the above embodiment. Regarding the control of the warp correction device 14, as described in each of the above-described embodiments, a warp detection device that detects the warp of the seat bar 7 is provided on at least one of the entrance side and the exit side of the warp correction device 14. The warp correction device 14 may be provided and the warp correction device 14 may be controlled based on the detection value of the warp detection device.

Next, a sixth embodiment will be described with reference to the drawings. The same equipment and the like as those in the above embodiment will be described with the same reference numerals. The configuration of this embodiment is substantially the same as that of the fifth embodiment, and as shown in FIG. 9, a second warp correction device 30 is provided between the bar joining device 29 and the induction heating device 4. is there.

In this embodiment, when the above-mentioned endless rolling is carried out, that is, the winding and rewinding device 28.
When the bar joining device 29 is used, the first warp straightening device 14 is used, and when the normal batch processing is performed, the second warp straightening device 30 is used. It is possible to correct the warp of the seat bar 7 according to the contents of.

Other configurations, operations, and effects are the same as those in the above embodiment. In all of the above-mentioned embodiments, the edge heater 6 may be omitted when the temperature decrease at both ends of the seat bar 7 in the width direction can be ignored. Further, since the bar heater 5 heats the entire seat bar 7, the bar heater 5 is designed so as to heat the end portion in the plate width direction of the seat bar 7 by the arrangement of coils and the like, and the edge heater 6 may be omitted. Good.

Further, the bar heater 5 is not limited to the above-mentioned configuration, and may be constructed by arranging the induction heating coils whose axes are oriented vertically in the upper side and the lower side of the seat bar 7, respectively. Good. In this case, since the distance between the upper and lower induction heating coils can be adjusted, the distance between the upper and lower induction heating coils may be adjusted depending on the thickness and warpage of the seat bar 7.

[0069]

[Examples] Actually, in each of the above-described embodiments based on the present invention, the ratio of the damage of the induction heating device and the defect quality defect of the finished product after finish rolling was examined, and the results are shown in FIG.

In FIG. 10, reference character C is the case where the warp correction device is not provided on the entrance side of the induction heating device. The code D is
This is the case of the equipment configuration based on the first embodiment. Reference symbol E is the case of the equipment configuration based on any of the above second to sixth embodiments.

As can be seen from FIG. 10, by adopting the invention of the present application, long-term equipment down due to equipment damage is significantly reduced, which is effective in reducing downtime.

It can also be seen that the number of semi-finished products also decreases. Here, the semi-finished product is a product that is scraped because the temperature is too low to be rolled.

[0073]

As described above, when the present invention is adopted, the warp of the seat bar can be corrected before the induction heating process, and the warp amount is reduced, so that the warped seat bar can be prevented. The frequency of contact with
Since the vertical gap between the induction heating coil and the seat bar can be set smaller, there is an effect that a predetermined heating efficiency can be secured while preventing the operation interruption due to damage of the induction heating equipment.

At this time, if the invention described in claim 2 is adopted, the induction heating coil is arranged so as to go around the outer periphery of the sheet bar in the plate width direction to form a tunnel-shaped bar passage, By passing the sheet bar through the induction heating coil, there is an effect that it is possible to heat the entire sheet bar, and especially for compensating for the temperature drop at the tip end portion and the tail end portion of the seat bar where the temperature effect occurs. It has the effect of being effective.

Further, when the invention described in claim 1 or 2 is adopted, by providing the winding and rewinding device and the bar joining device, finish rolling in a so-called endless state becomes possible, and the entire length of the material to be rolled can be rolled. It will be able <br/> stable finish rolling over the compensation temperature drop across the sheet bar is achieved by the induction heating apparatus, for example, with a possible rolling less than 1mm thin.

Further, when the invention described in claim 3 is adopted, the warp straightening device on the entrance side of the bar joining device corrects the warp of the sheet bar rewound from the take-up and rewinding device, and at the same time, the guide is performed. The warp of the sheet bar can be corrected before being conveyed to the heating device, and the above effects can be obtained.

Moreover, when the warp straightening device is also provided on the outlet side of the bar joining device, the warp straightening process can be performed by the warp straightening device on the inlet side of the bar joining device in the endless rolling.
In normal batch rolling, the warp straightening device on the outlet side of the bar joining device can perform warp straightening processing, so in both rolling operations, the warp straightening device can correct the warp before passing through the induction heating device. As a result, both rolling operations can be performed, and at the same time, the above effects can be obtained.

Further, when the invention according to claim 4 is adopted, in addition to the above effects, there is an effect that it is possible to properly correct the warp according to the state of the warp and grasp the correction result. .

Further, when the invention described in claim 5 or claim 6 is adopted, when there is no warp or the warp is small, the warp straightening device is opened so that the tip end portion of the seat bar becomes the warp straightening device. The effect that the frequency of occurrence of flaws in the straightening portion of the warp straightening device and the size of the flaw can be suppressed to be small, and that the warp correction processing can be performed on the seat bar having the warp exceeding the predetermined allowable range. There is.

Further, when the invention described in claim 7 is adopted, when the uncorrected warp is more than a predetermined value, the induction heating device is temporarily retracted, so that the induction heating device is damaged. This has the effect of avoiding long-term equipment down due to.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a hot rolling equipment row according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a bar heater according to the first embodiment of the present invention.

FIG. 3 is a schematic front view showing the bar heater according to the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram for explaining a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram for explaining a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram for explaining a fourth embodiment of the present invention.

FIG. 7 is a schematic configuration diagram for explaining a warp detection device according to a fourth embodiment of the present invention.

FIG. 8 is a schematic configuration diagram showing a hot rolling facility row according to a fifth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing a hot rolling facility row according to a sixth embodiment of the present invention.

FIG. 10 is a diagram showing reduction of equipment damage and reduction of semi-finished products by adopting the present invention.

[Explanation of symbols]

1 rough rolling mill 2 Finishing mill 3 table rollers 4 induction heating device 5 bar heater 6 Edge heater 7 seat bar 8 induction heating coil 14 Warp straightening device 16 Warp detection device 19 Orthodontic controller 20 Warp detection device 25 Forward / backward actuator 26 Back-and-forth controller 28 Winding and unwinding device 29 bar joining device 30 Second warp correction device

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI C21D 1/42 C21D 9/52 101 H05B 6/10 381 9/52 101 B21B 37/00 116L H05B 6/10 381 BBM (56) References JP-A-5-329519 (JP, A) JP-A-2-6009 (JP, A) JP-A-9-253701 (JP, A) JP-A-9-314201 (JP, A) JP-A-63 -128580 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21B 37/00-37/78 B21B 1/26 B21B 45/00 B21D 1/05 C21D 1/42 C21D 9 / 52 H05B 6/10

Claims (7)

(57) [Claims] 1. A hot-rolling facility in which an induction heating device for heating a sheet bar is provided on the inlet side of a finishing rolling mill, and a warp straightening device for correcting the warp of the sheet bar is provided on the inlet side of the induction heating device. Installed and installed upstream of the finishing mill
Between the rough rolling mill and the induction heating device
Winding and rewinding device that temporarily winds up and waits
And the preceding seat bar on the downstream side of the take-up / rewinding device.
Bar that joins the tail end of the seat and the leading end of the following seat bar
A hot rolling facility comprising: a joining device . 2. A sheet bar is heated on the entrance side of the finish rolling mill.
In hot rolling equipment equipped with induction heating
A sheet bar on the entrance side of the induction heating device to correct the warp of the seat bar.
A straightening device is provided, and the induction heating coil of the induction heating device is arranged so as to go around the outer circumference of the sheet bar in the width direction of the sheet , and is a rough rolling device installed upstream of the finishing mill.
Seat bar between the machine and the induction heating device
Winding and unwinding device that winds and waits, and its winding
The trailing edge and trailing edge of the preceding seat bar are located downstream of the rewinding device.
A bar joining device that joins the tip of the seat bar of
A hot rolling facility characterized by being provided . Wherein said warp correcting device, the input-side and hot-rolling facility according to claim 1 or claim 2, characterized in that provided on at least the entry side of the exit side of the bar joining apparatus. 4. A warp detection device for detecting a warp of a seat bar is provided on at least one of an entrance side and an exit side of the warp correction device, and the warp correction device is controlled based on a detection value of the warp detection device. The hot rolling equipment according to any one of claims 1 to 3 , further comprising a controller. 5. The hot rolling facility according to any one of claims 1 to 3 , wherein a warp straightening device for straightening the warp of the sheet bar is provided on the inlet side of the induction heating device, and the warp straightening device is provided. A warp detection device for detecting the warp of the seat bar is provided on the entrance side of the warp correction device only when the warp amount of the seat bar exceeds a predetermined allowable range based on the detection by the warp detection device. A hot rolling method characterized by carrying out. 6. The hot rolling facility according to any one of claims 1 to 3 , wherein a warp straightening device for straightening the warp of the sheet bar is provided on the inlet side of the induction heating device, and the warp straightening device is provided. A warp detection device for detecting the warp of the seat bar is provided on the exit side of the sheet bar, and if the warp amount of the seat bar is within the allowable range based on the detection by the warp detection device, the correction process by the warp correction device is not performed,
When the warp amount of the sheet bar exceeds the allowable range, the conveyance of the sheet bar is once stopped, the sheet bar is returned by a predetermined amount, and the warp correction device performs the warp correction process. Hot rolling method. 7. The hot rolling facility according to any one of claims 1 to 3 , wherein a warp straightening device for straightening the warp of the sheet bar is provided on the inlet side of the induction heating device, and the warp straightening device is provided. A warp detection device for detecting the warp of the seat bar is provided on the exit side of the sheet, and when the warp amount of the seat bar is a predetermined value or more based on the detection by the warp detection device, the induction heating device is temporarily retracted from the online position. Then, the hot rolling method is characterized in that the sheet bar is passed through without being heated by the induction heating device.