JPH11123425A - Hot rolling equipment and hot rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of heating while preventing the breakage of an induction heating device by providing a straightening device for straightening the camber of a sheet bar on the inlet side of the induction heating device. SOLUTION: A sheet bar which is roughly rolled with a roughing mill 1 is guided with a table roller 3 and sent to a finishing mill 2. An induction heating device 4 is arranged on the inlet side of the finishing mill 2 and the sheet bar is heated. The induction heating device 4 consists of a bar heater 5 for heating the whole in the width direction of the sheet bar and an edge heater 6 for heating the end parts in the width direction. A camber straightening device 14 is provided on the inlet side of the induction heating device 4. In this device, straightening rollers are arranged zigzag and up and down and a clearance between the upper and lower straightening rollers is adjustable. The camber of the sheet bar is straightened with the camber straightening device 14. In the case that the camber which is not straightened is more than a prescribed value, by temporally retreating the induction heating device, the long term breakdown of equipment or the like due to damage of the device is evaded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling plant for producing a hot-rolled steel strip, and more particularly to a device between a rough rolling mill and a finish rolling mill, in particular, a sheet bar stage at the entrance of the finishing rolling mill. TECHNICAL FIELD The present invention relates to a hot-rolling facility having a feature in a facility for performing induction heating in the apparatus.

[0002]

2. Description of the Related Art Conventionally, in the production of a hot-rolled steel strip, a sheet having uniform quality over the entire length has been obtained by heating at a sheet bar stage after rough rolling to make the temperature of the sheet bar uniform. Have been done. In recent years, for example, Japanese Patent Laid-Open No. 2-60
As described in Japanese Patent Application Laid-Open No. 09-0909 and the like, a method of heating a sheet bar between a rough rolling mill and a finishing rolling mill using an induction heating device is known.

[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 sheet bar as possible in order to minimize the decrease in heating efficiency. In addition, it is desirable to minimize the opening dimension in the height direction of the induction heating device. Generally, the gap between the induction heating coils is about 200 mm, and the heating efficiency in this case is 50%.
It is about. Further, in the case where a heat insulating material or the like is provided between the induction heating coil and the sheet bar to be conveyed to protect the coil, the gap between the induction heating device and the sheet bar in the vertical direction is substantially only about 150 mm. I can't secure it.

[0004] For this reason, when the leading end and the tail end of the roughly rolled sheet bar are warped, the inner wall of the opening of the induction heating device is hit at the longitudinal end of the sheet bar to be conveyed. In addition, when the heat insulating material or the like is damaged or severe, the induction heating coil is deformed and damaged, and there is a problem that the induction heating cannot be performed for a long time.

[0005] The present invention has been made in view of the above problems, and has as its object to provide a hot rolling facility that improves heating efficiency while preventing damage to an induction heating device.

[0006]

Means for Solving the Problems In order to solve the above problems, a hot rolling facility according to claim 1 of the present invention comprises:
In a hot rolling facility in which an induction heating device for heating a sheet bar is provided on an entrance side of a finish rolling mill, a warp straightening device for correcting a warpage of a sheet bar is provided on an entrance side of the induction heating device. It is assumed that.

In the present invention, it is possible to correct the warpage of the sheet bar before performing the induction heating process, thereby reducing the amount of warpage, suppressing the frequency at which the warped sheet bar contacts the induction heating device, and The vertical gap between the induction heating coil and the sheet bar can be set small.

Next, according to a second aspect of the present invention, in the configuration of the first aspect, the induction heating coil of the induction heating device is disposed so as to go around the outer periphery of the sheet bar in the sheet width direction. It is characterized by being performed.

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

In particular, it is effective in compensating for a temperature drop at the front end and the tail end of the sheet bar. Next, the invention described in claim 3 is based on the configuration described in claim 1 or claim 2,
A winding and rewinding device for temporarily winding and waiting the sheet bar between the rough rolling mill and the induction heating device installed on the upstream side of the finishing mill, A bar joining device for joining the tail end of the preceding sheet bar and the tip end of the succeeding sheet bar downstream is provided.

In the present invention, in addition to the above operation, by providing a winding and rewinding device and a bar joining device, it is possible to perform finish rolling in a so-called endless state, such as in batch rolling in which sheet bars are not joined. There is no unsteady portion at the longitudinal end of the sheet bar, and the finish rolling can be stably performed over the entire length of the material to be rolled. For example, a thin material having a thickness of 1 mm or less can be rolled.

Here, the winding and rewinding device winds the following material in a coil shape to absorb a time schedule error, and winds the material in a coil shape to stand by.
Temperature drop can be suppressed as compared with a looper.

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

According to a fourth aspect of the present invention, in the configuration of the third aspect, the warp correcting device is provided on at least an entrance side of the entrance side and the exit side of the bar joining apparatus. It is characterized by the following.

According to the present invention, the warpage of the sheet bar unwound from the winding / unwinding device is corrected by the warpage correcting device on the entry side of the bar joining device, and at the same time, the sheet bar is transported to the induction heating device. In addition, the correction of the warpage of the seat bar is realized.

Further, when a warp straightening device is also provided on the exit side of the bar joining device, the warp straightening process can be performed by the warp straightening device on the entrance side of the bar joining device in the case of the endless rolling.
In the case of normal batch rolling, the warp can be corrected by the warp correcting device on the exit side of the bar joining device, so that the warp is corrected by the warp correcting device before passing through the induction heating device in both rolling operations. Thus, the same operation as described above is obtained.

According to a fifth aspect of the present invention, in addition to the structure of any one of the first to fourth aspects, a sheet bar is provided on at least one of an entrance side and an exit side of the warp straightening device. And a controller for controlling the warp correcting device based on a detection value of the warp detecting device.

In the present invention, in addition to the above operation, it becomes possible to correct the warpage properly and to grasp the correction result in accordance with the state of the warpage. Next, according to a sixth aspect of the present invention, in the hot rolling equipment according to any one of the first to fourth aspects, a warp straightening device for straightening a sheet bar on an entrance side of the induction heating device. Provide a warp detecting device for detecting the warpage of the sheet bar on the entrance side of the warp straightening device, and only when the amount of warpage of the sheet bar exceeds a predetermined allowable range based on the detection by the warp detecting device, A hot rolling method characterized by performing a warp correction process by a warp correction device.

In the present invention, when there is no or small warpage, the frequency of occurrence of flaws in the straightening portion of the warp straightening device by opening the warp straightening device so that the front end portion of the sheet bar hits the straightening device. And the size of the flaw is kept small. At the same time, for a sheet bar having a warp exceeding a predetermined allowable range, a warp correction process is realized.

Here, when a flaw having a size equal to or larger than a predetermined value is generated in the warp correcting device, the abutting flaw is transferred when the succeeding material is corrected, which leads to poor sheet bar quality. In addition, since there is no warpage correction when there is no or small warpage, this also contributes to a reduction in the frequency of flaw transfer.

Next, according to a seventh aspect of the present invention, in the hot rolling equipment according to any one of the first to fourth aspects, the warpage of the sheet bar is corrected on the inlet side of the induction heating device. A warp straightening device is provided, and a warp detecting device for detecting the warpage of the sheet bar is provided on the exit side of the warp straightening device. If the amount of warpage of the sheet bar is within an allowable range based on the detection by the warp detecting device, the straightening is performed. If the warping amount of the sheet bar exceeds the allowable range without performing the straightening process by the device, the sheet bar is temporarily stopped, the sheet bar is returned by a predetermined amount, and the warping straightening process is performed by the warpage straightening device. Is performed.

Also in the present invention, when a warpage of a predetermined degree or more does not occur, the correction processing by the warp correction device is not performed, so that the same effect as the above-mentioned claim 6 is obtained. Next, according to an eighth aspect of the present invention, in the hot rolling equipment according to any one of the first to fourth aspects, a warp straightening device for straightening a sheet bar on the entry side of the induction heating device. A warp detecting device for detecting the warpage of the sheet bar is provided on the exit side of the warp straightening device. When the amount of warpage of the sheet bar is equal to or more than a predetermined value based on the detection by the warp detecting 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 without being heated by the induction heating apparatus.

In the present invention, when the warp that cannot be corrected is equal to or more than a predetermined value, the induction heating device is temporarily evacuated to avoid a long-term facility down due to breakage of the induction heating device.

[0024]

Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a hot rolling equipment row showing one example of the present 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 by a table roller 3 and sent to the finishing rolling mill 2 side. ing.

An induction heating device 4 for the sheet bar for heating the sheet bar is arranged on the entrance side of the finishing mill 2. The induction heating device 4 includes a bar heater 5 that is a heating device in the sheet bar width direction that is arranged in the transport direction and an edge heater 6 that is a sheet bar width direction end heating device.

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

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

The edge heaters 6 arranged downstream of the bar heater 5 are arranged at both ends in the width direction of the sheet bar 7 and are each constituted by a pair of upper and lower induction heating coils 8. Is an apparatus for induction-heating the end in the width direction from above and below.

A warp straightening device 14 is arranged on the entrance side of the induction heating device 4. The warp straightening device exemplified in the present embodiment is configured such that warp correcting straightening rollers are vertically arranged in a staggered manner, and the gap between the upper and lower straightening rollers can be adjusted.

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

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

During this conveyance, part of the heat held by the sheet bar 7 is dissipated into the atmosphere. In particular, the seat bar 7
There is a difference in the amount of heat dissipated into the atmosphere between the width direction end and the width direction center, and the temperature of the sheet bar 7 is lower at the width direction end than at the width direction center. When the temperature becomes low, a material defect occurs at the width direction end portion, but the width direction end portion is heated by the edge heater 6 to compensate for a temperature drop.

Although a temperature drop also occurs at the leading end and the tail end of the sheet bar 7, the temperature drop at the longitudinal end of the sheet bar 7 is compensated by being heated by the bar heater 5. Here, the detection of the end of the sheet bar 7 is performed, for example, by
This can be realized by providing a temperature sensor on the entrance side and performing feedback control based on a temperature signal from the sensor so as to reach a target temperature.

The temperature drop at the end of the sheet bar 7 causes a decrease in finish workability due to abnormal growth of crystal grains and causes a flaw on the finish roll. The heating by the bar heater 5 is performed when the sheet bar 7 passes through the tunnel-shaped induction heating coil 8. At this time, if the tip portion of the sheet bar 7 is warped, the sheet bar 7 may hit the induction heating coil 8 or the heat insulating material. However, in this embodiment, the sheet bar 7 is Since the sheet is passed through the induction heating device 4 after the warpage is corrected, the amount of warpage of the sheet bar 7 passing through the induction heating device 4 is suppressed, and the sheet bar 7 to the induction heating coil 8 or the like is suppressed. Contact is 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 the equipment and the like are avoided.

As described above, since the heating is performed after correcting the warpage, the gap between the induction heating coil 8 and the sheet bar 7 can be reduced, and the deterioration of the heating efficiency can be suppressed while preventing the equipment damage. be able to.

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

Next, a second embodiment will be described with reference to the drawings. In addition, among the same facilities as those in the above-described embodiment and the like that are not changed, description thereof will be omitted. The basic configuration of this embodiment is the same as that of the first embodiment, but as shown in FIG. 4, a warp detecting device 16 for detecting the warpage of the sheet bar 7 on the entrance side of the warp correcting device 14. Is different.

The warpage detecting device 16 comprises an upward warpage detecting device 17 and a downward warping detecting device 18. The upward warpage detecting device 17 includes a turning shaft 17 a that can turn up and down above the seat bar 7, and a rod 17 b having an upper end fixed to the turning shaft 17 a extends toward the upper surface of the seat bar 7. The gap between the lower end of the rod 17b and the sheet bar 7 is set small. When the sheet bar 7 is warped upward, the conveyed sheet bar 7 hits the rod 17b, and the rod 17b is moved by an amount corresponding to the warp.
To turn up. Further, a rotation amount detection sensor 17c is connected to the turning shaft 17a, and the rotation amount detection sensor 17c can supply a signal corresponding to the detected rotation amount to the warpage correction controller 19.

In the downward warpage detecting device 18, the central portion of the plate 18a is supported by the apron of the table roller 3 so as to be able to turn up and down, and a counterweight 18b is provided at the rear end of the plate 18a. The plate body 18a is vertically inclined and balanced so that the front side is slightly upward. The plate 18a is turned downward by hitting the plate 18a at the end of the sheet bar 7 that is warped downward. 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 corresponding to the detected rotation amount to the warpage correction controller 19.

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

At this time, if the amount of warpage determined by the above determination is within a predetermined allowable value, as shown in FIG. 4A, the upper correcting roller 14a is released upward to open the warping correcting device 14. If the amount of warpage determined by the above determination exceeds a predetermined allowable value, the correction process is performed by lowering the upper correction roller 14a as shown in FIG. 4B.

In FIG. 4, reference numeral 14c denotes a warp correcting device 1.
4 is a guide member provided on the entrance side, and can be moved up and down in synchronization with the upper correction roller 14a. In such a configuration, the warp detecting device 16 is arranged on the entrance side of the warp correcting device 14, so that the warp correcting device 14 is provided.
, The presence / absence of warpage of the sheet bar 7 and the amount of warp can be detected. For the sheet bar 7 whose warpage is small within the predetermined allowable range or has no warpage, the warp correcting device 14 is used.
, The frequency at which the front end portion of the sheet bar 7 abuts against the warp straightening device 14 and scratches the straightening rollers 14a, 14b and the like is suppressed, and only the sheet bar 7 having a predetermined or more warp is straightened. Is performed.

As a result, the rate of occurrence of defective quality of the sheet bar 7 due to the transfer of the abutting flaw can be reduced, and
The sheet bar 7 can pass through the induction heating device 4 in a state in which warpage is suppressed, and the heating efficiency is good.

Other functions and effects are the same as those of the first embodiment. Note that the warpage detection device 16 is not limited to the above configuration, and another known device 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. In addition, among the same equipments and the like as those in the above-described embodiment, the description of those that are not changed will be omitted.
The basic configuration of the present embodiment is the same as the first embodiment, but as shown in FIG.
4 is provided with a warpage detecting device 20 for detecting the warpage of the sheet bar 7 on the exit side of the sheet 4.

Since the warpage detecting device 20 is the same as that described in the second embodiment, its details are omitted, but the upward warpage detecting device 21 and the downward warpage detecting device 2 are not described.
The rotation amount detection sensors 21 c and 22 c of the upward warpage detection device 21 and the downward warpage detection device 22 respectively output a signal corresponding to the detected rotation amount to the warp correction controller 19.
It can be supplied to

The controller 19 for correcting warpage of the present embodiment.
Then, the amount of warpage 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 warpage is within the predetermined allowable range, the upper straightening roller 14a is released upward to open the warp straightening device 14. If it is determined that the amount of warpage exceeds the predetermined allowable range, a signal for stopping conveyance is supplied to a 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 sheet bar 7. Subsequently, a signal to resume conveyance after returning the sheet bar by a predetermined amount is supplied to a sheet bar conveyance controller (not shown).

In such a configuration, the seat bar 7
The correction by the warp correction device 14 is performed only when the warpage is equal to or more than a predetermined value. As a result, for the sheet bar 7 in which the warp is small within the predetermined allowable range or has no such warp, the warp straightening device 14 is opened, and the front end of the sheet bar 7 abuts on the straightening rolls 14a, 14b of the warp straightening device 14. The frequency of occurrence of flaws is suppressed to a low level, and only the sheet bar 7 having a warp of a predetermined degree or more is once again returned by the reverse running processing to perform the warp correction processing. Accordingly, 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 of the first embodiment. Note that the warpage detection device 20 is not limited to the above configuration, and another known device such as a non-contact type 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 after the warp correction is performed according to the second embodiment is detected by the warp detection device 20, and if the warp is equal to or more than a predetermined amount, the sheet bar 7 is moved backward to perform the correction again. . According to this, warpage correction can be performed more reliably.

Next, a fourth embodiment will be described with reference to the drawings. In addition, among the same equipment as the above embodiment, the description of the equipment that is not changed will be omitted. The configuration of the present embodiment is the same as that of the third embodiment, but as shown in FIG. 6, a bar heater 5 and an edge heater 6 which are induction heating devices 4 are moved by a forward / backward actuator 25 such as a hydraulic cylinder device. The seat bar 7 can be advanced and retracted in the width direction. The forward / backward actuator 25 operates based on a command from the forward / backward controller 26.

The warp detecting device 16 disposed on the output side of the warp correcting device 14 supplies a detection signal to the advance / retreat controller 26. The forward / backward controller 26 determines the amount of warpage based on a signal from the warp detection device 20 disposed on the exit side of the warp straightening device, and if it is determined that the amount of warpage is equal to or greater than a predetermined value, the controller 26 retracts to the forward / backward actuator 25. A command is supplied to retract the bar heater 5 and the edge heater 6.

In this embodiment, when the warp that has not been corrected even after passing through the warp correction device 14 is equal to or more than a predetermined value, the bar heater 5 and the edge heater 6 are retracted to guide the sheet bar 7. A collision with the heating device 4 is prevented, and as a result, a long-term facility down due to breakage of the facility 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 content of the third embodiment. As shown in FIG. 7, that is, as in the second embodiment, separately, the warp detecting device 16
May be provided, and the warp correction device 14 may be feedback-controlled based on the detection result of the warpage detection device 16 on the entry side.

Other functions and effects are the same as those in the above embodiment. Note that the warpage detection device 20 is not limited to the above configuration, and another known device such as a non-contact type sensor using a laser beam or the like may be used.

Next, a fifth embodiment will be described with reference to the drawings. It should be noted that the same equipment and the like as in the above embodiment will be described with the same reference numerals. As shown in FIG. 8, the basic configuration of this embodiment is the same as that of the first embodiment, except that the position of the warp correction device 14 is different, and the winding / unwinding device 28 and the bar joining device 29 are different from each other. The difference is that they have been added.

That is, between the exit side of the rough rolling mill 1 and the entrance side of the induction heating device 4, the winding and rewinding device 28, the warp straightening device 14, and the bar joining device 29 are arranged in this order from the rough rolling mill 1 side.
Is arranged.

The winding and rewinding device 28 is composed of a plurality of coilers 28a, which winds up the sheet bar 7 rolled by the rough rolling mill 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 sheet 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 preceding sheet bar 7 and the tip end of the succeeding sheet bar 7 by welding or the like, thereby finishing the sheet bar 7 in an endless state. It is possible to convey to the rolling mill 2 side.

In this configuration, the following sheet bar 7 is wound around a coiler and stored in a coil state, and the following sheet bar 7 is synchronized with the timing at which the tail end of the preceding sheet bar 7 passes through the bar joining device 29. And the trailing sheet bar 7 is fed out so that the leading end of the succeeding sheet bar 7 passes through the bar joining device 29, and the ends of both sheet bars 7 are joined by the bar joining device 29. By repeating this, finish rolling is performed in an endless state.

In this endless rolling, the finish rolling is performed in a state where the preceding material and the following material are connected to each other, so that the end rolling such as the batch process (when the process is performed without connecting each sheet bar 7) is performed. Since there is no unsteady portion at the end, stable finish rolling can be realized over the entire length of the material to be rolled. In particular, the equipment is capable of rolling even though it is difficult to pass unsteady portions such as rolling of thin materials.

As described above, as the material to be rolled becomes thinner, the temperature drop increases. However, by heating the entire sheet bar 7 with the bar heater 5, the temperature compensation can be surely realized. Here, the sheet bar that is wound up in a coil shape and waits is
Not only the thin material but also the temperature at the outer end (tip) and the inner end (tail end) of the sheet bar 7 is lower than that at the center in the longitudinal direction. By heating the whole at 5, the temperature drop can be compensated.

Further, in the present embodiment, the warp of the unwound sheet bar 7 is corrected by the warp correcting device 14 disposed on the exit side of the winding and rewinding device 28, so that the induction heating device is provided. The contact between the induction heating coil 8 and the sheet bar 7 in the vertical direction can be set small, as in the first embodiment, because the contact between the induction heating device 4 and the sheet bar 7 can be reduced by the sheet bar 7 passing therethrough. Is possible, that is, the heating efficiency is good.

The other structure, operation and effect are the same as those of the above embodiment. As for the control of the warp straightening device 14, as described in each of the above embodiments, a warp detecting device that detects the warpage of the sheet bar 7 is provided on at least one of the entrance side and the outgoing side of the warp straightening device 14. The warp correction device 14 may be provided based on the detection value of the warp detection device.

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

In this embodiment, when the above-described endless rolling is performed, that is, the winding and rewinding device 28
When using the bar warping device 29, the first warpage straightening device 14 is used, and when performing a normal batch process, the second warpage straightening device 30 is used. The warp of the sheet bar 7 can be corrected in accordance with the contents of (1).

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

Further, the bar heater 5 is not limited to the above-described configuration, and may be configured such that induction heating coils whose axes are vertically directed independently are arranged on the upper side and the lower side of the sheet 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 according to the thickness or warpage of the sheet bar 7.

[0069]

EXAMPLES Actually, in each of the above-mentioned embodiments based on the present invention, the damage of the induction heating device and the percentage of defective flaw quality of the finished product after finish rolling were examined. The results are shown in FIG.

In FIG. 10, reference numeral C denotes a case where no warp correcting device is provided on the inlet side of the induction heating device. The code D is
This is a case of the equipment configuration based on the first embodiment. Symbol E indicates a case of a facility configuration based on any of the second to sixth embodiments.

As can be seen from FIG. 10, by adopting the present invention, long-term equipment down due to equipment breakage is greatly reduced, which is effective in reducing down time.

It can also be seen that semi-finished products are also reduced. Here, a semi-finished product is a product that is too low in temperature and cannot be rolled to be scrap.

[0073]

As described above, when the present invention is employed, it is possible to correct the warpage of the sheet bar before performing the induction heating process, thereby reducing the amount of warpage. And reduce the frequency of contact with
Since the vertical gap between the induction heating coil and the sheet bar can be set smaller, there is an effect that a predetermined heating efficiency can be secured while preventing operation interruption due to breakage of the induction heating equipment.

At this time, when the invention described in claim 2 is adopted, the tunnel heating bar passage is formed by arranging the induction heating coil so as to go around the entire periphery of the sheet bar in the sheet width direction, There is an effect that the entire sheet bar can be heated by passing the sheet bar through the induction heating coil. It has the effect of being effective.

Further, when the invention described in claim 3 is adopted, the finish rolling in a so-called endless state can be performed by providing the winding and rewinding device and the bar joining device, and stable over the entire length of the material to be rolled. Finished rolling can be performed, and for example, a thin material of 1 mm or less can be rolled, and the temperature reduction of the entire sheet bar can be compensated by the induction heating device.

Further, when the invention described in claim 4 is adopted, the warpage of the sheet bar unwound from the winding / unwinding device is corrected by the warp correcting device on the entry side of the bar joining device, and at the same time, the guiding is performed. Before the sheet bar is conveyed to the heating device, the warpage of the sheet bar can be corrected, and the above-described effects can be obtained.

Further, when a warp straightening device is also provided on the exit side of the bar joining device, the warp straightening process can be performed by the warp straightening device on the entrance side of the bar joining device in the endless rolling.
In the case of ordinary batch rolling, the warp can be corrected by the warp correcting device on the exit side of the bar joining device, so that in both rolling operations, the warp can be corrected by the warp correcting device before passing through the induction heating device. Thus, the above-mentioned effects can be obtained at the same time as the above-mentioned both rolling operations can be performed.

Further, when the invention described in claim 5 is adopted, in addition to the above-mentioned effects, there is an effect that it is possible to correct the warpage properly according to the state of the warpage and to grasp the correction result. .

Further, when the invention described in claim 6 or 7 is adopted, when there is no or small warpage, the warp straightening device is opened, so that the front end portion of the sheet bar is connected to the warp straightening device. The frequency of occurrence of flaws in the straightening portion of the warp straightening device and the size of the flaws can be suppressed to be small, and the warp correction processing can be performed for a sheet bar having a warp exceeding a predetermined allowable range. There is.

In the case where the invention described in claim 8 is adopted, if the warp that could not be corrected is equal to or more than a predetermined value, the induction heating device is temporarily retracted to thereby damage the induction heating device. Therefore, there is an effect that long-term equipment down due to is avoided.

[Brief description of the drawings]

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

FIG. 2 is a schematic configuration diagram illustrating 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 row of hot rolling equipment according to a fifth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing a row of hot rolling equipment 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]

 DESCRIPTION OF SYMBOLS 1 Rough rolling mill 2 Finish rolling mill 3 Table roller 4 Induction heating device 5 Bar heater 6 Edge heater 7 Sheet bar 8 Induction heating coil 14 Warpage straightening device 16 Warpage detecting device 19 Straightening controller 20 Warpage detecting device 25 Forward / backward actuator 26 Forward / backward Controller 28 Take-up / unwind device 29 Bar joining device 30 Second warp straightening device

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C21D 1/42 C21D 1/42 J 9/52 101 9/52 101 H05B 6/10 381 H05B 6/10 381 B21B 37/00 BBM

Claims (8)

[Claims] In a hot rolling facility provided with an induction heating device for heating a sheet bar on an entrance side of a finish rolling mill, a warp straightening device for correcting a warpage of a sheet bar is provided on an entrance side of the induction heating device. A hot rolling facility characterized by being provided. 2. The induction heating coil of the induction heating device,
The hot-rolling equipment according to claim 1, wherein the hot-rolling equipment is arranged so as to go around the entire circumference of the sheet bar in the sheet width direction. 3. A winding and rewinding device for temporarily winding and waiting a sheet bar between a rough rolling mill installed upstream of the finishing mill and the induction heating device, and a winding thereof. 3. A bar joining device for joining a tail end of a preceding sheet bar and a tip end of a succeeding sheet bar downstream of the rewinding device.
Hot rolling equipment described in 1. 4. The hot rolling equipment according to claim 3, wherein the warp straightening device is provided at least on an entrance side of the bar joining device. 5. A warp detection device for detecting warpage of a sheet 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 claim 1, further comprising a controller. 6. The hot rolling equipment according to claim 1, further comprising: a warp straightening device for straightening a sheet bar on an entrance side of the induction heating device. A warp detecting device for detecting the warpage of the sheet bar is provided on the entry side, and only when the amount of warpage of the sheet bar exceeds a predetermined allowable range based on the detection by the warp detecting device, the warp correcting process by the warp correcting device. Hot rolling method. 7. The hot rolling equipment according to claim 1, further comprising a warp straightening device for straightening a sheet bar on an entrance side of the induction heating device, wherein the warp straightening device is provided. Provide a warp detection device to detect the warpage of the sheet bar on the exit side of the, if the amount of warpage of the sheet bar is within the allowable range based on the detection by the warp detection device, without performing the correction processing by the warp correction device,
When the amount of warpage of the sheet bar exceeds an allowable range, the conveyance of the sheet bar is temporarily stopped, the sheet bar is returned by a predetermined amount, and the warp correction device performs a warp correction process. Rolling method. 8. The hot-rolling equipment according to claim 1, further comprising a warp straightening device for straightening the sheet bar on the entry side of the induction heating device, wherein the warp straightening device is provided. A warp detecting device for detecting the warpage of the sheet bar is provided on the exit side of the device, and when the warp amount of the sheet bar is equal to or more than a predetermined value based on the detection by the warp detecting device, the induction heating device is temporarily retracted from the online position. And hot-rolling the sheet bar without heating the sheet bar with the induction heating device.