JPH11123438A - Hot rolling equipment and hot rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot rolling equipment provided with an induction heating device capable of heating a sheet bar while protecting an induction heating coil from the sheet bar. SOLUTION: A bar heater 5 to heat a sheet bar is arranged on an inlet side of a finish rolling mill, and the bar heater 5 forms a tunnel shaped space so that an induction heating coil 8 is arranged to direction its axis to a transfer direction of the sheet bar 7 so as to encircle a surrounding of the sheet bar 7 in the width direction. A guide member 9 is arranged between the induction heating coil 8 and the sheet bar 7, the guide member 9 is made of a pipe material in which cooling water flows, and the guide member main body 9 is extended in parallel along a transfer direction of the sheet bar 7 between the induction heating coil 8 and the sheet bar 7.

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.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a hot rolling facility provided with an induction heating device capable of heating the sheet bar while protecting the induction heating coil from the sheet bar. The task is to provide.

[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 provided with an induction heating device for heating a sheet bar on the entrance side of a finishing mill, the induction heating device guides the sheet bar between an induction heating coil and the sheet bar. A member is arranged, and the guide member is characterized in that the inside thereof is water-cooled.

In the present invention, since the guide member for guiding the sheet bar is provided between the sheet bar and the induction heating coil, even if the longitudinal end of the sheet bar is warped, the sheet bar may be provided. Is prevented by the guide member, thereby preventing damage to the equipment such as the induction heating coil and the heat-resistant material being damaged due to the warpage of the sheet bar. The sheet bar is guided by the guide member and conveyed to the exit side of the induction heating device. Is done.

In addition, the guide member may be subjected to induction heating,
Although it receives heat radiation from the sheet bar, the internal water cooling suppresses a decrease in the strength of the guide member. Next, a second aspect of the present invention is characterized in that, in the configuration described in the first aspect, the guide member extends along a sheet bar conveying direction.

In the present invention, in addition to the above operation, since the guide member extends along the sheet bar conveying direction,
Even if the sheet bar abuts on the guide member, it is prevented from hitting the guide bar, and the sheet is reliably sent in the transport direction.

Next, a third aspect of the present invention is directed to the first aspect.
Or, in the configuration described in claim 2, the guide member is
It is characterized by being made of austenitic stainless steel.

In the present invention, the guide member is made of austenitic stainless steel, so that the influence of induction heating can be suppressed to a small extent. The desired strength required for the guide member is ensured.

Next, according to a fourth aspect of the present invention, the induction heating coil of the induction heating device according to any one of the first to third aspects is such that the outer periphery of the sheet bar extends in the width direction of the sheet bar. It is arranged so as to go around the entire circumference.

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, it is possible to heat the entire sheet bar in the width direction.

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 5 is directed to a configuration in accordance with any one of claims 1 to 4, wherein the rough rolling mill and the induction heating device are installed upstream of the finishing mill. A winding and rewinding device that temporarily winds up the sheet bar and waits, and a tail end of a preceding sheet bar and a tip of a succeeding sheet bar downstream of the winding and rewinding device. A bar joining device for joining
It is characterized by having.

In the present invention, in addition to the above-mentioned functions, 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 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 and the tail end) are at a higher temperature than the intermediate portion. Although the drop is large, the above-described induction heating device can compensate for the drop in temperature at the end of the sheet bar. At this time, it is conceivable to raise the heating temperature of the heating furnace to perform temperature compensation,
It is disadvantageous in terms of generation of slag, increase in energy cost, and life of the furnace.

Next, according to a sixth aspect of the present invention, in addition to the configuration of the fourth or fifth aspect, a warp straightening device for straightening the sheet bar is provided on the entrance side of the induction heating device. It is characterized by the following.

In the present invention, in addition to the above-described functions, the sheet bar can be corrected for warpage before the induction heating process is performed, and the amount of warpage is reduced. The vertical gap between the heating coil and the sheet bar can be set small.

According to a seventh aspect of the present invention, in the configuration according to the sixth aspect, the warp straightening device is provided at least on the 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 and rewinding 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 conveyed to the induction heating device. In addition, the correction of the warpage of the seat bar is realized.

Further, in the case where 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.

Next, according to an eighth aspect of the present invention, in the configuration described in the sixth or seventh aspect, the warpage of the sheet bar is detected on at least one of the entrance side and the 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 is possible to correct the warp according to the state of the warp and to grasp the correction result. Next, the invention described in claim 9 is based on claim 1
The hot-rolling equipment according to any one of claims 1 to 5, further comprising: a warp straightening device for correcting a warpage of the sheet bar on an inlet side of the induction heating device, and a warpage of the sheet bar on an inlet side of the warp straightening device. Providing a warp detecting device for detecting the warpage, and performing the warp correcting process by the warp correcting device only when the amount of warpage of the sheet bar exceeds a predetermined allowable range based on the detection by the warp detecting device. It is a rolling method.

According to 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 due to the opening of the warp straightening device causing the front end portion of the sheet bar to hit the warp 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 size is generated in the warp correcting device, the abutting flaw is transferred when the succeeding material is corrected, leading to poor quality of the sheet bar. 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 tenth aspect of the present invention, in the hot rolling equipment according to any one of the first to fifth aspects, the warpage of the sheet bar is corrected on the entrance side of the induction heating device. Providing a warp straightening device, and providing a warp detecting device for detecting the warpage of the sheet bar on the exit side of the warp straightening device,
If the amount of warpage of the sheet bar is within the allowable range based on the detection by the warp detection device, the correction processing by the warp correction device is not performed, and if the amount of warpage of the sheet bar exceeds the allowable range, once the sheet bar is The conveyance is stopped, the sheet bar is returned by a predetermined amount, and the warp correction device performs a warp correction process.

Also in the present invention, when the 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 8 is obtained. Next, the invention described in claim 11 corresponds to claims 1 to 5
In the hot rolling equipment according to any one of the above, a warp straightening device for correcting the warpage of the sheet bar is provided on the inlet side of the induction heating device, and the warpage for detecting the warpage of the sheet bar on the outlet side of the warp straightening device. If the amount of warpage of the sheet bar is equal to or more than a predetermined value based on the detection by the warp detection device, the induction heating device is temporarily retracted from the online position, and the sheet bar is heated by the induction heating device. It is characterized in that it passes through without passing through.

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, thereby avoiding a long-term facility down due to breakage of the induction heating device.

[0030]

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.

On the entry side of the finishing mill 2, an induction heating device 4 for the sheet bar for heating the sheet bar is arranged. 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.

As shown in FIG. 2 which is a schematic side sectional view and FIG. 3 which is a schematic plan sectional view, the bar heater 5 is arranged so that the induction heating coil 8 orbits around the sheet bar 7 in the width direction. Are arranged in the conveying direction of the sheet bar 7 so that the sheet bar 7 can pass through the space inside the induction heating coil 8. The induction heating coil 8 is composed of a plurality of sets of coils divided into a plurality of pieces in the axial direction.
Each coil is supplied with current from a current supply device (not shown).

A guide member 9 is arranged between the induction heating coil 8 and the sheet bar 7. The guide members 9 of the present embodiment are independently arranged on the upper side and the lower side of the sheet bar 7, and are made of a plurality of pipe members having a circular cross section arranged in parallel in the width direction of the sheet bar 7 as shown in FIG. .
Each pipe member is provided with a guide portion main body 9a extending in parallel along the conveying direction of the sheet bar 7 between the induction heating coil 8 and the sheet bar 7, and communicates with the guide portion main body 9a. 8 at the axial end positions of the seat bars 7 respectively.
And a pair of feet 9b extending in a direction away from the main body.

The upper pipe group and the lower pipe group sandwiching the seat bar 7 are formed independently, and the ends of the feet 9b of the pipe material are respectively connected to the cooling water circulation pipes 10, 11 is connected. Cooling water circulation pipe 10,
Reference numeral 11 denotes a set of a cooling water supply pipe 10 and a cooling water return pipe 11. Thus, the inside of the pipe member constituting the guide member 9 is water-cooled.

An electric insulating material 12 is interposed in the middle of each of the feet 9b. Insulated by the electric insulating material 12, the current induced in the guide portion main body 9a is prevented from flowing toward the cooling water circulation pipes 10, 11, so that the current does not go around the induction heating coil 8. It has become.

Further, a heat insulating material 13 for protecting the induction heating coil 8 from heat radiation from the seat bar 7 is provided between the guide portion main bodies 9a. By setting the gap between the heat insulating material 13 and the sheet bar 7 to be slightly larger than the gap between the guide portion main body 9a and the sheet bar 7, the collision of the sheet bar 7 with the heat insulating material 13 and the guide portion can be prevented. It is prevented by the main body 9a.

Here, as the pipe material forming the guide portion main body 9a, for example, a Sch. 8
Use a 0A stainless steel pipe. At this time, since the loss of the induction heating by the guide portion main body 9a decreases as the outer diameter of the guide portion main body 9a increases, the pipe diameter and the like may be determined based on the balance between the loss amount and the strength.

Further, in view of the fact that the width of the sheet bar required to be passed is changed from 600 mm to 1900 mm and the shape of the leading end of the sheet bar is changed, as shown in FIG. The main body 9a may be attached at a pitch of 100 mm in the width direction of the sheet bar 7, for example.

Since the widthwise end of the sheet bar 7 is not located at the center of the sheet width direction, the pitch of the guide portion main body 9a is located at the center of the sheet width direction as shown in FIG. There is no problem even if you make it wider.

At this time, the relationship between the pipe outer diameter and the heating efficiency,
Investigation of the relationship between the strengths of one pipe material revealed that the relationship was as shown in FIG. That is, naturally, the strength of the guide portion main body 9a increases as the outer diameter of the pipe material increases, but the actual heating efficiency of the seat bar 7 decreases as the outer diameter increases. What is necessary is just to determine by suitably considering the amount, the thickness and the width of the sheet bar 7, and the like.

In the present embodiment, the amount of warpage of the sheet bar 7 passing through the induction heating device 4 is usually set because the warpage correction device 14 is disposed on the entrance side of the induction heating device 4 as described later. Can be kept small. Therefore, the case where a 20 mm diameter stainless steel pipe is used as described above is illustrated. The configuration of the guide portion main body 9a of the guide member 9 is not limited to a round pipe, but may be a square pipe,
It may be configured by laminating boards. In short, the guide portion main body 9a may be a member having a structure extending along the sheet bar 7 conveying direction and having a passage for allowing cooling water to pass through the inside thereof.

As the material of the pipe material, austenitic stainless steel is preferably used. By using austenitic stainless steel, the influence of induction heating can be suppressed to a small extent, which is advantageous in terms of strength and the like.

The edge heaters 6 arranged on the downstream side of the bar heater 5 are arranged at both ends in the width direction of the sheet bar 7 and are each composed of 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.

Further, 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, effects and the like of the hot rolling equipment having the above 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 front 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 in 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 of the sheet bar 7 is warped, the sheet bar 7 may hit the induction heating coil 8 or the heat insulating material 13,
Since the warped end of the sheet bar 7 hits the guide body 9a before hitting the induction heating coil 8 or the like, the induction heating coil 8 and the heat insulating material 13 are damaged, that is, the induction heating coil 8 is damaged.
The equipment is prevented from being damaged, and stoppage of the equipment is avoided.

At this time, since the guide portion main body 9a extends in the conveying direction of the sheet bar 7, even if the warped sheet bar 7 collides with the guide portion main body 9a, the guide portion main body 9a is not moved. It is guided by the guide portion main body 9a and guided to the outlet side of the induction heating device 4 without hitting.

In the bar heater 5, the guide portion main body 9a is also subjected to induction heating in order to heat the entire sheet bar 7, but since the austenitic stainless steel is used,
The effect of induction heating is also small. In addition, since the internal water cooling is performed, a decrease in guide strength due to induction heating or heating by receiving heat radiation from the sheet bar 7 can be suppressed.

Further, in the present embodiment, the seat bar 7
Is configured to pass through the induction heating device 4 after the warp is corrected by the warp correction device 14, so that the amount of warpage of the sheet bar 7 passing through the induction heating device 4 is suppressed, and The contact of the seat bar 7 with 9a is suppressed. As a result, the gap between the induction heating coil 8 and the sheet bar 7 can be reduced, and a decrease in heating efficiency can be suppressed while preventing equipment damage.

The warp correcting device 14 may be omitted by increasing the gap between the inner wall of the bar heater 5 and the sheet bar 7. However, in this case, the heating efficiency is reduced more than the above, and there is a possibility that the bar heater needs to be lengthened or the passage speed of the sheet bar 7 needs to be reduced.

Here, when compensating for the temperature drop by the induction heating device 4, it is advantageous that the sheet 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.

In the above-described embodiment, an example in which the guide member 9 is provided only in the bar heater 5 is described. However, the edge heater 6 may be protected by providing the guide member 9 having a similar configuration.

Since the roll 3a of the table roller 3 is disposed on the lower surface side of the sheet bar 7, the gap between the sheet bar 7 and the induction heating coil 8 can be set smaller than that on the upper surface side. Alternatively, the gap on the lower surface side of the seat bar 7 may be increased, and the guide member 9 on the lower surface side of the seat bar 7 may be omitted.

When the temperature drop at both ends in the width direction of the sheet bar 7 can be ignored, the edge heater 6 may be omitted, and the temperature drop at both ends in the longitudinal direction of the sheet bar 7 can be ignored. In some cases, the bar heater 5 may be omitted.

The guide section main body 9a does not necessarily need to be set parallel to the sheet bar 7 conveying direction. For example, the guide section main body 9a is tilted up and down so that the distance from the sheet bar 7 becomes wider at the entrance side of the bar heater 5. Thus, when the front end portion of the sheet bar 7 passes through the inside of the bar heater 5, it may be more difficult to hit the guide member 9.

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. 5, a warp detecting device 16 for detecting the warpage of the sheet bar 7 on the entry 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 pivotable 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. 5A, the upper straightening roller 14a is released upward to open the warpage straightening 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. 5B.

In FIG. 5, 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 poor quality of the sheet bar 7 due to the transfer of the abutting flaw is suppressed to be small, and the sheet bar 7 is
It is possible to pass through the induction heating device 4 in a state where the warpage is suppressed, and the heating efficiency is good.

Other functions and effects are the same as those in 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 this embodiment is the same as that of 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 warp detecting device 20 is the same as that described in the second embodiment, its details are omitted, but the upward warp detecting device 21 and the downward warp 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 in 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 result of performing the warp correction according to the second embodiment is detected by the outgoing-side warp detection device 20, and when the detected value is equal to or more than a predetermined value, the sheet bar 7 is moved backward to correct again. Things. According to this,
More reliable warpage correction becomes possible.

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 this embodiment is the same as that of the third embodiment, but as shown in FIG. 7, the bar heater 5 and the edge heater 6 which are the 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 completely 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, so that the guiding by the sheet bar 7 is performed. 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, and as shown in FIG. 8, that is, separately provided on the entrance side of the warp correction device 14 as shown in FIG.
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. The basic configuration of this embodiment is the same as that of the first embodiment, as shown in FIG. 9, except that the position of the warp straightening device 14 is different, and that the winding / unwinding device 28 and the bar joining device 29 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, in order from the side of the rough rolling mill 1, the winding / unwinding device 28, the warp straightening device 14, and the bar joining device 29.
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 succeeding sheet bar 7 is wound around a coiler and stored in a coil state, and the trailing sheet bar 7 is synchronized with the timing when 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, so that the end rolling such as the batch processing (when the processing 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 the material to be rolled becomes thinner as described above, the temperature drop increases. However, by heating the entire sheet bar 7 with the bar heater 5, the temperature compensation can be reliably 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. Can.

Other structures, operations and effects 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. 10, 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 / unwinding 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).

The other structures, operations and effects are the same as those of the above embodiment. In all of the above embodiments, since the bar heater 5 heats the entire seat bar 7,
The edge heater 6 may be omitted by designing so as to heat the end portion of the sheet bar 7 in the width direction of the sheet higher by the arrangement of the coil and the like.

The bar heater 5 is not limited to the above-described configuration, but may be configured such that induction heating coils whose axes are vertically directed independently are arranged on the upper and lower sides 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.

The order of installation of the bar heater 5 and the edge heater 6 may be reversed.

[0091]

As described above, according to the present invention, since the guide member for guiding the sheet bar is provided between the sheet bar and the induction heating coil, the end of the sheet bar is warped. Even when the sheet bar is generated, the sheet bar is blocked by the guide member, and the warp of the sheet bar prevents the induction heating coil and the heat-resistant material from being damaged, thereby preventing the equipment from being damaged.

At this time, the guide member receives the induction heating and the heat radiation from the sheet bar, but since the inside is water-cooled, a decrease in the strength of the guide member is suppressed.
At this time, if the invention described in claim 2 is adopted, the guide member extends along the sheet bar conveyance direction, so that even if the sheet bar abuts on the guide member, the sheet bar hangs. There is an effect that the paper can be reliably sent in the transport direction without any trouble.

Further, when the invention according to claim 3 is employed, the guide member is made of austenitic stainless steel, so that the influence of induction heating can be suppressed to a small extent, and further, the strength of the guide member can be suppressed from being reduced. The use of stainless steel has the effect that the desired strength required for the guide member is ensured.

Further, when the invention described in claim 4 is adopted, 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 passage, and the induction heating coil is formed. There is an effect that it is possible to heat the entire sheet bar by passing the sheet bar through the coil, and in particular, it is possible to effectively compensate for the temperature drop at the front end portion and the tail end portion of the sheet bar where a temperature drop occurs. effective.

Further, when the invention according to claim 5 is adopted, by providing the winding and rewinding device and the bar joining device, it is possible to perform finish rolling in a so-called endless state, and secure a stable finish rolling operation and the like. As a result, rolling of a thin material of, for example, about 1 mm can be realized, and the temperature reduction is compensated by a heating device.

Further, according to the invention described in claim 6, the warpage of the sheet bar can be corrected before the induction heating process is performed, the amount of warpage is reduced, and the strength of the guide member is improved. Since the vertical gap between the heating coil and the sheet bar can be set to be small, there is an effect that a predetermined heating efficiency can be secured while preventing operation interruption due to breakage of the induction heating equipment.

Further, when the invention described in claim 7 is adopted, the warpage of the sheet bar unwound from the winding and rewinding device is corrected by the warpage 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 entry 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 8 is adopted, there is an effect that the warpage can be corrected and the correction result can be grasped according to the warp state of the sheet bar. Also,
By adopting the invention described in claim 9 or claim 10,
When there is no or small warp, the warp straightening device is opened, so that the frequency of occurrence of a flaw in the straightening portion of the warp straightening device due to the front end of the sheet bar hitting the warp straightening device and the size of the flaw are kept small. In addition, for a sheet bar having a warp exceeding a predetermined allowable range, there is an effect that a warp correction process is realized.

Further, when the invention described in claim 11 is adopted, if the uncorrected warpage is equal to or more than a predetermined value,
By temporarily retracting the induction heating device, there is an effect that long-term equipment down due to breakage of the induction heating device can be 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 side sectional view showing a bar heater according to the first embodiment of the present invention.

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

FIG. 4 is a diagram showing a relationship among a nominal diameter, strength, and heating efficiency of the pipe according to the first embodiment of the present invention.

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

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

FIG. 7 is a schematic configuration diagram for explaining a fourth embodiment of the present invention.

FIG. 8 is a schematic configuration diagram illustrating a warp detection device according to a fourth embodiment of the present invention.

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

FIG. 10 is a schematic configuration diagram showing a hot rolling equipment row according to a sixth embodiment of 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 9 Guide member 9a Guide portion main body 9b Foot 10, 11 Cooling water circulation pipe line 12 Electric insulating member 13 Heat-resistant material 14 Warp straightening device 16 Warp detecting device 19 Straightening controller 20 Warp detecting device 25 Forward / backward actuator 26 Forward / backward controller 28 Winding / unwinding device 29 Bar joining device 30 Second warping straightening device

Continuation of the front page (51) Int.Cl. ⁶ identification code FI C21D 1/42 C21D 9/52 101 H05B 6/10 381 9/52 101 B21B 37/00 BBM H05B 6/10 381 116L

Claims (11)

[Claims] 1. A hot rolling facility provided with an induction heating device for heating a sheet bar on an entrance side of a finish rolling mill, wherein the induction heating device includes a sheet between an induction heating coil and the sheet bar. A hot rolling facility, wherein a guide member for guiding a bar is disposed, and the guide member is internally water-cooled. 2. The hot rolling equipment according to claim 1, wherein the guide member extends along a sheet bar conveying direction. 3. The guide member according to claim 1, wherein the guide member is made of austenitic stainless steel.
Hot rolling equipment described in 1. 4. The induction heating coil of the induction heating device,
The hot-rolling equipment according to any one of claims 1 to 3, wherein the hot-rolling equipment is arranged so as to go around the entire periphery of the sheet bar in the sheet width direction. 5. 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. 5. 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 Crab. 6. The hot rolling equipment according to claim 4, wherein a warp straightening device for straightening the sheet bar is provided on an entrance side of the induction heating device. 7. The hot rolling equipment according to claim 6, wherein the warp straightening device is provided at least on an inlet side of the bar joining device. 8. A warp detecting device for detecting warpage of a sheet bar is provided on at least one of an entrance side and an outgoing side of the warp correcting device, and the warp correcting device is controlled based on a detected value of the warp detecting device. The hot rolling equipment according to claim 6, further comprising a controller. 9. 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 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. 10. The hot-rolling equipment according to claim 1, further comprising a warp straightening device for straightening the sheet bar on the entrance side of the induction heating device. 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. 11. 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.