JP2008110368A - Apparatus and method for slow cooling coiled wire rod - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for cooling a coiled wire capable of slow cooling the coiled wire rod uniformly with simple facilities for a long time. <P>SOLUTION: Rotary rolls 20 having a diameter not smaller than half the coil diameter D of the coiled wire rod 10 are arranged zigzag on the intermediate portion of a conveyor 6 for carrying out the gradual cooling operation. The coiled wire rod is carried zigzag rightward and leftward so as to displace not smaller than half the coil diameter D in the direction of the width. As a result, the temperature difference in the direction of the width after finishing the gradual cooling operation becomes within the required range. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to cooling of a coiled wire after forming a hot-rolled wire into a coil (winding shape), and more particularly to an equipment and method for performing slow cooling by natural cooling.

When manufacturing a coil-shaped wire, for example, as described in Patent Document 1, a hot-rolled wire is placed on a conveyor (conveyance path) while being sequentially formed into a coil with a laying head. After the coiled wire is slowly conveyed by the conveyor, the wire is cooled and then focused on the focusing facility.
Here, since the material of the wire is determined by cooling during conveyance, it is important to cool the wire with a uniform and desired cooling pattern on the conveyor (conveyance path).

  And in patent document 1, while conveying a wire in the surrounding atmosphere which has a stepwise temperature gradient in a conveyance direction, in order to prevent the overheating in an surrounding atmosphere, external air blowing control and the overlap density of both sides of a coiled wire It is possible to provide a uniform temperature in the width direction over the entire length of the coiled wire rod by providing refrigerant spray control that promotes cooling of the end portion having a high temperature and heat compensation control that thermally compensates the supercooled portion of the wire coil. It is designed to be cooled.

In addition, from the demand for high-strength material, high-strength steel wire mainly composed of bainite structure is also required, and as its cooling pattern, it is forcedly cooled down to bainite temperature range after rolling, and then, It is necessary to hold in that temperature range for a long time until the bainite progresses sufficiently. In this case as well, although there is a difference that the bainite temperature range is lower than the annealing start temperature of the soft material, it is necessary to cool with the above cooling pattern.
Japanese Patent Publication No. 60-45252

However, in the cooling equipment of the above prior art, in order to eliminate a large temperature deviation in the width direction in the coiled wire due to the difference in the overlap density in the width direction of the coiled wire, outside air blowing equipment, refrigerant spraying equipment, heat compensation control, etc. However, there are problems in terms of economic efficiency, such as complicated facilities.
This invention is made paying attention to the above points, and makes it a subject to provide the cooling equipment of the coil-shaped wire which can reduce the temperature deviation of the width direction with simple cooling equipment.

In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention has a conveyance path on which a wire shaped into a coil shape is placed after hot rolling and conveys the wire while being gradually cooled. In the slow cooling equipment of the coiled wire material provided,
For at least part of the conveyance direction of the conveyance path, the roll is provided with one or two or more rolls that displace the coiled wire rod in the width direction by bringing the circumferential surface into contact with the coiled wire rod mounted on the conveyance path. The roll diameter can be rotated about the vertical axis, and the roll diameter is set to ½ or more of the coil diameter of the target coiled wire.
By setting the roll diameter to ½ or more of the coil diameter, the coiled wire conveyed by one roll can be greatly displaced in the width direction.

Next, the invention described in claim 2 is a coiled wire wire slow cooling facility provided with a transporting path on which a wire formed into a coil shape after hot rolling is placed and transported while gradually cooling the wire. In
For at least a part of the conveying direction of the conveying path, the coiled wire rod placed on the conveying path is brought into contact with the circumferential surface to displace the coiled wire rod in the width direction, and the coil shape is provided. The one or two or more rolls are arranged so that the amount of displacement in the width direction of the wire becomes 1/2 or more of the coil diameter.
By displacing the coiled wire in the width direction by ½ or more, the overlap of the coiled wire can be greatly dispersed.

Next, the invention described in claim 3 is the configuration described in claim 1 or claim 2, wherein the roll is rotatable around the vertical axis, and the peripheral surface of the roll has a circumferential surface. A plurality of blade members arranged in the direction protrude in the outer diameter direction, and the blade member has an upper surface inclined in the circumferential direction with respect to a horizontal plane.
A part of the coiled wire that is overlapped by the blade member can be temporarily scooped up, and the overlap can be temporarily dispersed also in the vertical direction.

Next, the invention described in claim 4 is directed to the configuration described in any one of claims 1 to 3, wherein the roll has a circumferential surface in contact with the coiled wire in the conveying direction of the coiled wire. It is characterized in that it is rotationally driven around the vertical axis so as to move toward the center.
By rotating the roll, it is possible to suppress wrinkling when the coiled wire comes into contact with the roll.
Next, the invention described in claim 5 is the structure described in any one of claims 1 to 4, wherein the transport speed by the transport path is stepwise from the upstream side toward the downstream side. It is characterized by being slow.
By decelerating the conveyance speed in stages, it is possible to change the overlap of the coiled wire rods in stages.

Next, the invention described in claim 6 is a method of gradually cooling a coiled wire rod in which a wire rod shaped into a coil shape after hot rolling is conveyed along a conveyance path to gradually cool the coiled wire rod. ,
The coiled wire being conveyed is meandered in the width direction at least half the coil diameter of the coiled wire at least in the middle thereof.
Next, the invention described in claim 7 is characterized in that, with respect to the configuration described in claim 6, the overlapping portions of the coiled wire material being transferred are temporarily separated in the vertical direction.

  According to the present invention, it is possible to meander the coiled wire material being conveyed in the width direction. For this reason, by greatly changing the position where the coiled wire material overlaps in the width direction, it is possible to disperse places where it is difficult to cool, thereby reducing temperature deviation in the width direction.

Next, a first embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic configuration diagram showing equipment after hot rolling according to the first embodiment. FIG. 2 is a schematic plan view showing a conveyance path for conveying the coiled wire.
(Constitution)
First, the structure will be described. The steel wire (wire material) hot-rolled to a predetermined wire diameter by the hot rolling mill 1 is continuously fed to the laying head 2 and sequentially coiled (winding) by the laying head 2. And is supplied to the cooling facility 3 and cooled by the cooling facility 3 and then focused on the focusing device 4.

  The cooling facility 3 is divided into an upstream forced cooling zone Z1 and a subsequent natural cooling zone Z2. Moreover, the roller conveyors 5 and 6 (conveyance path) which mount and convey the coil-shaped wire 10 sent from the laying head 2 are provided. The conveyors 5 and 6 are divided into a conveyor 5 arranged in the forced cooling zone Z1 and a conveyor 6 arranged in the natural cooling zone Z2. Here, the conveyer 5 in the forced cooling zone Z1 and the conveyer 6 in the natural cooling zone Z2 are driven independently, and the respective conveying speeds can be made different.

A blast cooling device 11 composed of a cold air blower or the like is disposed below the conveyor 5 disposed in the forced cooling zone Z1. Then, the cold air from the blast cooling device 11 is supplied to the coiled wire rod 10 being conveyed, whereby rapid cooling is performed with a predetermined temperature pattern. That is, by adjusting the conveying speed of the conveyor 5, the temperature of the cold air, and the amount of blowing, the coiled wire 10 is set to be cooled at once to the bainite temperature range before the transition to the natural cooling zone Z2. .
In the natural cooling zone Z2, the coiled wire 10 is naturally cooled for a predetermined time while being conveyed by the conveyor 6 for a predetermined time.

A plurality of rolls 20 that can come into contact with the coiled wire 10 being conveyed are arranged at a midway position in the conveyance direction of the conveyor 6 located in the natural cooling zone Z2. The plurality of rolls 20 are supported so as to be rotatable around an axis extending vertically. The plurality of rolls 20 are arranged in a staggered manner in the transport direction across the center position in the width direction of the coiled wire 10 to be transported. In addition, each roll 20 is set so that position adjustment is possible at least in the width direction of the coiled wire 10, and the position in the width direction is adjusted according to the coil diameter D of the corresponding coiled wire 10.
In the plurality of rolls 20 arranged in a staggered manner, the conveyed coiled wire 10 is arranged so as to be displaced by a half or more of the coil diameter D in the width direction.

  FIG. 2 is an example in which three rolls 20 arranged in a staggered manner are repeatedly displaced in the width direction by a half or more of the coil diameter D. That is, the coiled wire 10 that has been transported at a predetermined transport speed abuts on the peripheral surface of the first roll 20a, and is pressed so as to receive a reaction force in a direction corresponding to the contact angle. The sheet is conveyed while being displaced by more than ½ of the coil diameter D in the width direction, and further receives a reaction force in the opposite direction in the width direction according to the contact angle by contacting the peripheral surface of the second roll 20b. The coiled wire 10 is meandered while being pushed so as to be displaced by a half or more of the coil diameter D in the width direction. Further, by coming into contact with the peripheral surface of the third roll 20c, the reaction force in the reverse direction is again received according to the contact angle, but the third roll 20c is so moved that the subsequent movement becomes the central portion in the original traveling direction. The position of is adjusted.

(Function and effect)
In the cooling equipment 3, the wire continuously hot rolled by the hot rolling mill 1 is sent to the laying head 2, and is sequentially formed into a winding shape (coil shape) by the laying head 2. Further, in the forced cooling zone Z1 in the cooling facility 3, the wire 10 is forcibly cooled by a gust while being conveyed at a predetermined conveyance speed, and the temperature is lowered to a predetermined temperature, for example, a bainite temperature region. For this reason, the conveyor 5 is driven at a predetermined conveyance speed at which the temperature can be lowered at a stretch.

Subsequently, in order to hold the coiled wire 10 that has become the baitniteization temperature range for a long time in the temperature range until the bainite progresses sufficiently, while being slowly conveyed by the conveyor 6 in the natural cooling zone Z2. Natural cooling is performed.
Thus, it is necessary to perform natural cooling only for a certain long time. For this reason, the conveyance speed of the natural cooling zone Z2 is set to be slower than that of the forced cooling zone Z1.
Here, since the coil-shaped wire 10 overlaps more on the end side than the central portion in the width direction and has a high overlap density, the end portion in the width direction is relatively difficult to cool.

  On the other hand, the coiled wire 10 is conveyed by three rolls 20 while being transported while being gradually cooled while being displaced in the width direction by a half or more of the coil diameter D. By sequentially changing the overlapping position in the width direction, the temperature deviation in the width direction due to the overlap of the coiled wire rods 10 is dispersed. In particular, if meandering is performed on both sides in the width direction so as to be displaced by a half or more of the coil diameter D, the overlap on the end side of the coiled wire 10 on the side moved in the width direction is completely displaced as shown in FIG. Go. Furthermore, by making it meander larger than ½ of the coil diameter D on both sides, the overlapping density on both sides can be reliably dispersed, and the temperature deviation in the width direction can be more effectively suppressed to be small. As a result, the temperature deviation in the width direction after the end of slow cooling can be reduced.

For this reason, in order to eliminate the temperature deviation in the width direction, there is no need for partial supercooling or heating as in the conventional example, or the partial supercooling or heating is reduced in throughput. I can do it.
Moreover, in the said embodiment, only making the coil-shaped wire 10 contact | abut on the surrounding surface of one roll 20 by making the diameter of the roll 20 into 1/2 or more of the coil diameter D makes the said coil-shaped wire 10 suitable. As described above, it is possible to greatly move in the width direction, and it is possible to simplify the equipment when causing large meandering.

  Here, the roll 20 may be configured to rotate by a reaction force caused by the contact of the coil, but the moving direction of the portion in contact with the coil on the circumferential surface of the roll 20 is the conveyance direction of the coiled wire 10. It is preferable to rotate the roll 20 around the support shaft so as to be equal. In this case, the peripheral speed of the roll 20 is set to the same or substantially the same speed (for example, ± 5%) as the conveying speed of the coiled wire 10. As described above, when the roll 20 is driven to rotate, it is possible to avoid or reduce scratches when the coiled wire 10 abuts on the circumferential surface of the roll 20.

Moreover, you may comprise the roll 20 surrounding surface with elastic bodies, such as rubber | gum. If it does in this way, while suppressing the wrinkle generation | occurrence | production at the time of the coil-shaped wire 10 contact | abutting, it becomes possible to displace the coil-shaped wire 10 more in the width direction with the spring of an elastic body.
Moreover, in the said embodiment, although the case where the three rolls 20 are set is illustrated, it is preferable that there are four or more.
In addition, even if one roll 20 is moved to one side in the width direction by more than 1/2 of the coil diameter D, there is an effect. It is possible to more effectively suppress the temperature deviation in the width direction by moving the sheet by 1/2 or more of D.

(Example)
Here, the three rolls 20 as described above are arranged and gradually cooled so that the center of the coiled wire 10 meanders a displacement of half the coil diameter D in the width direction to both the right side and the left side. FIG. 3 shows the result of the temperature distribution in the width direction at the end of the slow cooling in the case of carrying out the above. For comparison, the result of the temperature distribution in the width direction at the end of the slow cooling in the conventional example in which the large meandering is not performed is also described.
The experimental conditions are as follows.
The equipment conditions are the same as those in the above embodiment.
Length of each conveyance path: 90m
Condition of blast Wind volume: 95000Nm ³ / hr
Cooling air temperature: 32 ° C
Wire diameter: 9mm
Coil diameter D of wire rod: 1200mm
As can be seen from FIG. 3, when the meandering is not performed, if there is a temperature deviation of about 80.degree. C., the meandering is about half the coil diameter D to the left and right. It can be seen that the temperature deviation of 40 ° C. and the temperature deviation can be reduced to about half of the conventional example.
And it is assumed that the temperature deviation can be further suppressed by meandering to the left and right larger than ½ of the coil diameter D.

(Second Embodiment)
Next, a second embodiment will be described with reference to the drawings. Note that components similar to those in the above embodiment are described with the same reference numerals.
(Constitution)
The basic configuration of this embodiment is the same as that of the first embodiment, but the form of the roll 20 is different.
As shown in FIG. 4, the roll 20 of the present embodiment includes a plurality of propeller-shaped blade members 21. That is, a plurality of plate-like blade members 21 arranged in the circumferential direction protrude in the outer diameter direction with respect to the circumferential surface of the roll 20, and the upper surface of the blade member 21 is inclined in the circumferential direction with respect to the horizontal plane. The inclination of the upper surface of the blade member 21 is inclined so that the downstream side in the conveyance direction of the coiled wire is on the lower side at the position in contact with the coiled wire 10. Further, the height of the blade member 21 is adjusted to a height that enters between the overlapping wires.
Here, in the present embodiment, the roll 20 is rotationally driven so that the peripheral speed of the roll 20 is slightly faster than the conveying speed of the coiled wire 10, for example, by 10% or more.

(Function and effect)
In the present embodiment, the temperature deviation is reduced by changing the overlapping position of the coiled wire rod 10 in the width direction by meandering so as to be displaced in the width direction (lateral direction) as described above by the peripheral surface of the roll 20. To do.
Further, in the present embodiment, as shown in FIG. 4, the rotating blade member 21 is inserted between the overlapping coiled wire rods 10, and the peripheral speed rotates faster than the coiled wire rods 10. The upper coiled wire 10 is lifted upward so as to be lifted up once and separated from the lower coiled wire 10. As a result, the coiled wire 10 is also displaced vertically so that the temperature deviation at the end in the width direction can be further eliminated.

In particular, as can be seen from FIG. 2, the coil-shaped wire 10 pushed in the width direction by the roll 20 has a higher density of the wire 10 near the roll 20. By relieving the contact between the portions of the wire 10 where the density of the wire 10 is high, the difficulty of cooling the meandering wire 20 on the roll 20 side is eased.
In this case, since the temperature deviation can be mitigated by the blade member 21 as well, it is not necessary to meander more than 1/2 of the coil diameter D in the width direction. .

(Third embodiment)
Next, a third embodiment will be described with reference to the drawings.
The basic configuration of this embodiment is the same as that of the first and second embodiments. However, the conveying speed of the conveyor is gradually reduced (slowed) toward the downstream side.
In this embodiment, a conveyor is comprised from four conveyors which can be driven independently, respectively along with a conveyance direction like FIG. In FIG. 5, the roll 20 is omitted for easy viewing. However, for example, the roll 20 is arranged on the central conveyor 6 b.

Here, in the following description, the four conveyors 5 and 6 are used for convenience, the conveyor 5 in the forced cooling zone Z1 is the first conveyor, and the conveyor 6 in the natural cooling zone Z2 is the second conveyor 6a, the third conveyor from the upstream side. It will be called a conveyor 6b and a fourth conveyor 6c.
The four conveyors 5 and 6 are installed such that the adjacent conveyors are positioned such that the tip of the downstream conveyor is positioned below the tail end of the upstream conveyor and a step is provided. For example, the height of the second conveyor 6a is set lower than the height of the first conveyor 5, the height of the third conveyor 6b is set lower than the height of the second conveyor 6a, and is higher than the height of the third conveyor 6b. The height of the fourth conveyor 6c is set low.

And the conveyance speed V1 of the 1st conveyor 5, the conveyance speed V2 of the 2nd conveyor 6a, the conveyance speed V3 of the 3rd conveyor 6b, and the conveyance speed V4 of the 4th conveyor 6c are higher than the upstream side as the following relationship. Deceleration is set so that the conveyance speed of the downstream conveyor becomes slower, and the conveyance speed is gradually reduced toward the downstream side. Each deceleration rate is set to the same ratio, for example. Note that the rotational speeds of the drive units of the conveyors 5 and 6 are individually controlled based on a speed command from the controller.
V1>V2>V3> V4
The speed reduction ratio is selected based on experimental results so that the temperature deviation in the width direction at the end of natural cooling is within an allowable range, for example, 30 ° C. or less.

(Function and effect)
Next, the effect by the said cooling equipment 3 is demonstrated.
In the cooling equipment 3, the wire continuously hot rolled by the hot rolling mill 1 is sent to the laying head 2, and is sequentially formed into a winding shape (coil shape) by the laying head 2. Further, in the forced cooling zone Z1 in the cooling facility 3, the wire 10 is forcibly cooled by the blast while being transported at a predetermined transport speed by the first conveyor 5, and the temperature is lowered at a stretch to a predetermined temperature, for example, a bainite temperature region. . For this reason, the 1st conveyor 5 is driven by the predetermined | prescribed conveyance speed which can be temperature-fallen at a stretch.

Subsequently, in order to hold the coiled wire 10 that has become the baitniteization temperature range for a long time in the temperature range until the bainite progresses sufficiently, in the natural cooling zone Z2, the second to fourth conveyors 6 Natural cooling is performed while being conveyed.
Thus, it is necessary to perform natural cooling only for a certain long time. For this reason, the conveyance speed of the 2nd-4th conveyor 6 is set so that it may become slower than the 1st conveyor 5 of the forced cooling zone Z1.

Here, since the overlap density on the side in the width direction is higher than that in the center in the width direction, the rate of temperature drop is lower on the end side compared to the center when naturally cooled. In particular, the denser the coiled wire rods 10 that are conveyed, the more prominent.
For this reason, assuming that the transport speed of the second to fourth conveyors 6 is simply delayed with respect to the transport speed of the first conveyor 5, the coil is transferred from the first conveyor 5 to the second conveyor 6 a. Since the overlap of the wire rods 10 is increased and the overlap is further increased, that is, during natural cooling, natural cooling is performed with almost no change in the overlap density in the width direction. In the finished state, the temperature difference between the width direction center portion and the width direction end portion side becomes large. For this reason, in order to improve the temperature difference in the width direction, it is necessary to partially heat the low temperature part or partially cool the high temperature part.

  On the other hand, in this embodiment, without reducing the transfer speed all at once, the transfer speed is gradually reduced step by step, so that the overlap of the coils is increased step by step during natural cooling. By changing the density stepwise, the temperature deviation in the width direction due to the overlapping of the coiled wire rods 10 is adjusted so as to gradually accumulate as long-time slow cooling progresses. For this reason, even if it is the same slow cooling time, the temperature deviation of the width direction at the time of completion | finish of natural cooling can be restrained small compared with the case where a conveyance speed is decelerated at a stretch. In order to exert this effect, it is preferable to divide the conveyor in the natural cooling zone Z2 into a large number within a feasible range from the viewpoint of uniform temperature, and at least three or more It is preferable to divide.

Here, as in the examples described later, in the case of the conventional example, the longer the natural cooling time, the greater the temperature deviation in the width direction. However, the conveyance speed is sequentially reduced based on the present invention. If it performs, it will also become possible to adjust so that temperature deviation may be suppressed, so that the natural cooling time is lengthened. That is, even if there is no special heating device or the like, it is possible to keep the temperature deviation small while ensuring the necessary natural cooling time.
Furthermore, as described in the first and second embodiments, the temperature deviation in the width direction can be further reduced by relaxing the temperature deviation caused by meandering by the roll 20.
As a result, in this embodiment, it is not necessary to separately cool the partial heating, and the cooling facility 3 can be simplified and economical.

  Moreover, in this embodiment, when the conveyance speed is reduced stepwise and the conveyance speed is switched, the coiled wire 10 is moved by providing a step to move the coiled wire 10 when the step is dropped. The temperature deviation in the width direction is somewhat eliminated by causing the loosening of the wire, and the entanglement of the coiled wire 10 when the overlapping state (density) of the wire 10 changes when the conveyance speed is changed Prevent in part.

Moreover, the deceleration rate at the time of switching each conveyor is adjusted so that it may change according to the wire diameter of the wire to supply. The adjustment is performed so that the degree of deceleration between the conveyors increases as the wire diameter decreases.
For example, in the controller, with respect to the reference wire diameter, the reference speed reduction rate ((upstream speed-downstream speed) at the time of transfer to each conveyor so that the temperature deviation in the width direction at the end of natural cooling is an allowable temperature deviation. ) / Upstream speed)) is set, and the standard deceleration rate is multiplied by the deviation (or ratio) between the wire diameter of the supplied wire and the reference wire diameter multiplied by a predetermined gain. When the vehicle is changed, the deceleration rate is calculated, the transport speed of each conveyor at which the calculated deceleration rate is obtained, and a drive command is supplied to the drive unit of each conveyor.

The degree of deceleration between the conveyors may be constant or different.
Here, in the said embodiment, although the level | step difference is provided between each conveyor, it does not need to provide. Providing a step has a higher effect as described above.
Moreover, when providing a level | step difference between the conveyors 5 and 6, you may provide some gradients that a downstream side (tail end side) becomes high about each conveyor.
In the first and second embodiments, the conveyor 6 may be divided into a plurality of sections so that a step is formed at the boundary.

(Example)
Next, using the cooling facility 3, the conveyance speed of the second to fourth conveyors 6 was changed, and the temperature distribution in the width direction (temperature deviation situation) after passing through the natural cooling zone was determined. . In addition, the following experiment was implemented when the roll 20 was not used.
Table 1 shows the transport speeds of the second to fourth conveyors 6a to 6c based on the transport speed of the first conveyor 5 during forced cooling in each example.

And the result of the temperature distribution of the width direction after passing through a natural cooling zone on the following conditions became like FIG.
The experimental conditions are as follows.
The equipment conditions are the same as those in the above embodiment.
Length of each conveyance path: 80 m
Condition of blast Wind volume: 95000Nm ³ / hr
Cooling air temperature: 32 ° C
Wire diameter: 12.5 mm
Coil diameter D of wire rod: 1200mm
As can be seen from FIG. 6, as in Conventional Example 1, when the speed is reduced by 30% from the transport speed of the first conveyor 5 in the forced cooling zone Z1 and the cooling is performed at the transport speed as it is, the natural release is performed. When the cooling is finished, a temperature deviation of about 65 ° C. occurs in the width direction.

Further, when the natural cooling time (slow cooling time) is increased by 50% from the transport speed of the first conveyor 5 and slow cooling is performed at the same transport speed as in Conventional Example 2, When the natural cooling is finished, the temperature deviation in the width direction is increased to about 90 ° C. That is, in the conventional example, it can be seen that the temperature deviation in the width direction increases as the natural cooling time increases.
On the other hand, as in the first aspect of the present invention, when the vehicle is decelerated stepwise at a rate of 10% with respect to the conveyance speed of the first conveyor 5 in the forced cooling zone Z1, The temperature deviation in the width direction is about 40 ° C., and it can be seen that the temperature deviation is improved by about 25 ° C. as compared with the conventional example 1 in which the temperature in the center in the width direction is substantially the same. In this case, the natural cooling time is slightly shorter in the present invention 1 than in the first conventional example.

Further, as in the second aspect of the present invention, in the case where the natural cooling is finished when the vehicle is decelerated stepwise at a rate of 20% with respect to the conveyance speed of the first conveyor 5 in the forced cooling zone Z1, The temperature deviation in the width direction is approximately 30 ° C., and the temperature deviation in the width direction can be reduced in spite of the longer natural annealing time than in the first aspect of the present invention.
Further, as in the third aspect of the present invention, in the case where the natural cooling is finished when the vehicle is decelerated stepwise at a rate of 30% with respect to the conveyance speed of the first conveyor 5 in the forced cooling zone Z1, The temperature deviation is about 15 ° C., and although the natural slow cooling time is longer than that of the present invention 2, the temperature deviation in the width direction can be further reduced to make it more uniform.

As described above, in this embodiment, when the natural cooling time is increased according to the required natural cooling time, the temperature deviation in the width direction is further reduced and made more uniform unlike the conventional example. I can do it.
As described above, in this embodiment, if the number of times of deceleration and the degree of deceleration are selected according to the required natural cooling time and the allowable temperature deviation in the width direction, partial heating or partial cooling is performed separately. Thus, it is understood that long-time slow cooling with a uniform temperature distribution can be realized by natural cooling.
In addition, in the said Example, although the case where the deceleration rate was set on the basis of the conveyance speed of the 1st conveyor 5 at the time of forced cooling was illustrated, the deceleration rate between the conveyors of a front | former stage may be sufficient, The deceleration rate at each stage may be appropriately changed.

Next, under the above experimental conditions, the experiment was performed by changing the wire diameter and the deceleration rate, and when the boundary condition in which the temperature deviation in the width direction at the end of natural cooling was 30 ° C. or less was obtained, The result was obtained. In FIG. 7, the speed ratio is (speed after deceleration / speed before deceleration).
As can be seen from FIG. 7, in order to keep the temperature deviation within a certain range, the smaller the wire diameter, the larger the overall deceleration must be set. Thus, it is preferable to perform control so as to change the deceleration rate according to the wire diameter.
Here, although the said Example is an Example at the time of not performing meandering by the roll 20, it is an Example of 1st Embodiment that a temperature deviation can be relieve | moderated more by adding the meandering by the roll 20 to this. It is clear from.

It is a figure explaining the equipment outline concerning a 1st embodiment based on the present invention. It is a schematic plan view which shows the conveyance path which concerns on 1st Embodiment based on this invention. It is a figure which shows the temperature distribution of the width direction which concerns on 1st Embodiment based on this invention. It is a figure explaining the roll which concerns on 2nd Embodiment based on this invention. It is a figure explaining the installation outline | summary which concerns on embodiment based on this invention. It is a figure which shows the temperature distribution of the width direction. It is a figure explaining the relationship between a wire diameter and speed ratio (downstream speed / upstream speed) required in order to make temperature deviation below predetermined temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot rolling mill 2 Laying head 3 Cooling equipment 4 Converging apparatus 5 1st conveyor 6 Conveyor 10 Coil-shaped wire 11 Impact wind cooling apparatus 20 Roll 21 Blade | wing member D Coil diameter Z1 Said forced cooling zone Z2 Natural cooling zone

Claims (7)

In the slow cooling equipment for the coiled wire rod, which is provided with a conveyance path for carrying the wire rod while being gradually cooled, on which the wire rod shaped into a coil shape after hot rolling is placed.
For at least part of the conveyance direction of the conveyance path, the roll is provided with one or two or more rolls that displace the coiled wire rod in the width direction by bringing the circumferential surface into contact with the coiled wire rod mounted on the conveyance path. A coiled wire slow cooling facility characterized by being rotatable about the vertical axis and having a roll diameter set to ½ or more of the coil diameter of the target coiled wire. In the slow cooling equipment for the coiled wire rod, which is provided with a conveyance path for carrying the wire rod while being gradually cooled, on which the wire rod shaped into a coil shape after hot rolling is placed.
For at least a part of the conveying direction of the conveying path, the coiled wire rod placed on the conveying path is brought into contact with the circumferential surface to displace the coiled wire rod in the width direction, and the coil shape is provided. The slow cooling equipment for a coiled wire rod, wherein the one or two or more rolls are arranged so that the amount of displacement in the width direction of the wire rod becomes ½ or more of the coil diameter.   The roll is rotatable around the vertical axis, and a plurality of blade members arranged in the circumferential direction are projected in the outer diameter direction on the peripheral surface of the roll, and the upper surface of the blade member is in relation to the horizontal plane. The slow cooling facility for a coiled wire according to claim 1 or 2, wherein the coiled wire is inclined in the circumferential direction.   4. The roll according to claim 1, wherein the roll is rotationally driven around a vertical axis so that a peripheral surface in contact with the coiled wire moves in a direction in which the coiled wire is conveyed. The slow cooling facility for the coiled wire described in item 1.   The slow cooling equipment for coiled wire according to any one of claims 1 to 4, wherein a transport speed by the transport path is gradually decreased from the upstream side toward the downstream side. In the method of gradually cooling a coiled wire rod, the wire rod shaped into a coil shape after hot rolling is gradually cooled by transporting the wire rod along the transport path.
A method of gradually cooling a coiled wire, wherein the coiled wire being conveyed is meandered in the width direction at least half the coil diameter of the coiled wire at least in the middle thereof.   The method of gradually cooling a coiled wire rod according to claim 6, wherein the overlapping portions of the coiled wire rod being conveyed are temporarily separated from each other in the vertical direction.

Images