JP2003285119A - Method for rewinding and cooling cylindrical metal coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for cooling a cylindrical metal coil effectively and uniformly in a short time. <P>SOLUTION: The inner cylinder of the cylindrical metal coil 1 formed by winding a metal strip is mounted on a rewinder 2 capable of rewinding in a smaller diameter than the inner diameter of the coil. While the metal strip rewound in a smaller diameter than the initial diameter, space is provided between coil layers. A cooling nozzle 6 and/or a cooling roll 8 are put in the space so that the coil is cooled by the cooling nozzle and/or the cooling roll from the inner circumference side toward the outer circumference side. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can effectively cool and heat a cylindrical metal coil wound in a tight coil shape of a metal such as a steel plate or an aluminum plate, and promote reaction of an atmospheric gas with a metal surface. In addition to providing a method for winding a cylindrical metal coil, a new efficient and uniform cooling method, especially for a cooling method that significantly impairs productivity in batch heat treatment and has a large temperature deviation and a large influence on quality TECHNICAL FIELD The present invention relates to a cooling method for a highly efficient cylindrical metal coil.

[0002]

2. Description of the Related Art A cylindrical metal coil heated in a batch furnace is usually cooled as it is in a batch furnace and then taken out of the furnace. However, since the cylindrical metal coil is a lump, the heat transfer from the inside of the coil is slow when cooling from the outside, and it takes a lot of time to cool the whole,
There is a problem of poor productivity. Further, because of cooling from the outside, the cylindrical metal coil cools from the outside and tries to contract from the outside, so that there is a problem that distortion and scratches occur inside the coil.

Various proposals have been made to solve these problems. For example, JP-A-53-60811 proposes to control the circulation of atmospheric gas during the heating, soaking, and cooling processes. Also, JP-A-57-11
In Japanese Patent No. 6731, a corrugated insertion plate is inserted between layers of coils, and an annealing time is shortened by passing an atmosphere gas and a cooling medium in a state where a space is provided.
Japanese Patent No. 226124 proposes cooling by bringing a water cooling box into contact with the coil end surface.

[0004]

However, merely controlling the circulation of the atmospheric gas results in heat transfer from the outside of the coil, and it is extremely difficult to fundamentally promote heat transfer and make the temperature uniform. Further, in the method of inserting a corrugated insertion plate between the layers of the coil and passing the atmosphere gas and the cooling medium in the state where a space is provided, it is difficult to insert and wind the insert while securing the space, and While it is easy for push defects to occur and for the temperature to deviate from the end face and the center when cooling from the end face of the coil, the coil has a space in the insert, which makes it difficult to be constrained. There is a problem that it is easily deformed. Further, in the method of contacting the water cooling box with the coil end surface, contact heat transfer cannot be expected because the coil end surface is almost uneven, so cooling cannot be expected to such an extent that the device becomes large-scale. Further, even if the radiant heat transfer is promoted to some extent, a large temperature deviation occurs between the coil end surface and the coil central portion, which is not preferable.

Therefore, the present invention improves productivity, which is an essential problem of a cylindrical metal coil, due to too long cooling time, and cools while suppressing temperature deviation in the coil as much as possible. An object of the present invention is to provide a cooling method for a cylindrical metal coil.

[0006]

The gist of the present invention is as follows. (1) The diameter of a winder for a horizontally wound cylindrical metal coil is reduced, and the cylindrical metal coil is lifted from below and wound while the outer periphery is constrained so that the cylindrical metal coil does not rotate. After creating a space between the coiling machine and the cylindrical metal coil, the winding machine is rotated to wind the cylindrical metal coil in order from the inner circumference side to the outer circumference side while leaving a space between the coil layers. A method for winding a cylindrical metal coil, characterized in that the winding is performed. (2) When winding the cylindrical metal coil in the order from the inner circumference side to the outer circumference side while leaving a space between the coil layers by the winding method described in (1), a cooling nozzle is inserted into the space formed between the coil layers. Then, a cooling medium is sprayed from the cooling nozzle to perform cooling in order from the inner circumference side of the coil toward the outer circumference side thereof. (3) When winding the cylindrical metal coil in the order from the inner circumference side to the outer circumference side of the cylindrical metal coil while leaving a space between the coil layers by the winding method described in (1), a cooling roll is inserted into the space formed between the coil layers. Then, the metal coil is pressed against the winder by the cooling roll to perform cooling in order from the inner circumference side of the coil toward the outer circumference side thereof. (4) The method for cooling a cylindrical metal coil according to (3), wherein a cooling nozzle is further inserted into the space formed between the coil layers, and a cooling medium is sprayed from the cooling nozzle. (5) The cooling nozzle to be inserted into the space formed between the coil layers is divided in the coil width direction, and the discharge amount of the cooling medium of each cooling nozzle is controlled for each nozzle (2) or (4). The method for cooling a cylindrical metal coil according to claim 1. (6) A method of winding or cooling a cylindrical metal coil, which comprises performing the method according to any one of (1) to (5) a plurality of times.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic sectional view of the cylindrical metal coil 1 as seen from the end face side, and FIG. 2 shows a schematic sectional view as seen from the side surface. In the present invention, a winding method and a cooling method were considered while creating a space in the cylindrical metal coil. First, a method of winding the cylindrical metal coil while providing a space between layers will be described. Providing a space between the layers of the cylindrical metal coil is, for example, to rapidly and uniformly cool the heated and high temperature coil, conversely to heat the coil with hot air, or to prevent chemical reaction on the coil surface. Used to promote.

The cylindrical metal coil 1 is set by inserting the central space portion into the horizontal winder 2 and biting the coil end into the winder. When the winding machine 2 is reduced in diameter to a diameter smaller than the inner diameter of the cylindrical metal coil 1 by a necessary amount, a required space is created between the lower end of the winding machine 2 and the inner peripheral lower surface of the cylindrical metal coil 1. . At this time, the coil regulation rolls 3 and 4 are lightly pressed to the outside of the cylindrical metal coil 1. When the cylindrical metal coil 1 is lifted by the lifting device 5 in this state, the winder 2 and the cylindrical metal coil 1
A space is created over the entire circumference between and. If the winding machine 2 starts winding as it is, the coil is re-wound with a diameter smaller than the original diameter, but at this time, a space is sequentially formed between the coil layers from the winding machine 2 side. In order to generate this space in a stable manner, the cylindrical metal coil 1 is placed on the outside so that the entire cylindrical metal coil 1 does not rotate, and the cylindrical metal coil 1 is subjected to a force that does not cause deformation or flaws in the coil. You may restrain it so that it will not rotate. Further, although the coil regulation rolls are two points in FIG. 1, it is possible to press the coil regulation rolls in an appropriate number.

When a space is forcibly created between the metal coil layers in this manner, the surface of the metal facing the space is directly exposed to the atmospheric gas. Therefore, in the tightly wound cylindrical metal coil, the surfaces of the metal strips come into close contact with each other, so that heating, cooling and surface reaction from the inside of the cylindrical metal coil, which are extremely difficult, can be easily realized. That is, when it is desired to heat, the metal strip can be heated by convective heat transfer by blowing the gas or liquid having a temperature higher than that of the cylindrical metal coil toward the metal strip in the space forcibly generated. On the contrary, when it is desired to cool the metal strip, it is possible to cool the metal strip by convective heat transfer by blowing the gas or liquid at a temperature lower than that of the cylindrical metal coil against the metal strip in the space where the gas or liquid is forcibly generated. Become. In addition, as in the case of forming a coating by reacting with atmospheric gas on the metal surface such as carburizing or decarburizing, electromagnetic steel, etc.,
In order to promote the reaction with the atmospheric gas, the reaction of the metal surface can be promoted by flowing the atmospheric gas of the required components and temperature between the metal strips in the space in which the gas is forcibly generated. it can.

Of these, cooling is particularly problematic in the actual batch heat treatment of a cylindrical metal coil because it impairs productivity and causes quality deterioration due to temperature deviation. A cooling method using the winding method will be described. In the method for cooling a cylindrical metal coil according to the present invention, in order to cool from the inside of the cylindrical metal coil 1, the cylindrical metal coil 1 is detachably attached to the space created between the cylindrical metal coil 1 and the winding machine 2 as described above. A cooling nozzle 6 for spraying a different cooling medium is inserted. And from the cooling nozzle 6,
By blowing the cooling medium onto the space, the cylindrical metal coil 1 can be cooled in order from the inside.
As for the cooling method, when a space is created between the coil layers, the cooling nozzle 6 is inserted between the coil layers, the metal coil is cooled to a predetermined temperature or cooled to a predetermined temperature, and then withdrawn, and the coil is wound again to make a new space. The method of intermittently cooling by repeating the above, or the method of continuously cooling while rotating the cooling nozzle in accordance with the formation of the layers of the cylindrical metal coil 1 may be used.

In this manner, the winding of the cylindrical metal coil 1 by the winding machine 2 sprays the cooling medium with the cooling nozzle 6 to cool the coil, so that the cylindrical metal coil 1 is made substantially uniform. Can be cooled. Usually, in the case of cooling a cylindrical metal coil, since the cooling is performed from the outer surface, the center of the coil remains at a high temperature, so that the outside of the cylindrical metal coil 1 cools and heat contracts, which causes stress. However, the metal strip may be distorted, causing the metal strip to have a defective shape, the metal strips sticking to each other, or the magnetic steel sheet to cause magnetic defects. On the other hand, in the present invention, such a problem does not occur because the metal strip is cooled in order from the inside of the coil. Further, in the case of external cooling, the heat transfer inside the cylindrical metal coil is slow and the cooling time is long, but in the case of the present invention, the cooling is performed directly from the inside of the coil, so the cooling time is extremely short. be able to.

Further, since the cylindrical metal coil 1 is also cooled from the outer surface by convective heat transfer or radiant heat transfer, it is inevitably cooled from the coil end surface side, and the temperature on the center side is high and the both end sides are low in the coil width direction. There is a temperature distribution. Therefore, in order to make the temperature distribution of the entire coil uniform,
It is effective to divide the cooling nozzle for cooling inserted in the cylindrical metal coil 1 in the width direction of the cylindrical metal coil 1 and control the air volume of the cooling medium in the width direction to achieve uniform cooling. . In this case, in the coil width direction, the temperature falls in a specific range from both ends. Therefore, if the nozzles are divided into 6a, 6b, and 6c as shown in FIG. Can be controlled. For temperature control, for example, a temperature sensor may be attached to the nozzle to control cooling while looking at the temperature distribution in the width direction, or it is necessary to predict the temperature distribution after rewinding by calculation and strengthen the cooling in the center of the coil beforehand. It is better to control the cooling according to.

Although the cooling nozzle is provided in only one place in the space between the cylindrical metal coil 1 and the winder 2 in FIGS. 1 and 2, it may be provided in a plurality of places if necessary, and the nozzle has a discharge port. Although only one direction is shown in FIG. 1, it may be provided in any space in the space between the coil layers in any direction in all directions. Although the cooling medium is not particularly specified, air is generally used economically. However, when increasing the cooling rate, hydrogen gas with a low specific heat or a mixture of gas and water is used. Water, liquid nitrogen, or the like may be used, and nitrogen, hydrogen, or an inert gas may be used to prevent oxidation, and a medium suitable for the purpose may be selected without particular restrictions. The cooling capacity is generally controlled by controlling the discharge amount and discharge pressure of the cooling medium discharged from the cooling nozzle 6, and the temperature of the cooling medium may be controlled.

In order to cool the cylindrical metal coil 1 more effectively, the present invention uses a cooling roll 8 as shown in FIGS. As the cooling roll, there are one that cools the roll shell by passing cooling water inside and a method that heat-exchanges the heat taken by the roll shell by installing a heat pipe in the shell, and the shell itself is made of normal iron, Some are made of cast iron and some are made of good conductive materials such as copper, aluminum and carbon. The shell surface is coated with ceramics or the like to prevent abrasion and oxidation.

FIG. 3 shows a schematic cross-sectional view of the cylindrical metal coil 1 as seen from the end face side, and FIG. 4 shows a schematic cross-sectional view as seen from the side. This cooling roll 8 cools by contact heat transfer by pressing a metal strip wound around the winder 2, and also effectively performs cooling by radiative heat transfer when the temperature of the cylindrical metal coil 1 is high. . Further, the cooling roll 8 also has a function of adjusting the winding shape by pressing the metal strip plate against the winding machine 2 when the cylindrical metal coil 1 is wound around the winding machine 2.

Like the cooling nozzle, the cooling roll 8 may be intermittently taken in and out of the space created between the coil layers as described above, or it may be moved in accordance with the creation of the continuously created space. May be. By these methods, when the winding is loose, it is possible to prevent the metal strips that are in contact with each other from slipping due to the tightening of the metal strips during winding, causing scratches on the metal surface. In addition, the space generated between the winding machine 2 side and the cylindrical metal coil 1 can be stably formed and continued.

When sufficient cooling cannot be achieved by the cooling roll 8 alone, more effective cooling can be achieved by using the cooling nozzle 6 in combination with the cooling medium for cooling. In this case, as described above, if the cooling nozzle is divided into a plurality of parts in the width direction like 6a, 6b and 6c as shown in FIG. 4 and cooling is controlled, more effective cooling control can be performed.

The above-mentioned cooling method is not limited to one time but a plurality of times, such as when the temperature cannot be lowered to a required temperature only once or when a certain temperature range needs to be cooled at a certain cooling rate in metallurgy. It may be divided into two times. As described above, if this cooling method is used, the cylindrical metal coil 1
Since it can be cooled from the inside in order, the cooling time can be greatly shortened and the productivity can be dramatically improved, the coil temperature deviation can be reduced, and the stress generation due to heat shrinkage etc. can be reduced, enabling high quality cooling. To do.

[0019]

EXAMPLES The effects of the present invention were confirmed by experiments. In the experiment, a cold-rolled steel sheet with a thickness of 1 mm and a width of 300 mm was used with an induction heating device for 60
It was heated to 0 ° C. and wound up and cooled by a winder.
The winding machine can be expanded and contracted to have inner diameters of 500 mm, 400 mm, and 300 mm. First, after winding at 500 mm, the diameter was reduced to 400 mm and re-winding was performed. In the experiment, with the configuration as shown in FIG. 1, restriction rolls 3 and 4 were provided in front of and behind the coil wound after heating to prevent the wound coil from moving forward and backward, and the winding machine 2 was reduced in diameter. Between the winder 2 and the cylindrical coil 1 (lower side of the winder)
I opened a space. After that, the entire coil was lifted by the jack type lifting device 5, and a gap was provided between the winding machine 2 and the inside of the cylindrical coil 1 as a whole. Outside diameter 3 on top of this gap
A slit nozzle provided with a 2 mm slit was inserted into a 0 mm pipe and cooled (Example 1). The temperature during cooling is 10 at both ends of the coil in the width direction of the steel plate with a thermocouple at the center of the coil.
The temperature was measured by welding at the position of mm and the center.

An experiment (Example 2) in which cooling was carried out using a slit nozzle 6b having the same diameter as that of Example 1 which covers the center of the coil width and slit nozzles 6a and 6c which cover both ends of 10 mm (Example 2), an outer diameter of 30 mm Experiments in which only the water-cooled roll 8 of No. 1 was used to cool by pressing with a linear pressure reduction force of 10 MPa (Example 3), and an experiment in which one slit nozzle used in the experiment of Example 1 was provided in the experiment of Example 3 (execution Example 4), an experiment using the three-division slit nozzle used in the experiment of Example 2 (Example 5), an experiment of performing Example 4 twice (Example 6), and a case of performing natural cooling. Table 1 shows the results of the cooling rate and temperature deviation and the winding shape for the experiment (comparative example).
Shown in.

In the experiment, when the coil was heated and wound to a thickness of 100 mm, cooling was started. The nozzle used for cooling and the water-cooled roll were moved by a mechanism that moves in accordance with the space generated between the layers. Cooling start temperature is 500 ° C
Before and after. In addition, the discharge air velocity from the slit nozzle is
The central portion of the single slit nozzle and the three-division slit nozzle was 10 m / s, and the central portion of the three-division slit nozzle was 8 m / s. The cooling rate in the table represents the average cooling rate from 500 ° C. to 300 ° C., and the maximum temperature deviation represents the absolute value of the temperature difference between the plate width center and the plate edge. The winding shape is a visual result.
Moreover, the result of the present invention 6 in which cooling was performed twice shows a cooling rate from 500 ° C. to 100 ° C.

[0022]

[Table 1]

From Table 1, all the cooling of the examples according to the present invention have a cooling rate of 60 times or more compared with natural cooling, which is a good result. Also, the temperature deviation is slightly higher in the case of only the water-cooled roll, but is better than that of the comparative example and is even better in the other examples. Particularly, the values in Examples 2 and 5 using the divided slit nozzles in which the cooling rate was controlled in the width direction were extremely good values. In addition, Example 6 in which cooling was performed twice
In this case, it is considered that the temperature deviation was reduced because the heat diffusion progressed after being wound once and the inside of the coil was soaked and then cooled again.

On the contrary, in Example 3 in which the water-cooled roll was used alone, the temperature deviation was slightly large. This was because the water-cooled roll had a thermal crown, resulting in uneven contact with the steel sheet. It is considered that the temperature deviation is somewhat larger than that in the other examples, but it is not a value that causes a particular problem. Regarding the winding shape, in Examples 1 and 2 in which no roll was used, the winding was slightly loose, but it was almost satisfactory and there was no particular problem. On the other hand, when a roll was used, the winding was firm and the shape was good.

[0025]

According to the cooling method of the present invention, a large coil temperature distribution caused by cooling from the outer surface, which is an essential problem for cooling a cylindrical metal coil, is generated, and the cooling time is too long, resulting in productivity. Can be solved. That is, since the cooling is sequentially performed from the inner side over the entire circumference of the cylindrical metal coil, the cooling time can be dramatically shortened, the temperature distribution is extremely good, and the defective shape and the quality variation can be suppressed, so that the yield loss can be reduced. Moreover, since a large-scale device is not required, the capital investment is small, the space is small, and the production cost can be significantly reduced. Further, since the cooling rate can be controlled, it is possible to deal with multifunctional heat treatment.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a cooling method using a cooling nozzle of a cooling method for a cylindrical metal coil according to the present invention.

FIG. 2 is a schematic diagram illustrating a cooling method using a divided cooling nozzle of a cooling method for a cylindrical metal coil according to the present invention.

FIG. 3 is a schematic diagram illustrating a cooling method using a water-cooling roll and a cooling nozzle in a cooling method for a cylindrical metal coil according to the present invention.

FIG. 4 is a schematic diagram for explaining a cooling method using a water cooling roll and a split cooling nozzle in a cooling method for a cylindrical metal coil according to the present invention.

[Explanation of symbols]

1 Cylindrical metal coil 2 winder 3 coil regulation roll 4 coil regulation roll 5 Lifting device 6, 6a, 6b, 6c Cooling nozzle 7 winder 8 water-cooled rolls

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B21C 47/26 B21C 47/26 A C21D 9/52 102 C21D 9/52 102 // C21D 9/68 9 / 68

Claims (6)

[Claims] 1. The diameter of a winder for a horizontally wound cylindrical metal coil is reduced, and the cylindrical metal coil is lifted from below while the outer periphery is constrained so that the cylindrical metal coil does not rotate. After creating a space between the winder and the cylindrical metal coil, the winder is rotated to open a space between the coil layers in order from the inner circumference side to the outer circumference side of the cylindrical metal coil. A method for winding a cylindrical metal coil, which comprises winding while winding. 2. The winding method according to claim 1, wherein when winding the cylindrical metal coil in order from the inner circumference side to the outer circumference side while opening a space between the coil layers, a cooling nozzle is provided in the space formed between the coil layers. A method for cooling a cylindrical metal coil, characterized in that the cylindrical metal coil is inserted, and a cooling medium is sprayed from the cooling nozzle to perform cooling in order from the inner peripheral side of the coil toward the outer peripheral side. 3. The winding method according to claim 1, wherein when winding the cylindrical metal coil in order from the inner circumference side to the outer circumference side while opening a space between the coil layers, a cooling roll is provided in the space formed between the coil layers. A method for cooling a cylindrical metal coil, which is characterized in that the metal coil is inserted, and the metal coil is pressed against the winder by the cooling roll to perform cooling in order from the coil inner peripheral side to the outer peripheral side. 4. The method for cooling a cylindrical metal coil according to claim 3, wherein a cooling nozzle is further inserted into a space formed between the coil layers, and a cooling medium is sprayed from the cooling nozzle. 5. The cooling nozzle to be inserted into the space formed between the coil layers is divided in the coil width direction, and the discharge amount of the cooling medium of each cooling nozzle is controlled for each nozzle. Item 5. A method for cooling a cylindrical metal coil according to Item 4. 6. A winding method or a cooling method for a cylindrical metal coil, wherein the method according to claim 1 is performed a plurality of times.