JPH07242950A - Method for continuously cooling high temperature wire rod - Google Patents

Abstract

PURPOSE:To provide a continuous cooling method of a high temp. wire rod, by which a cooling device is not required to be large and the cooling can effi ciently be executed and the productivity can be improved. CONSTITUTION:The metallic wire rod S running in the longitudinal direction and heated at >=500 deg.C is wound on a first water-cooling type free roller 1 and successively wound on the water-cooling type driving roller 2, then the wire rod is alternately wound on a water-cooling type free roller 3 and the water- cooling type driving roller 2 plural turns to be cooled. Winding angle theta on the first water-cooling type free roller 1 and winding angle beta of a first turn on the water-cooling type driving roller 2 are made to be <270 deg.C to cool the wire rod.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously cooling a metal wire rod heated to a high temperature for heat treatment such as annealing with a water-cooled roller, and more particularly to a welding wire (mild steel, high tensile strength). The present invention relates to a continuous cooling method for a high temperature wire which is suitable for use in heat treatment in the manufacturing process of steel, stainless steel, etc.

[0002]

2. Description of the Related Art Generally, air cooling is adopted as a cooling method for annealing a metal wire rod. For example, in the production of a wire rod for welding, as disclosed in Japanese Patent Publication No. 60-21209, a wire rod for welding is used. Is sequentially wound around a drive roller group and a free roller group provided at a predetermined interval, and air-cooled in the process of traveling and passing through these roller groups.

[0003]

By the way, the annealing temperature of the wire rod is generally about 500 to 1200 ° C. although it varies depending on the steel type. Such a high-temperature wire is described in Japanese Patent Publication No. 21209/1985.
In the case of cooling by the method described in the publication, the cooling efficiency is poor due to air cooling, and it takes time to cool to a predetermined temperature, and the productivity is reduced. Further, in terms of equipment, it is necessary to widen the distance between the drive roller group and the free roller group or to increase the number of rollers in each roller group to cover the poor cooling efficiency, which is a large scale.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to enable efficient cooling without increasing the equipment size and improve productivity. It is intended to provide a continuous cooling method for a high temperature wire which can be performed.

[0005]

In order to achieve the above object, a continuous cooling method for a high temperature wire according to the present invention is a method in which a metal wire heated in a longitudinal direction and heated to 500 ° C. or higher is first cooled with water. After being wound around the free roller and then the water-cooled drive roller, when further wound around the second water-cooled free roller and the water-cooled drive roller a plurality of times alternately for cooling, the winding around the first water-cooled free roller is performed. The angle and the winding angle of the first wheel around the water-cooled drive roller are wound to less than 270 degrees for cooling.

In the continuous cooling method for the high temperature wire rod, the first water-cooled free roller and the second water-cooled free roller may be provided on the same rotary shaft center. The water-cooled drive roller may be composed of either one roller or a plurality of rollers.

In the continuous cooling method for the high temperature wire rod, the winding angle around each roller may be 90 ° to 180 °.

In the above continuous cooling method for high temperature wire rods, the second water-cooled free roller has the plurality of water-cooled free rollers on the same rotary shaft and / or the water-cooled drive roller has the same plurality of water-cooled drive rollers. It may be provided on the rotating shaft.

Further, in the above continuous cooling method for high temperature wire rods, a plurality of water-cooled drive rollers are provided on the same rotary shaft, and a plurality of water-cooled drive rollers behind the water-cooled drive rollers are provided. The roller may be a water-cooled free roller.

[0010]

The structure and operation of the present invention will be described in detail below. The present inventors, after finding the above-mentioned problems,
Various studies were conducted to improve the cooling efficiency of the high temperature wire.

As one of the measures for improvement, it can be considered to directly contact the cooling water while the high temperature wire is running.
However, this method using cooling water cannot be applied to those that dislike rust, or those that dislike moisture intrusion such as a flux-cored wire for welding that has a linear gap penetrating in and out. I found the problem.

As one of the improvement measures, it is conceivable that the rollers forming the drive roller group and the free roller group shown in Japanese Patent Publication No. Sho 60-21209 mentioned above are of the internal water cooling type. FIG. 4 is a schematic view of the arrangement when this water-cooled roller is used. However, one drive roller and one free roller are provided for simplification of description. The rollers used for the driving roller 6 and the free roller 7 shown in the figure are of a type in which cooling water is circulated inside, and although the structure is omitted in the figure, it is a water-cooled structure of a structure commonly used for supplying and draining water through a rotary shaft. Type roller.

In order to cool the high temperature wire S by using the water-cooled drive roller 6 and the water-cooled free roller 7 shown in FIG. 4, as shown in the above Japanese Patent Publication No. 60-21209, the water-cooled drive roller 6 and the water-cooled drive roller 6 are used. The high temperature wire S is sequentially wound around each roller of the water-cooled free roller 7. By the way, when this was tested, the following new problems were found. That is, when the wire rod S heated to a high temperature of 500 to 1200 ° C. is cooled by this method, the wire breakage occurs at the portion b that exits the water-cooled drive roller 6 in the first wheel on the wire entry side.

The reason for this is considered as follows. Generally, the first wheel wound around the water-cooled drive roller 6 on the entry side has a larger winding angle θ than the other wheels thereafter. Therefore,
Since the contact length with the water-cooled drive roller 6 is increased, the temperature drop of the wire rod S is increased and the shrinkage amount of the wire rod S is also increased. The contraction of the wire S in the longitudinal direction is caused by the water-cooled drive roller 6
A contact frictional resistance with is generated and is stored as stress inside the wire rod S. This stress is released when the wire rod S separates from the water-cooled drive roller 6, and a large tension is generated between the wire rod S and the water-cooled free roller 7. Further, since the wire rod S is still at a considerably high temperature in the b portion exiting the water-cooled drive roller 6, the wire rod S is air-cooled as the temperature of the wire rod S moves to the c portion, and the b portion is higher in temperature than the c portion. It is conceivable that a wire break will occur at the portion b exiting the water-cooled drive roller 6.

The present invention has been made in order to solve the problems of the above-mentioned improvement measures, and the gist thereof is that a metal wire rod running in the longitudinal direction, which is heated to 500 ° C. or higher, is first cooled with water. Type free roller, and then the water-cooled drive roller, and then the second water-cooled drive roller and the water-cooled drive roller are alternately wound a plurality of times to cool the first water-cooled drive roller. This is a continuous cooling method for high-temperature wire rods, in which the winding angle and the winding angle of the first wheel around the water-cooled drive roller are wound to less than 270 degrees for cooling.

In the above structure, the reason why the high temperature wire rod on the wire entry side is first wound around the first water-cooled free roller is to prevent wire breakage, and is the result of various experiments. As described in paragraph [0014], the mechanism is that the water-cooled roller that the high-temperature wire contacts first has a large amount of shrinkage of the wire and a large amount of stress stored inside the wire. Therefore, by using this water-cooled roller as an independent free roller, the contraction at the time of opening is eliminated by the rotation of the roller, and the water-cooled drive roller can be relatively easily operated with the first roller.
Since the winding angle around the water-cooled free roller can be set to less than 270 degrees, it is considered that the disconnection could be prevented. In addition, since disconnection can be prevented, productivity can be improved.

After being wound around the first water-cooled free roller, the water-cooled drive roller, and then the second water-cooled free roller and the water-cooled drive roller are alternately wound a plurality of times, so that the high-temperature wire can be efficiently used. Can be cooled. However, in this cooling process, the temperature of the wire rod that has been repeatedly cooled decreases and the amount of shrinkage decreases, but this amount of shrinkage is reduced to the second water-cooled type that is composed of one water-cooled free roller with a body length. If only the free rollers are used, the shrinkage amount of the wound wire rods in different stages may be different and the shrinkage may not be absorbed, and the wire may be broken. It is preferable to use a water-cooled free roller. Further, when the water-cooled drive roller is constituted by a substantially integrated single roller, it is desirable that the roller has a body length and has a taper surface in the body longitudinal direction to absorb the contraction amount of the wire.

Further, although the first water-cooled free roller and the second water-cooled free roller are provided independently, their rotary shafts may be provided on the same rotary shaft center, in which case the equipment space can be reduced. There are advantages.

Further, the water-cooled drive rollers may be separate water-cooled drive rollers, but from the viewpoint of space saving of equipment, it is preferable that they are provided on the same rotary shaft or the rollers themselves are integrated.

Further, the water-cooled drive roller may be a plurality of water-cooled drive rollers corresponding to each winding, like the second water-cooled free roller. Further, in this case, the rear water-cooling drive rollers among the water-cooling drive rollers may be water-cooling free rollers.

Next, the reason why the winding angle around the first water-cooled free roller and the winding angle of the first wheel around the water-cooled drive roller is less than 270 degrees will be described. The wire wound around the water-cooled roller is cooled and contracts to generate a force for winding the roller. This is because the larger the winding angle θ is, the larger the winding angle is, so that the stress is less likely to be released and the wire is easily broken. If the winding angle is less than 270 degrees, such a problem is solved. And more preferably 90
Degrees of 180 to 180 degrees are good, and the reason for this is that the contraction amount also becomes large especially when the wire temperature rises. In that case, 180 degrees or less is desirable. However, if the winding angle is too small, the cooling efficiency will be impaired, so 90 ° or more is preferable. The wrapping angle of the second water-cooled free roller and the water-cooled drive roller after the second wheel is preferably less than 270 degrees.
Of course, 90 degrees to 180 degrees is preferable.

The temperature of the high-temperature wire is set to 500 ° C. or higher because the shrinkage amount is small at a temperature lower than 500 ° C. and the disconnection is unlikely to occur.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 is a schematic view of the arrangement of a water-cooled roller applied to a continuous cooling method for a high-temperature wire according to the present invention, in which 1 is a first water-cooled free roller and 2 is a The water-cooled drive roller 3 is a second water-cooled free roller. In this figure, each of the water-cooled drive roller 2 and the second water-cooled free roller 3 is composed of one roller having a body length, and the water-cooled drive roller 2 absorbs the shrinkage amount of the wire in the body longitudinal direction. A tapered surface is provided for this purpose.

A high tensile strength steel wire S having a wire diameter of 1.0 mm was cooled under the following cooling conditions by using a cooling device having the above-mentioned roller arrangement, and the broken state was investigated. The survey results are shown in Table 1. Cooling conditions Wire traveling speed: 100 m / min Wire temperature: 700 ° C Wire winding angle: Shown in Table 1 Roller diameter: Shown in Table 1

[0026]

[Table 1] Remark 1) The winding angle θ around the first water-cooled free roller 1 was adjusted by changing the wire entry direction in relation to the winding angle β of the first wheel around the water-cooled drive roller 2. Remark 2) The survey results show the average number of wire breaks per day.
◎: 0.1 times or less, ○: 0.1 to 0.2 times or less, ×: more than 0.2 times

[Embodiment 2] FIG. 2 is a cross-sectional view of a water-cooled free roller applied to a method for continuously cooling a high-temperature wire according to the present invention. The first water-cooled free roller 1 and the second water-cooled free roller are shown. The rotating shafts of 3 are configured to have the same axis. In the figure, reference numerals 4 and 5 denote water supply / drainage devices for cooling water to the water-cooled rollers.

FIG. 3 is a perspective view showing an outline of the arrangement of the water-cooled free roller and the water-cooled drive roller. Using a cooling device having such a roller arrangement, the state of disconnection was investigated under the same conditions as in Test No. 4 of Example 1 above. The survey results showed that the average number of wire breaks per day was 0.11 times. Further, in the case of this example, the first water-cooled free roller 1 and the second water-cooled free roller 3 have the same axis of rotation, so that space can be saved.

[0029]

As described above, according to the continuous cooling method for a high temperature wire according to the present invention, the wire can be efficiently cooled in the process of traveling at a temperature of 500 ° C. or higher and the productivity can be improved. Further, it is not necessary to make the cooling equipment large-scale.

[Brief description of drawings]

FIG. 1 is a schematic view of an arrangement of water-cooled rollers applied to a continuous cooling method for high-temperature wire according to the present invention.

FIG. 2 is a cross-sectional view of a water-cooled free roller applied to the method for continuously cooling a high-temperature wire according to the present invention.

FIG. 3 is a schematic view of the arrangement of a water-cooled roller of another embodiment applied to the continuous cooling method for a high temperature wire according to the present invention.

FIG. 4 is a schematic view of the arrangement of water-cooled rollers used in the test.

[Explanation of symbols]

1: First water-cooled free roller 2: Water-cooled drive roller 3: Second water-cooled free roller 4,5: Cooling water supply / drainage device S: High temperature wire α: Winding angle β around the first water-cooled free roller β: Winding angle of the first wheel around the water-cooled drive roller

Claims (7)

[Claims] 1. A metal wire rod, which runs in the longitudinal direction and is heated to 500 ° C. or higher, is first wound around a first water-cooled free roller and then a water-cooled drive roller, and then a second water-cooled free roller and a water-cooled system. When alternately wound around the drive roller a plurality of times for cooling, the winding angle around the first water-cooled free roller and the winding angle around the first wheel around the water-cooled drive roller should be less than 270 degrees. A continuous cooling method for a high-temperature wire characterized by cooling. 2. The continuous cooling method for a high-temperature wire rod according to claim 1, wherein the first water-cooled free roller and the second water-cooled free roller are provided on the same rotary shaft center. 3. The continuous cooling method for a high temperature wire rod according to claim 1, wherein the water-cooled drive roller is constituted by one roller which is substantially integrated. 4. The winding angle of the first water-cooled free roller and the winding angle of the first wheel around the water-cooled drive roller are 90.
The continuous cooling method for a high-temperature wire according to claim 1, wherein the high-temperature wire is in the range of 180 to 180 degrees. 5. The continuous cooling method for a high temperature wire rod according to claim 1, wherein the second water-cooled free roller is constituted by providing a plurality of water-cooled free rollers on the same rotary shaft. 6. The continuous cooling method for a high temperature wire rod according to claim 1, wherein the water-cooled drive roller comprises a plurality of water-cooled drive rollers provided on the same rotary shaft. 7. The continuous cooling method for a high-temperature wire according to claim 6, wherein the plurality of water-cooled drive rollers behind the plurality of water-cooled drive rollers are water-cooled free rollers.