JP2003290814A - Method and apparatus for producing composite material for metallic fibers - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing metallic fibers in which an expensive extra-low carbon steel is unnecessary to use and carbon steel is not converted to stainless steel. <P>SOLUTION: In this method and an apparatus for producing a composite material for producing metallic fibers, the diameter of a steel pipe 5 having a plurality of coated wire rods 4 inserted therein is shrunk with cold-working and subsequently, hot-rolling is performed. The shrinkage of the pipe diameter with the cold-working is performed with a press pipe-shrinkage device 15. The hot-rolling is performed by heating the pipe with only an induction heating furnace or with a combination of a combustion-type heating furnace and the induction heating furnace and then applying rolling. A hoop 3 and the steel pipe 5 contains ≤0.04 mass% carbon. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal fiber composite material for producing metal fibers such as stainless steel, a method and apparatus for producing the same, and a method for producing the metal fibers.

[0002]

2. Description of the Related Art In the case of producing a fiber bundle of a metal that is hardly soluble in an acid solution represented by stainless steel, a wire rod as a metal fiber raw material is coated with carbon steel to form a coated wire rod. A large number of coated wire rods are inserted into a steel pipe, and hot rolled into a wire rod as a composite material for metal fibers.This wire rod is cold-drawn and thinned to chemically dissolve and remove the coated carbon steel and steel pipe. The method is known. Thereby, only the metal that is hardly soluble in the acid solution remains as fibers, and it is possible to easily manufacture a bundle of metal fibers having a diameter of about 10 μm.

As a method of forming a coated wire in which the surface of a wire as a raw material of metal fiber is coated with carbon steel, a billet having a metal as a raw material of metal fiber and an outer side of carbon steel is hot extruded or rolled. There are a manufacturing method and a method of manufacturing a wire rod as a metal fiber raw material by coating with a steel strip. The latter method is preferable because the metal fiber can be produced inexpensively and efficiently.

When producing stainless steel fibers by the above-mentioned method, regarding the carbon steel coating the surface of the stainless steel wire rod and the steel pipe into which a large number of the coated wire rods are inserted, if the carbon content of these steels is high. During the hot working in the metal fiber manufacturing process, the stainless steel is largely carburized by the diffusion of carbon from these steels to the stainless steel.
As a result, there arise problems that the manufactured fiber becomes brittle and the corrosion resistance is deteriorated to cause disconnection and strength reduction, or it is not possible to obtain a fiber bundle with uniform characteristics in the same cross section, and the yield is decreased. In Japanese Unexamined Patent Publication (Kokai) No. 61-137623, a stainless steel wire rod is coated with an ultra-low carbon steel strip having a carbon content of 0.008 wt% or less to obtain a composite linear material, and a large number of the composite linear material is made of stainless steel. A method is disclosed in which a carbon steel pipe having a carbon content lower than that of a steel wire rod is inserted, hot-rolled, cold-drawn and annealed repeatedly to obtain a thin wire, and both carbon steels are chemically removed. Since ultra low carbon steel is used as carbon steel, it is said that carburization of stainless steel can be prevented during hot working.

Regarding the production of metal fibers by the above-mentioned method, in the method of chemically removing carbon steel after thinning, a metal which is hardly soluble in an acid solution is used as a metal constituting the metal fibers. You can Specifically, it can be used as a method for producing stainless steel fibers or titanium fibers. It is also possible to adopt a method of removing carbon steel by an electrolysis method after thinning.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The steel disclosed in Japanese Patent No. 7623 has a carbon content of 0.00 as a strip steel covering a stainless steel wire rod as a metal fiber raw material.
It is necessary to use carbon steel of 8 mass% or less, and it is also necessary to use a steel pipe having a carbon content lower than that of a stainless steel wire rod for inserting a coated wire rod. These ultra-low carbon steels are expensive and have been a factor that increases the manufacturing cost of the metal fibers to be manufactured.

In the conventional manufacturing method, not only carburization of carbon steel into stainless steel but also diffusion of Ni and Cr from stainless steel into carbon steel is caused during hot rolling of a steel pipe into which a large number of covered wire rods are inserted. It was observed that carbon steel turned into stainless steel. When carbon steel becomes stainless steel,
It becomes difficult for the carbon steel to melt during the carbon steel dissolution treatment in the final step, and it becomes impossible to smoothly produce metal fibers.

The present invention provides a method capable of producing a metal fiber without using an expensive ultra-low carbon steel, and a method capable of preventing the carbon steel from becoming stainless steel. To aim.

[0009]

[Means for Solving the Problems] Conventionally, in a method for producing a wire rod as a composite material for metal fibers by hot rolling, a large number of coated wire rods whose surface is covered with carbon steel are inserted into a steel pipe, When inserting a large number of covered wire rods into a steel pipe, the filling rate of the coated wire rod inside the steel pipe after insertion is at most 50 to 75% (Fig. 5 (a)). It is difficult to insert the wire smoothly. Moreover, the same rolling as the normal wire rod rolling is used for the hot rolling. If a steel pipe with an internal filling rate of 75% or less (Fig. 5 (a)) is hot roll-rolled, will the steel pipe be deformed unevenly in the initial rolling stage, causing biting to the left and right and making subsequent rolling difficult? However, even if it can be rolled, the cross-sectional shape and cross-sectional diameter of the fiber become uneven, and the product cannot be obtained. Therefore, conventionally, as shown in FIG. 6 (c), the material to be rolled was taken out and cooled in the course of hot rolling, and then the left and right bite portions were ground and removed, and the terminal portions having a bad shape were cut and removed. After that, the wire is again rolled. For this reason, the product cost becomes extremely high, and the yield is reduced because the terminal portion having a bad shape is removed. In addition, in terms of quality, the fiber shape is not stable, and the heating furnace has to
Since it has been charged in a circumstance, diffusion of elements between the carbon steel and the stainless steel progresses violently, and there have been problems such as poor corrosion resistance of stainless fibers and deterioration of melting workability. As a means for solving this diffusion problem, in the one disclosed in JP-A-61-137623, the carbon amount of the strip steel covering the stainless steel wire rod as the metal fiber raw material is 0.008 mass% or less. Stipulates. Further, the phenomenon that carbon steel became stainless steel was caused by the hot rolling performed twice. In addition, since it is necessary to perform surface grinding and terminal processing after the first hot rolling, there is a problem that the work load increases, which causes a cost increase.

On the other hand, as shown in FIG. 3, when the steel pipe 9 into which a large number of covered wire rods are inserted is cold pressed and compressed by the press shrinking device 14, only the steel pipe is compressed and the covered wire rod becomes dense. Since they are arranged, the filling rate can be increased to the extent that non-uniform deformation, which is harmful in hot rolling, does not occur (FIG. 5B). When a steel pipe having a high filling rate is hot-rolled, non-uniform deformation does not occur during rolling, and it is possible to produce a composite material for a metal fiber having a good shape by one hot-rolling. . Since the hot rolling is performed once, the diffusion of elements between the carbon steel and the stainless steel is slight, and it is not necessary to use expensive ultra low carbon steel having a carbon content of 0.008% or less as the carbon steel. It is also possible to prevent carbon steel from becoming stainless steel.

The present invention has been made based on the above findings, and the gist thereof is as follows. (1) A coated wire rod 4 in which a wire rod 2 as a metal fiber raw material is coated with a steel strip 3 is used, a large number of the coated wire rods 4 are inserted into a steel pipe 5, the steel pipe 5 is cold-reduced, and then hot rolled. A method for producing a composite material for metal fibers, which is characterized by carrying out. (2) A composite for metal fibers, characterized in that a steel pipe 5 into which a large number of covered wire rods 4 in which a wire rod 2 as a metal fiber raw material is covered with a strip steel 3 is inserted is prepared, and the steel pipe is cold-compressed. Material manufacturing method. (3) The method for producing a composite material for metal fibers according to the above (1) or (2), wherein the cold shrinking is performed by press shrinking. (4) In the hot rolling, the induction heating furnace alone or a combustion type heating furnace and an induction heating furnace are used for heating, and then rolling is performed, followed by rolling, and the composite for metal fibers according to the above (1) or (3). Material manufacturing method. (5) The strip steel 3 and the steel pipe 5 have a carbon content of 0.
04 mass% or less, The manufacturing method of the composite material for metal fibers in any one of said (1) thru | or (4) characterized by the above-mentioned. (6) The method for producing a composite material for metal fibers according to any one of (1) to (5) above, wherein the wire material 2 as the metal fiber raw material is a stainless steel wire material. (7) A method for producing a composite material for metal fibers according to any one of the above (1) to (6), characterized in that a steel rod 6 is inserted into the central portion of a steel pipe together with the large number of covered wire rods 4. . (8) The composite material for metal fibers produced by the method for producing a composite material for metal fibers according to any one of (1), (3) to (5) above is drawn by wire drawing, and then the strip is drawn. A method for producing a metal fiber, which comprises removing steel and a steel pipe.

(9) A strip steel coating device 11 for coating a wire rod 2 as a metal fiber raw material with a strip steel 3 to form a coated wire rod 4, and an insertion device 14 for inserting a large number of the coated wire rods 4 into a steel pipe 5.
An apparatus for producing a composite material for metal fibers, comprising: an apparatus for cold-rolling the steel pipe, and a hot-rolling apparatus 20 for rolling the rolled steel pipe. (10) The cold shrinking device is a press shrinking device 15
The manufacturing apparatus of the composite material for metal fibers as described in (9) above. (11) The hot rolling apparatus 20 has an induction heating furnace alone or a combustion type heating furnace and an induction heating furnace, and performs rolling after heating in these heating furnaces, (9) or ( 10) An apparatus for producing a composite material for metal fibers according to 10).

(12) A composite material for metal fibers, comprising a large number of fine wires for metal fibers covered with a steel strip, the outer periphery of which is covered with a steel pipe and hot-rolled, wherein the steel strip and the steel pipe are Is a composite material for metal fibers having a carbon content of 0.04 mass% or less. (13) The composite material for metal fibers as described in (12) above, further comprising a steel wire in the center, and the steel content of the steel wire is 0.04 mass% or less.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described with reference to FIGS.
A description will be given based on (a). In the present invention, a wire rod 2 as a metal fiber raw material is covered with a band steel 3 to form a covered wire rod 4 (Fig. 1), and a large number of the covered wire rods 4 are inserted into a steel pipe 5 (Fig. 2) to cool the steel pipe 5. Between the pipes (FIG. 3) and then hot rolling to obtain a composite material 7 for metal fibers (FIG. 4). The composite material 7 for metal fibers is drawn by cold drawing,
Then, by removing the strip steel and the steel pipe, the diameter 1
A metal fiber of about 0 μm is manufactured. The manufacturing process flow is shown in FIG. As a method of removing carbon steel such as the strip steel 3 and the steel pipe 5, a chemical method of dissolving with an acid or an electrolysis method can be adopted. When the method of dissolving and removing with an acid is adopted, stainless steel or titanium which is hardly soluble in an acid solution can be adopted as the metal as the metal fiber.

The case of producing stainless steel fibers as the metal fibers will be described below as an example, but it goes without saying that the present invention can be applied to the production of metal fibers other than stainless steel as described above.

Stainless steel as a raw material for metal fibers is previously processed into a wire 2 by a conventional method such as rolling a wire. Usually, it is preferable to use a wire rod having a diameter of about 5.5 mm. As stainless steel, it can be applied to all steel types, and also to superalloys.

This stainless steel wire rod 2 is coated with a steel strip 3. The steel strip 3 is coated for the purpose of preventing fusion between stainless steels during hot surface reduction processing. After the hot working and wire drawing, the strip steel 3 is removed. When the method of chemically removing is adopted, carbon steel is used as the material of the steel strip 3. By immersing the material after wire drawing in an acid solution, the strip steel 3 is dissolved and removed, and the stainless steel fibers are recovered without being dissolved in the acid solution.

As the steel strip 3, a continuous steel strip whose width is slightly larger than the circumference of the stainless steel wire is used. Figure 1 (b)
As shown in, the strip steel 3 is continuously curved, and the stainless steel wire rod 2 is fed into the curved center portion in parallel with it. Then, as shown in FIG. 1A, the strip steel coating device 1
The strip steel 3 is coated around the stainless steel wire rod 2 by 1 and the overlapping portions at both ends of the strip steel are reduced in diameter by a roll to form a coated wire rod 4 whose cross section is shown in FIG. 1 (c).

A cutting device 12 for cutting the coated wire 4 coated with the steel strip.
Cut a fixed size to a predetermined size and bundle a large number. The binding device 13 can be used. After that, as shown in FIG. 2, the bundled covered wire rods 8 are inserted into the steel pipe 5 by the insertion device 14 including the clamp 19 with the feed mechanism 18. When the method of chemically removing the steel pipe 5 is adopted, carbon steel is used as the material of the steel pipe, as in the case of the strip steel. The filling rate of the covered wire rod 4 in the steel pipe is preferably as high as possible, but in order to smoothly insert the covered wire rod 4 into the steel pipe, the filling rate is usually about 75% (Fig. 5).
(A)). When the stainless steel wire rod 2 having a diameter of 5.5 mm is cold drawn to a diameter of 3.1 mm and the steel pipe 5 having an inner diameter of 128 mm is used, the filling rate is 75
%, About 900 coated steel pipes 4 can be inserted into the steel pipe.

The steel pipe 9 into which the coated wire rod has been inserted is then cold-rolled, thereby increasing the filling rate of the coated wire rod 4 in the steel pipe. As a cold shrinking method, see FIG.
As shown in (a), it is preferable to use a press constricting device 14 that presses using a press mold (upper pressing mold 15 and lower pressing mold 16) having a cylindrical half shape having a diameter after contraction. In the case of a compressed pipe, the pressing pressure may be small if the length of the press die is shorter than the length of the steel pipe in which the covered wire rod is inserted, as shown in FIG. 3. In that case, the steel pipe is gradually fed while pressing. For example, the inner diameter 128.
The diameter of a steel pipe of 4 mm is reduced at a diameter reduction ratio of 3.5% to obtain an inner diameter of 123.
If it is 4 mm, the filling rate in the steel pipe before the diameter reduction of 75% can be changed to 82% after the diameter reduction.

As a method of cold shrinking, in addition to the press shrinking tube shown in FIG. 3, a cold drawing method or a cold rolling method using a roll with a hole die can be adopted. As for the shape of the steel pipe after the contracted pipe, the pressed contracted pipe is preferable because a good uniform shape can be realized.

By increasing the filling rate of the covered wire rod in the steel pipe by a cold shrink tube before hot rolling, even if the same method as the ordinary wire rod rolling is used for the hot rolling, the inner covered wire rod will not be removed. Does not deform unevenly. Therefore, it is possible to reduce the surface to a predetermined size by one hot rolling to obtain a composite material for metal fibers, and prevent carburization of carbon steel into stainless steel and conversion of carbon steel into stainless steel. Further, since it is not necessary to perform surface grinding or terminal processing after the first hot rolling, it is possible to reduce the work load.

The filling rate of the covered wire in the steel pipe after cold shrinking is preferably 82% or more.

In the conventional method of hot rolling without cold shrinking, in order to reduce the non-uniform deformation in the hot-pressed circle as much as possible, the coated wire rod in the steel pipe before rolling It was necessary to keep the filling rate of as high as possible. Specifically, unless the filling rate is 75% or more, even if the hot rolling is performed twice, the deformation after the first hot rolling is severe and stable production is difficult. On the other hand, when it was attempted to maintain the filling rate at 82% or more, it was difficult to perform smooth filling. On the other hand, in the present invention in which cold shrinking is performed, if the filling rate before cold shrinking is about 73% or more, cold shrinking and subsequent heat shrinking will not occur without uneven deformation. Hot rolling can be performed. Therefore, the covered wire rod can be inserted into the steel pipe very smoothly in a short time, and the working efficiency can be improved.

In the conventional method, since it was necessary to perform hot rolling twice, carburizing into stainless steel due to diffusion of metal components in the heating furnace in particular twice becomes a problem. In order to prevent this, it was necessary to reduce the carbon content of the steel strip covering the stainless steel to 0.008% or less. Further, since the stainless steel component diffuses into the strip steel, there is a problem that the solubility of the strip steel due to an acid is poor. In the present invention, since the number of times of hot rolling can be once, the heating process, which is a process in which diffusion mainly proceeds, can also be performed once, and the diffusion of metal components in hot rolling can be significantly suppressed. Will be possible. Therefore, in the case of heating by using the combustion type heating furnace 21 in hot rolling, a strip steel covering a wire rod as a metal fiber raw material,
For any of the steel pipes for inserting the coated wire, it is possible to use low carbon steel in a range that is usually easily available. As a result, an inexpensive material can be used as compared with the conventional one, and the manufacturing cost of the metal fiber can be reduced. Furthermore, since the diffusion of stainless steel components from the stainless steel wire rod to the strip steel is suppressed, it is possible to prevent the strip steel from becoming stainless steel and to smoothly dissolve the strip steel and the steel pipe with acid after the completion of wire drawing. You can proceed.

In ordinary wire rod rolling, a combustion type heating furnace 21 such as a pusher type heating furnace or a walking beam type heating furnace is used as a heating method before rolling. In these combustion type heating furnaces 21, it is necessary to secure sufficient in-furnace time to make the rolling material uniform, and even if hot rolling is performed once, carburization of stainless steel wire or stainless steel of carbon steel is required. There is no eradication.

In the present invention, more preferable results can be obtained by using the induction heating furnace 22 alone or combining the heating in the combustion heating furnace 21 and the heating in the induction heating furnace 22 as the heating method. This is because the heating by the induction heating furnace 22 can heat the material to a predetermined temperature in a shorter time as compared with the combustion heating furnace 21, so that the diffusion of the metal component during the heating can be suppressed.
A method in which initial heating is first performed in the combustion heating furnace 21 and then final heating is performed in the induction heating furnace 22 is preferable. Figure 4
A walking beam type heating furnace is provided as the combustion type heating furnace 21, followed by an induction heating furnace 22, and a rough rolling mill 23.
Winding line 2 through intermediate rolling mill 24 and finishing rolling mill 25
6 is an example of a wire rod rolling device that winds the material after rolling in 6.
Further, FIG. 6B is a diagram showing a manufacturing flow when hot rolling is performed using a combustion type heating furnace and an induction heating furnace.

The induction heating furnace 22 is composed of a plurality of coils and a plurality of control devices, and it is possible to select an optimum heat pattern according to each manufacturing type. Further, in order to cope with overheating of the surface layer portion due to the surface layer effect, by providing an appropriate space between the coils, heat dissipation of the surface layer portion can be promoted and the temperature variation in the cross section can be minimized. By moving the rolled material in the induction heating furnace 22 at a constant speed,
The coils are sequentially heated according to the electric power supplied to them, and the final coil finishes them to a predetermined temperature.

In the conventional heating by the combustion type heating furnace alone,
It requires heating for a long period of time, especially for soaking time at a temperature of 1000 ° C. or higher for about 1 hour, and the diffusion of components progresses during soaking at such a high temperature for a long time, which causes carburization and carbonization of stainless steel. The conversion of steel to stainless steel was in progress. In the heating using both the combustion heating furnace and the induction heating furnace, the soaking time at a temperature of 1000 ° C. or higher in the combustion heating furnace can be shortened to about several minutes. Since the steel pipe is carbon steel, when it is heated at high temperature for a long time in the conventional combustion furnace, the oxidation loss of carbon steel that does not have oxidation resistance increases,
Although it was necessary to increase the wall thickness of the steel pipe, this problem can be solved by adopting an induction heating furnace.

In the present invention in which the induction heating furnace 22 alone or the combustion type heating furnace 21 and the heating of the induction heating furnace 22 are combined, the diffusion of metal components during heating can be further reduced by shortening the heating time. Therefore, it becomes possible to use carbon steel having a carbon content of about 0.04% or less for both the strip steel 3 for coating the wire rod as the metal fiber raw material and the steel pipe 5 for inserting the coated wire rod. The cost can be reduced. The dissolution of the steel strip and the steel pipe by the acid after the completion of wire drawing can be more smoothly proceeded.

The carbon content of the strip steel 3 for coating the wire 2 as the metal fiber raw material and the steel pipe 5 for inserting the coated wire 4 is
It is preferably 0.03% or more. As a result, it becomes possible to inexpensively prepare the strip steel 3 and the steel pipe 5.

In the present invention, as shown in FIGS. 5 (c) and 5 (d), a steel rod 6 may be inserted in the center of the steel pipe 5 together with the large number of covered wire rods 4.

As described above, in the present invention, the wire rod 2 as the metal fiber raw material is the coated wire rod 4 coated with the steel strip 3, and a large number of the coated wire rods 4 are inserted into the steel pipe 5 to form the steel pipe. The composite material for metal fibers 7 is manufactured by cold shrinking and then hot rolling. This composite material for metal fibers 7 is a composite material for metal fibers, which has a large number of thin wires for metal fibers covered with strip steel, the outer periphery of which is covered with a steel pipe and hot rolled. Here, the strip steel and the steel pipe preferably have a carbon content of 0.04 mass% or less. Further, it has a steel wire in the center, and the steel wire has a carbon content of 0.0
It is preferably 4% by mass or less.

Subsequently, the composite material 7 for metal fibers is drawn by drawing to reduce the wire diameter to a target diameter, and then the strip steel and the steel pipe are removed to finally produce metal fibers. When a steel rod is inserted in the center of the steel pipe, this steel rod is also removed. As for the wire drawing work, a cold drawing work method which is usually carried out can be adopted, and if necessary, annealing treatment is carried out during the wire drawing or after the wire drawing is completed.

The strip steel 3, the steel pipe 5, and the steel rod 6 can be removed by a dissolution removal method using a chemical agent or an electrolysis removal method. If the metal fiber is stainless steel or titanium fiber, immerse the material after wire drawing in an acid solution to dissolve only the strip steel, steel pipe and steel rod with the acid solution, and take out only the metal fiber. You can

In the present invention, the material after hot rolling is called a composite material for metal fibers, and the material before hot rolling is also called a composite material for metal fibers. The composite material for metal fibers that has been subjected to the cold-shrinking tube is further hot-rolled thereafter, drawn by wire drawing, and then the metal steel is produced by removing the strip steel and the steel tube. be able to.

[0037]

EXAMPLES The invention was applied in the production of stainless steel fibers. SUS316L stainless steel was rolled into a wire 2 having a diameter of 5.5 mm. Carbon content 0.0
A strip steel 3 having a mass of 37%, a width of 12 mm and a thickness of 0.25 mm was prepared, and the strip steel 3 was coated on the stainless steel wire rod 2 by the apparatus shown in FIG. First, the strip steel 3 is continuously curved, and in parallel with this, the stainless steel wire 2 is fed to the curved center portion. After that, the strip steel 3 is coated on the entire circumference of the stainless steel wire rod 2 by the strip steel coating device 11, and the overlapping portions at both ends of the strip steel are reduced in diameter by rolls to obtain a coated wire rod 4 as shown in FIG. 1 (c). . The coated wire rod 4 is cut into a length of 3.0 m by the cutting device 12, and a total of 900 coated wire rods 4 are bundled in a cylindrical shape, and the diameter of the center of the cylinder is 19 m.
A steel rod 6 having a length of m and a length of 3.0 m is arranged. The covered wire rods bundled in a columnar shape are bound by a binding device 13 so as to be easily inserted into a steel pipe. The steel pipe 5 has a carbon content of 0.031 mass%, an outer diameter of 140 mm, a wall thickness of 5.7 mm, and a length of 3.0 m. The rate is 75% (Fig. 5
(C)). Stainless wire rod 2, strip steel 3, steel rod 6, steel pipe 5
The detailed components of are shown in Table 1.

[0038]

[Table 1]

Next, as shown in FIG. 3 (a), the steel pipe 9 with the covered wire rod inserted therein is cold-press-contracted. An upper press die 16 and a lower press die 17 each having a shape obtained by half-dividing a cylinder having a diameter of 135 mm are used as the press shrink tube. By pressing the steel pipe 9 into which the covered wire is inserted using these press dies, the steel pipe is contracted to a diameter of 135 mm (Fig. 5).
(D)). The shape after the contracted tube was very good, and it was not necessary to grind the surface or perform end processing. After the contraction, the filling rate of the covered wire in the steel pipe could be 82%.

The steel tube after the contracted tube was heated by a walking beam type heating furnace and an induction heating furnace. Then, hot rolling was carried out by a wire rod rolling device 20 which is usually used as shown in FIG. 4 to produce a composite material for metal fibers having a diameter of 5.5 mm. No surface grinding or terminal processing was required in the middle of hot rolling, and the composite material 7 for metal fiber having a good shape could be manufactured. The diameter of the stainless steel thin wire in the composite material for metal fibers is about 0.1 mm, and each of these stainless steel thin wires is covered with a thin strip steel.

This composite material for metal fibers 7 was cold drawn by a usual method to obtain a fine wire having a diameter of 0.8 mm. After that, the steel pipe on the outer periphery, the strip steel around the metal fibers, and the steel wire in the central portion were dissolved by immersing in an acid solution, and a bundle of stainless steel fibers having a diameter of 8 μm could be obtained.

Despite the use of steel pipes, steel strips and steel rods having a carbon content of 0.03% or more, no carburization phenomenon was observed in stainless steel fibers, and good quality stainless steel fibers were produced. I was able to. Further, since the stainless steel component did not diffuse into the strip steel, the strip steel could be melted smoothly.

[0043]

INDUSTRIAL APPLICABILITY The present invention provides a coated wire material in which a wire material as a metal fiber raw material is coated with a band steel, and a large number of the coated wire materials are inserted into a steel pipe and hot rolled to produce a composite material for metal fiber. In doing so, cold shrinking is performed before hot rolling to increase the filling rate of the coated wire rod in the steel pipe, preventing non-uniform deformation during hot rolling, and performing hot rolling only once. Made it possible. As a result, it is possible to reduce the manufacturing cost of the metal fiber by eliminating the need for double hot rolling and surface grinding or end treatment during the hot rolling. In addition, when the coated wire rod is inserted into the steel pipe, it is possible to insert it at a low filling rate, and the efficiency of the insertion work can be improved.

Further, by reducing the hot rolling from twice to once, the diffusion of metal components during the hot rolling is suppressed, and the upper limit of the carbon content of the carbon steel used as the strip steel and the steel pipe is relaxed. I was able to. In particular, by using a walking beam type heating furnace and an induction heating furnace together, heating can be performed for a short time, and the carbon content upper limit of carbon steel used as a strip steel or a steel pipe can be 0.04%. We were able to reduce costs. Further, the diffusion of stainless steel components into these carbon steels was suppressed, and it became possible to smoothly perform the melting in the carbon steel melting step.

[Brief description of drawings]

FIG. 1 is a view showing a situation in which a wire rod is covered with a strip steel,
(A) is an overall schematic view, (b) is a partial view showing a covering state,
(C) is a sectional view of the covered wire.

FIG. 2 is a schematic view showing a situation in which a large number of covered wire rods are inserted into a steel pipe.

3A and 3B are schematic diagrams showing a cold press shrink tube device of the present invention, in which FIG. 3A is a state before pressing and FIG. 3B is a diagram showing a state after pressing.

FIG. 4 is a schematic view showing a hot rolling apparatus of the present invention.

5A and 5B are views showing a cross-sectional situation of a steel pipe into which a covered wire rod is inserted, wherein FIGS. 5A and 5C are diagrams showing a situation before contraction and FIGS. 5B and 5D are diagrams showing a situation after contraction.

FIG. 6 is a diagram showing a manufacturing flow of the present invention and a conventional manufacturing flow.

[Explanation of symbols]

1 metal fiber 2 Wire rod (stainless steel wire rod) as metal fiber raw material 3 band steel 4 covered wire 5 steel pipe 6 steel rod 7 Composite material for metal fibers 8 Bundled covered wire rod 9 Steel pipe with covered wire rod inserted 11 Steel strip coating device 12 cutting device 13 Binding device 14 Insertion device 15 Press reduction tube device 16 Top press type 17 Lower press die 18 Feeding mechanism 19 clamps 20 Hot rolling equipment 21 Walking beam type heating furnace 22 Induction heating furnace 23 rough rolling mill 24 Intermediate rolling mill 25 Finishing mill 26 winding line 31 wire drawing equipment

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Hanatani             3434 Shimada, Hikari-shi, Nippon Steel Works             Inside the Shoko Ironworks F term (reference) 4E002 AA07 AC14 BD20 CA20                 4E096 EA03 EA13

Claims (13)

[Claims] 1. A coated wire rod in which a wire rod as a metal fiber raw material is coated with a band steel, a large number of the coated wire rods are inserted into a steel pipe, the steel pipe is cold-reduced, and then hot-rolled. A method for producing a composite material for metal fibers, comprising: 2. A composite material for metal fibers, characterized in that a steel pipe is prepared by inserting a large number of coated wire rods in which a wire rod as a metal fiber raw material is coated with a strip steel, and the steel pipe is cold-compressed. Production method. 3. The method for producing a composite material for metal fibers according to claim 1, wherein the cold shrink tube is a press shrink tube. 4. The composite material for metal fibers according to claim 1, wherein the hot rolling is performed by heating only in an induction heating furnace or in a combustion heating furnace and an induction heating furnace, and then rolling. Manufacturing method. 5. The method for producing a composite material for metal fibers according to claim 1, wherein the strip steel and the steel pipe have a carbon content of 0.04 mass% or less. 6. The method for producing a composite material for metal fibers according to claim 1, wherein the wire material as the metal fiber raw material is a stainless steel wire material. 7. The steel rod is inserted into the central portion of the steel pipe together with the plurality of covered wire rods.
A method for producing a composite material for metal fibers according to any one of 1. 8. A composite material for metal fibers manufactured by the method for manufacturing a composite material for metal fibers according to claim 1, 3 or 5 is drawn by wire drawing, and then the strip steel and the steel pipe. A method for producing a metal fiber, which comprises removing 9. A strip steel coating device for coating a wire rod as a metal fiber raw material with a strip steel to form a coated wire rod, an insertion device for inserting a large number of the coated wire rods into a steel pipe, and cold shrinking of the steel pipe. An apparatus for producing a composite material for metal fibers, comprising: an apparatus for pipeting and a hot rolling apparatus for rolling a reduced steel pipe. 10. The apparatus for producing a composite material for metal fibers according to claim 9, wherein the apparatus for cold shrinking is a press shrinking apparatus. 11. The hot rolling apparatus has an induction heating furnace alone or a combustion heating furnace and an induction heating furnace, and performs rolling after heating in these heating furnaces. An apparatus for producing a composite material for metal fibers according to. 12. A composite material for metal fibers, comprising a large number of fine wires for metal fibers covered with a steel strip, the outer periphery of which is covered with a steel pipe and hot-rolled, wherein the steel strip and the steel pipe are And a carbon material having a carbon content of 0.04% by mass or less. 13. The composite material for metal fibers according to claim 12, further comprising a steel wire in the central portion, wherein the steel wire has a carbon content of 0.04 mass% or less.