JPS594203B2 - Method for manufacturing hot extrusion billets for manufacturing metal fibers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a hot extrusion method for manufacturing a wire rod containing a large number of thin metal wires for fibers by organically combining hot extrusion and hot wire rod rolling processes. This relates to a billet manufacturing method.

The present inventors have previously discovered that, instead of the conventional method of manufacturing metal fibers mainly based on cold wire drawing, they organically combined hot extrusion and hot wire rolling to produce a large number of fiber metals within the cross section of the wire. We have succeeded in developing a method for efficiently obtaining metal fibers by obtaining a wire containing fine wires and using this as a wire, and have already filed an application as Japanese Patent Application No. 49-88875.

In this method, a billet made of textile metal on the inside and ordinary steel on the outside is hot extruded to make a billet for wire rod, then hot rolled into a wire rod, which is then drawn and straightened to a predetermined length. Perform primary analysis.

A large number of these wire rods are further inserted into a common steel p-tube to form an aggregate, and a billet for hot extrusion is again made.

This billet is hot extruded to produce a billet for wire rod rolling, and by hot rolling this billet, a wire rod containing a large number of fine fiber wires is manufactured.

Such a wire rod is then processed to the required metal fiber diameter by a known cold wire drawing process, and then only the ordinary steel is melted with nitric acid, etc., and only the fine metal wires are easily separated and left to become metal fibers. .

In this case, the ordinary steel covering the thin metal wire is used as an isolation material.

This prevents the thin metal wires from burning together due to heating during the manufacturing process.

However, in order to obtain metal fibers, one wire rod is rolled with several thousand thin metal wires inside it, and after being reduced to the required diameter through a process such as cold drawing, a separator is removed using a solvent. The metal fibers are extracted by melting and separating, but since the diameter of the metal fibers is more than 10 microns and the separating material is several microns, it takes a very long time to melt to the center, and the metal fibers are melted in a continuous line. In some cases, the central portion may remain as an undissolved portion, which hinders the entire dissolution process.

This tendency is disadvantageous because the number of thin metal wires encapsulated increases and the thickness of the isolation material gradually decreases as the wire diameter becomes smaller.Productivity can be improved by increasing the number of thin metal wires encapsulated in the wire. This was a major obstacle in achieving this goal.

Therefore, the inventor of the present invention has attempted to solve these problems, and when producing a billet for hot extrusion using an aggregate of a large number of composite wire rods, the present inventor has attempted to separate the aggregate with approximately the same material as the separator of the composite wire rods. It was discovered that it is possible to prevent undissolved portions from remaining in the center at the end of melting by separating the plates into several pieces and dissolving these separation plates in advance during melting, thereby speeding up the time for the solvent to reach the center. The application has been filed as 112317-1983.

However, although this method has been able to prevent the undissolved portion from remaining in the center, separation using a separator plate results in distortion of the cross-sectional shape of the composite wire rod in the billet for wire rod rolling in the vicinity of the separator plate.

This is because when a billet for wire rods is obtained by hot extrusion from a tube into which many composite wire rods are inserted, if there is only a composite wire rod, the adjacent gaps are approximately the same, so if deformation force is applied from the outer periphery, the It deforms freely according to force, and when the deformation force is uniform, its cross section becomes approximately hexagonal and uniform.

However, when partitioned by a separation plate, the uniformity of the gap between composite wires is lost, and free movement is restricted during deformation, resulting in extreme distortion in the vicinity of the separation plate and an uneven cross-sectional shape.

The present invention aims to solve such unresolved problems in Japanese Patent Application No. 50-112317 and improves the drawbacks. By partitioning the body into several parts by dissolving separation lines having approximately the same material as the isolation material of the composite wire and allowing the separation lines to move freely together with the composite wire during deformation, no local distortion occurs in the cross-sectional shape. It can be made substantially uniform over the entire area, and it is possible to prevent an undissolved part from remaining in the center during dissolution.

These separation lines are approximately the same as the isolating material when producing billets for hot extrusion.If an appropriate number of separation lines are installed in advance for the sole purpose of melting the material, there will be no mismatch between the thin metal wire and the isolating material, and the overall metal Since the thin wire can undergo deformation, the thin metal wire has an overall uniform cross-sectional shape.

The metal fiber-containing wire made in this way has a faster melting time during melting work, and there is no unmelted part, making it possible to easily melt and separate the metal fibers near the center, which also shortens the melting time. Helpful.

However, the thickness of the separation lines that partition composite wire rod assemblies during hot extrusion billet production is not particularly limited, but it is preferable that the separation lines be approximately the same diameter as the composite wire rods in terms of uniform deformation. If the number of separating wires required is too large, the number of metal wires will decrease, and if it is too small, the melting effect will be weakened. Therefore, the rows and number of separation wires should be selected appropriately depending on the number and diameter of the composite wires to be assembled. good.

Regarding the material, it is most preferable to use a material having the same or similar composition as the thin metal wire isolating material in view of uniform dissolution, but the material is not limited thereto and may be of a different material that is easily dissolved.

Although dissolution is quick only in the center where undissolved material is likely to occur, an even greater effect can be exerted if a dissolving material is present.

Example First, to make a billet for hot extrusion, the outer diameter was 2 as the outer shell material.
00Rψ, wall thickness 15mm, length 700m ultra-low carbon (C
: 0.01%, Si: 0.25%, Mn: 0.30%, P: 0.018%, S: 0.025%) using a steel pipe, into which a stainless steel of 5US316 and an outer diameter of 170m+++ψ was inserted. and hot extrusion into 80w square, 35
A billet of m was obtained.

This billet was hot wire-rolled to obtain a composite wire coil having an outer diameter of 8 Mψ and a length of about 420 m (outer diameter of the included stainless steel was about 6.8 mmψ).

Next, the wire rod was drawn to 2.5 ψ and made into a straight line 1 as shown in the drawing. Outer diameter 200rr divided into 6 parts by EIE mψ separation line 3 (material SS41) row
A billet for hot extrusion was made by inserting 3,000 pieces as inserts into the isolation material 2 of an ordinary steel pipe with an ψ, wall thickness of 15 wn, and length of 700 mm, hot extrusion was performed, and a wire rod billet of 80 + Ian square was wire-rolled. 9rrr! A wire coil of rLψ was obtained.

This wire has 3000 stainless steel wires with a diameter of about 95μ.
This included ultra-low carbon steel as a separator around each fine stainless steel wire, and the outer layer of the wire was entirely covered with ordinary steel.

In order to obtain stainless steel fibers from this wire, the 9 ψ wire is drawn to approximately 1.13 my + + ψ by an appropriate wire drawing process, and then the outer shell material and isolation material are dissolved with nitric acid to obtain 12 μ stainless steel fibers. Ta.

In this dissolution and separation of the stainless steel fibers, no undissolved residual fibers were generated, the dissolution time was significantly shortened, and the cross-sectional shape of the obtained stainless steel fibers was generally uniform and good.

There is no need to eliminate the problem that the work efficiency is reduced due to the long melting time in the cold working process, that is, the process of drawing and heat-treating the metal fiber wire produced by the present invention to produce a specified metal fiber. Because of this, it is possible to employ continuous melting work, which has the effect of shortening the work time accordingly.

By the way, the dissolution time for stainless steel fibers is approximately 1
It was about /2.

As described above, the present invention has the great advantage of doubling work efficiency and greatly improving productivity (economical efficiency).

[Brief explanation of the drawing]

The drawing is an explanatory view of a billet for hot extrusion in an example. 1: Composite wire, 2: Separation material, 3: Separation wire.

Claims (1)

[Claims] 1. When manufacturing a billet for hot extrusion using a composite wire rod whose outer layer is a separator and whose inner layer is a metal wire for fiber, the aggregate is formed by an appropriate number of melting and separation line arrays reaching from the center to the outer layer. A method for producing a hot extrusion billet for producing metal fibers, characterized by separating the billet.