JPS5926361B2 - Method for manufacturing metal fiber wire containing multiple stainless steel wires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for producing a wire rod containing a large number of fine metal wires for fibers by organically combining hot extrusion and hot wire rod rolling processes. be.

The present inventors have previously developed a method for manufacturing metal fibers that consists mainly of cold wire drawing, by organically combining hot extrusion and hot wire rolling. We have succeeded in developing a method for efficiently obtaining metal fibers by obtaining wire rods containing fine metal wires and using them as strands, and have already filed an application as Japanese Patent Application No. 49-88875.

In this method, a billet made of fiber metal on the inside and ordinary steel on the outside is first hot extruded to create a billet for wire rod, hot rolled into a wire rod, drawn and straightened, and then rolled into a predetermined length. Cut at the right angle.

A large number of these wire rods are further inserted into a common steel 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 using nitric acid, etc., so that only the fine metal wire remains and is easily separated from the metal fiber. It is something to do. In this case, the ordinary steel covering the thin metal wires acts as a separator to prevent the thin metal wires from seizing together due to heating during the manufacturing process. However, when making stainless steel into metal fibers, if the material of the separator used to prevent stainless steel from seizing is ordinary steel, processes such as hot extrusion, wire rod rolling, and wire drawing are necessary to obtain the stainless steel fibers. Because of this, the stainless steel undergoes heat treatment such as heating with a steel billet or annealing with a wire rod, which causes the so-called carburization phenomenon in which carbon in the separator covering the surface of the stainless steel diffuses into the stainless steel.

When this carburizing phenomenon occurs, the carburized fine stainless steel wire becomes brittle and becomes extremely susceptible to breakage.
When it comes to stainless steel fibers with a diameter of about μ, there is a serious drawback in that many wire breaks occur.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and it is an object of the present invention to provide a method for producing a wire rod for metal fibers, in which stainless steel fibers without wire breakage can be obtained by using steel with a low carbon content as a separator. .

Ordinary steel (C: about 0.10-0.40%) as an isolation material
When stainless steel fibers are used, the carbon contained in the separator diffuses into the stainless steel when passing through a high temperature region during the manufacturing process, resulting in brittle grain boundaries and weakening the strength of the stainless steel fibers themselves. This results in many disadvantages, such as a significant deterioration in the quality of the stainless steel fibers, which causes breakage of the stainless steel fibers during processing, and the quality of the stainless steel fibers, which also increases dispersion. In order to prevent such build-up, the material of the present invention is to use steel with an extremely low carbon content that does not carburize compared to stainless steel, thereby altering the various materials of the stainless steel itself. This makes it possible to obtain stainless steel fibers without wire breakage.

The separator in the present invention has a carbon content of 0.02 as its material.
% or less, but there are no particular restrictions on other components. This only needs to prevent carburization of the stainless steel, and will ultimately be melted and discarded, and high quality is not required for anything other than carbon. Copper may also be used as an isolation material.

In this case, there is no carburization phenomenon as in the present invention, and breakage cannot occur due to this, but since the melting point is lower than that of steel,
As mentioned above, there is a risk that the separator will melt during processing such as hot extrusion and rolling, and it will not be able to fulfill its role as a separator. Therefore, ultra-low carbon steel is optimal as a material that can withstand high temperatures of 1100° C. or higher during rolling. Example First, to make a billet for hot extrusion, an extremely low carbon (C: 0.01%, Si: 0
．． 25%, Mn: 0.30%, P: 0.018%, S:
Using a steel pipe (0.025%), a stainless steel of SUS3l6 with an outer diameter of 170 mm was inserted and hot extruded.
A billet of 0u square and 3.5 m in length was obtained.

This billet was rolled into a hot wire rod with an outer diameter of 8V1φ (outer diameter of the enclosed stainless steel round about 6.8φ) and a length of about 42mm.
A 0 m composite wire coil was obtained. Then, the wire was connected to 2.5V.
! After drawing the wire to lφ, it is made into a straight line, which has an outer diameter of 200u.
A billet for hot extrusion was made by inserting 3,280 wire rods as inserts into a regular steel pipe with a diameter of 15 mm and a wall thickness of 15 mm and a length of 700 mm.The billet for hot extrusion was then hot extruded and the 80 mm square wire billet was rolled into a wire rod with a width of 13 mm. Got the coil.

This wire has 328 stainless steel wires with a diameter of approximately 138μ.
Ultra-low carbon steel was present 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 rod, the 13u wide wire rod is drawn to a diameter of approximately 1.13mm, and then the outer shell material and isolation material are dissolved with nitric acid to produce 12μ stainless steel fibers. Obtained.

This stainless steel fiber had no breakage and was of very good quality and properties.

Cold heating the metal fiber wire manufactured by the present invention,
That is, in the process of wire drawing and heat treatment to produce a predetermined stainless steel fiber, there is no need to worry about carburization, so it is possible to increase the annealing temperature, and there is an advantage that the heat treatment time can be shortened accordingly. For example, in order to satisfy various properties as a stainless steel fiber, the necessary annealing temperature is around 800℃, but this can be raised to 900℃, which can shorten the heating holding time accordingly. It becomes possible to increase the speed of heat treatment by about 2 to 3 times.

Therefore, the effect is that the heat treatment efficiency is doubled and the productivity (economical efficiency) is greatly increased. In addition, since the separator is made of ultra-low carbon steel, the wire drawability is good, and the cold working limit (wire drawing limit) can be improved, making it possible to increase the speed of wire drawing and adopt a high area reduction ratio, which reduces the average The area ratio is 15-20% compared to 10% when using conventional ordinary steel, and the area reduction rate during the process is 30-20%.
Cold heating of stainless steel fibers can be greatly improved from 50% to 80 to 85%, and at the same time, a continuous wire drawing machine can be applied, and the number of annealing times can be reduced from 6 to 2.
It has many effects such as greatly simplifying the wire drawing heat treatment and easily increasing efficiency.

Claims (1)

[Claims] 1 A billet for hot working with an interior made of stainless steel and an exterior made of ultra-low carbon steel with a carbon content of 0.02% or less is subjected to hot extrusion and hot wire rod rolling, and the outer layer is made of the ultra-low carbon steel and the inner layer is A method for manufacturing a wire rod for metal fiber containing a large number of fine stainless steel wires, characterized in that a composite wire rod in which a portion is made of stainless steel is obtained, the composite wire rod is formed into an aggregate, and hot extrusion and hot wire rolling are performed again. .