JPH116034A - Metal wire - Google Patents

Abstract

(57) [Summary] [Problem] To achieve high strength and high ductility by a homogeneous structure, and to improve abrasion resistance and corrosion resistance. Has high strength or extremely high wear and corrosion resistance,
Provide a new metal wire. SOLUTION: A structure in which a dissimilar element is mechanically alloyed with a matrix metal is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal wire, and more particularly to a metal wire having high strength and high ductility, and also having good wear resistance and corrosion resistance. The toughness refers to the total properties of ductility and toughness, and is generally used in the field of wires where it is difficult to independently evaluate the toughness value. An index representing the toughness includes a twist value.

[0002]

2. Description of the Related Art For example, metal wires used for tension members of optical fibers, rock fall prevention nets, various springs, reinforcing wires of aluminum transmission lines, wire ropes, PC wires, and the like have strength, ductility, and abrasion resistance. It is important to have excellent wear resistance and corrosion resistance. In particular, there is a strong demand for high strength from the viewpoint of weight reduction. Further, in the use of these metal wires, since the metal wire also needs rigidity, it is desirable that the diameter is not less than a certain level, for example, 0.5 mm or more in the use of an optical fiber tension member.

However, a metal wire having a high strength, for example, a tensile strength of about 3000 N / mm ^2, generally has an extremely small diameter. For example, for a metal wire having a diameter of 0.20 mm, Japanese Patent Publication No. 33772/1990 discloses that a low-temperature transformation-generated phase composed of acicular martensite, bainite, or a mixed structure thereof has a predetermined volume fraction with respect to the ferrite phase in the ferrite phase. It has been proposed to perform cold drawing at a high area reduction rate under a heat treatment by using a wire having a composite structure dispersed in a steel sheet. According to this technique, a wire having a predetermined structure is used to increase the working limit, that is, to increase the working degree, thereby obtaining a high-strength steel wire. That is, since a high working ratio is required to obtain high strength in a metal wire, the diameter of the obtained metal wire naturally becomes small. In order to increase the diameter of the obtained metal wire, it is conceivable to increase the thickness of the wire to be subjected to wire drawing.
Since it is difficult to control the structure by heat treatment for processing, the desired processing rate cannot be secured.

The strength level of a general high-strength steel wire is 5 mmφ, 2000 N / mm ² , and even 1 mmφ has a maximum strength of 25 mm.
It is about 00 N / mm ² , and there is a problem that the ductility is inferior. In addition, grain refinement of the structure is known as a technique for achieving both strength and ductility, and a method of increasing the amount of wire drawing is effective for this grain refinement. Since the wire diameter decreases as the processing amount increases, it is difficult to secure a desired wire diameter.

On the other hand, as a technique for drawing a wire material which is difficult to wire, for example, stainless steel, a so-called convergence drawing technique is known. In other words, Japanese Patent Publication No. 50-39069 discloses that a plurality of stainless steel wires are coated with a medium carbon steel sheath material and then drawn, and then the sheath material is melted to obtain a stainless steel thin wire. Is disclosed. With this technique, it is possible to wire a difficult-to-process material without breaking, but as with the technique in the above-mentioned publication, the wire diameter decreases as the processing amount increases, so that a desired wire diameter must be secured. Is difficult. Furthermore, since the metal wire obtained by the convergence drawing method achieves high strength only by work hardening, not only dislocations but also microcracks are generated and ductility is reduced. Therefore, when trying to achieve both strength and ductility, high strength is not achieved. Even if the strength is not as high as 3000 N / mm ² class, there is still a basic demand for a technique capable of obtaining strength and ductility higher than expected from the conventional alloy composition.

On the other hand, in order to improve the wear resistance, it is a general method to secure the strength by alloy composition and heat treatment. However, it is difficult to cope with severe wear resistance conditions by this method.
Also, there is a disadvantage that the cost is relatively high. By the way, it is conceivable to apply a wear-resistant coating only to the outer periphery of the metal wire, but it is less reliable than the method of improving the wear resistance of the wire material itself, and large bending and twisting deformations are added. Since it is not available, it is inferior in handling. In addition, the productivity of the coating process becomes a bottleneck in this method, resulting in an increase in cost. Further, regarding the corrosion resistance, the anticorrosion coating has low productivity, the improvement of the corrosion resistance depending only on the alloy composition is disadvantageous in terms of cost, and it is difficult at present to obtain an extremely high corrosion resistance level. Therefore, in addition to the abrasion resistance, there is naturally a demand for a technique capable of obtaining characteristics higher than conventionally expected from the alloy composition, if not extremely high, in addition to the corrosion resistance.

[0007]

SUMMARY OF THE INVENTION Therefore, the present invention
A homogeneous structure achieves high strength and high toughness and improved wear resistance and corrosion resistance.Especially, it is possible to achieve extremely high strength or extremely high wear resistance without using thin wires like conventional high strength steel wires. An object of the present invention is to provide a novel metal wire having corrosion resistance.

[0008]

SUMMARY OF THE INVENTION The present invention provides a metal wire having a structure in which a different element is mechanically alloyed with a matrix metal. Further, the present invention is a metal wire characterized in that a heterogeneous element is mechanically alloyed with a matrix metal and has a structure in which ceramics are uniformly and finely dispersed.

[0009] In the above structure, the content of the different element can exceed the solid solubility limit of the element in the parent phase metal by the smelting method, and as a result, various properties are further improved. Furthermore, it is advantageous for implementation that the crystal grain size of the structure is 20 nm or less or that the structure contains an amorphous structure.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In a metal wire according to the present invention, homogenization is achieved by forming a structure in which a dissimilar element is mechanically alloyed with a matrix metal, thereby obtaining strength, ductility and corrosion resistance. There is a characteristic in the place where the aim was to improve. A structure in which a different element is mechanically alloyed with the matrix metal (hereinafter referred to as a mechanically alloyed structure) refers to a large mechanical energy generated by mechanical treatment with respect to a macro structure of the matrix metal. Means that the crystal grains of the parent metal are refined down to nanometer dimensions, and the microstructure of the parent metal is also alloyed with the same fine dissimilar elements. , A non-equilibrium phase or an amorphous phase.

That is, the mechanically alloyed structure is highly homogenized. In other words, although the dissimilar elements are alloyed into the matrix metal in the same manner as in the solid solution state in the melting method, the mechanical alloying structure is Due to its much more uniform structure and uniform solid solution in the matrix matrix, the toughness,
The abrasion resistance and corrosion resistance are improved over the ingots of the same composition. It is to be noted that such a homogeneous alloy structure cannot be obtained simply by imparting a process to the alloy. Even if the alloy is used as a base material, some kind of different element (may be a partial component of the base material alloy) is mechanically obtained. It requires a process of alloying.

FIG. 1 shows a Fe-8 wt% Cu-based metal wire having a mechanically alloyed structure according to the present invention, and a wire drawn after a so-called patenting process, in which a strength of 2000 N / mm ² or more can be obtained relatively easily. The results obtained by examining the hardness distribution in the radial direction of a high carbon steel wire obtained by wire working are shown. As shown in FIG. 1 (a), it can be seen that the metal wire of the present invention has higher hardness than the high carbon material. Moreover,
In the metal wire of the present invention, it is extremely characteristic that a certain hardness can be obtained in the radial direction. Normally, the hardness in the radial direction generally increases in the surface layer, as in a high carbon steel wire shown in FIG. 1 (b). This is because a difference occurs in the cooling rate in the patenting process between the surface layer portion of the wire and the inside. In this regard, since the mechanical alloying structure is homogeneous, there is no difference between the surface layer portion and the inside of the wire.

In particular, the mechanically alloyed structure has, due to its nature, the solid solubility limit of the dissimilar element in the matrix metal by the melting method of the element (including the solid solubility limit of a relatively stable supersaturated solid solution). ), The above-described solid solution strengthening action is further strengthened. That is, since the mechanical alloying structure is a structure obtained by mechanical processing, it is possible to alloy in an amount exceeding the metallurgical regulation and contains a dissimilar element that becomes supersaturated in the melting method in a solid solution state. I can do it. In such an alloy, it is possible to obtain a metal wire having a strength level equal to or higher than the strength level which was conventionally obtained only with a small diameter.

Here, when the mechanical alloying structure is crystalline, the crystal grain size is preferably reduced to 20 nm or less, more preferably to 10 nm, or contains an amorphous material. This is advantageous in improving toughness, and it is possible to obtain a strength level higher than previously obtained only with a small diameter. In addition, in the case of a structure containing an amorphous material or when a material having an anticorrosive function to different elements, for example, Cu, Zn, Cr and Ni, is contained, the corrosion resistance is particularly remarkably improved.

In the above-mentioned mechanical alloying structure,
Furthermore ceramics, for example _{SiO 2, TiO 2, WC,} SiN, SiC
By dispersing BN and BN uniformly and finely, remarkable increase in strength and remarkable improvement in wear resistance can be achieved by finer oxides, carbides or nitrides. Here, “uniform and fine” means, for example, that the distribution of macroscopic distribution is uneven, as seen in the mixing of ceramics during melting,
This means that there is no apparent coarsening due to agglomeration of the ceramic particles, and it is difficult to obtain it unless the application of mechanical energy. Even if this ceramic is contained, containing a supersaturated heterogeneous element, and having a crystal grain size of 20 nm or less or being amorphous,
Of course, it is equally advantageous.

In the metal wire according to the present invention, it is not necessary to limit the composition of the metal wire. However, a single metal or alloy is suitable as the matrix metal, and a metal which is alloyed with the matrix metal as the different element is a target. Therefore, when the matrix metal is an alloy, it may be an alloy component thereof. For example, Cu: 5-10wt%
(Dissimilar elements) and the balance of Fe (matrix metal),
Composition of Si: 5 to 7 wt% and balance of Fe or C: 0.1 to 1.
Compositions of 0 wt% and the balance Fe are advantageously suitable. In the case where the matrix metal is an alloy, the composition includes Mo: 1 to 5 wt% (heterogeneous element) and the balance of Fe-2 wt% Cu (matrix metal).

Next, a mechanical treatment for obtaining a mechanically alloyed structure will be specifically described with reference to FIG. First, a plurality of wires 1 of the matrix metal, for example, 3 to 20 wires, are guided to a convergence roll 3 shown in detail in FIG. 3 through large and small head plates 2a and 2b, and a group of wires is aligned. ,
This group of wires is wrapped in a swaging roll 4 whose cross section is shown in FIG. 4 with a covering material 5 of a different element that is also guided from the convergence roll 3 to the swaging roll 4. Then a plurality of rows of roller dies or dies 6,
Preferably, wire drawing is performed through at least three stands. Here, the area reduction rate, that is, the coating material 5 on the entrance side of the six rows of dies
From Shin wire cross-sectional area A ₂ Metropolitan of the cross-sectional area A ₁ and the exit side of the wire bundle including a ratio obtained by _{(A 1 -A 2) / A} 1 × 100, 90% or more, preferably 95 %, More preferably
Perform wire drawing to 99% or more. Thereafter, the obtained drawn wire 7 is wound around a take-up roll 8. The above is a basic process. The coating may be applied to each wire 1 before the wires are bundled.

Further, the drawn wire 7 obtained in the above basic step
Are prepared and used as the wire 1 described above, and the above basic steps are repeated in the same manner. By repeating this basic step at least three times, the finally obtained metal wire has the above-mentioned mechanical alloying structure.

Here, in order to contain a different element by supersaturation or to reduce the crystal grain size to 20 nm or less, it is possible to achieve this by increasing the above-mentioned area reduction rate or increasing the number of repetitions of the basic steps. On the other hand, in order to make it amorphous, the component system may be further adjusted in addition to the above. For example, 43at% Cu-57
At% Ti or the like is suitable for amorphization. In order to finely and uniformly contain ceramics in the mechanical alloying structure,
The ceramic powder may be supplied from the feeder 9 to the inside of the coating material 5 on the entry side of the swaging roll 4 shown in FIG. The feeder 9 is not limited to ceramic, and can supply powder of carbon, Si, Ti, or the like as needed. In addition, in order to adjust the component composition of the metal wire, the thickness of the coating material and the number of basic steps may be controlled.

In the mechanical treatment, the drawn material obtained by wrapping with a covering material and drawing is used as a starting material for a new drawing process, and then wrapped with a covering material and drawn. The process is characterized by the promotion of alloying by repeating the process, and the so-called focused wire drawing method, in which the coating material is melted after wire drawing to obtain an internal fine wire, follows a completely different processing history. . And as already mentioned, even if the processing is simply repeated to a single metal or alloy by the focused wire drawing method,
The target organization here cannot be obtained. In the drawing process, heat treatment such as stress relief can be performed as necessary.

[0021]

【Example】

Example 1 C: 0.2 wt% according to the procedure shown in FIG.
After wrapping four wires (2.0 mmφ) substantially containing Fe and containing Cu with a thickness of 0.05 mm, the area reduction rate is 75%.
Was performed on five stands. Using the drawn wire obtained in this basic step, the same basic step was further repeated five times, and then passed through a 1 mmφ die to produce a 1 mm diameter metal wire. As a result, an alloyed metal wire having a composition of C: 0.2 wt%, Cu: 6.1 wt%, and the balance substantially Fe was obtained.

The cross-sectional structure of the thus obtained metal wire was observed with a scanning electron microscope to measure the particle size, and the hardness, strength, ductility and corrosion resistance in the radial direction were evaluated. Table 1 shows the measurement and evaluation results. As a comparison, 2000N obtained by patenting
The same measurement and evaluation were performed for the / mm ² class metal wire. Table 1 shows the measurement and evaluation results.

The strength was evaluated by the tensile strength in a normal tensile test. The ductility was evaluated by the number of twists up to breaking by a torsion test (based on JISG 3521). Twisting conditions were length 100 × D (diameter).

The corrosion resistance was evaluated by the amount of corrosion in an air exposure (at Okinawa) test. The exposure period was one year. Abrasion resistance, carbide bars of 20 mm.phi, under tension 50kgf load, contacting repeated 10 ⁶ times the metal wire was evaluated in the abrasion amount. The surface roughness of the cemented carbide rod was set to _Rmax = 1 μm.

[0025]

[Table 1]

[Embodiment 2] According to the procedure shown in FIG.
When wrapping 5 wires (1mmφ) with Fe-10wt% Mo composition in iron foil (0.1mm thickness), add SiO ₂ powder from feeder, then wrap the wire in iron foil, then reduce the surface area Rate: 80% wire drawing was performed on 5 stands. The same basic process was repeated five times using the drawn wire material obtained in this basic process, and then passed through a 1 mmφ die to produce a 1 mmφ metal wire. As a result, C: 0.2 wt%, Mo: 8 wt%, SiO ₂ : 5 wt%
% And the balance was substantially Fe, resulting in an alloyed metal wire. Observing the cross-sectional structure of the metal wire thus obtained with a scanning electron microscope and measuring the particle size, confirming that the SiO ₂ is uniformly and finely distributed, as well as the hardness, strength, The ductility, corrosion resistance and abrasion resistance were evaluated. Table 2 shows the measurement and evaluation results.
In addition, the comparative example in the same table is the same metal wire as the comparative example in Table 1.

[0027]

[Table 2]

[Embodiment 3] According to the procedure shown in FIG.
When wrapping five Cu wires (1mmφ) with Cu foil (0.05mm thickness), add Ti powder from the feeder, then wrap the wire with Cu foil, and wire-draw with 80% reduction in area. Performed on 5 stands. Using the drawn wire obtained in this basic step, the same basic step was further repeated seven times, and then passed through a 1 mmφ die to produce a 1 mm diameter metal wire. As a result, 43at%
A metal wire having a Cu-57 at% Ti composition was obtained. The metal wire thus obtained was examined for amorphization by X-ray diffraction. That is, for the intensities of the main diffraction peaks of Cu, Ti, and CuTi, an intensity ratio is determined with the intensity of the peak measured for a pure substance (pure compound) as 1, and when the sum is 0.5 or more, the intensity ratio is not sufficient. It was determined that it had crystallized. Furthermore, hardness, strength, toughness, corrosion resistance and abrasion resistance in the radial direction were evaluated. Table 3 shows the measurement and evaluation results. In addition, the comparative example in the same table is the same metal wire as the comparative example in Table 1.

[0029]

[Table 3]

[0030]

According to the present invention, a microscopically homogeneous structure can be obtained, so that high strength and improvement in toughness and further improvement in corrosion resistance are advantageously realized, and various properties are excellent.
A relatively large diameter metal wire can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a hardness distribution in a radial direction of a metal wire.

FIG. 2 is an explanatory view showing a procedure for manufacturing a metal wire of the present invention.

FIG. 3 is a diagram showing details of a collecting roll.

FIG. 4 is a sectional view of a swaging roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wire rod 2a, 2b End plate 3 Focusing roll 4 Swaging roll 5 Coating material 6 Die 7 Wire drawing material 8 Take-up roll 9 Feeder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C22C 33/00 C22C 33/00 (72) Inventor Shuji Takeuchi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Within the Technical Research Institute (72) Inventor Kazuo Arai 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Pref.

Claims (5)

[Claims] 1. A metal wire having a structure in which a different element is mechanically alloyed with a matrix metal. 2. A metal wire characterized in that a heterogeneous element is mechanically alloyed with a matrix metal and the ceramic has a structure in which ceramics are uniformly and finely dispersed. 3. The metal wire according to claim 1, wherein the content of the dissimilar element exceeds the solid solubility limit of the parent phase metal by a smelting method of the element. 4. The metal wire according to claim 1, wherein the grain size of the structure is 20 nm or less. 5. The metal wire according to claim 1, 2 or 3, wherein the structure contains an amorphous material.