JPH0742666B2 - Reinforcement material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reinforcing material used as a reinforcing material such as rubber and plastic, and particularly to a wire diameter of 160 μm or less and a tensile strength of 3 μm.
Ultrafine metal wire with a new fibrous fine metallographic structure of 00 kgf / mm ² or more and 5-100 Å ultrafine cells produced by cold wire drawing and arranged in a fibrous shape at 50-1000 Å intervals Reinforcement material consisting of.

[Prior Art] Conventionally, chemical fibers such as carbon fibers and aramid fibers, and fine metal wires such as piano wires (high carbon steel wires) have been used as reinforcing materials for reinforcing rubber and plastics. For example, in pneumatic tires for automobiles, steel cords formed by twisting brass-plated wires on the surface of a piano wire are excellent in strength characteristics and are currently used in large quantities. By the way, in order to improve the performance of the tires, etc.,
It is desirable to reduce the weight, and for that purpose, it is required to further reduce the diameter of the wire and increase the strength thereof. In order to achieve this object, it is important that the workability is excellent in order to make the diameter smaller, and that the workability can be strengthened in order to increase the strength.

Therefore, in order to achieve the above-mentioned object, the present inventors continued their earnest research on a metal structure capable of significantly improving the tensile strength, and found the following points. That is, a wire material which is a Fe-C-Si-Mn-based iron-based alloy and has a composite metal structure in which a low-temperature transformation-forming phase composed of acicular martensite, bainite, or a mixed structure thereof is uniformly dispersed in a ferrite phase. However, if a wire rod having such a metal structure is used, an ultrafine wire having a wire diameter of 160 μm or less can be easily and surely obtained by cold drawing. Then, if such a wire rod is subjected to heavy working by 99% or more by cold drawing, a uniform fibrous fine metallographic structure is formed in which the composite structure in which the ferrite phase and the low temperature transformation forming phase are combined extends in one direction. , The ultrafine wire having such a metal structure has a tensile strength of 300 to 600 kgf /
It was found that the toughness was dramatically improved to mm ² , and the toughness was comparable to conventional piano wire and stainless steel wire.

Such a fibrous fine metallic structure is a completely new structure which has not been known so far. From the viewpoint that the fibrous fine metallographic structure is a main factor for improving the tensile strength, the inventors further conducted research on the strengthening mechanism, and as a result, the metallographic structure having the ultrahigh strength as described above. Found that the distance between the fibers is 50 to 1000Å and the fibrous composite structure is composed of ultrafine cells of 5 to 100Å.

[Problems to be solved by the invention]

However, in order to further improve the strength characteristics of a tire or the like when the reinforcing reinforcing material such as rubber or plastic has a smaller diameter and higher strength, the following characteristics are further required. That is, the smaller the diameter, the greater the effect of corrosion, so that it has better corrosion resistance, and that the adhesiveness with a matrix member such as rubber is improved to match the increase in strength of the wire itself. It is important to maintain a stable structure in the case of liquefaction.

The ultrafine wire having the above-mentioned fibrous fine metallographic structure developed by the present inventors has obtained satisfactory results in terms of the above-mentioned workability and strengthening by processing, but as it is-
However, improvement of these points is desired.

The present invention has been made in view of the above circumstances, and provides a reinforcing material capable of ensuring structural stability such as corrosion resistance, adhesiveness with a matrix member, and coding, which is suitable for a reduction in diameter and an increase in strength. Is characterized by.

[Means for solving problems]

Therefore, the invention of the first item of the present application is that C: 0.01 to 0.50 wt%, Si: 1.0
wt% or less, Mn: 5.0 wt% or less, balance iron and unavoidable impurities, ferrite phase, martensite,
5 to 5% produced by the wire drawing hard working of 99% or more in combination with the low temperature transformation forming phase consisting of bainite or their mixed composition
Ultra-high-strength metal ultrafine wire with a wire diameter of 160 μm or less and a tensile strength of 300 kgf / mm ² or more, which has 100 Å ultra-fine cells arranged in a fiber in one direction and has a fibrous fine metal structure with a fiber interval of 50 to 1000 Å 1 to 100 per 1 kg of the metal ultrafine wire on the surface of
A reinforcing material comprising a wire coated with a metal in a ratio of g. The invention according to the second aspect of the present invention is a reinforcing material obtained by further coating the surface of the wire according to the first aspect with a resin. The invention according to claim 3 is a reinforcing material characterized in that a plurality of wires according to claim 1 or 2 are twisted, combined, or woven, and the invention according to claim 4 The invention according to item 1 is characterized in that the wire according to item 1 or 2 is formed by twisting a plurality of strands, forming a yarn, or woven the same, and further coating any of resin, rubber, or metal. It is a reinforcing material.

Here, the reason why various conditions are set in the present invention will be described.

(1) A point where the surface of a metal ultrafine wire is coated with a metal This metal coating is mainly for improving corrosion resistance, and the metal coating improves rigidity as compared with a bare wire, and a composite yarn. It is also intended to make it easier to fabricate and fabricate. That is, since the metal ultrafine wire of the present invention is steel, rusting is unavoidable as it is. Then, when the ultrafine wire is used as in the present invention, corrosion such as rust becomes a fatal problem as compared with the case of a large diameter.

The coating metals for this purpose are Ni, Cu, Z.
It can be selected from metals having general corrosion resistance such as n, Al, Cr and Ti, or noble metals such as Ag, Au and Pt, and simple metals and alloys.

As a method for coating these metals, generally used means such as wet plating methods such as electroplating and hot dipping, and dry plating methods such as PCD, CVD and sputtering can be adopted.

And for the coating amount of these metals, the metal ultrafine wire 1k
It should be 1 to 100 g per g. If it is less than 1 g, it is difficult to exert the above coating effect, while if it exceeds 100 g, the above coating effect is saturated, and conversely the coating is too thick,
Secondary disadvantages such as powdering during processing occur.

(2) A point of further coating the above metal coating with resin This is mainly for improving the adhesiveness with rubber and the like and for stabilizing the coded structure, and also for improving the corrosion resistance and maintaining the strength. I am trying. That is, in the case of the above-mentioned ultrafine wire only with a metal coating, since there is a gap between each thin wire, corrosion is likely to occur due to the capillary phenomenon due to the gap, and the thin wires move and rub against each other due to the gap. , The adhesion to the matrix rubber etc. is not sufficient and the cord structure cannot be retained. On the other hand, when the metal-coated metal ultrafine wire or the one obtained by forming a woven or woven fabric of the metal is coated with a resin, the gap is almost eliminated, and the problem caused by the movement of the thin wires can be solved. Examples of the coating resin include polyester, epoxy,
A thermosetting resin such as polyamide-imide or a thermoplastic resin such as polyether ether ketone can be selected.

(3) Point where C is 0.01 to 0.5 wt% In order to obtain the fibrous fine metallic structure according to the present invention and the above tensile strength, it is necessary to regulate the amount of C added. A range of 0.50% was found to be suitable. If it exceeds 0.5%, the workability is deteriorated, and if it is less than 0.01%, the strengthening by working is not sufficient.

(4) Si content of 1.0 wt% or less Si is effective as a strengthening element for the ferrite phase, but 1.0
%, If added excessively, decarburization of the wire surface is likely to occur, and the transformation temperature shifts to the extremely high temperature side, so that the wire surface is not quenched during heat treatment for complex structure, and only the wire surface becomes ferrite phase. Therefore, the strength is significantly adversely affected. Therefore, the upper limit of Si content is 1.0%.

(5) Point where Mn is 5.0 wt% or less Mn has the effect of strengthening the ultrafine wire and enhancing the hardenability of both phases, but even if added in excess of 5.0%, this effect saturates. Therefore, the upper limit of the added amount is 5.0%.

Further, elements whose content is preferably controlled, elements which may be added, and inevitable impurities are described.

H is a harmful element that embrittles steel, and its effect increases as the strength increases, so in the present invention, H
The amount should be regulated to 1 PPM or less, particularly preferably 0.5 PPM. As a method of reducing the amount of H, means such as degassing treatment with molten steel, hot rolling on wire rods, cooling control after heat treatment, and low temperature dehydrogenation control are effective.

In the present invention, in order to refine the metal structure of the ultrafine wire, N
At least one element selected from b, V and Ti can be added. These elements are used for the refinement of the structure.
Both require 0.005% or more addition, but even if added too much, the effect is saturated and it is economically disadvantageous, so the upper limit is made 0.5%.

Inevitable impurities include S, P, N, Al, and the like.

S is preferably 0.005% or less in order to reduce the amount of MnS, whereby the ductility can be further improved. On the other hand, by adding rare earth elements such as Ca and Ce, M
It is also preferable to adjust the shape of the nS inclusions.

Since P is an element with significant grain boundary segregation, its content is
It is preferably 0.01% or less.

N is an element that is most easily aged when it exists in a solid solution state, and it aged during processing to impair the workability, or aged after processing to deteriorate the ductility of the ultrafine wire obtained by wire drawing, It is preferably 0.003% or less.

Al forms oxide inclusions, and since these inclusions are difficult to deform and hinder the workability of the wire, it is usually preferable to set it to 0.01% or less. Also, as the Si / Al ratio in the ultrafine wire increases, silicate inclusions increase, and especially when the amount of Al is small, the silicate inclusions increase rapidly, which not only deteriorates the wire drawability but also causes wire drawing. The characteristics of the obtained ultrafine wire are deteriorated. Therefore, in the present invention, the Si / Al ratio is preferably 1000 or less, particularly preferably 250 or less.

In the composite structure of the wire rod, it is desirable that the volume fraction of the low-temperature transformation forming phase in the ferrite phase is in the range of 15 to 75%. This is for the following reason. If it is less than 15%, it will be 16 due to cold drawing of the wire with such a composite structure.
Although an ultrafine wire of 0 μm or less can be obtained, the obtained ultrafine wire does not have a fibrous fine metallographic structure as described above, the fibrous structure is incomplete, and the tensile strength is 30%.
It will be 0 kgf / mm ² or less. On the other hand, when the volume fraction of the low-temperature transformation forming phase in the ferrite phase is more than 75%, the wire rod is easily broken during wire drawing, and even if the wire can be drawn without breaking, the obtained ultrafine wire is As in the case of the above 15% or less, it does not have a fine fibrous structure, the fibrous structure is incomplete, and the tensile strength is as low as 300 kgf / mm ² or less.

Regarding the volume fraction of the wire, the wire diameter and the volume fraction of the wire are regulated by the form of the low temperature transformation generation phase, that is, whether the phase is mainly needle-like or mainly lumpy. It In addition, needle-shaped (elongated here)
Or acicular) means that the particles have directionality,
The term “globular” means that the particles do not have directionality.

That is, when 80% or more of the low-temperature transformation-producing phase is acicular, the low-temperature transformation-producing phase has a volume fraction of 50% or less and a wire diameter of 3.5 m.
If it is m or less and 80% or more is lumpy, the volume fraction should be 50% or less and the wire diameter should be 2.0 mm or less. When the low-temperature transformation-producing phase has a mixed structure of needles and lumps, the volume fraction should be 75% or less and the wire diameter should be 3.5 mm or less. The lower limit of the wire diameter that the wire should have is not particularly limited, but is usually 0.3 mm in view of the current processing technology.

Here, a method for manufacturing the ultrahigh-strength metal ultrafine wire of the present application will be described.

First, C: 0.01 to 0.50% by weight, Si: 1.0% or less, Mn: 5.0
% Or less, wire diameter 3.5 mm consisting of balance Fe and unavoidable impurities
After heating the following wire to a temperature in the range of 700-1100 ℃,
After cooling (this heating or cooling may be carried out multiple times), a low temperature transformation forming phase consisting of martensite, bainite or a mixed structure thereof, which may partially contain retained austenite, is added to the ferrite phase. 15-75 by volume
A wire having a composite structure uniformly dispersed in the range of 10% is manufactured. Incidentally, such a manufacturing method is disclosed in JP-A-62-20
It is described in Japanese Patent No. 824.

Then, the composite structure wire rod thus obtained is subjected to heavy working by cold drawing of 99% or more, and the ferrite phase and the low temperature transformation-generated phase are compounded to continuously extend in one direction as a metal structure. Form a fine fibrous structure. By increasing the degree of processing in this way, the fibrous structure becomes finer and the fiber spacing becomes narrower. As described above, the cell size and the fiber spacing produced by the processing are 5
It becomes a fibrous fine metallographic structure of ~ 100Å, 50 ~ 1000Å.
It should be noted that the fine wire obtained by wire drawing with a size of less than 99% has an incomplete structure in the middle of the development of the fibrous structure, and therefore has a low strength.

[Action]

According to the reinforcing material of the present invention, the metal ultrafine wire serving as the base of the reinforcing material is 5 to 100 Å produced by the strong working of cold drawing.
The processing cells of are arranged in a fiber in one direction, and the fiber spacing forms a fibrous fine metallographic structure of 50 to 1000Å,
As explained in the strengthening mechanism above, 300-600kgf /
It has an ultra high strength of mm ² . Therefore, for example, when it is used as a tire reinforcing material, the strength of this tire can be dramatically improved, and in the case of the strength of the conventional level, the amount of reinforcing fibers used can be significantly reduced, and the weight of the tire can be reduced accordingly. You can

The metal fine wire for reinforcing fiber of the present invention has excellent cold workability, and a wire having a diameter of 160 μm or less can be easily and surely obtained by appropriately selecting the wire diameter and the workability of the wire. Therefore, for example, it is easy to adopt a wire having a diameter of 10 to 100 μm and make it into a stranded wire or woven fabric. In this case, by combining it with a chemical fiber having an excellent specific strength, The inferior toughness and life can be compensated by the metal ultrafine wire of the present invention, and the weight reduction can be achieved also from this point.

Further, since the metal ultrafine wire of the present invention is coated with a metal such as Ni, the corrosion resistance can be improved. That is, since the metal ultrafine wire of the present invention has an extremely small diameter, it causes a fatal problem when rust occurs, but in the present invention, the corrosion resistance corresponding to the ultrathinning is obtained. Furthermore, since a resin film is formed on this metal film, the gap between the thin wires when twisted is eliminated, the movement of each thin wire is suppressed, and the adhesiveness with the matrix member and the coding structure are improved. The stability can be improved.

〔Example〕

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

1 and 2 show a tire cord according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a tire cord, which has a center line 1a and a peripheral line 1b having a Ni plating film 4 formed on the surface thereof.
1 g is made into a stranded wire, and the outer periphery thereof is further coated with a resin layer 3 made of polyester. The second
In the figure, the tire cord 2 is formed by twisting the center line 2a, which is also coated with the Ni plating film 4, and the outer peripheral lines 2b to 2g, and coating the outer periphery with the resin layer 3. Here, the center lines 1a and 2a are made of fine metal wires having the characteristics of columns A1 and B1 of Table 2, respectively, and the outer peripheral lines 1b to
1g and 2b to 2g each consist of an ultrafine metal wire having the characteristics of columns A2 and B1 in Table 2. Each of A1, A2 and B1 has the composition shown in column A or B of Table 1, respectively.

Table 3 shows the results of comparison of breaking strength between the tire cords 1 and 2 within the scope of the present invention and the tire cords not coated with resin.

As is clear from the table, the tire cord of the present invention,
It can be seen that, by applying the resin coating, the breaking strength is improved as compared with that without the resin coating.

FIG. 3 is a diagram for explaining an effect of improving corrosion resistance of a tire cord within the scope of the present invention in a salt spray test (JIS method).

In the figure, curves a to d show the corrosion resistance of the tire cords having the configurations in columns a to d of Table 4, respectively. As is clear from the figure, the Ni-plated product (characteristic line C), and
It can be seen that in the tire cord of the present invention (characteristic curve d) in which the polyester resin layer is formed on the Ni plating, the area ratio of rust generation is significantly reduced.

〔The invention's effect〕

As described above, according to the reinforcing material of the present invention, as the reinforcing fibers, the processing cells of 5 to 100 Å are arranged in a fibrous shape, and the fiber spacing is 50 to 1000 Å the wire diameter forming the ultrafine grain metallographic structure. Ultra-high-strength ultrafine metal wires with a tensile strength of 160 μm or less and a tensile strength of 300 to 600 kgf / mm ² were used, a certain amount of metal coating was formed on this, and a resin coating was also formed, so the strength of the reinforcing fiber is much higher than before. In addition to being able to increase the strength, there is an effect that the corrosion resistance corresponding to the ultrafine wire and the increase in strength, the adhesiveness with the matrix rubber, and the stability of the cord structure can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are sectional views of a tire cord according to an embodiment of the present invention, and FIG. 3 is a characteristic diagram showing the results of its corrosion resistance test. In the figure, 1 and 2 are tire cords, 3 is a resin layer, and 4 is a metal plating layer.

Claims (4)

[Claims] 1. C: 0.01 to 0.50 wt%, Si: 1.0 wt% or less, Mn:
It contains 5.0 wt% or less, the balance is iron and unavoidable impurities, and the ferrite phase and the low-temperature transformation-generated phase composed of martensite, bainite, or a mixed structure of these are complex, and 99% or more The resulting 5-100Å ultrafine cells are arranged in a fiber in one direction and the fiber spacing is
Wire diameter 160 with fibrous microstructure of 50 to 1000Å
Reinforcing material comprising a wire formed by coating the surface of an ultra-high-strength ultrafine metal wire having a tensile strength of 300 μm / mm ² or more and a tensile strength of 300 kgf / mm ² or more with 1 to 100 g per 1 kg of the ultrafine metal wire. . 2. A reinforcing material, characterized in that the surface of the wire according to claim 1 is further coated with a resin. 3. A reinforcing material obtained by forming a plurality of wires according to claim 1 or 2 into a plurality of twisted wires, twisted yarns, or woven fabrics. 4. A plurality of wires according to claim 1 or 2 which are twisted, combined or woven, and further coated with either resin, rubber or metal. Reinforcement material characterized by.