JPS5920427A - Steel wire for steel core of steel reinforced al twisted wire and its production - Google Patents

Abstract

PURPOSE:To provide a high tensile steel wire for a steel core of a steel reinforced Al twisted wire for aerial cables having excellent tensile strength and resistance to fatigue by regulating the contents of C, Si, Mn, Al and P, S, N, O as impurities. CONSTITUTION:A high tension steel wire for a steel core is constituted of 0.6- 1.2% C, <=2% Si, <=2% Mn, <=0.1% Al, and the balance Fe and unavoidable impurities. The contents of P, S, N and O as impurities are regulated to <=0.025% P, <=0.015% S, <=0.03% P+S, <=0.005% N and <=0.002% O. The tensile strength of such steel wire is >=180kgf/mm.<2> and the resistance to fatigue >=40kgf/mm.<2>. The steel wire has the tensile strength and winding and rewinding characteristics superior to those of conventional galvanized steel reinforced cables and has also an extremely good fatigue characteristic and high temp. strength.

Description

Detailed Description of the Invention The present invention provides fgj from copper core Al used for overhead power transmission lines.
(hereinafter referred to as AC8R) relates to improvements in high tensile strength steel wire for core alignment.

In recent years, AC8R for overhead power transmission lines has been developed to improve the mechanical properties of copper core wires1, for example, not only static strength such as tensile strength, but also to improve the mechanical properties of copper core wires due to higher load or increased dynamic load.
It is essential to improve the fatigue properties, which is dynamic strength. Due to the height difference, the tension on the overhead wire tends to become extremely large. ■Power transmission capacity must be increased to meet the increasing demand for electricity (AC8R diameter is being increased, and the weight of the overhead wires is increasing, resulting in a significant increase in the tension of the overhead wires. ■Due to the severe wind and snow characteristic of mountainous areas As the diameter increases, the tension increases due to ice and snow accumulation and wind pressure, and the complex dynamic tension load increases due to various types of photography. Because of the high-voltage power transmission (1 million W), the temperature of AC8R increases rapidly due to Joule heat (sometimes reaching 400-500C).

Therefore, it is necessary to increase the tensile strength and improve the fatigue properties, and it is also desired to secure tensile strength in a high temperature range (hereinafter referred to as high temperature strength).

In addition, the current AC8R is designed as a synthetic stranded wire so that tension acts on both the copper core wire and the AI stranded wire wound on the outside, and the aluminum stranded wire is designed to share the tension. Some are designed to be open and have only the copper core wire carry the tension. However, even with the former AC8R, which is a composite tension sharing type, cases are often experienced where the copper core wire essentially shares most of the total tension due to temperature rises during power transmission, etc., so the mechanical characteristics of AC8R It is no exaggeration to say that almost everything depends on the characteristics of the copper core wire.

Conventionally, the copper core wire of ACSR mentioned above is generally JISG353.
Galvanized steel wires specified in 7 are used, but such conventional steel wires have not only tensile strength but also fatigue properties and other mechanical properties such as those listed in ■ to ■ above. , it is simply impossible to satisfy the requirement to withstand the harsh conditions of use these days.

The present inventors previously proposed a new steel composition for AC8R in Japanese Patent Application No. 57-3607 ("High tensile strength steel wire for alignment of copper core Al stranded wire"). According to it, the tensile strength exceeds that of conventional galvanized steel wire.

A high tensile strength steel for copper cores of AC8R having excellent winding and unwinding properties, extremely good fatigue strength, and high temperature strength can be obtained, which satisfies the following 8) to 8).

(b) In order to increase the tensile strength of the overhead wire, the standard tensile strength of the vII line has been increased from 130 to 260 kgf/m.
r? ? shall be.

(b) In order to ensure safety under harsh usage environments, the fatigue strength is higher than before, and fatigue limit ≦ tensile strength TS)
Xo, 19.

To ensure safe tension when the temperature of HAC8R rises during normal and abnormal conditions,
The tensile strength of is as shown below.

T 5(Tl≧TS(ul X (1,42-0,00
28T) Preferably TS(rl≧TS(RIX (1,
29-0,0019T) However, T5(T): TSTSIRI at a temperature of T°C: TS at room temperature) When manufacturing AC8R or carrying out overhead wire work, one roll must be returned with one roll to prevent breakage or cracking. In a winding test where the curvature radius of 5 windings is 3.0 times the radius of the wire, preferably 1.5 times the radius of the wire, the probability of breakage or crack occurrence (hereinafter referred to as defective rate) is 50. % or less.

The present invention aims to further improve the fatigue strength of such high tensile strength steel powder.

Its characteristics are: C: 0.6-1.2%, Si: 2% or less + Mn:
Less than 2%.

Al: 0.1% or less, and optionally Cr: 5
% or less, Cu: 196 or less, Si and Ni: 1% or less, and/or.

V: 0.5% or less, Nb: 0.2% or less, Ti: 0.2
% or less and Zr: Contains one or more types of 0.2% or less.

The balance consists of Fe and unavoidable impurities, including P, S, N, and oxygen as impurities.

P≦0.025% S≦0.015% P+8≦0
．． The steel has a composition that satisfies the following conditions: 03%N≦0.005% and oxygen≦0.002%. The thickness of the Fe-Zn alloy layer is 15 μm or less, and the tensile strength is 180 kgf/mm'
that's all.

Fatigue strength 40 kgf/mtr? That's all. High tensile strength Zn-plated steel wire for alignment of copper core Al-wiss wire; And, the wire rod of the material having the above steel composition is subjected to tenting treatment to form an austenitic structure, and after pearlite transformation, pickling and lubrication treatment. Perform wire drawing processing,
High tensile strength Z for alignment of a from copper core Al, which consists of then immersion zinc coating for 15 seconds or less at a bath temperature of 4500℃ or less.
This is a method for manufacturing n-plated steel wire.

According to the present invention, in order to further improve dynamic properties such as fatigue strength, (11) the austenite grain size of the austenite structure is adjusted to 20 to 60 μm.
At the same time, the area reduction rate during the stretching process is 70 to 9.
It shall be 5%.

(1) The lamella spacing of the pearlite structure obtained by the pearlite transformation is 0.2 μm or less, and
The area reduction rate during the wire drawing process is 70 to 95%.

(Itl) The above-mentioned patenting treatment is a lead patenting treatment, and the lead patenting treatment is carried out so that the decarburization state of the wire surface layer after the lead patenting treatment is such that the total decarburization depth≦150μm and the ferrite decarburization depth≦50μm. To manage.

[lv) The lubrication treatment prior to the wire drawing process is performed using a zinc phosphate base lubricant, and the amount of the lubricant applied is 3 to 7 gβ. Within the same period, the obtained Zn plated steel wire may be cooled with water in an appropriate combination.

Thus, according to the present invention, the tensile strength is 180 kgf/m.
- As a result, a high tensile strength Zn-plated steel wire having a fatigue strength of 40 kgf/m or more and meeting the current requirements as already mentioned can be obtained.

The reasons for limiting the ingredients in the present invention will be described in detail below.

C: A useful component for securing the tensile strength necessary for high-tensile steel wire that requires heat resistance. If it is less than 0.6%, the target strength of 180 kgf/m or more cannot be achieved, and If it exceeds 1 or 2%, it will adversely affect the winding and unwinding characteristics, so it was set at 0.6 to 1.2%.

Sl: A component effective in increasing the fatigue properties and high-temperature strength of high-carbon high-strength steel wires, but if it exceeds 2%, the ductility decreases significantly and the winding and unwinding characteristics are adversely affected. So %2
% or less.

Mn: Effective for improving the tensile strength of large diameter steel wires.

If added in a large amount, the pearlite will become coarse and its strength will actually decrease. If it exceeds 2%, it becomes difficult to secure the necessary tensile strength, so it is set to 2% or less.

P: A component that has a significant influence on the winding and unwinding characteristics,
In high carbon steel, the winding and unwinding properties deteriorate as the tensile strength increases, so in order to prevent this deterioration and ensure the necessary winding and unwinding properties, it is necessary to keep the two companies at an extremely low level. There is a need. Generally, P exists in a relatively large amount in high carbon steel due to P returned from slag during refining, but 0.025
If it exceeds 0.025%, it becomes difficult to secure the necessary winding and unwinding characteristics.

Sb is a component that has a significant influence on the unwinding characteristics and fatigue properties of high carbon steel, where the winding, unwinding characteristics, and fatigue characteristics deteriorate as the tensile strength increases. In order to prevent this and ensure the necessary winding and unwinding characteristics and fatigue characteristics, it is necessary to suppress Sl to an extremely low level. Normal high carbon steel contains about 0.02% Sl, but 0.
If it exceeds 0.015%, it will be difficult to secure the above-mentioned required winding and unwinding characteristics and fatigue characteristics, so if it exceeds 0.015% or less, P+S: 0-0396, the necessary winding and unwinding characteristics will not be achieved. Since it may be difficult to ensure both the necessary fatigue properties, the content is set at 0.03% or less. In addition, in order to further improve the winding and unwinding characteristics and fatigue characteristics,
．． 0.028% or less is preferable.

N: A component that has a large influence on the winding and unwinding characteristics.
Lower is preferable. In particular, the tensile strength T S ) is 18
At 0 kgf/m- or more, if it exceeds 0.005%, the winding and unwinding characteristics may be extremely deteriorated.

It was set to 0.005% or less.

Oxygen double winding is a component that has a large influence on both unwinding characteristics and fatigue characteristics. If it exceeds 0.0029s.

The defect rate in the winding test with a diameter 3.0 times the wire diameter exceeds 5096, and the tensile strength (TS) is 180 kgf/mrr?
The fatigue limit of the above high carbon steel wire is TSX0.
19 cannot be achieved, so it is set to 0.002% or less. In addition, if it is 0.002 to 0.0010%, the above 3
．． The defect rate in the 0x diameter winding test was 0%, and 1.
The defective rate in the 5x diameter winding test was improved to 50%, and o
, o o io% or less, the defective rate in the above 1.5 diameter winding test is improved to 30% or less, so it is preferable that the content be as low as possible.

Cr, Cu, Ni: All of these are added as necessary.

This is the basis for improving the tensile strength, especially of large-diameter steel wires.

Cr is thus an effective component for tensile strength, and has a particularly remarkable effect on large-diameter steel wires, but Cr
By adding , remarkable high temperature strength can be obtained.

However, if it exceeds 5%, it becomes difficult to secure the necessary winding, unwinding and fatigue characteristics, so it is set at 5% or less. Also,
Cu*Ns is a component that has similar effects to Mn, and can improve tensile strength and ductility in large-diameter steel wires by improving hardenability, but if it exceeds 1%, pearlite It coarsens the structure, lowers tensile strength and ductility, delays the completion time of transformation, and tends to cause trouble in the patent book process, so it is set at 1% or less.

V*Nb, Ti, Zr: These elements are effective in refining and strengthening the steel structure, and are particularly effective in improving the winding and unwinding characteristics of high carbon steel wires with high tensile strength.

However, V was 0.5%, and Nb, Ti, and Zr were each 0.5%.
If it exceeds 2%, the amount of coarse carbides of undissolved V + Nb, Ti, and Zr will increase, and the effect of improving the #I winding and unwinding characteristics will be significantly diminished and the characteristics will deteriorate. Therefore, ■
is 0.5% or less, Nb*Ti*Zr is 0.2%
The following was made.

The thickness of the Zn alloy layer is limited to 15 μm or less, which is in contrast to the Fe-Zn alloy layer of conventional products, which has a thickness of 20 to 25 μm. It is preferable to make it as small as possible in order to improve fatigue strength. In particular, by regulating the steel composition as described above, the fatigue strength can be reduced to 40 kgf/mrr? that's all.

Preferably, it is synergistically improved to, for example, 44 kgf/m- or more.

To limit the thickness of the Fe-Zn alloy layer to 15 μm or less, the plating bath temperature can be lowered or the immersion plating time can be shortened, but generally the plating bath temperature is set at 450°C. The immersion plating time may be controlled to 15 seconds or less.

Figure 1 shows the Fe
- A graph that generally shows the relationship between the thickness of the Zn alloy layer and fatigue strength based on data obtained from a series of experiments. Figure 2 shows the relationship between the thickness of the Fe-Zn alloy layer and immersion in the plating bath. A similar graph showing the relationship with time (in the figure, bath temperature 44
The case where water cooling was applied 4 seconds after plating at 0 C is shown as ○, the same (the case where water cooling was applied 4 seconds after plating at 450 C is shown as △), and Figure 3 shows the same relationship with the bath temperature. A similar graph showing the relationship (in the figure, the subscript is immersion time (see
), each of the three curves shows the immersion time (tl is 9 sec).
, 15sec, and 30sec. ).

Steel composition CSt Mn AX P S N O ・0.820, 270.750.0340.0170.
0100.0040.001 As is clear from the data shown in Figures 1 to 3, in order to obtain a fatigue strength of 40 kgf/m or more, the thickness of the Fe-Zn alloy layer must be 18
A particularly critical improvement is achieved by limiting the bath temperature to below .mu.m, preferably below 15 .mu.m, and for which purpose it is desirable for the purposes of the invention to limit the bath temperature to below 450C and the immersion time to below 15 seconds. In other words, if these two conditions are taken into account, the thickness of the Fe--Zn alloy layer can be controlled with a practical level of accuracy.

Next, after 12 seconds of immersion in a plating bath, various time periods had elapsed, the samples were allowed to cool and the state of alloy formation was examined. . The results are shown in Figure 4. The growth of the alloy layer is 5 up to a thickness of 15 μm.
It can be seen that 11 is completed in seconds. However, in order to prevent the formation of alloys by water cooling after plating, it is necessary to perform water cooling within 5 seconds after plating.

By the way, in order to prevent the steel wire from breaking or cracking during AC311j manufacturing or overhead line work, the twisting characteristics were made higher than before, and in a twisting test with a grip spacing 100 times the S diameter, no breakage or cracking occurred. It is required that the number of times the screw is twisted (hereinafter referred to as the twist value) before cracking occurs is, for example, 20 or more times.

Therefore, in a preferred embodiment of the present invention, the austenite grain size of the austenite structure obtained by performing the Patente gravelling process is 20 to 60 μm and/or the lamella spacing of the pearlite structure is 0.20 μm or less, and It is desirable to further improve the dynamic fatigue properties by setting the area reduction rate during wire drawing to 70 to 95%.

In order to improve fatigue strength, it is better to have a smaller austenite grain size, but if the grain size is too small, the twisting properties will deteriorate. Therefore, in the present invention, the austenite grain size is preferably in the range of 20 to 60 μm. Conventionally, this austenite grain size is generally 100 μm.
That's about it.

Figure 5 is a graph generally showing the relationship between pearlite lamella spacing (μm) and twist value (turns) when manufacturing Zn-plated steel wire with the same steel composition as above, based on a series of experimental data. It is. The austenite grain size at this time is approximately 97μ
It was m. Twisting value ff: In order to make 20 times or more, the lamella spacing should be 24 μm or less, preferably 0.20 μn1.
It can be seen that the following is necessary.

The austenite grain size and pearlite lamella spacing can generally be adjusted by appropriately adjusting the steel type components and manufacturing conditions. For example, in lead patenting treatment, the heating rate, heating temperature, and heating time are determined. In addition, instead of the lead patente wrapping, other patentening treatment methods (for example, various surface patente rounding treatment methods in which adjustment cooling is performed after hot rolling) are used, and the composition of the steel and hot rolling conditions are further adjusted. Controlled rolling method, etc. to optimize adjustment alone or in combination
This can also be done by using the above methods in combination and managing each condition appropriately.

Those skilled in the art will already be aware of the means for adjusting the austenite, grain size, and lamellar spacing of pearlite. In addition, the wire drawing processing rate expressed as the area reduction rate of the steel wire is.

If the carbon content is less than 70%, the target value of tensile strength is 180 kgf/m for carbon steel and low alloy steel with C content of 0.6 to 1.2%.
rr/ and the target value of durability ratio 0.
19 becomes difficult to achieve. Further, when the wire drawing rate exceeds 95%, the fatigue strength rapidly decreases, the durability ratio becomes less than 0.18, and the winding and unwinding characteristics are also adversely affected.

Similarly, if it exceeds 95%, uniform twisting will not proceed in the twisting test, and abnormal breakage may occur at an extremely low number of twists, which is undesirable.

In a preferred embodiment of the manufacturing method according to the present invention, a lead batente rolling process is adopted as the patente rolling process, but the degree of decarburization of the surface layer of the wire after the lead patente rolling process determines whether the fatigue strength is good or not. is significantly related to In other words, what is lead patenting?

It increases the deformability of the wire rod and makes wire drawing easier. Generally, it is heated to 900 to 1000℃ in a heating furnace.
The method is to maintain the temperature for 5 hours and then cool it in a lead bath at 530°C. When the wire is subjected to this lead patenting, the decarburized state of the wire is a ferrite decarburized layer that does not contain any carbide in the outermost layer. exists, and below it there is an incompletely decarburized layer that partially contains carbide. If the depth of ferrite decarburization is indicated by the symbol DmF, and the total decarburization depth including the incomplete decarburized layer is indicated by the symbol DmT, these two decarburization indexes and the fatigue strength of Zn-plated steel wire The relationship is as shown in FIGS. 6 and 7.

The steel composition at this time is experimental data for a Zn-plated steel wire obtained by immersion Zn plating at a bath temperature of 450 C for 12 seconds using the above-mentioned method. In the case of the illustrated vil I, if the total decarburization depth exceeds 150 μm or the ferrite decarburization depth exceeds 50 μm, 40 kgf/m-
It is not possible to obtain higher fatigue strength. In the case of the example shown in Figure 6,
DmF was 10 μm2, and in the case of FIG. 7, DmT was 150 μm. Therefore, in a preferred embodiment of the method of the present invention employing lead patenting treatment, Dm
T≦150 μm and DmF≦50 μm.

Decarburization management as described above can be achieved by adjusting the setting of treatment conditions in the lead removal treatment. The heating temperature and holding time may be adjusted according to Al1, and the atmosphere (air-fuel ratio, etc.) may be controlled.

Generally, if the heating temperature is low and the holding time is shortened by 1,
Also, the atmosphere is O! If you reduce the acid content.

Crabs whose decarburization is suppressed, respectively, and 1 of the present invention.
There is no concern that the adoption of such a method for managing decarburization as described above as a preferred embodiment will hinder the achievement of the original purpose of the lead/temperature process.

Regarding this type of Zn-plated steel wire, conventionally,
DmT exceeds 150 .mu.m and is about 170 to 200 .mu.m, and DmF also usually exceeds 50 .mu.m to about 60 to 70 .mu.m.

The wire thus obtained is subjected to a lubrication treatment prior to wire drawing. Here, lubrication treatment is generally performed first after lead patenting and pickling.

A zinc phosphate-based base lubricant 1, such as Bonderite (trade name: Nippon Barker Co., Ltd. M), is applied by dipping or the like, and a sodium stearate-based lubricant, such as Bondarube (same as above), is further applied thereon. The goal is to form a dove of sodium stearate between these two layers.

Regarding lubrication treatment, 1. According to what the present inventors found, the amount of adhesion of the base lubricant is 7y/rr? The durability ratio shows the best value below. On the other hand, if the amount of the base lubricant applied is less than 3 fl/-, the original function of lubrication will be impaired and there will be a risk of seizure during wire drawing.

However, in the conventional method, the amount of N applied to this base lubricant is:
Since the height is 10L or more, excellent fatigue properties cannot be expected. Conventionally, the application of such lubricant has generally been carried out with the sole purpose of preventing seizing during wire drawing, and for this reason, the amount of lubricant applied has been reduced to 10 y/min from the standpoint of safety.
lr? There were more than necessary.

Next, the present invention will be further explained by examples.

Example 1 Steel grades 1 to 11 having the steel compositions shown in Table 1 were produced in a 4-ton air furnace and hot rolled into wire rods having a diameter of 8.0 mm. This wire was heated to 9,000 ℃ and subjected to lead patenting treatment. The austenite grain size during the Patente bending process is 30 μm, the lamella spacing of the pearlite structure after the Patente bending process is 0.15 μm, and the total decarburization layer depth is DmT.
) A Batente-hardened material with a 50 μm ferrite decarburized layer depth of zero was obtained. Next, after pickling, lubrication treatment was performed so that the amount of zinc phosphate coating as a base lubricant was 6P/I, and the wire was continuously pressed to a wire rod with a diameter of 3.11 wires (area reduction rate = 85.9 %).

For zinc immersion plating, the Zn plating bath temperature is 450C.

The immersion plating time was 12 seconds, and water cooling was performed after plating 4tν.

Table 2 summarizes the mechanical properties of each steel sample.

From the same table, it can be seen that the mechanical properties of the steel of the present invention are clearly superior to each of the comparative steels.

[Brief explanation of the drawing]

Figure 1 is a graph generally showing the relationship between the thickness of the Fe-Zn alloy layer and fatigue strength in Zn-plated steel wire; Figure 2 is a graph showing the relationship between the thickness of the Fe-Zn alloy layer and the immersion time in the plating bath. A similar graph showing the relationship between Fe-
A similar graph showing the relationship between the thickness of the Zn alloy layer and the bath temperature; Figure 4 is a graph showing the relationship between the growth of the PE-7RN alloy layer and the cooling time; Figure 5 is a graph showing the relationship between the growth of the PE-7RN alloy layer and the cooling time; Figure 5 is the graph showing the relationship between the thickness of the Zn alloy layer and the bath temperature; A graph showing the relationship between the lamella spacing of the structure and the torsion value; Figure 6 is a graph showing the relationship between the total decarburization depth by lead patenting treatment and the fatigue strength of the steel wire obtained at that time; and Figure 7 is a graph showing the relationship between the lamella spacing of the structure and the twist value. , is a graph showing the relationship between the decarburization depth and fatigue strength of ferrite. Applicant's representative Patent attorney Akira Hirose - Figure 1 Ee-2'/1 go 44 (μ 姐 2 Figure 3) Figure 3. 4 Figure Leather, 5 Figure 1 1 Marlite Lanora in front of the monkey line (μrn) ice Figure DmT, 'All 1 Return: Military Cμ Town

Claims (1)

[Claims] tll C: 0.6 to 1.2%, St: 2% or less,
Mn: 2% or less, AJ: 0.1% or less, the balance consists of Fe and unavoidable impurities, P, S, N and oxygen as impurities are: P≦0.025% S≦0.015% P1S
≦0.03%N≦0.005% Oxygen≦0.002
It has a steel composition that satisfies each condition of %, and has a tensile strength of 180 k
gf/m? Above, fatigue strength 40kgf/mn? That's all. Copper core A/ High tensile strength Zn plated steel wire for alignment of horizontal wire. (2) The thickness of the Fe-Zn alloy layer is 15 μm or less7. A Zn-plated steel wire according to claim (1). 131C: 0.6 to 1.2%, st: 2% or less,
Mn: 2% or less, Al: 0.1% or less, and C
r: 5% or less. Contains Cu: 1% or less and Nt: 1% or less of one kind or 2f11 or more, the balance consists of Fe and inevitable impurities, and P, S, N and oxygen as impurities are P≦0.025% S≦ 0.015% P+S≦0
．． It has a steel composition that satisfies the following conditions: 03%N≦0.005% and oxygen≦0.002%, and has a tensile strength of 180kgf/m.
m' or more, fatigue strength 40kgf/mrr? That's all,
High-strength Zn-plated steel iIJ for aligning copper-core aluminum wire. 14) The Zn-plated steel wire according to claim (3), wherein the thickness of the Fe-Zn alloy layer is 154 m or less. (5) C: 0.6-1.2%, Si: 2% or less + M
n: 2% or less, AJ: 0.1% or less, and V
: 0.5% or less, Nb: 0.2% or less, Ti: 0.
2% or less and Zr: 0.2% or less of one or two of the following
P≦0.025% S≦0.015% P+8≦0
．． It has a steel composition that satisfies the following conditions: 03%N≦o, oos% oxygen≦0.002%, and has a tensile strength of 180kgf/
mi or more, fatigue strength 40 kgf/mn? That's all. Copper core A/High tensile strength Zn plated steel wire for alignment of stranded wires. (I in which the thickness of the 67Fe-Zn alloy layer is 1.5 pm or less. Zn-plated steel wire according to claim (5). (7) C: 0.6 to 1.2%, Si: 2% or less, M
n: 2% or less, Al: 0. i%% or less Furthermore, Cr: 5% or less, Cu: 1% or less, and Ni: 1%
One or more of the following: Further, one or more of the following: V: 0.5% or less, Nb: 0.2% or less, Ti: 0.2% or less, and Zr: 0.2% or less , the balance is Fe and unavoidable impurities, and the impurities are P, S, N and oxygen. P≦0.025% S≦0.015% p
10sso, o3%N≦0.005% Oxygen≦0.00
It has a steel composition that satisfies each condition of 2%, and has a tensile strength of 180k.
gf/m- or more, fatigue strength 40 kgf/mrr? More than that, copper core haO steel core copper core tensile strength Zn plated steel 1M
. (The thickness of the 81Fe-Zn alloy layer is 15 μm or less,
A Zn-plated steel wire according to claim (7). 191 C: 0.6 to 1.2%, Si: 2% or less
Mn: 2% or less, Al: 0.1% or less, and if necessary Cr: 5% or less, Cu: 1% or less, and Ni
: 1% or less of one or more kinds, and/or V
: 0.5% or less, Nb: 0.2% or less, Ti: 0.2
% or less and Zr: 0.2% or less of type 1 or 2
The remainder is Fe and unavoidable impurities, P, S, N and oxygen as impurities, P≦0.025% S≦0.015% P10S
≦0.03%N≦0.005% Oxygen≦0.002%
A wire rod made of a material having a steel composition that satisfies each of the following conditions is subjected to a puttyening treatment to form an austenite structure, and after pearlite transformation, it is pickled and lubricated, and then wire drawn. The thickness of the Fe-Zn alloy layer is 15 μm or less and the tensile strength is 180 kgf/mn? Above, fatigue strength is 40kgf/mr! That's all. Copper core M
A method for producing high-tensile Zn-plated steel wire for alignment of horizontal wires. tlo+ The austenite grain size of the austenite structure is 20 to 60 μm, and the wire drawing is 0
υ A manufacturing method in which the lamella spacing of the pearlite structure obtained by the pearlite transformation is 0.20 μm or less. Side The manufacturing method according to which the patenting process is a lead battening process, and the decarburized state of the wire surface layer after the lead patenting process is: Total decarburization depth: 6150 μm Ferrite decarburization depth: 650 μm. Q31 The lubrication treatment prior to the wire drawing process is performed using a phosphorus and zinc acid base lubricant, and the base lubricant 04)
Obtained within 5 seconds after immersion galvanizing treatment