JPS59116359A - Alloy wire of high strength, high twistability and low thermal expansibility - Google Patents

Abstract

PURPOSE:To obtain a core wire rod of high strength, high twistability and low thermal expansibility by using a steel having a specified composition contg. Ni, Mo and Co as the material of a steel core wire for ACSR. CONSTITUTION:A steel wire contg. 30-45% Ni, 0.5-4.5% Mo, 0.31-0.45% C, 1-10% Co and <0.5% Si and <1% Mn as deoxidizing elements is used as a reinforcing core wire for ACSR (aluminum cable steel reinforced). The composition of the steel wire has quantitative relation between Co and Ni represented by an equation Co<=8-0.3(Ni-35). A core wire for ACSR with superior tensile strength, superior twistability and high resistance to sag due to thermal expansion accompanying temp. rise during power transmission is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is based on a low-temperature I-strength alloy wire that has high strength and high twisting properties to be used in a steel core wire for AC8R.

In general, the AC8R is designed to have a certain amount of space around it, mainly due to safety concerns, as it causes a sag called a cateply curve.
71 HP was required, and because of space constraints, especially in the city, it was necessary to make the sag as small as possible. The conventional AC8R has a 7-strand high carbon steel core wire for reinforcement, but this core wire has a tensile strength of 120 ko/mM or more and a torsion value of 2.
It is corroded at the point (on the 0th axis), but the coefficient of thermal expansion is 13X
10'/C: Because of the large value of 0, there was a tendency for the material to expand significantly as the temperature rose due to power transmission, resulting in large sagging.

In particular, recently there has been a demand for an increase in the amount of power transmitted in urban areas due to an increase in power consumption.
It is necessary to increase the diameter of R, so AC8
The sagging of the R will become even larger, and we will have to widen the vacant land of the existing ridge, but at present, securing the land will result in a large loss of 1-up, and it will be difficult to increase the diameter of the existing AC8R alone. It is being

Attempts have been made to use a core wire with a small coefficient of thermal expansion as a means of reducing sagging. Invar (Fe-3) is an alloy with smaller thermal expansion than conventional alloys.
6Ni alloy) and super-r alloy (Fe-35N
i -2Co alloy) is known, but these are treated with M processing in the middle of the bullet hole, and C also has a tensile strength of 100 kQ, -'
In addition, carbon etc. are added to the instep as a reinforcing measure to improve tensile strength and torsion (f) is lowered, and twisted wire is applied during the production of steel core wire. Above all, the toughness is IL(I), the application Ij of ΔC3R1\, and the inability to TiJ.

At this dawn, in order to eliminate these conventional drawbacks, we
．． It provides an alloy wire with excellent tensile strength and twistability. That is, this invention has Ni: 30 to 45%, IVI+1: 0°5~/,
5%, C: 0.31~O, '15%, CO; 1-.1
0%, the remainder is Fe, and the rest is contained as an acid element. $1 is Q, 5% or less, and lyl n is 1
% or less as unavoidable impurities, and the relationship between N1 and C11 is CO≦8-0.3<Nt-35)2.

Ni to 30/IO%, CO 1 to 10%, CO
≦8 0.3 (The reason why Ni-35>2 is set is as follows., "J",) Figure 1 (△) shows Fe-N
It shows the change in the average thermal expansion coefficient of 1-co gold alloy Q~300''C, where Ni is 3O-n0% and CO is 1~10%.
There is a composition with low thermal expansion around %.

FIG. 1(B) is a partially enlarged view of FIG. 1(A), and -! In order to suppress the thermal expansion coefficient to 3×10/'C or less, the composition τ must be within the range of curve 1.

Now, it is necessary to set the balance of Ni and C(l to Co≦8-0.3 (Ni-35>', which is the display formula for song FA1. If it deviates, the coefficient of thermal expansion will exceed 3, OX 10', "C", which is not preferable.

The lower the carbon content, the better the thermal expansion coefficient, but as shown in Figure 2, if the carbon content is less than 0.3%, the tensile strength is 130%.
k(1/-, and therefore, it is not practical in terms of strength unless C is 0.3% or more. On the other hand, if the C content is too high, the thermal expansion coefficient becomes high, and C'h< 0,45%
When exceeding 0, the average coefficient of thermal expansion at 300℃ is 3.
．． Since it no longer satisfies 5X10/℃, C is 0.3
It is necessary to specify it in the range of 1.-0.45.

Regarding 1MO, the addition of 1MO increased the glue strength, and M
Rather than O going into solid solution in the matrix, in this alloy C
The carbide of M (120) is precipitated at the connecting angle, and the precipitation of this carbide makes it possible to obtain high twisting characteristics.
The figure shows this situation, and the C1 tensile strength of b is 130 k (
17/mrl i 1 noise 17 with a diameter of 3 mm
Curve 2 shows the twist value, and curve 3 shows the thermal expansion coefficient. From this, twist value is 20 times or more, heat 11HN 1
a3.5X 10-'/'lX As shown below, 12-b is MO
is 0.5=4.5%, and if M(l is 4°5 or more, the expansion will be large and it will be impractical.

Since the coefficient of thermal expansion of Sl becomes large when the content is 11'1, it should be kept at 0.5% or less, which is required by steelmakers, and Mn')
In order to solve the problem of melting, it is necessary to set it to 196 or less.

EXAMPLE The alloy shown in Table 1 was rolled into a wire with a diameter of 12 mm, and after pickling and phosphate coating, it was processed into a wire drawing machine with a J-shape diameter of 9 mm. 85 by atmospheric annealing furnace
Annealing was performed at 0° C. for 5 hours to remove the strain and soften the material, and at the same time precipitate Mo2c carbide, resulting in a structure suitable for exhibiting a high torsion value. After annealing, pickling, ]-ting, and 89% processing using a wire drawing machine to create a wire with a diameter of 3
A wire of mm was manufactured. Table 2 shows the results of measuring the tensile strength, torsion value, and coefficient of thermal expansion of this wire.
As shown in Table 1d5 and Table 2 above, N011 to 4 of the alloys of the present invention have a tensile strength of 1301 (g/-
More than 20 twists, thermal expansion coefficient 3゜5X10-
'/'C or less, it exhibits characteristics that are highly practical. On the other hand, comparative in No. 5 has a low tensile strength due to a low C content, No. 6 has a low torsion value due to the absence of MO, and No. 7 has a thermal expansion coefficient due to a large amount of MO. is large,
N098 has a low tensile strength of 120K due to the low gold content of C.
! 7/mA, which is a value that is not practical.

- Explained J: Uni, this Bonmei set the balance of Ni-C-Mo-Co appropriately as the steel core wire for ACS R, and precipitated Mo2C carbide in the manufacturing process to make it suitable for high twisting. By covering the metal structure, the tensile strength is increased to 13
0 kg/mrA or more, twisting 1ifl 20 times or more, average coefficient of thermal expansion from 0 to 300°C 3.5x1o-'
This makes it possible to produce a temperature of less than , /°C. Therefore, if this is used, it is possible to increase the cross-sectional area of AC8R to cope with the increase in the amount of power transmitted without having to rebuild the current transmission tower.
It is possible to suppress the sagging caused by the temperature rise of 8R to the same level as before or even lower than that of the conventional type.

[Brief explanation of the drawing]

Figure 1 (△) is a thermal expansion coefficient characteristic diagram of 1Te-Ni-Co alloy, Figure 1 (B) is a partially enlarged view, Figure 2 is a diagram of the relationship between C content and tensile strength, Figure 3 is a relationship diagram between MO content, torsion value, and thermal expansion coefficient. 1...C0-N+ relationship curve, 2...Twisted (straight curve), 3...Curve of thermal expansion coefficient.

Claims (1)

[Claims] 1, Ni: 30 to 45%, Mo: 0.5-1゜5%, C: 0.31-0.45%, Co: 1 to 10% to 4'', the remainder is ``e and n+1''S; contained as an acid element is 0.5% or less, Mll is 1% or less and unavoidable impurities (-4), and the relationship between Ni and CO is CO≦8-0.3 ( Ni -35)2d4jruJ
, -') is specially set to high strength, high twist, and low thermal expansion alloy wire.・