JP6812461B2 - High-strength low thermal expansion alloy wire - Google Patents

Description

Cross-reference of related applications

This application claims priority based on Japanese Patent Application No. 2017-083035, which was filed on April 19, 2017, and the entire disclosures thereof are incorporated herein by reference.

In the present invention, it is desired to avoid changes in dimensions and shape due to thermal expansion, but the high strength used in core wire materials for low-sag transmission lines, wire rods for precision machine parts, etc., which may raise the temperature during use. The present invention relates to a strong low thermal expansion alloy wire and a high strength low thermal expansion coated alloy wire.

Conventionally, various high-strength low-heat expansion alloy wires are known. For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 7-228947) describes C: 0.1-0.4%, Si: 0.2-1.5%, Mn: 0.1-in terms of weight ratio. 1.5%, Ni: 33-42%, Co: 5.0% or less, Cr: 0.75 to 3.0%, V: 0.2 to 3.0%, B: 0.003% or less, O: 0.003% or less, Al: 0.1% or less, Mg: 0.1% or less, Ti: 0.1% or less, Ca: 0.1% or less, and the balance is from Fe and unavoidable impurities. A high-strength, low-thermal expansion alloy wire is disclosed, which is characterized by having a relationship of 1.0% ≤ V + Cr ≤ 5.0%.

Further, in Patent Document 2 (Japanese Unexamined Patent Publication No. 2002-256395), in terms of mass%, C: 0.1-0.4%, V: more than 0.5% to 3.0%, Ni: 25 to 50. %, A high-strength, low-thermal expansion alloy wire having excellent twisting properties, which satisfies 2 ≦ V / C ≦ 9 and is composed of the balance Fe and unavoidable impurities is disclosed. In Patent Document 2, the high-strength low-heat expansion alloy wire contains one or more of Al, Mo, Ti, Nb, Ta, Zr, Hf, W, and Cu in a total of 5% or less. It is disclosed that it is also good.

Further, in Patent Document 3 (Japanese Unexamined Patent Publication No. 2003-82439), C: 0.20 to 0.40%, Si: ≤0.8%, Mn: ≤1.0%, P: in% by weight. ≦ 0.050%, S: ≦ 0.015%, Cu: ≦ 1.0%, Ni: 35-40%, Cr: ≦ 0.5%, Mo: 1.5 to 6.0%, V: 0.05 to 1.0%, O: ≦ 0.015%, N: ≦ 0.03%, Mo / V ≧ 1.0, (0.3Mo + V) ≧ 4C, and the balance Fe And has a composition of unavoidable impurities, with average linear thermal expansion coefficients from 20 to 230 ° C and 230 to 290 ° C of 3.7 × ^10-6 or less and 10.8 × ^10-6 or less, respectively. An Invar alloy wire having excellent strength and twisting characteristics is disclosed.

Japanese Unexamined Patent Publication No. 7-228947 JP-A-2002-256395 Japanese Unexamined Patent Publication No. 2003-82439

Conventional high-strength low-thermal expansion alloy wires as disclosed in Patent Documents 1 to 3 achieve high hardness by precipitation hardening by aging heat treatment, but the optimum conditions for aging heat treatment (temperature and holding time of the temperature). ), For example, the range of optimum conditions for obtaining the maximum hardness is narrow, so that it is difficult to obtain the desired hardness.

Therefore, the present invention is an alloy wire having characteristics required for a high-strength low-thermal expansion alloy wire (for example, high strength, high twist value, good ductility, low coefficient of thermal expansion, etc.), and is used during production of the alloy wire. It is an object of the present invention to provide an alloy wire which can be used in a wide range of conditions for heat treatment to obtain a desired hardness.

The present inventors appropriately control the composition of the alloy wire, the composition of the carbides existing in the crystal grains, the dispersed state of the carbides existing in the crystal grains, and the like, and thus have the characteristics required as a high-strength low thermal expansion alloy wire. An alloy wire having (for example, high strength, high twist value, good ductility, low thermal expansion rate, etc.), and a wide range of conditions can be used for heat treatment to obtain a desired hardness when manufacturing the alloy wire. We have found that various alloy wires can be realized, and have completed the present invention.

The present invention provides the following high-strength low-heat expansion alloy wire and high-strength low-heat expansion coated alloy wire.
(1) In terms of mass%, C: 0.1% or more and 0.4% or less, Si: 0.1% or more and 2.0% or less, Mn: more than 0% and 2.0% or less, Ni: 25% or more and 40 % Or less, V: 0.5% or more and 3.0% or less, Mo: 0.4% or more and 1.9% or less, Cr: 0% or more and 3.0% or less, Co: 0% or more and 3.0% or less , B: 0% or more and 0.05% or less, Ca: 0% or more and 0.05% or less, Mg: 0% or more and 0.05% or less, Al: 0% or more and 1.5% or less, Ti: 0% or more 1.5% or less, Nb: 0% or more and 1.5% or less, Zr: 0% or more and 1.5% or less, Hf: 0% or more and 1.5% or less, Ta: 0% or more and 1.5% or less, W: 0% or more and 1.5% or less, Cu: 0% or more and 1.5% or less, O: 0% or more and 0.005% or less, and N: 0% or more and 0.03% or less, and the balance is Fe. A high-strength, low-thermal expansion alloy wire composed of unavoidable impurities.
(Mo, V) C-based composite carbide containing both Mo and V is present in the crystal grains of the alloy wire.
When the amounts of Mo, V and C contained in the alloy wire are [Mo], [V] and [C], respectively, the value of ([Mo] +2.8 [V]) / [C] is 9. 6 or more and 21.7 or less,
When the amounts of Mo and V contained in the (Mo, V) C-based composite carbide are {Mo} and {V}, respectively, the value of {Mo} / {V} is 0.2 or more and 4.0 or less. The high-strength, low-thermal expansion alloy wire.
(2) In the crystal grains, the density of the (Mo, V) C-based composite carbide is 10 pieces / μm ² or more, and the diameter is 150 nm or less with respect to the total number of the (Mo, V) C-based composite carbides. The high-strength, low-thermal expansion alloy wire according to (1), wherein the ratio of the number of (Mo, V) C-based composite carbides is 50% or more.
(3) In mass%, Cr: contains more than 0% and 3.0% or less.
When the amounts of Mo, V and Cr contained in the alloy wire are [Mo], [V] and [Cr], respectively, the value of ([Mo] + [V]) / [Cr] is 1.2 or more. The high-strength, low-thermal expansion alloy wire according to (1) or (2).
(4) In mass%, contains Co: more than 0% and 3.0% or less.
When the amounts of Co and Ni contained in the alloy wire are [Co] and [Ni], respectively, [Co] + [Ni] is 35% or more and 40% or less, any of (1) to (3). High-strength low-heat expansion alloy wire described in nickel.
(5) In terms of mass%, one or more of B: more than 0% and 0.05% or less, Ca: more than 0% and 0.05% or less, and Mg: more than 0% and 0.05% or less. The high-strength low-thermal expansion alloy wire according to any one of (1) to (4), which comprises.
(6) In terms of mass%, Al: more than 0% and 1.5% or less, Ti: more than 0% and 1.5% or less, Nb: more than 0% and 1.5% or less, Zr: more than 0% and 1.5% or less. , Hf: more than 0% and less than 1.5%, Ta: more than 0% and less than 1.5%, W: more than 0% and less than 1.5%, and Cu: more than 0% and less than 1.5%. The high-strength, low-thermal expansion alloy wire according to any one of (1) to (5), which comprises a seed or two or more kinds.
(7) The high-strength, low-thermal expansion alloy wire according to any one of (1) to (6), which contains N: more than 0% and 0.03% or less in mass%.
(8) The high-strength, low-thermal expansion alloy wire according to any one of (1) to (7), which has a tensile strength of 1400 MPa or more.
(9) The high-strength low-thermal expansion according to any one of (1) to (8), wherein the twist value measured at a distance between gauge points 100 times the final wire diameter of the alloy wire is 20 times or more. Alloy wire.
(10) The high-strength, low-thermal expansion alloy wire according to any one of (1) to (9), which has an elongation of 0.8% or more.
(11) The average coefficient of linear thermal expansion between two points from 15 ° C to 100 ° C is 3 × 10 ^-6 / ° C or less (15 to 100 ° C), and the average linear thermal expansion between two points from 15 ° C to 230 ° C. coefficient of 4 × ^{10 -6} / ℃ or less (15-230 ° C.), an average coefficient of linear thermal expansion between the two points from 100 ° C. to 240 ° C. is 4 × ^{10 -6} / ℃ or less (100 to 240 ° C.), and , The high intensity according to any one of (1) to (10), wherein the average coefficient of linear thermal expansion between two points from 230 ° C. to 290 ° C. is 11 × 10 ⁻⁶ / ° C. or less (230 to 290 ° C.). Low thermal expansion alloy wire.
(12) High-strength low-heat including the high-strength low-heat expansion alloy wire according to any one of (1) to (11) and an Al-coated layer or a Zn-coated layer formed on the surface of the high-strength low-heat expansion alloy wire. Expansion coated alloy wire.

According to the present invention, an alloy wire having the characteristics required for a high-strength low thermal expansion alloy wire (for example, high strength, high twist value, good ductility, low thermal expansion rate, etc.), which is desired when manufacturing the alloy wire. Alloy wires and coated alloy wires that can be used in a wide range of conditions for heat treatment to obtain the hardness of the above are provided. The alloy wire and coated alloy wire of the present invention are desired to avoid dimensional and shape changes due to thermal expansion, but are used as core wire materials for low-sag transmission lines and wire rods for precision machine parts, which may raise the temperature during use. It is useful as a high-strength low-thermal expansion alloy wire used for such purposes.

FIG. 1 shows an example of a curve in which the horizontal axis is the aging temperature and the vertical axis is the tensile strength when the heating time is fixed at 6 hours and the heating temperature is changed between 610 and 650 ° C. for aging heat treatment. It is a conceptual diagram which shows. FIG. 2 shows a curve in which the horizontal axis is the aging temperature and the vertical axis is the tensile strength when the heating temperature is fixed at 650 ° C. and the heating time is changed between 30 minutes and 9 hours for aging heat treatment. It is a conceptual diagram which shows an example.

<Composition of alloy wire>
Hereinafter, the composition of the alloy wire of the present invention will be described. In addition, in this specification, "%" means mass% unless otherwise specified.

C: 0.1% or more and 0.4% or less C is an essential element of the alloy wire of the present invention. C is effective for strengthening solid solution, precipitation hardening by carbide formation, and strengthening thereof. From the viewpoint of effectively exerting such an effect of C, the content of C is adjusted to 0.1% or more, preferably 0.13% or more, and more preferably 0.15% or more. On the other hand, if the C content is excessive, the ductility is lowered and the linear thermal expansion coefficient is increased. Therefore, the C content is adjusted to 0.4% or less, preferably 0.38% or less, and more preferably 0.36% or less.

Si: 0.1% or more and 2.0% or less Si is an essential element of the alloy wire of the present invention. Si is effective in strengthening solid solution. From the viewpoint of effectively exerting such an effect of Si, the Si content is adjusted to 0.1% or more, preferably 0.2% or more, and more preferably 0.3% or more. On the other hand, if the Si content is excessive, the coefficient of linear thermal expansion increases. Therefore, the Si content is adjusted to 2.0% or less, preferably 1.7% or less, and more preferably 1.3% or less.

Mn: More than 0% and 2.0% or less Mn is an essential element of the alloy wire of the present invention. Mn acts as a deoxidizer and is effective in strengthening the solid solution. From the viewpoint of effectively exerting the effect of Mn, the content of Mn is adjusted to more than 0%, preferably 0.1% or more, and more preferably 0.2% or more. On the other hand, if the Mn content is excessive, the coefficient of linear thermal expansion increases. Therefore, the Mn content is adjusted to 2.0% or less, preferably 1.8% or less, and more preferably 1.3% or less.

Ni: 25% or more and 40% or less Ni is an essential element of the alloy wire of the present invention. Ni is effective in realizing a low coefficient of linear thermal expansion. From the viewpoint of effectively exerting such an effect of Ni, the content of Ni is adjusted to 25% or more, preferably 30% or more, and more preferably 34% or more. On the other hand, if the Ni content is excessive, it becomes difficult to realize a low coefficient of linear thermal expansion, and the cost of the alloy wire increases. Therefore, the Ni content is adjusted to 40% or less, preferably 39% or less, and more preferably 38% or less.

V: 0.5% or more and 3.0% or less V is an essential element of the alloy wire of the present invention. V is effective for precipitation hardening and strengthening by forming carbides, and is also effective for suppressing ductile deterioration by suppressing coarsening of carbides in crystal grains and promoting fine precipitation of carbides in crystals. From the viewpoint of effectively exerting such an effect of V, the V content is adjusted to 0.5% or more, preferably 0.6% or more, and more preferably 0.7% or more. On the other hand, if the V content is excessive, the above-mentioned effect is saturated, an increase in the effect commensurate with the increase in the content cannot be obtained, and the coefficient of linear thermal expansion increases. Therefore, the V content is adjusted to 3.0% or less, preferably 2.8% or less, and more preferably 2.6% or less.

Mo: 0.4% or more and 1.9% or less Mo is an essential element of the alloy wire of the present invention. Mo is effective for precipitation hardening and strengthening by forming carbides, and is also effective for suppressing ductile deterioration by suppressing coarsening of carbides in crystal grains and promoting fine precipitation of carbides in crystals. From the viewpoint of effectively exerting the effect of Mo, the content of Mo is adjusted to 0.4% or more, preferably 0.5% or more, and more preferably 0.7% or more. On the other hand, if the Mo content is excessive, the above effect is saturated, the effect corresponding to the increase in the content cannot be obtained, and the coefficient of linear thermal expansion increases. Therefore, the Mo content is adjusted to 1.9% or less, preferably 1.7% or less, and more preferably 1.5% or less.

([Mo] +2.8 [V]) / [C] values When the amounts of Mo, V and C contained in the alloy wire of the present invention are [Mo], [V] and [C], respectively, ( The value of [Mo] +2.8 [V]) / [C] is 9.6 or more and 21.7 or less. If the value of ([Mo] +2.8 [V]) / [C] is less than 9.6, the content of C becomes relatively excessive and the ductility decreases. Therefore, the value of ([Mo] +2.8 [V]) / [C] is adjusted to 9.6 or more, preferably 10.0 or more, and more preferably 10.8 or more. When the value of ([Mo] +2.8 [V]) / [C] is 9.6 or more, precipitation hardening and its strengthening by carbide formation can be realized, and ductility can be optimized. On the other hand, when the value of ([Mo] +2.8 [V]) / [C] exceeds 21.7, the content of V and the content of Mo become relatively excessive, and the effects of V and Mo are saturated. However, the increase in the effect corresponding to the increase in the content cannot be obtained, and the coefficient of linear thermal expansion increases. Therefore, the value of ([Mo] +2.8 [V]) / [C] is adjusted to 21.7 or less, preferably 21.3 or less, and more preferably 21.0 or less.

The alloy wire of the present invention contains the above essential elements, and the balance is composed of Fe and unavoidable impurities, but if necessary, one or more of the following optional elements and impurities can be contained.

Cr: 0% or more and 3.0% or less Cr is an arbitrary element of the alloy wire of the present invention. Cr is effective in strengthening the solid solution. When it is desired to effectively exert the effect of Cr, the Cr content is adjusted to more than 0%, preferably 0.1% or more, and more preferably 0.3% or more. On the other hand, if the Cr content is excessive, the strength and ductility decrease due to the formation of coarse carbides, and the linear thermal expansion coefficient increases. Therefore, the Cr content is adjusted to 3.0% or less, preferably 2.5% or less, and more preferably 2.0% or less.

When the amounts of Mo, V and Cr contained in the alloy wire of the present invention are [Mo], [V] and [Cr], respectively, the value of ([Mo] + [V]) / [Cr] is preferable. Is 1.2 or more. When the value of ([Mo] + [V]) / [Cr] is less than 1.2, the content of Cr becomes relatively excessive, precipitation hardening is inhibited by the formation of coarse carbides, and ductility is achieved. Decreases. Therefore, the value of ([Mo] + [V]) / [Cr] is adjusted to 1.2 or more, preferably 1.3 or more, and more preferably 1.5 or more. The upper limit of the value of ([Mo] + [V]) / [Cr] is not particularly limited, but is preferably 8.0 or less, more preferably 6.0 or less.

Co: 0% or more and 3.0% or less Co is an arbitrary element of the alloy wire of the present invention. Co has the same effect as Ni and is effective in stabilizing the coefficient of linear thermal expansion by increasing the Curie point. When it is desired to effectively exert such an effect of Co, the content of Co is adjusted to more than 0%, preferably 0.1% or more, and more preferably 0.3% or more. On the other hand, if the Co content is excessive, the alloy wire cost increases and the linear thermal expansion coefficient increases. Therefore, the Co content is adjusted to 3.0 or less, preferably 2.8 or less, and more preferably 2.5% or less.

When the amounts of Co and Ni contained in the alloy wire of the present invention are [Co] and [Ni], respectively, [Co] + [Ni] is preferably 35% or more and 40% or less. If [Co] + [Ni] is less than 35%, it becomes difficult to realize a low coefficient of linear thermal expansion. Therefore, [Co] + [Ni] is preferably adjusted to 35% or more, more preferably 36% or more, and even more preferably 37% or more. When [Co] + [Ni] is 35% or more, a low coefficient of linear thermal expansion can be realized. On the other hand, if [Co] + [Ni] exceeds 40%, it becomes difficult to realize a low coefficient of linear thermal expansion, and the cost of alloy wire increases. Therefore, [Co] + [Ni] is preferably adjusted to 40% or less, more preferably 39.5% or less, and even more preferably 39% or less.

B: 0% or more and 0.05% or less B is an arbitrary element of the alloy wire of the present invention. B is effective for improving hot workability and strengthening grain boundary oxidation resistance by strengthening grain boundaries. When it is desired to effectively exert such an effect of B, the content of B is adjusted to more than 0%, preferably 0.001% or more, and more preferably 0.002% or more. On the other hand, if the B content is excessive, the hot workability is lowered. Therefore, the content of B is adjusted to 0.05% or less, preferably 0.03% or less, and more preferably 0.01% or less.

Ca: 0% or more and 0.05% or less Ca is an arbitrary element of the alloy wire of the present invention. Ca is effective in improving hot workability by fixing S. When it is desired to effectively exert the effect of Ca, the Ca content is adjusted to more than 0%, preferably 0.005% or more, and more preferably 0.01% or more. On the other hand, if the Ca content is excessive, the hot workability is lowered. Therefore, the Ca content is adjusted to 0.05% or less, preferably 0.04% or less, and more preferably 0.03% or less.

Mg: 0% or more and 0.05% or less Mg is an arbitrary element of the alloy wire of the present invention. Mg is effective in improving hot workability by fixing S. When it is desired to effectively exert such an effect of Mg, the content of Mg is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.015% or more. On the other hand, if the Mg content is excessive, the hot workability is lowered. Therefore, the Mg content is adjusted to 0.05% or less, preferably 0.045% or less, and more preferably% 0.04 or less.

Al: 0% or more and 1.5% or less Al is an arbitrary element of the alloy wire of the present invention. Al is effective for removing oxide-based inclusions by deoxidizing effect, strengthening solid solution, precipitation hardening and strengthening thereof. When it is desired to effectively exert such an effect of Al, the content of Al is adjusted to more than 0%, preferably 0.005% or more, and more preferably 0.01% or more. On the other hand, if the Al content is excessive, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the Al content is adjusted to 1.5% or less, preferably 1.3% or less, and more preferably 1.0% or less.

Ti: 0% or more and 1.5% or less Ti is an arbitrary element of the alloy wire of the present invention. Ti is effective for precipitation hardening and its strengthening, and can be used as a substitute element for V or Mo. When it is desired to effectively exert such an effect of Ti, the content of Ti is adjusted to more than 0%, preferably 0.001% or more, and more preferably 0.005% or more. On the other hand, if the Ti content is excessive, the aging hardening ability is lowered, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the Ti content is adjusted to 1.5% or less, preferably 1.3% or less, and more preferably 1.0% or less.

Nb: 0% or more and 1.5% or less Nb is an arbitrary element of the alloy wire of the present invention. Nb is effective for precipitation hardening and its strengthening, and can be used as a substitute element for V or Mo. When it is desired to effectively exert such an effect of Nb, the content of Nb is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.02% or more. On the other hand, if the Nb content is excessive, the aging hardening ability is lowered, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the Nb content is adjusted to 1.5% or less, preferably 1.3% or less, and more preferably 1.0% or less.

Zr: 0% or more and 1.5% or less Zr is an arbitrary element of the alloy wire of the present invention. Zr is effective for precipitation hardening and its strengthening, and can be used as a substitute element for V or Mo. When it is desired to effectively exert such an effect of Zr, the content of Zr is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.02% or more. On the other hand, if the Zr content is excessive, the aging hardening ability is lowered, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the Zr content is adjusted to 1.5% or less, preferably 1.3% or less, and more preferably 1.0% or less.

Hf: 0% or more and 1.5% or less Hf is an arbitrary element of the alloy wire of the present invention. Hf is effective for precipitation hardening and its strengthening, and can be used as a substitute element for V or Mo. When it is desired to effectively exert such an effect of Hf, the content of Hf is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.02% or more. On the other hand, if the Hf content is excessive, the aging hardening ability is lowered, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the Hf content is adjusted to 1.5% or less, preferably 1.4% or less, and more preferably 1.3% or less.

Ta: 0% or more and 1.5% or less Ta is an arbitrary element of the alloy wire of the present invention. Ta is effective for precipitation hardening and its strengthening, and can be used as a substitute element for V or Mo. When it is desired to effectively exert the effect of Ta, the content of Ta is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.02% or more. On the other hand, if the Ta content is excessive, the aging hardening ability is lowered, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the Ta content is adjusted to 1.5% or less, preferably 1.4% or less, and more preferably 1.3% or less.

W: 0% or more and 1.5% or less W is an arbitrary element of the alloy wire of the present invention. W is effective for precipitation hardening and its strengthening, and can be used as a substitute element for V or Mo. When it is desired to effectively exert such an effect of W, the content of W is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.02% or more. On the other hand, if the W content is excessive, the aging hardening ability is lowered, the ductility is lowered, the coefficient of thermal expansion is increased, and the alloy wire cost is increased. Therefore, the W content is adjusted to 1.5% or less, preferably 1.4% or less, and more preferably 1.3% or less.

Cu: 0% or more and 1.5% or less Cu is an arbitrary element of the alloy wire of the present invention. Cu is effective for precipitation hardening and its strengthening by forming Cu particles, and raises the Curie point. When it is desired to effectively exert such an effect of Cu, the content of Cu is adjusted to more than 0%, preferably 0.01% or more, and more preferably 0.02% or more. On the other hand, if the Cu content is excessive, the hot workability is lowered and the alloy wire cost is increased. Therefore, the Cu content is adjusted to 1.5% or less, preferably 1.3% or less, and more preferably 1.0% or less.

O: 0% or more and 0.005% or less O is an impurity of the alloy wire of the present invention. O reduces ductility by forming oxides. Therefore, the content of O is adjusted to 0.005% or less, preferably 0.003% or less, and more preferably 0.001% or less.

N: 0% or more and 0.03% or less N is an arbitrary element of the alloy wire of the present invention. N has the same effect as C, such as strengthening the solid solution. When it is desired to effectively exert such an effect of N, the content of N is adjusted to more than 0%, preferably 0.01% or more. On the other hand, if the N content is excessive, ductility is reduced due to nitride formation. Therefore, the N content is adjusted to 0.03% or less, preferably 0.025% or less.

The alloy wire according to one embodiment of the present invention is one of B: more than 0% and 0.05% or less, Ca: more than 0% and 0.05% or less, and Mg: more than 0% and 0.05% or less. Includes seeds or two or more.

The alloy wire according to another embodiment of the present invention has Al: more than 0% and 1.5% or less, Ti: more than 0% and 1.5% or less, Nb: more than 0% and 1.5% or less, Zr: 0%. Super 1.5% or less, Hf: 0% or more 1.5% or less, Ta: 0% or more 1.5% or less, W: 0% or more 1.5% or less, and Cu: 0% or more 1.5% Includes one or more of% or less.

<Structure of alloy wire>
Hereinafter, the structure of the alloy wire of the present invention will be described.
The alloy wire of the present invention has crystal grains in which (Mo, V) C-based composite carbide containing both Mo and V (hereinafter, may be referred to as “composite carbide”) is present inside.

When the amounts of Mo and V contained in the (Mo, V) C-based composite carbide are {Mo} and {V}, respectively, the value of {Mo} / {V} is 0.2 or more and 4.0 or less. .. If the value of {Mo} / {V} is less than 0.2, Mo-deficient carbides are formed, the hardness and strength are lowered, and the intragranular carbides are formed and grown quickly in the aging heat treatment, resulting in high hardness. The temperature range of the aging heat treatment that can maintain high strength is narrowed, and high hardness and high strength cannot be obtained under aging conditions in a wide temperature range. Therefore, the value of {Mo} / {V} is adjusted to 0.2 or more, preferably 0.3 or more, and more preferably 0.4 or more. When the value of {Mo} / {V} is 0.2 or more, precipitation hardening and its strengthening can be optimized. On the other hand, when the value of {Mo} / {V} exceeds 4.0, V-deficient carbides are formed, the hardness and strength decrease, and the formation and growth of intragranular carbides occur quickly in the aging heat treatment, resulting in high. The temperature range of the aging heat treatment that can maintain the hardness and high strength becomes narrow, and high hardness and high strength cannot be obtained under the aging conditions in a wide temperature range. Therefore, the value of {Mo} / {V} is adjusted to 4.0 or less, preferably 3.7 or less, and more preferably 3.4 or less. When the value of {Mo} / {V} is 4.0 or less, precipitation hardening and its strengthening can be optimized.

The value of {Mo} / {V} is obtained as follows. A test piece is taken from the alloy wire and the cross section of the test piece is polished. The composition of carbides present inside the crystal grains is analyzed using a transmission electron microscope (TEM) and an energy dispersive X-ray fluorescence analyzer (EDX). Specifically, TEM was used to observe the cross section of the polished test piece in a microstructure, and EDX was used to identify (Mo, V) C-based composite carbides present inside the crystal grains, and (Mo). , V) Measure the amount of Mo and V contained in the C-based composite carbide, and determine the value of {Mo} / {V}.

The density of the (Mo, V) C-based composite carbide in the crystal grains is preferably 10 pieces / μm ² or more. If the density of the (Mo, V) C-based composite carbide in the crystal grains is less than 10 pieces / μm ² , the amount of precipitates is small and the strength may be low, but (Mo, V) C in the crystal grains. When the density of the system composite carbide is 10 pieces / μm ² or more, precipitation hardening and its strengthening can be optimized.

Ratio of the number of (Mo, V) C-based composite carbides with a diameter of 150 nm or less to the total number of (Mo, V) C-based composite carbides in the crystal grains (presence of (Mo, V) C-based composite carbides with a diameter of 150 nm or less) The rate) is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more. When the ratio of the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less to the total number of (Mo, V) C-based composite carbides in the crystal grains is less than 50%, a large number of coarse particles are formed. Although the strength may be low, if the ratio of the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less to the total number of (Mo, V) C-based composite carbides in the crystal grains is 50% or more, Precipitation hardening and its strengthening can be optimized.

The density of the (Mo, V) C-based composite carbide and the abundance of the (Mo, V) C-based composite carbide having a diameter of 150 nm or less in the crystal grains are measured using TEM and EDX as follows. The cross section of the polished test piece is observed by microstructure using TEM, and the (Mo, V) C-based composite carbide existing inside the crystal grains is identified by electron diffraction and composition analysis using EDX. In addition, the total number of (Mo, V) C-based composite carbides is counted from the TEM bright-field image observed and photographed at a magnification of 5,000 to 200,000 according to the size of the carbides present in the crystal grains, and the TEM brightness is also counted. The number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less existing in the field image is counted. Density of (Mo, V) C-based composite carbides (pieces / μm) based on the observed area of the TEM bright-field image and the total number of (Mo, V) C-based composite carbides present in the TEM bright-field image. ² ) is calculated. Then, based on the total number of (Mo, V) C-based composite carbides counted by the above method and the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less, the total number of (Mo, V) C-based composite carbides is total. The ratio of the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less to the number (presence rate of (Mo, V) C-based composite carbides having a diameter of 150 nm or less) is determined. The major axis of the (Mo, V) C-based composite carbide (that is, the diameter of the circle circumscribing the (Mo, V) C-based composite carbide) is defined as the diameter of the (Mo, V) C-based composite carbide.

<Characteristics of alloy wire>
The tensile strength (TS) of the alloy wire of the present invention is preferably 1300 MPa or more, more preferably 1400 MPa or more, and even more preferably 1500 MPa or more. The elongation (EL) of the alloy wire of the present invention is preferably 0.8% or more, more preferably 1.0% or more. TS and EL are measured by performing a tensile test on a test piece made from an alloy wire in accordance with JIS Z 2241.

The twist value of the alloy wire of the present invention measured at a distance between reference points 100 times the final wire diameter of the alloy wire of the present invention is preferably 20 times or more, more preferably 60 times or more. The measurement of the twist value is carried out as follows. One end of a test piece made from an alloy wire is fixed, the other end of the test piece is twisted, and the number of twists until the test piece breaks is measured as a twist value. The distance between the gauge points is 100 × D (D represents the final wire diameter of the test piece), and the twisting speed is 60 rpm. In the present invention, the "wire diameter" means the diameter of a circle when the cross section of the test piece is a circle, and the equivalent circle diameter converted from the area of the cross section when the cross section of the test piece is not a circle. Means. Further, in the present invention, the "circle equivalent diameter" means the diameter of a circle having the same area as the cross-sectional area of the test piece.

The average coefficient of linear thermal expansion between two points of the alloy wire of the present invention from 15 ° C. to 100 ° C. is preferably 3.4 × ^10-6 / ° C. or less, more preferably 3.0 × ^10-6 / ° C. or less. Is. The average coefficient of linear thermal expansion between two points of the alloy wire of the present invention from 15 ° C. to 230 ° C. is preferably 4.4 × 10 ^-6 / ° C. or less, more preferably 4.0 × 10 ^-6 / ° C. or less. Is. The average coefficient of linear thermal expansion between two points of the alloy wire of the present invention from 100 ° C. to 240 ° C. is preferably 4.4 × 10 ^-6 / ° C. or less, more preferably 4.0 × 10 ^-6 / ° C. or less. Is. The average coefficient of linear thermal expansion between two points of the alloy wire of the present invention from 230 ° C. to 290 ° C. is preferably. It is 11.4 × ^10-6 / ° C or less, more preferably 11.0 × ^10-6 / ° C or less. The measurement of the coefficient of linear thermal expansion is carried out as follows. The displacement of the test piece during the temperature rise process was measured with a Formaster tester (Formastro-EDP, manufactured by Fuji Denpa Koki Co., Ltd.), and the average coefficient of linear thermal expansion between two points from 15 ° C to 100 ° C was 15 ° C. Average coefficient of linear thermal expansion between two points from 230 ° C to 230 ° C, average linear thermal expansion coefficient between two points from 100 ° C to 240 ° C, and average linear thermal expansion coefficient between two points from 230 ° C to 290 ° C. To measure.

<Form of alloy wire>
The form of the alloy wire of the present invention is not particularly limited as long as it is linear. Examples of the form of the alloy wire of the present invention include a round wire, a flat wire, a square wire, and the like. The wire diameter of the alloy wire of the present invention is not particularly limited, but is, for example, 2.0 to 3.8 mm. The meaning of "wire diameter" is as described above.

<Manufacturing method of alloy wire>
The alloy wire of the present invention can be produced, for example, by the following method. A steel material having a desired shape such as a round bar or a square material is obtained by melting steel having the alloy composition of the present invention, producing ingots or blooms by ingot or continuous casting, and then hot forging or hot rolling. Mold into. After that, the alloy wire of the present invention can be produced by sequentially performing solution heat treatment, wire drawing, and aging heat treatment on the steel material. For example, the solution treatment can be carried out at a heating temperature of 1200 ° C. and a heating time of 30 minutes. The solution heat treatment can be omitted by immediately performing rapid cooling such as water cooling after the steel material manufacturing process in hot forging or hot rolling. The aging heat treatment can be carried out, for example, at a heating temperature of 625 ° C. and a heating time of 2 hours. It is preferable that the steel material is cold-worked after the solution heat treatment and before the aging heat treatment.

The alloy wire having the alloy composition of the present invention has a wide range of aging heat treatment conditions (temperature and holding time of the temperature) in which high hardness can be obtained. Therefore, when the hardness is imparted by the aging heat treatment, it is possible to avoid a decrease in hardness due to changes in manufacturing conditions (for example, material, heating temperature, heating time, etc.), poor control, and the like. Further, in the aging heat treatment, even if an excessive heat treatment is performed, it is possible to avoid a significant decrease in hardness due to the excessive heat treatment. Such stability is caused by the precipitation of (Mo, V) C-based composite carbide having a value of {Mo} / {V} of 0.2 or more and 4.0 or less inside the crystal grains in the aging heat treatment. It is an effect.

<Coated alloy wire>
The coated alloy wire of the present invention includes the alloy wire of the present invention and an Al-coated layer (Al film) or a Zn-coated layer (Zn film) formed on the surface of the alloy wire of the present invention. The coated alloy wire of the present invention has the same effect as the alloy wire of the present invention, and also has corrosion resistance due to the Al coating layer or the Zn coating layer. The Al coating layer can be formed by a known method such as conform extrusion. The Zn coating layer can be formed by a known method such as plating.

Hereinafter, the present invention will be described in more detail based on Examples.
A 50 kg alloy having the component compositions shown in Table 1 (Examples No. 1 to 30 of the present invention) and Table 2 (Comparative Examples No. 31 to 55) was melted in a vacuum induction melting furnace (VIM) to obtain an ingot. .. The ingot was heated at 1200 ° C. for 1 hour and forged into a steel bar having a diameter of 20 mm. This steel bar was solution-treated under the conditions of a heating temperature of 1200 ° C. and a heating time of 30 minutes. The steel bar after the solution treatment was turned to a diameter of 15 mm, and then wire drawing was performed at room temperature to produce an alloy wire having a wire diameter of 8 mm. In Tables 1 and 2, [Mo], [V] and [C] represent the amounts of Mo, V and C contained in the alloy, respectively.

[Evaluation of carbides in crystal grains after aging heat treatment]
A test piece (length 10 mm) prepared from an alloy wire having a wire diameter of 8 mm was subjected to aging heat treatment under the conditions of a heating temperature of 500 to 1000 ° C. and a heating time of 30 minutes to 24 hours.

The composition of carbides present inside the crystal grains of the test piece after the aging heat treatment was analyzed using a transmission electron microscope (TEM) and an energy dispersive X-ray fluorescence analyzer (EDX). Analysis by TEM and EDX was performed as follows. Using TEM, microstructure observation of the cross section of the polished test piece was performed, and EDX was used to identify (Mo, V) C-based composite carbides present inside the crystal grains, and (Mo, V) C-based. The amounts of Mo and V contained in the composite carbide were measured, and the values of {Mo} / {V} were determined. The results are shown in Table 3 (Examples No. 1 to 30 of the present invention) and Table 4 (Comparative Examples No. 31 to 55). In Tables 3 and 4, {Mo} and {V} represent the amounts of Mo and V contained in the (Mo, V) C-based composite carbide, respectively.

The densities of (Mo, V) C-based composite carbides present inside the crystal grains of the test piece after the aging heat treatment were analyzed using TEM and EDX. Analysis by TEM and EDX was performed as follows. The cross section of the polished test piece was observed by microstructure using TEM, and the (Mo, V) C-based composite carbide present inside the crystal grains was identified by electron diffraction and composition analysis using EDX. Then, the amounts of Mo and V contained in the (Mo, V) C-based composite carbide were measured, and the values of {Mo} / {V} were determined. The value of {Mo} / {V} of the composite carbide targeted in the present invention is 0.2 to 4.0. Regarding the quantification of the dispersed state, the total number of (Mo, V) C-based composite carbides is counted from the TEM bright-field image observed and photographed at a magnification of 5,000 to 200,000 according to the size of the carbides existing in the crystal grains. At the same time, the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less present in the TEM bright-field image was counted. Density of (Mo, V) C-based composite carbides (pieces / μm) based on the observed area of the TEM bright-field image and the total number of (Mo, V) C-based composite carbides present in the TEM bright-field image. ² ) was requested. Then, based on the total number of (Mo, V) C-based composite carbides counted by the above method and the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less, the total number of (Mo, V) C-based composite carbides is total. The ratio of the number of (Mo, V) C-based composite carbides having a diameter of 150 nm or less to the number (presence rate of (Mo, V) C-based composite carbides having a diameter of 150 nm or less) was determined. The major axis of the (Mo, V) C-based composite carbide (that is, the diameter of the circle circumscribing the (Mo, V) C-based composite carbide) was defined as the diameter of the (Mo, V) C-based composite carbide. The value of {Mo} / {V} of the (Mo, V) C-based composite carbide satisfies 0.2 to 4.0, and at the same time, the density is 10 pieces / μm ² or more and the diameter is 150 nm or less (Mo, V). V) When the abundance rate of the C-based composite carbide is 50% or more, "A: The target composite carbide is present and the dispersed state is good", (Mo, V) C-based composite carbide {Mo} / { When the value of V} satisfies 0.2 to 4.0, but the density is less than 10 pieces / μm ² or the abundance of (Mo, V) C-based composite carbide having a diameter of 150 nm or less is less than 50%. "B: The target composite carbide exists, but the dispersion state is poor", (Mo, V) When the value of {Mo} / {V} of the C-based composite carbide does not satisfy 0.2 to 4.0. Was evaluated as "F: defective composite carbide". Evaluation F is outside the scope of the present invention. The results are shown in Table 3 (Examples No. 1 to 30 of the present invention) and Table 4 (Comparative Examples No. 31 to 55).

[Evaluation of thermal aging stability]
A test piece (length 100 mm) prepared from an alloy wire having a wire diameter of 8 mm was subjected to aging heat treatment by fixing the heating time to 6 hours and changing the heating temperature between 61 to 650 ° C. For the test pieces before aging treatment and after aging heat treatment, JIS14A test pieces were prepared by machining, and tensioned according to JIS Z 2241 using a tensile tester (100 kN universal testing machine, manufactured by Shimadzu Corporation). A test was carried out and the tensile strength (TS) was measured. Create a curve with the horizontal axis as the aging temperature and the vertical axis as the tensile strength (see Fig. 1), and based on this curve, set the temperature range in which a tensile strength of 96% or more of the maximum tensile strength (MAX6hr) can be secured. I asked. When the temperature range in which 96% or more of the maximum tensile strength (MAX6hr) can be secured is 30 ° C. or higher, "A: good thermal aging stability", and when it is less than 30 ° C., "F: The thermal aging stability is poor. " The results are shown in Table 5 (Examples No. 1 to 30 of the present invention) and Table 6 (Comparative Examples No. 31 to 55). In FIG. 1, a curve in which the heating time is fixed at 6 hours and the heating temperature is changed between 610 and 650 ° C. and the aging heat treatment is performed, the horizontal axis is the aging temperature and the vertical axis is the tensile strength. As an example, in this curve, the temperature range in which a tensile strength of 96% or more of the maximum tensile strength (MAX6hr) can be secured is 32 ° C.

[Evaluation of aging stability over time]
A test piece (length 100 mm) prepared from an alloy wire having a wire diameter of 8 mm was subjected to aging heat treatment by fixing the heating temperature at 650 ° C. and changing the heating time between 30 minutes and 9 hours. For the test pieces before the aging treatment and after the aging heat treatment, JIS14A test pieces were prepared by machining and pulled according to JIS Z 2241 using a tensile tester (500 kN universal testing machine, manufactured by Shimadzu Corporation). A test was carried out and the tensile strength (TS) was measured. Create a curve with the horizontal axis as the aging temperature and the vertical axis as the tensile strength (see Fig. 2), and based on this curve, a time range in which a tensile strength of 97% or more of the maximum tensile strength (MAX 650 ° C.) can be secured. Asked. "A: Good aging stability over time" when the time range in which 97% or more of the maximum tensile strength (MAX 650 ° C.) can be secured is 3 hours or more, and "F" when it is less than 3 hours. : Poor aging stability over time ”. The results are shown in Table 5 (Examples No. 1 to 30 of the present invention) and Table 6 (Comparative Examples No. 31 to 55). In FIG. 2, the horizontal axis is the aging temperature and the vertical axis is the tensile strength when the heating temperature is fixed at 650 ° C. and the heating time is changed between 30 minutes and 9 hours for aging heat treatment. This is an example of a curve, and in this curve, the time range in which a tensile strength of 97% or more of the maximum tensile strength (MAX 650 ° C.) can be secured is 3.8 hours.

When both the thermal aging stability and the aging stability over time were evaluated as A, the following evaluations were performed, but when any of them was evaluated as F, the following evaluations were not performed.

[Evaluation of tensile properties after aging treatment]
A test piece (length 300 mm) prepared from an alloy wire having a wire diameter of 8 mm was subjected to aging heat treatment under the conditions of a heating temperature of 500 to 1000 ° C. and a heating time of 30 minutes to 24 hours. The test piece after the aging heat treatment was subjected to wire drawing at room temperature to prepare a test piece (length 400 mm or more) having a wire diameter of 3.1 mm. Tensile test piece with wire diameter 3.1 mm and gauge length 250 mm using a tensile tester (100 kN universal tester, manufactured by Shimadzu Corporation) at room temperature with a stroke speed of 20 mm / min or less. Was carried out, and the tensile strength (TS) and the elongation (EL) were measured. "A: Very good tensile properties" when TS is 1500 MPa or more and EL is 0.8% or more, and "B" when TS is less than 1500 MPa and 1400 MPa or more and EL is 0.8% or more. : Good tensile properties ”, TS is less than 1400 MPa, 1300 MPa or more, and EL is 0.8% or more“ C: Generally good tensile properties ”, TS is less than 1300 MPa, or EL is 0.8% When it was less than, it was evaluated as "F: poor tensile properties". The results are shown in Table 5 (Examples No. 1 to 30 of the present invention) and Table 6 (Comparative Examples No. 31 to 55). Here, when it was evaluated as A, B, or C, the following evaluation was performed, but when it was evaluated as F, the following evaluation was not performed.

[Evaluation of twist value after aging heat treatment]
The twist value of a test piece (length 310 mm) having a wire diameter of 3.1 mm produced in the same manner as above was measured. The twist value was measured as follows. One end of the test piece was fixed, the other end of the test piece was twisted, and the number of twists until the test piece broke was measured as the twist value. The distance between the gauge points was 100 D (D represents the final wire diameter of the test piece), and the twisting speed was 60 rpm. When the twist value is 60 times or more, "A: the twist value is extremely good", when the twist value is 20 to 59 times, "B: the twist value is good", and the twist value is 20 times. When it was less than, it was evaluated as "F: bad twist value". The results are shown in Table 5 (Examples No. 1 to 30 of the present invention) and Table 6 (Comparative Examples No. 31 to 55). Here, when it was evaluated as A or B, the following evaluation was performed, but when it was evaluated as F here, the following evaluation was not performed.

[Evaluation of linear thermal expansion coefficient after aging heat treatment]
The coefficient of linear thermal expansion of a test piece having a wire diameter of 3.1 mm produced in the same manner as above was measured. The coefficient of linear thermal expansion was measured as follows. The displacement of the test piece during the temperature rise process was measured with a Formaster tester (Formastro-EDP, manufactured by Fuji Denpa Koki Co., Ltd.), and the average coefficient of linear thermal expansion between two points from 15 ° C to 100 ° C was 15 ° C. Average coefficient of linear thermal expansion between two points from 230 ° C to 230 ° C, average linear thermal expansion coefficient between two points from 100 ° C to 240 ° C, and average linear thermal expansion coefficient between two points from 230 ° C to 290 ° C. Was measured. When the average coefficient of linear thermal expansion between two points from 15 ° C to 100 ° C is 3.0 × ^10-6 / ° C or less, “A: The coefficient of linear thermal expansion is extremely low”, 3.0 × ^10-6. / a of less than 3.5 × ^{10 -6} / ° C. beyond ° C. "B: a low linear thermal expansion coefficient", the case of 3.5 × ^{10 -6} / ° C. or more "F: coefficient of linear thermal expansion It was evaluated as "high". Further, when the average coefficient of linear thermal expansion between two points from 15 ° C. to 230 ° C. is 4.0 × 10 ^-6 / ° C. or less, “A: The coefficient of linear thermal expansion is extremely low” 4.0 × 10. ^-6 / case of less than 4.5 × ^{10 -6} / ° C. beyond ° C. "B: a low linear thermal expansion coefficient", the case of 4.5 × ^{10 -6} / ° C. or more "F: linear thermal expansion The coefficient is high. " Further, when the average coefficient of linear thermal expansion between two points from 100 ° C. to 240 ° C. is 4.0 × 10 ^-6 / ° C. or less, “A: The coefficient of linear thermal expansion is extremely low”, 4.0 × 10. ^-6 / case of less than 4.5 × ^{10 -6} / ° C. beyond ° C. "B: a low linear thermal expansion coefficient", the case of 4.5 × ^{10 -6} / ° C. or more "F: linear thermal expansion The coefficient is high. " Further, when the average coefficient of linear thermal expansion between two points from 230 ° C. to 290 ° C. is 11.0 × 10 ^-6 / ° C. or less, “A: the coefficient of linear thermal expansion is extremely low”, 11.0 × 10. ^-6 / a of less than 11.5 × ^{10 -6} / ° C. beyond ° C. "B: a low linear thermal expansion coefficient", the case of more than 11.5 × ^{10 -6} / ° C. "F: linear thermal expansion The coefficient is high. " From the results of measuring and evaluating the above four temperature ranges, a comprehensive evaluation of the coefficient of linear thermal expansion of each test piece was further performed. In the evaluation of the average coefficient of linear thermal expansion from 15 ° C to 230 ° C, the average coefficient of linear thermal expansion from 100 ° C to 240 ° C, and the average coefficient of linear thermal expansion from 15 ° C to 290 ° C, all have one A or B evaluation. The overall evaluation when the other three are A evaluations is "A: The coefficient of linear thermal expansion is extremely low", and the overall evaluation when the other two are A evaluations are "B: The coefficient of linear thermal expansion is very low". The overall evaluation when one is A and the other three are B is "C: The coefficient of linear thermal expansion is generally low", and the overall evaluation when F is one or more is "F: Linear thermal expansion". The coefficient is high. " The results are shown in Table 5 (Examples No. 1 to 30 of the present invention) and Table 6 (Comparative Examples No. 31 to 55).

In addition, Comparative Example No. 49 and No. In No. 50, since B and Mg were excessive, the hot workability was poor, and many cracks were generated during forging, so that an evaluation test piece could not be produced, and therefore various evaluations were not performed.

Example No. of the present invention. 1-No. 26 is
Condition a: Satisfying the alloy composition of the present invention.
Condition b: (Mo, V) C-based composite carbide is present inside the crystal grains.
Condition c: ([Mo] +2.8 [V]) / [C] value is 9.6 or more and 21.7 or less, Condition d: {Mo} / {V} value is 0.2 or more 4 .0 or less,
Condition e: In the crystal grains, the density of the (Mo, V) C-based composite carbide is 10 pieces / μm ² or more, and the diameter is 150 nm or less with respect to the total number of (Mo, V) C-based composite carbides (Mo, V). V) The ratio of the number of C-based composite carbides is 50% or more.
Condition f: When the Cr content is more than 0%, the value of ([Mo] + [V]) / [Cr] is 1.2 or more.
Condition g: When the content of Co is more than 0%, [Co] + [Ni] is 35% or more and 40% or less.
All of the characteristics required for a high-strength, low-thermal expansion alloy wire were evaluated as A or B, that is, they had high strength, high twist value, good ductility, and low coefficient of thermal expansion. In addition, the present invention example No. 1-No. No. 26 was excellent in aging stability (thermal aging stability and aging stability over time).

In addition, the present invention example No. 27-No. No. 30 satisfies all the conditions a to d, and is generally excellent in wear resistance, high strength, good ductility, low coefficient of thermal expansion and aging stability (thermal aging stability and aging stability over time). There is a C rating that does not satisfy any one of the conditions e to g and is slightly inferior to the B rating in any one of them.

On the other hand, Comparative Example No. 31-No. 55 does not satisfy any one or more of the conditions a to d, and at least one of strength, twisting characteristics, ductility, coefficient of thermal expansion and aging stability (thermal aging stability and aging stability over time). The species had an F rating and lacked the required properties.

Claims (11)

By mass%
C: 0.1% or more and 0.4% or less,
Si: 0.1% or more and 2.0% or less,
Mn: More than 0% and less than 2.0%,
Ni: 25% or more and 40% or less,
V: 0.5% or more and 3.0% or less,
Mo: 0.4% or more and 1.9% or less,
Cr: 0% or more and 3.0% or less,
Co: 0% or more and 3.0% or less,
B: 0% or more and 0.05% or less,
Ca: 0% or more and 0.05% or less,
Mg: 0% or more and 0.05% or less,
Al: 0% or more and 1.5% or less,
Ti: 0% or more and 1.5% or less,
Nb: 0% or more and 1.5% or less,
Zr: 0% or more and 1.5% or less,
Hf: 0% or more and 1.5% or less,
Ta: 0% or more and 1.5% or less,
W: 0% or more and 1.5% or less,
Cu: 0% or more and 1.5% or less,
O: 0% or more and 0.005% or less, N: 0% or more and 0.03% or less, and the balance is a high-strength low-thermal expansion alloy wire composed of Fe and unavoidable impurities.
(Mo, V) C-based composite carbide containing both Mo and V is present in the crystal grains of the alloy wire.
When the amounts of Mo, V and C contained in the alloy wire are [Mo], [V] and [C], respectively, the value of ([Mo] +2.8 [V]) / [C] is 9. 6 or more and 21.7 or less,
When the amounts of Mo and V contained in the (Mo, V) C-based composite carbide are {Mo} and {V}, respectively, the value of {Mo} / {V} is 0.2 or more and 4.0 or less. The high-strength, low-thermal expansion alloy wire. In mass%, Cr: contains more than 0% and 3.0% or less,
When the amounts of Mo, V and Cr contained in the alloy wire are [Mo], [V] and [Cr], respectively, the value of ([Mo] + [V]) / [Cr] is 1.2 or more. The high-strength, low-thermal expansion alloy wire according to claim 1 . In mass%, contains Co: more than 0% and 3.0% or less.
The high according to claim 1 or 2 , wherein when the amounts of Co and Ni contained in the alloy wire are [Co] and [Ni], respectively, [Co] + [Ni] is 35% or more and 40% or less. Strong low thermal expansion alloy wire. In terms of mass%, B: more than 0% and 0.05% or less, Ca: more than 0% and 0.05% or less, and Mg: more than 0% and 0.05% or less, including one or more. The high-strength, low-thermal expansion alloy wire according to any one of claims 1 to 3 . By mass%, Al: more than 0% and less than 1.5%, Ti: more than 0% and less than 1.5%, Nb: more than 0% and less than 1.5%, Zr: more than 0% and less than 1.5%, Hf: One or two of more than 0% and less than 1.5%, Ta: more than 0% and less than 1.5%, W: more than 0% and less than 1.5%, and Cu: more than 0% and less than 1.5%. The high-strength, low-thermal expansion alloy wire according to any one of claims 1 to 4 , which comprises more than one species. The high-strength, low-thermal expansion alloy wire according to any one of claims 1 to 5 , which contains N: 0% and 0.03% or less in mass%. The high-strength, low-thermal expansion alloy wire according to any one of claims 1 to 6 , which has a tensile strength of 1400 MPa or more. The high-strength, low-thermal expansion alloy wire according to any one of claims 1 to 7 , wherein the twist value measured at a distance between gauge points 100 times the final wire diameter of the alloy wire is 20 times or more. The high-strength, low-thermal expansion alloy wire according to any one of claims 1 to 8 , which has an elongation of 0.8% or more. The average coefficient of linear thermal expansion between two points from 15 ° C to 100 ° C is 3 × 10 ^-6 / ° C or less (15 to 100 ° C), and the average coefficient of linear thermal expansion between two points from 15 ° C to 230 ° C is 4. × ^10-6 / ° C or lower (15 to 230 ° C), average linear thermal expansion coefficient between two points from 100 ° C to 240 ° C is 4 × ^10-6 / ° C or lower (100 to 240 ° C), and 230 ° C. The high-strength low-thermal expansion alloy according to any one of claims 1 to 9 , wherein the average coefficient of linear thermal expansion between two points from to 290 ° C. is 11 × 10 ^-6 / ° C. or less (230 to 290 ° C.). line. A high-strength low-thermal expansion-coated alloy comprising the high-strength low-thermal expansion alloy wire according to any one of claims 1 to 10 and an Al-coated layer or a Zn-coated layer formed on the surface of the high-strength low-thermal expansion alloy wire. line.

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