Copper-coated steel wire, spring, stranded wire, insulated electric wire, and cable

Patent metadata

Field	Value
Publication number	US-12224079-B2
Application number	US-201917616560-A
Country	US
Kind code	B2
Filing date	Jun 28, 2019
Priority date	Jun 28, 2019
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

A copper-coated steel wire includes a core wire made of a stainless steel, and a coating layer made of copper or a copper alloy and covering an outer peripheral surface of the core wire. In a cross section perpendicular to a longitudinal direction of the core wire, the outer peripheral surface of the core wire has a value of an arithmetic mean roughness Ra of not less than 25% and not more than 90% of a thickness of the coating layer.

First claim

The invention claimed is:

1. A copper-coated steel wire comprising:
a core wire made of a stainless steel; and
a coating layer made of copper or a copper alloy and covering an outer peripheral surface of the core wire;
a thickness of the coating layer being not less than 7.5 μm and not more than 200 μm, and
in a cross section perpendicular to a longitudinal direction of the core wire, the outer peripheral surface of the core wire having a value of an arithmetic mean roughness Ra of not less than 30% and not more than 60% of a thickness of the coating layer.

2. The copper-coated steel wire according to claim 1 , wherein in the cross section perpendicular to the longitudinal direction of the core wire, the outer peripheral surface of the core wire has a value of a maximum cross-sectional height Rt of not less than 45% and not more than 300% of the thickness of the coating layer.

3. The copper-coated steel wire according to claim 1 , wherein the steel constituting the core wire is a ferritic stainless steel.

4. The copper-coated steel wire according to claim 1 , wherein the steel constituting the core wire is an austenitic stainless steel.

5. The copper-coated steel wire according to claim 4 , wherein the austenitic stainless steel has a component composition satisfying the following expression (1):
−400≥1032−1667×( A+B )−27.8× C− 33× D− 61× E− 41.7× F   [Math. 1]

where A represents a carbon content [mass %], B represents a nitrogen content [mass %], C represents a silicon content [mass %], D represents a manganese content [mass %], E represents a nickel content [mass %], and F represents a chromium content [mass %].

6. The copper-coated steel wire according to claim 1 , wherein the coating layer has an alloy layer disposed in a region including an interface with the core wire, the alloy layer containing an alloy of nickel and a metallic element contained in the steel constituting the core wire.

7. The copper-coated steel wire according to claim 1 , having a tensile strength of not less than 300 MPa and not more than 3400 MPa.

8. The copper-coated steel wire according to claim 1 , further comprising a surface layer disposed to include a surface of the copper-coated steel wire, the surface layer including at least one selected from the group consisting of a gold layer, a silver layer, a tin layer, a palladium layer, a nickel layer, and an alloy layer of these metals.

9. A spring made of the copper-coated steel wire according to claim 1 .

10. A stranded wire comprising a plurality of the copper-coated steel wires according to claim 1 twisted together.

11. An insulated electric wire comprising:
the stranded wire according to claim 10 ; and
an insulating layer disposed to cover an outer periphery of the stranded wire.

12. A cable comprising:
the stranded wire according to claim 10 ;
an insulating layer disposed to cover an outer periphery of the stranded wire; and
a shielding portion disposed to surround an outer peripheral surface of the insulating layer.

13. An insulated electric wire comprising:
the copper-coated steel wire according to claim 1 ; and
an insulating layer disposed to cover an outer periphery of the copper-coated steel wire.

14. A cable comprising:
a conductor portion of a wire shape;
an insulating layer disposed to cover an outer peripheral surface of the conductor portion; and
a shielding portion disposed to surround an outer peripheral surface of the insulating layer,
the shielding portion including a plurality of the copper-coated steel wires according to claim 1 .

15. A cable comprising:
the copper-coated steel wire according to claim 1 ;
an insulating layer disposed to cover an outer periphery of the copper-coated steel wire; and
a shielding portion disposed to surround an outer peripheral surface of the insulating layer.

16. The cable according to claim 15 , wherein the shielding portion includes a plurality of the copper-coated steel wires according to claim 1 .

17. A copper-coated steel wire comprising:
a core wire made of a stainless steel; and
a coating layer made of copper or a copper alloy and covering an outer peripheral surface of the core wire;
a thickness of the coating layer being not less than 7.5 μm and not more than 200 μm, and
in a cross section perpendicular to a longitudinal direction of the core wire, the outer peripheral surface of the core wire having a value of a maximum cross-sectional height Rt of not less than 45% and not more than 300% of a thickness of the coating layer.

18. A copper-coated steel wire comprising:
a core wire made of a stainless steel; and
a coating layer made of copper or a copper alloy and covering an outer peripheral surface of the core wire;
a thickness of the coating layer being not less than 7.5 μm and not more than 200 μm,
in a cross section perpendicular to a longitudinal direction of the core wire, the outer peripheral surface of the core wire having a value of an arithmetic mean roughness Ra of not less than 25% and not more than 90% of a thickness of the coating layer,
in the cross section perpendicular to the longitudinal direction of the core wire, the outer peripheral surface of the core wire having a value of a maximum cross-sectional height Rt of not less than 45% and not more than 300% of the thickness of the coating layer,
the steel constituting the core wire being an austenitic stainless steel,
the coating layer having an alloy layer disposed in a region including an interface with the core wire, the alloy layer containing an alloy of nickel and a metallic element contained in the steel constituting the core wire, and
the copper-coated steel wire having a tensile strength of not less than 300 MPa and not more than 3400 MPa.

Assignees

• Sumitomo Electric Industries

Inventors

• Akada Takumi
• Sato Daigo

Classifications

• H01B7/0009

  Details relating to the conductive cores · CPC title

• F16F2228/007

  of solids, e.g. hardness · CPC title

• F16F2224/0208

  Alloys · CPC title

• F16F1/045

  Canted-coil springs · CPC title

• F16F1/021

  characterised by their composition, e.g. comprising materials providing for particular spring properties (composition and manufacture of clock or watch springs G04B1/145) · CPC title