Copper-coated steel wire and canted coil spring

Patent metadata

Field	Value
Publication number	US-11459644-B2
Application number	US-201816965420-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Feb 1, 2018
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

A copper-coated steel wire includes: a core wire made of steel having a pearlite structure; and a coating layer covering a surface of the core wire and made of Cu or a Cu alloy. The steel contains C by greater than or equal to 0.5% by mass and less than or equal to 1.0% by mass, Si by greater than or equal to 0.1% by mass and less than or equal to 2.5% by mass, Mn by greater than or equal to 0.3% by mass and less than or equal to 0.9% by mass, and the balance consisting of Fe and inevitable impurities. In a cross section perpendicular to a longitudinal direction, a value of surface roughness Ra of the core wire is greater than or equal to 25% and less than or equal to 70% 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 steel having a pearlite structure; and
a coating layer covering a surface of the core wire and made of Cu or a Cu alloy,
wherein the steel contains C by greater than or equal to 0.5% by mass and less than or equal to 1.0% by mass, Si by greater than or equal to 0.1% by mass and less than or equal to 2.5% by mass, Mn by greater than or equal to 0.3% by mass and less than or equal to 0.9% by mass, and the balance consisting of Fe and inevitable impurities,
wherein in a cross section perpendicular to a longitudinal direction, a value of surface roughness Ra of the core wire is greater than or equal to 25% and less than or equal to 70% of a thickness of the coating layer, and
wherein the coating layer is a plating layer, and an oxygen concentration at an interface between the core wire and the coating layer is less than or equal to 10% by mass.

2. The copper-coated steel wire according to claim 1 , wherein the steel further contains at least one element selected from a group consisting of Ni by greater than or equal to 0.1% by mass and less than or equal to 0.4% by mass, Cr by greater than or equal to 0.1% by mass and less than or equal to 1.8% by mass, Mo by greater than or equal to 0.1% by mass and less than or equal to 0.4% by mass, and V by greater than or equal to 0.05% by mass and less than or equal to 0.3% by mass.

3. The copper-coated steel wire according to claim 2 , wherein the steel contains C by greater than or equal to 0.55% by mass and less than or equal to 0.7% by mass, Si by greater than or equal to 1.35% by mass and less than or equal to 2.3% by mass, Mn by greater than or equal to 0.3% by mass and less than or equal to 0.9% by mass, Cr by greater than or equal to 0.2% by mass and less than or equal to 1.8% by mass, V by greater than or equal to 0.05% by mass and less than or equal to 0.30% by mass, and the balance consisting of Fe and inevitable impurities.

4. The copper-coated steel wire according to claim 1 , wherein a content of Si of the steel is greater than or equal to 1.35% by mass and less than or equal to 2.3% by mass.

5. The copper-coated steel wire according to claim 1 , wherein the steel contains C by greater than or equal to 0.6% by mass and less than or equal to 1.0% by mass, Si by greater than or equal to 0.12% by mass and less than or equal to 0.32% by mass, Mn by greater than or equal to 0.3% by mass and less than or equal to 0.9% by mass, and the balance consisting of Fe and inevitable impurities.

6. The copper-coated steel wire according to claim 1 , wherein the steel contains C by greater than or equal to 0.6% by mass and less than or equal to 1.0% by mass, Si by greater than or equal to 0.7% by mass and less than or equal to 1.0% by mass, Mn by greater than or equal to 0.3% by mass and less than or equal to 0.9% by mass, and the balance consisting of Fe and inevitable impurities.

7. The copper-coated steel wire according to claim 1 , wherein at an interface between the core wire and the coating layer, an. alloy layer made of an alloy of a metal constituting the core wire and a metal constituting the coating layer is formed.

8. The copper-coated steel wire according to claim 1 , wherein tensile strength is greater than or equal to 900 MPa and less than or equal to 3800 MPa.

9. The copper-coated steel wire according to claim 1 , wherein conductivity is greater than or equal to 15% IACS and less than or equal to 80% IACS.

10. The copper-coated steel wire according to claim 1 further comprising:
on a surface of the coating layer, a surface layer including at least one selected from a group consisting of an Au layer, an Ag layer, a Sn layer, a Pd layer, a Ni layer, and an alloy layer of these metals.

11. The copper-coated steel wire according to claim 1 , wherein the thickness of the coating layer is greater than or equal to 10 μm and less than or equal to 65 μm.

12. The copper-coated steel wire according to claim 1 , wherein a diameter of the core wire is greater than or equal to 0.01 mm and less than or equal to 1.0 mm.

13. A canted coil spring made of the copper-coated steel wire according to claim 1 .

Assignees

• Sumitomo Electric Industries

Inventors

• Akada Takumi
• Izumida Hiromu

Classifications

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• F16F1/045

  Canted-coil springs · CPC title

• F16F2228/007

  of solids, e.g. hardness · CPC title

• C22C38/44

  with molybdenum or tungsten · 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