US 12,224,079 B2
Copper-coated steel wire, spring, stranded wire, insulated electric wire, and cable
Takumi Akada, Osaka (JP); and Daigo Sato, Osaka (JP)
Assigned to Sumitomo Electric Industries, Ltd., Osaka (JP)
Appl. No. 17/616,560
Filed by Sumitomo Electric Industries, Ltd., Osaka (JP)
PCT Filed Jun. 28, 2019, PCT No. PCT/JP2019/025936
§ 371(c)(1), (2) Date Dec. 3, 2021,
PCT Pub. No. WO2020/261564, PCT Pub. Date Dec. 30, 2020.
Prior Publication US 2022/0238248 A1, Jul. 28, 2022
Int. Cl. H01B 1/02 (2006.01); F16F 1/02 (2006.01); H01B 7/00 (2006.01); F16F 1/04 (2006.01)
CPC H01B 1/02 (2013.01) [F16F 1/021 (2013.01); H01B 7/0009 (2013.01); F16F 1/045 (2013.01); F16F 2224/0208 (2013.01); F16F 2228/007 (2013.01)] 18 Claims
OG exemplary drawing
 
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.