The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 2018
Filed:
Feb. 06, 2015
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Daisuke Hirakami, Kisarazu, JP;
Makoto Okonogi, Chiba, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A steel wire according to an aspect of the present invention includes a predetermined chemical composition, in which a wire diameter R of the steel wire is 1.0 mm to 3.5 mm, a soft portion is formed along an outer circumference of the steel wire, the Vickers hardness of the soft portion is lower than that of a position of the steel wire at a depth of ¼ of the wire diameter R by Hv 30 or higher, the thickness of the soft portion is 5 μm to 0.1×R mm, the metallographic structure of a center portion of the steel wire contains 95% to 100% of pearlite by area %, the average lamellar spacing of pearlite in a portion from a surface of the steel wire to a depth of 5 μm is less than that of pearlite at the center of the steel wire, the difference between the average lamellar spacing of pearlite in the portion from the surface of the steel wire to the depth of 5 μm and the average lamellar spacing of pearlite at the center of the steel wire is 3 nm to 60 nm, and the tensile strength is 1100 MPa or higher.