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:
May. 27, 2014
Filed:
Jul. 09, 2010
Masayuki Hashimura, Tokyo, JP;
Hitoshi Demachi, Tokyo, JP;
Takayuki Kisu, Tokyo, JP;
Shoichi Suzuki, Narashino, JP;
Motonobu Suehiro, Narashino, JP;
Jun Kawaguchi, Narashino, JP;
Keiichi Maekawa, Wako, JP;
Atsushi Murakami, Wako, JP;
Masayuki Hashimura, Tokyo, JP;
Hitoshi Demachi, Tokyo, JP;
Takayuki Kisu, Tokyo, JP;
Shoichi Suzuki, Narashino, JP;
Motonobu Suehiro, Narashino, JP;
Jun Kawaguchi, Narashino, JP;
Keiichi Maekawa, Wako, JP;
Atsushi Murakami, Wako, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Suzuki Metal Industry Co., Ltd., Tokyo, JP;
Honda Motor Co., Ltd., Tokyo, JP;
Abstract
High strength steel wire for spring containing, by mass %, C: 0.67% to less than 0.75%, Si: 2.0 to 2.5%, Mn: 0.5 to 1.2%, Cr: 0.8 to 1.3%, V: 0.03 to 0.20%, Mo: 0.05 to 0.25%, W: 0.05 to 0.30%, and N: 0.003 to 0.007%, having a total of contents of Mn and V of 0.70%≦Mn+V≦1.27% and a total of contents of Mo and W of 0.13%≦Mo+W≦0.35%, limiting P: 0.025% or less, S: 0.025% or less, and Al: 0.003% or less, and having a balance of iron and unavoidable impurities, having a microstructure comprised of, by volume percent, over 6% to 15% of retained austenite and tempered martensite, having a prior-austenite grain size number of 10 or more, having a density of presence of spheroidal carbides with a circle equivalent diameter of 0.2 to 0.5 μm of 0.06 particles/μmor less, having a density of presence of spheroidal carbides with a circle equivalent diameter of over 0.5 μm of 0.01 particles/μmor less, and having a tensile strength of 2100 to 2350 MPa.