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:
Aug. 30, 2011
Filed:
Mar. 25, 2004
Sumie Suda, Kobe, JP;
Nobuhiko Ibaraki, Kobe, JP;
Noritoshi Takamura, Kanagawa, JP;
Naoki Terakado, Nagano, JP;
Satoru Tendo, Nagano, JP;
Tadayoshi Fujiwara, Amagasaki, JP;
Tetsuo Jinbo, Amagasaki, JP;
Sumie Suda, Kobe, JP;
Nobuhiko Ibaraki, Kobe, JP;
Noritoshi Takamura, Kanagawa, JP;
Naoki Terakado, Nagano, JP;
Satoru Tendo, Nagano, JP;
Tadayoshi Fujiwara, Amagasaki, JP;
Tetsuo Jinbo, Amagasaki, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe-shi, JP;
NHK Spring Co., Ltd., Yokohama-shi, JP;
Shinko Wire Co., Ltd., Amagasaki-shi, JP;
Abstract
A steel wire has tempered martensite, comprises, as essential components, by mass, C: 0.53 to 0.68%; Si: 1.2 to 2.5%; Mn: 0.2 to 1.5%; Cr: 1.4 to 2.5%; Al: 0.05% or less; further comprises, as a selective component, Ni: 0.4% or less; V: 0.4% or less; Mo: 0.05 to 0.5%; or Nb: 0.05 to 0.5%; and further comprises remainder essentially consisting of Fe and inevitable impurities, wherein the grain size number of prior austenite is 11.0 or larger, and the proof stress ratio (σ/σ), namely, a ratio of 0.2% proof stress (σ) to tensile strength (σ) is 0.85 or lower. Satisfying the above requirements makes it possible to produce a steel wire for high-strength spring excellent both in workability (cold workability), and in sag resistance and fatigue properties.