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:
Jul. 11, 2006
Filed:
Dec. 19, 2001
Nobuhiko Ibaraki, Kobe, JP;
Atushi Inada, Kobe, JP;
Sumie Suda, Kobe, JP;
Noritoshi Takamura, Sagamihara, JP;
Satoru Tendoh, Ina, JP;
Tadayoshi Fujiwara, Mino, JP;
Tetsuo Jinbo, Hirakata, JP;
Nobuhiko Ibaraki, Kobe, JP;
Atushi Inada, Kobe, JP;
Sumie Suda, Kobe, JP;
Noritoshi Takamura, Sagamihara, JP;
Satoru Tendoh, Ina, JP;
Tadayoshi Fujiwara, Mino, JP;
Tetsuo Jinbo, Hirakata, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
NHK Spring Co., Ltd., Yokohama, JP;
Shinko Wire Co., Ltd., Amagasaki, JP;
Abstract
Disclosed is a steel wire rod for hard-drawn springs capable of exhibiting fatigue strength and sag resistance equivalent to or higher than springs made of an oil-tempered wire. The steel wire rod contains carbon in a range from 0.5 to less than 0.7 mass %, silicon in a range from 1.4 to 2.5 mass %, manganese in a range from 0.5 to 1.5 mass %, chromium in a range from 0.05 to 2.0 mass %, and vanadium in a range from 0.05 to 0.40 mass %, and has an area ratio Rp with respect to pearlite which satisfies the mathematical expression (1):(area %)≧55×[]+61  (1)where [C] denotes the content (mass %) of carbon.