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:
Nov. 10, 2009
Filed:
Mar. 25, 2004
Sumie Suda, Kobe, JP;
Nobuhiko Ibaraki, Kobe, JP;
Sumie Suda, Kobe, JP;
Nobuhiko Ibaraki, Kobe, JP;
Kobe Steel, Ltd., Kobe-shi, JP;
Abstract
The spring steel according to the present invention is a spring steel excellent in sag resistance and fatigue property containing: C: 0.5 to 0.8% by mass (hereinafter, referred to as %), Si: 1.2 to 2.5%, Mn: 0.2 to 1.5%, Cr: 1.0 to 4.0%, V: 0.5% or less (including 0%), P: 0.02% or less (excluding 0%), S: 0.02% or less (excluding 0%), Al: 0.05% or less (excluding 0%), and Fe and inevitable impurities as the balance, wherein the Si content and the Cr content satisfy the following formula (1):0.8×[Si]+[Cr]≧2.6  (1)(wherein, [Si] and [Cr] respectively represent the Si content (%) and the Cr content (%)). The spring steel is useful in improving both sag resistance and fatigue property.