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:
Jun. 03, 2014
Filed:
Dec. 15, 2010
Atsushi Sugimoto, Aichi, JP;
Kiyoshi Kurimoto, Kanagawa, JP;
Akira Tange, Kanagawa, JP;
Yurika Goto, Kanagawa, JP;
Mamoru Akeda, Kanagawa, JP;
Atsushi Sugimoto, Aichi, JP;
Kiyoshi Kurimoto, Kanagawa, JP;
Akira Tange, Kanagawa, JP;
Yurika Goto, Kanagawa, JP;
Mamoru Akeda, Kanagawa, JP;
NHK Spring Co., Ltd., Kanagawa, JP;
Abstract
Disclosed is steel for a leaf spring with high fatigue strength containing, in mass percentage, C: 0.40 to 0.54%, Si: 0.40 to 0.90%, Mn: 0.40 to 1.20%, Cr: 0.70 to 1.50%, Ti: 0.070 to 0.150%, B: 0.0005 to 0.0050%, N: 0.0100% or less, and a remainder composed of Fe and impurity elements. Also disclosed is a high fatigue-strength leaf spring part obtained by forming the steel. The steel for a leaf spring is prepared to have a Ti content and a N content to satisfy a relation of Ti/N≧10. Preferably, the leaf spring part is subjected to a shot peening treatment in a temperature range of the room temperature through 400° C. with a bending stress of 650 to 1900 MPa being applied to it.