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:
Dec. 31, 2024
Filed:
Oct. 15, 2020
Nippon Steel Corporation, Tokyo, JP;
Aisin Corporation, Kariya, JP;
Nhk Spring Co., Ltd., Yokohama, JP;
Nippon Steel SG Wire Co., Ltd., Tokyo, JP;
Shinya Teramoto, Tokyo, JP;
Yutaka Neishi, Tokyo, JP;
Michimasa Aono, Tokyo, JP;
Shuji Kozawa, Tokyo, JP;
Yoichi Oi, Kariya, JP;
Naoki Takabayashi, Kariya, JP;
Junji Tanaka, Kariya, JP;
Fumio Takahashi, Yokohama, JP;
Shigekazu Nishimoto, Yokohama, JP;
Mitsuhiro Kondo, Yokohama, JP;
Tatsuro Ochi, Tokyo, JP;
Shoichi Suzuki, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
AISIN CORPORATION, Kariya, JP;
NHK SPRING CO., LTD., Yokohama, JP;
NIPPON STEEL SG WIRE CO., LTD., Tokyo, JP;
Abstract
A damper spring having an excellent fatigue limit is provided. A damper spring according to the present embodiment includes a nitrided layer formed in an outer layer, and a core portion that is further inward than the nitrided layer. The chemical composition of the core portion consists of, in mass %, C: 0.53 to 0.59%, Si: 2.51 to 2.90%, Mn: 0.70 to 0.85%, P: 0.020% or less, S: 0.020% or less, Cr: 1.40 to 1.70%, Mo: 0.17 to 0.53%, V: 0.23 to 0.33%, Cu: 0.050% or less, Ni: 0.050% or less, Al: 0.0050% or less, Ti: 0.050% or less, N: 0.0070% or less, and Nb: 0 to 0.020%, with the balance being Fe and impurities. In the core portion, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 500 to 8000 pieces/μm.