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:
May. 17, 2022
Filed:
May. 14, 2018
Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.), Kobe, JP;
Hirokazu Natsumeda, Kobe, JP;
Toshio Murakami, Kobe, JP;
Kenji Saito, Kakogawa, JP;
Tadao Murata, Kakogawa, JP;
Kobe Steel, Ltd., Kobe, JP;
Abstract
Disclosed is a high-strength sheet containing: C: 0.15% by mass to 0.35% by mass, a total of Si and Al: 0.5% by mass to 3.0% by mass, Mn: 1.0% by mass to 4.0% by mass, P: 0.05% by mass or less (including 0% by mass), S: 0.01% by mass or less (including 0% by mass), and Ti: 0.01% by mass to 0.2% by mass, with the balance being Fe and inevitable impurities, wherein the steel structure satisfies that: a ferrite fraction is 5% or less, a total fraction of tempered martensite and tempered bainite is 60% or more, a retained austenite fraction is 10% or more, a fresh martensite fraction is 5% or less, retained austenite has an average grain size of 0.5 μm or less, retained austenite having a grain size of 1.0 μm or more accounts for 2% or more of the total amount of retained austenite, and a prior austenite grain size is 10 μm or less.