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. 14, 2017
Filed:
Sep. 28, 2011
Yoshihiko Ono, Tokyo, JP;
Kenji Takahashi, Tokyo, JP;
Kaneharu Okuda, Tokyo, JP;
Yusuke Fushiwaki, Tokyo, JP;
Michitaka Sakurai, Tokyo, JP;
Yoshihiko Ono, Tokyo, JP;
Kenji Takahashi, Tokyo, JP;
Kaneharu Okuda, Tokyo, JP;
Yusuke Fushiwaki, Tokyo, JP;
Michitaka Sakurai, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
A high strength steel sheet is formed of steel having the composition containing by mass % over 0.015% and less than 0.100% C, less than 0.50% Si, over 1.0% and less than 2.0% Mn, 0.05% or less P, 0.03% or less S, 0.01% or more and 0.3% or less sol. Al, 0.005% or less N, less than 0.35% Cr, 0.0010% or more and 0.0050% or less B, less than 0.15% Mo, less than 0.030% Ti, and iron and unavoidable impurities as a balance, wherein the steel satisfies 2.1≦[Mneq]≦3.1, the microstructure of the steel includes a ferrite and a second phase, a volume fraction of the second phase is set to 2.0 to 12.0%, a total ratio of a volume fraction of martensite and a volume fraction of retained γ to the volume fraction of second phase is 60% or more, and the number of carbides which are present within ferrite particles, have an aspect ratio of 3.0 or less and have a diameter of 0.25 to 0.90 μm is set to 10000 pieces/mmor less.