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. 16, 2014
Filed:
Nov. 09, 2010
Toshio Ogawa, Tokyo, JP;
Naoki Matsutani, Tokyo, JP;
Koichi Goto, Tokyo, JP;
Shinichiro Watanabe, Tokyo, JP;
Nobuhiro Fujita, Tokyo, JP;
Toshiki Nonaka, Tokyo, JP;
Toshio Ogawa, Tokyo, JP;
Naoki Matsutani, Tokyo, JP;
Koichi Goto, Tokyo, JP;
Shinichiro Watanabe, Tokyo, JP;
Nobuhiro Fujita, Tokyo, JP;
Toshiki Nonaka, Tokyo, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Abstract
The high-strength steel sheet includes, by mass %: C: 0.01% to 0.10%; Si: 0.15% or less; Mn: 0.80% to 1.80%; P: 0.10% or less; S: 0.015% or less; Al: 0.10% to 0.80%; Cr: 0.01% to 1.50%; N: 0.0100% or less; and a balance consisting of iron and inevitable impurities, in which a metallic structure is composed of ferrite and a hard second phase, the area fraction of the ferrite is 80% or more, the area fraction of the hard second phase is 1% to 20%, the fraction of unrecrystallized ferrite in the ferrite is less than 10%, the ferrite grain sizes are 5 μm to 20 μm, and the fraction of the ferrite crystal grains having an aspect ratio of 1.2 or less in the entire ferrite crystal grains is 60% or more.