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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.:

US 10351937 B1

PDFFull Text
Date of Patent:
Jul. 16, 2019

Filed:

Jul. 27, 2012

High-strength steel sheet excellent in impact resistance and manufacturing method thereof, and high-strength galvanized steel sheet and manufacturing method thereof

Applicants:

Hiroyuki Kawata, Tokyo, JP;

Naoki Maruyama, Tokyo, JP;

Akinobu Murasato, Tokyo, JP;

Akinobu Minami, Tokyo, JP;

Hajime Hasegawa, Tokyo, JP;

Chisato Wakabayashi, Tokyo, JP;

Tsuyoshi Oki, Tokyo, JP;

Inventors:

Hiroyuki Kawata, Tokyo, JP;

Naoki Maruyama, Tokyo, JP;

Akinobu Murasato, Tokyo, JP;

Akinobu Minami, Tokyo, JP;

Hajime Hasegawa, Tokyo, JP;

Chisato Wakabayashi, Tokyo, JP;

Tsuyoshi Oki, Tokyo, JP;

Assignee:

NIPPON STEEL CORPORATION, Tokyo, JP;

Attorney:

Birch, Stewart, Kolasch & Birch, LLP

Primary Examiner:

Paul A Wartalowicz

Assistant Examiner:

Stephani Hill

Int. Cl.
CPC ...
C22C 38/38 (2006.01); C22C 38/34 (2006.01); C22C 38/28 (2006.01); C22C 38/22 (2006.01); C22C 38/16 (2006.01); C22C 38/14 (2006.01); C22C 38/12 (2006.01); C22C 38/08 (2006.01); C22C 38/06 (2006.01); C22C 38/04 (2006.01); C22C 38/02 (2006.01); C22C 38/00 (2006.01); C25D 5/48 (2006.01); C23C 2/02 (2006.01); C23C 2/06 (2006.01); C23C 2/28 (2006.01); C21D 8/02 (2006.01); C25D 5/36 (2006.01); C22C 18/00 (2006.01); C22C 18/04 (2006.01); B32B 15/01 (2006.01); C25D 7/06 (2006.01);
U.S. Cl.
CPC ...
C22C 38/38 (2013.01); B32B 15/013 (2013.01); C21D 8/0247 (2013.01); C22C 18/00 (2013.01); C22C 18/04 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/22 (2013.01); C22C 38/28 (2013.01); C22C 38/34 (2013.01); C23C 2/02 (2013.01); C23C 2/06 (2013.01); C23C 2/28 (2013.01); C25D 5/36 (2013.01); C25D 5/48 (2013.01); C25D 7/0614 (2013.01); Y10T 428/12611 (2015.01); Y10T 428/12799 (2015.01);
Abstract

The present invention provides a high-strength steel sheet excellent in impact resistance. The high-strength steel sheet contains predetermined contents of C, Si, Mn, P, S, Al, Ti, N, and O, with the balance being iron and inevitable impurities, and has a steel sheet structure in which, in a ⅛ thickness to ⅜ thickness region across ¼ of a sheet thickness, 1 to 8% retained austenite is contained in volume fraction, an average aspect ratio of the retained austenite is 2.0 or less, an amount of solid-solution Mn in the retained austenite is 1.1 times an average amount of Mn or more, and TiN grains having a 0.5 μm average grain diameter or less are contained, and a density of AlN grains with a 1 μm grain diameter or more is 1.0 pieces/mmor less, wherein a maximum tensile strength is 900 MPa or more.

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