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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 11220722 B1

PDFFull Text
Date of Patent:
Jan. 11, 2022

Filed:

Aug. 29, 2017

Steel sheet and method for manufacturing the same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Noriaki Kohsaka, Tokyo, JP;

Yoshikazu Suzuki, Tokyo, JP;

Takeo Kikuchi, Tokyo, JP;

Yoshimasa Himei, Tokyo, JP;

Assignee:

JFE Steel Corporation, Tokyo, JP;

Attorney:

RatnerPrestia

Primary Examiner:

Anthony J Zimmer

Assistant Examiner:

Dean Mazzola

Int. Cl.
CPC ...
C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/06 (2006.01); C22C 38/58 (2006.01); C22C 38/60 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/22 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/54 (2006.01); C21D 6/00 (2006.01); C22C 38/38 (2006.01); C23C 2/06 (2006.01); C23C 2/40 (2006.01); C23C 2/28 (2006.01); C23C 2/02 (2006.01); C22C 18/04 (2006.01); C22C 18/00 (2006.01);
U.S. Cl.
CPC ...
C21D 8/0263 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 9/46 (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 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/22 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01); C22C 38/38 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/54 (2013.01); C22C 38/58 (2013.01); C22C 38/60 (2013.01); C23C 2/02 (2013.01); C23C 2/06 (2013.01); C23C 2/28 (2013.01); C23C 2/40 (2013.01); C21D 2211/001 (2013.01); C21D 2211/004 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01); C22C 18/00 (2013.01); C22C 18/04 (2013.01);
Abstract

Provided are a steel sheet having a tensile strength of 950 MPa or more and good toughness and a method for manufacturing the same. The steel sheet has a specific composition and a metallographic structure containing: a ferrite area fraction of 30% or less (including 0%), a tempered martensite area fraction of 70% or more (including 100%), and a retained austenite area fraction of 4.5% or less (including 0%), wherein the average aspect ratio of an iron based carbide, precipitated in tempered martensite grains, having a grain size in the largest 10% is 3.5 or more.

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