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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 11578375 B1

PDFFull Text
Date of Patent:
Feb. 14, 2023

Filed:

Jul. 20, 2016

High-strength hot-rolled steel sheet and method for manufacturing the same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Kazuhiko Yamazaki, Tokyo, JP;

Shunsuke Toyoda, Tokyo, JP;

Noriaki Moriyasu, Tokyo, JP;

Kentaro Irisa, Tokyo, JP;

Assignee:

JFE STEEL CORPORATION, Tokyo, JP;

Attorney:

Oliff PLC

Primary Examiner:

Robert S Jones, Jr

Assistant Examiner:

Jiangtian Xu

Int. Cl.
CPC ...
C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/38 (2006.01); C22C 38/00 (2006.01); C22C 38/06 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); C22C 38/60 (2006.01); C22C 38/20 (2006.01); C22C 38/22 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/02 (2006.01); C22C 38/40 (2006.01); C22C 38/04 (2006.01); C22C 38/34 (2006.01);
U.S. Cl.
CPC ...
C21D 8/0226 (2013.01); C21D 8/0263 (2013.01); C21D 9/46 (2013.01); C22C 38/00 (2013.01); C22C 38/001 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/20 (2013.01); C22C 38/22 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01); C22C 38/34 (2013.01); C22C 38/38 (2013.01); C22C 38/40 (2013.01); C22C 38/60 (2013.01); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/004 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract

A high-strength hot-rolled steel sheet that has excellent punching workability and hole expandability, and a method for manufacturing the same. The hot-rolled steel sheet has a tensile strength of 980 MPa or more. The hot-rolled steel sheet has a chemical composition containing C, Si, Mn, P, S, Al, N, Ti, Cr, and B, and has a microstructure including a bainite phase having an area ratio of 85% or more as a main phase, and a martensite phase or martensite-austenite constituent having an area ratio of 15% or less as a second phase, the balance being a ferrite phase. The second phase has an average grain diameter of 3.0 μm or less, prior-austenite grains have an average aspect ratio of 1.3 or more and 5.0 or less, and recrystallized prior-austenite grains have an area ratio of 15% or less relative to non-recrystallized prior-austenite grains.

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