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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 11085101 B1

PDFFull Text
Date of Patent:
Aug. 10, 2021

Filed:

Mar. 30, 2018

Hot-pressed member and method for manufacturing same, and cold-rolled steel sheet for hot pressing and method for manufacturing same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Katsutoshi Takashima, Tokyo, JP;

Takashi Kobayashi, Tokyo, JP;

Yoshimasa Funakawa, Tokyo, JP;

Seiji Nakajima, Tokyo, JP;

Assignee:

JFE STEEL CORPORATION, Tokyo, JP;

Attorney:

Kenja IP Law PC

Primary Examiner:

Daniel J Schleis

Int. Cl.
CPC ...
B32B 15/01 (2006.01); C21D 9/46 (2006.01); B21D 22/02 (2006.01); C21D 1/18 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/16 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); C23C 2/06 (2006.01); C23C 2/12 (2006.01); C23C 2/40 (2006.01);
U.S. Cl.
CPC ...
C21D 9/46 (2013.01); B21D 22/022 (2013.01); B32B 15/012 (2013.01); B32B 15/013 (2013.01); C21D 1/18 (2013.01); C21D 6/001 (2013.01); C21D 6/002 (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 8/0263 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/16 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01); C23C 2/06 (2013.01); C23C 2/12 (2013.01); C23C 2/40 (2013.01); C21D 2211/004 (2013.01); C21D 2211/008 (2013.01); Y10T 428/12799 (2015.01); Y10T 428/12958 (2015.01);
Abstract

Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing as high as TS: 1780 MPa or more and excellent delayed fracture resistance after projection welding by properly adjusting its chemical composition and its microstructure such that at least 5 Ti-based precipitates having a grain size of 0.10 μm or less are present on average per 100 μmof a cross section parallel to a thickness direction of the member within a range of 100 μm in a thickness direction from a surface of the member, a volume fraction of martensite is 95% to 100% within a depth range of 20 μm to 100 μm in the thickness direction from the surface of the member, and at least 10 cementite grains having a grain size of less than 0.20 μm are present on average in a prior austenite grain.

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