logo

For the Inventor, By the Inventor

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 11420247 B1

PDFFull Text
Date of Patent:
Aug. 23, 2022

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:

Seth Dumbris

Assistant Examiner:

Kim S Horger

Int. Cl.
CPC ...
B32B 15/00 (2006.01); B21D 22/02 (2006.01); B32B 15/01 (2006.01); C21D 1/18 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/32 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/50 (2006.01); C23C 30/00 (2006.01);
U.S. Cl.
CPC ...
B21D 22/022 (2013.01); B32B 15/012 (2013.01); B32B 15/013 (2013.01); C21D 1/18 (2013.01); C21D 6/004 (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); C21D 9/46 (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 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/32 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/50 (2013.01); C23C 30/005 (2013.01); C21D 2211/004 (2013.01); C21D 2211/008 (2013.01);
Abstract

Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing of 1780 MPa or more, excellent delayed fracture resistance, and high cross tensile strength after resistance spot welding by properly adjusting its chemical composition and its microstructure such that a prior austenite average grain size is 8 μm or less, a volume fraction of martensite is 90% or more, and at least 10 cementite grains having a grain size of 0.05 μm or more are present on average per 200 μmof a cross section parallel to a thickness direction of the member, and such that at least 10 Ti-based precipitates having a grain size of less than 0.10 μm are present on average per 100 μmof the cross section parallel to the thickness direction of the member in a range of 100 μm in the thickness direction from a surface of the member.

Find Patent Forward Citations

Loading…