IDiyas

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 11970758 B1

PDFFull Text
Date of Patent:
Apr. 30, 2024

Filed:

Oct. 21, 2019

Hot-rolled steel sheet

Applicant:

Nippon Steel Corporation, Tokyo, JP;

Inventors:

Hiroshi Shuto, Tokyo, JP;

Akifumi Sakakibara, Tokyo, JP;

Shinsuke Kai, Tokyo, JP;

Koutarou Hayashi, Tokyo, JP;

Hiroshi Kaido, Tokyo, JP;

Assignee:

NIPPON STEEL CORPORATION, Tokyo, JP;

Attorney:

Birch, Stewart, Kolasch & Birch, LLP

Primary Examiner:

Jophy S Koshy

Int. Cl.
CPC ...
C21D 9/46 (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 38/10 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/26 (2006.01); C22C 38/34 (2006.01); C22C 38/38 (2006.01);
U.S. Cl.
CPC ...
C22C 38/38 (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); 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 38/08 (2013.01); C22C 38/10 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/26 (2013.01); C22C 38/34 (2013.01); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01); C21D 2211/009 (2013.01);
Abstract

This hot-rolled steel sheet has a predetermined chemical composition. The metallographic structure at a sheet thickness ¼ depth from a surface and at a center position in a sheet width direction in a sheet width cross section parallel to a rolling direction contains, by area %, 77.0% to 97.0% of bainite and tempered martensite in total, 0% to 5.0% of ferrite, 0% to 5.0% of pearlite, 3.0% or more of residual austenite, and 0% to 10.0% of martensite. The average grain size of the metallographic structure excluding the residual austenite is 7.0 μm or less. The C concentration in the residual austenite is 0.5 mass % or more. The number density of iron-based carbides having a diameter of 20 nm or more is 1.0×10carbides/mmor more.

Find Patent Forward Citations

Loading…