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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 9657382 B1

PDFFull Text
Date of Patent:
May. 23, 2017

Filed:

Dec. 14, 2012

High-strength hot rolled steel sheet

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Yoshimasa Funakawa, Fukuyama, JP;

Tetsuo Yamamoto, Bangkok, TH;

Hiroshi Uchomae, Kawasaki, JP;

Hiroshi Nakano, Kurashiki, JP;

Taro Kizu, Kawasaki, JP;

Assignee:

JFE Steel Corporation, , JP;

Attorney:

DLA Piper LLP (US)

Primary Examiner:

Deborah Yee

Int. Cl.
CPC ...
C22C 38/14 (2006.01); C22C 38/28 (2006.01); C22C 38/50 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/60 (2006.01); C22C 38/00 (2006.01); C22C 38/06 (2006.01); C21D 8/02 (2006.01); C21D 8/04 (2006.01); C22C 38/08 (2006.01); C22C 38/10 (2006.01); C22C 38/12 (2006.01); C22C 38/16 (2006.01); C22C 38/22 (2006.01); C21D 9/46 (2006.01);
U.S. Cl.
CPC ...
C22C 38/60 (2013.01); C21D 8/0247 (2013.01); C21D 8/0263 (2013.01); C21D 8/0415 (2013.01); C21D 8/0426 (2013.01); C21D 8/0463 (2013.01); C22C 38/00 (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 38/22 (2013.01); C22C 38/28 (2013.01); C21D 9/46 (2013.01); C21D 2211/004 (2013.01); C21D 2211/005 (2013.01); Y10T 428/12799 (2015.01); Y10T 428/12972 (2015.01);
Abstract

A high-strength hot rolled steel sheets with excellent stretch flangeability has small variations in mechanical properties in individual coils. Variations in strength from place to place in a coil are decreased by minimally reducing the Si and Mn contents to suppress the occurrence of problems such as segregation. Further, the microstructure of the steel sheets is configured such that a ferrite phase represents an area ratio of not less than 95%, the ferrite crystal grains have an average grain size of not less than 1 μm, and the ferrite crystal grains contain TiC with an average particle size of not more than 7 nm dispersed in the crystal grains.

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