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.:
Date of Patent:
Apr. 25, 2017
Filed:
Feb. 28, 2013
Applicant:
Jfe Steel Corporation, Chiyoda-ku, Tokyo, JP;
Inventors:
Hidetaka Kawabe, Tokyo, JP;
Takeshi Yokota, Tokyo, JP;
Reiko Sugihara, Tokyo, JP;
Shigeyuki Aizawa, Tokyo, JP;
Kazuki Nakazato, Tokyo, JP;
Assignee:
JFE Steel Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21D 8/02 (2006.01); C22C 38/14 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C21D 8/04 (2006.01); C21D 9/48 (2006.01); C21D 1/25 (2006.01); C21D 1/26 (2006.01);
U.S. Cl.
CPC ...
C21D 8/0263 (2013.01); C21D 1/25 (2013.01); C21D 1/26 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0278 (2013.01); C21D 8/0473 (2013.01); C21D 9/48 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/14 (2013.01); C21D 8/0436 (2013.01); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract
A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ≦5 μm to a total volume fraction of the tempered martensite phase is 80% to 100%.