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:
May. 11, 2021
Filed:
Aug. 20, 2015
Applicant:
Jfe Steel Corporation, Tokyo, JP;
Inventors:
Assignee:
JFE STEEL CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21D 9/46 (2006.01); B32B 15/01 (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); C23C 2/06 (2006.01); C22C 38/60 (2006.01); C22C 38/14 (2006.01); C22C 38/42 (2006.01); C22C 38/22 (2006.01); C22C 38/44 (2006.01); C22C 38/12 (2006.01);
U.S. Cl.
CPC ...
C21D 9/46 (2013.01); B32B 15/013 (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 8/0247 (2013.01); C22C 38/00 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/22 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/60 (2013.01); C23C 2/06 (2013.01); B32B 2311/20 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract
A high-strength steel sheet having a tensile strength of at least 780 MPa and excellent punchability comprises a ferrite phase, a martensite phase, and a bainite phase. The area ratio of the martensite phase is 20%-50%; the area ratio of crystal grains having an average crystal grain diameter of less than 1.0 μm in the martensite phase is 5%-30%; the area ratio of crystal grains having an average crystal grain diameter of 1.0-4.0 μm is 70%-95%; and the area ratio of crystal grains having an average crystal grain diameter of more than 4.0 μm is less than 5%.