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:
Jul. 23, 2019
Filed:
Apr. 24, 2015
Jfe Steel Corporation, Tokyo, JP;
Shigeki Kitsuya, Tokyo, JP;
Katsuyuki Ichimiya, Tokyo, JP;
Kazukuni Hase, Tokyo, JP;
Shigeru Endo, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
A steel plate has excellent strength and toughness in a mid-thickness part thereof, despite having a plate thickness of 100 mm or greater. The steel plate has a chemical composition containing specific amounts of C, Si, Mn, P, S, Cr, Ni, Al, N, B, and O, with the balance being Fe and incidental impurities, and having an equivalent carbon content Ceqof 0.65 or greater. The steel plate has a yield strength of 620 MPa or greater, a plate thickness of 100 mm or greater, and has a microstructure in which prior γ grain size in a mid-thickness part of the steel plate has a maximum value, expressed as an equivalent circle diameter, of 150 μm or less, and a total area ratio of martensite and bainite in the mid-thickness part is 80% or greater.