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. 17, 2018
Filed:
Oct. 01, 2012
Jfe Steel Corporation, Tokyo, JP;
Masao Yuga, Chita, JP;
Shigeki Kitsuya, Kurashiki, JP;
Kenji Hayashi, Kurashiki, JP;
Minoru Suwa, New York, NY (US);
JFE Steel Corporation, Tokyo, JP;
Abstract
A high-tensile steel plate has a chemical composition containing, by mass, specific amounts of C, Mn, Si, P, S, Al, Ni, B, N, one or more elements selected from Cr, Mo, V, Cu, Ti, and Ca as needed, Ceq≤0.80, and a center-segregation zone hardness index HCS satisfying 5.5[C]+15[P]+0.90[Mn]+0.12[Ni]+0.53[Mo]≤2.5. The hardness of a center-segregation zone satisfies HV/HV≤1.35+0.006/C−t/750. A steel having the above-described chemical composition is subjected to hot rolling at a specific slab-heating temperature at a specific rolling reduction ratio, subsequently reheated, cooled at a cooling rate of 0.3° C./s or more until the temperature of a central portion in a plate-thickness direction reaches 350° C. or less, and tempered to a specific temperature range.