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, 2012
Filed:
Mar. 27, 2008
Tatsuo Yokoi, Tokyo, JP;
Kazuya Ootsuka, Tokyo, JP;
Yukiko Yamaguchi, Tokyo, JP;
Tetsuya Yamada, Tokyo, JP;
Tatsuo Yokoi, Tokyo, JP;
Kazuya Ootsuka, Tokyo, JP;
Yukiko Yamaguchi, Tokyo, JP;
Tetsuya Yamada, Tokyo, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
This hot rolled steel contains, in terms of mass %, C: 0.01 to 0.1%, Si: 0.01 to 0.1%, Mn: 0.1 to 3%, P: not more than 0.1%, S: not more than 0.03%, Al: 0.001 to 1%, N: not more than 0.01%, Nb: 0.005 to 0.08%, and Ti: 0.001 to 0.2%, with a remainder being iron and unavoidable impurities, wherein a formula: [Nb]×[C]≦4.34×10is satisfied, a grain boundary density of solid solution C is not less than 1 atom/nmand not more than 4.5 atoms/nm, and a grain size of cementite grains precipitated at grain boundaries within the steel sheet is not more than 1 μm.