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:
Nov. 09, 2010
Filed:
Oct. 22, 2004
Tadashi Ishikawa, Futtsu, JP;
Takehiro Inoue, Futtsu, JP;
Hiroshi Shimanuki, Futtsu, JP;
Tadashi Koseki, Futtsu, JP;
Jun Otani, Oita, JP;
Masanori Minagawa, Oita, JP;
Akihiko Kojima, Futtsu, JP;
Tadashi Ishikawa, Futtsu, JP;
Takehiro Inoue, Futtsu, JP;
Hiroshi Shimanuki, Futtsu, JP;
Tadashi Koseki, Futtsu, JP;
Jun Otani, Oita, JP;
Masanori Minagawa, Oita, JP;
Akihiko Kojima, Futtsu, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
A large-heat-input butt-welded joint of welded structures prepared by butt-welding high-strength steel plates over 50 mm in thickness, having excellent brittle fracture resistance, is characterized by: (a1) the hardness of the weld metal is not more than 110% of the hardness of the base metal or (a2) the hardness of the weld metal is not less than 70% and not more than 110% of the hardness of the base metal, and, as required, (b) the width of the weld metal is not more than 70% of the plate thickness of the base metal, (c) the width of the region affected by welding whose hardness is softened to not more than 95% of the hardness of the non-heat-affected base metal has a width not less than 5 mm, and/or (d) the prior austenite grain size in the heat-affected zone (HAZ) contacting the welding fusion line is not more than 200 μm.