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:
Jun. 24, 2014
Filed:
Jun. 06, 2011
Shuichi Nakamura, Tokyo, JP;
Kazuhiro Kojima, Tokyo, JP;
Shuichi Nakamura, Tokyo, JP;
Kazuhiro Kojima, Tokyo, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Abstract
An ultrahigh-strength welded joint with superior strength and toughness, and a method for producing the ultrahigh-strength welded joint by means of single-pass welding by using laser hybrid welding, are provided, wherein the welded joint comprising a steel plate having a plate thickness of 4 mm to 12 mm and including weld metal of almost full martensite structure, wherein, in a cross-section of the welded joint in a direction perpendicular to a welding direction, a cross-sectional shape of the weld metal has a width Wof 2.0 to 7.0 mm at a surface of the steel plate and a width Wof 0.5 to 2.4 mm at a position where is separated from the surface by three-quarters of the plate thickness, wherein the weld metal comprises, by mass %, C: over 0.09% to 0.24%; Si: 0.2% to 1.0%; Mn: 0.5% to 2.5%; P: 0.02% or less; S: 0.02% or less; Al: 0.004% to 0.08%; Ti: 0.005% to 0.15%; O: 0.005% to 0.05%; and Ni: 1.0% to 9%, and wherein a carbon equivalent (Ceq) is 0.40% to 1.00%, a value Y as defined by equation (([Si]+[Mn])/40+[Al]+[Ti]) is 0.07% to 0.20%.