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:
Oct. 06, 2015
Filed:
May. 02, 2011
Atsuro Iseda, Tokyo, JP;
Takashi Nakashima, Tokyo, JP;
Tetsuo Yokoyama, Tokyo, JP;
Tadashi Kawakami, Tokyo, JP;
Takuya Hanada, Tokyo, JP;
Atsuro Iseda, Tokyo, JP;
Takashi Nakashima, Tokyo, JP;
Tetsuo Yokoyama, Tokyo, JP;
Tadashi Kawakami, Tokyo, JP;
Takuya Hanada, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
After an inner wall tube, made of steel or alloy containing not less than 2% of Cr, whose outer surface thereof is machined and/or ground to a thickness of 0.1 mm or more including the scale layer, is inserted into an outer wall tube, made of ferritic steel containing not less than 2% of Cr, in which an oxide scale layer containing Cr and having a thickness of 10 to 30 μm is formed in the inner surface thereof, cold working at an outside diameter reduction rate of 5 to 30% is performed. Similarly cold worked after an inner wall tube having an oxide scale layer on the outer surface thereof, is inserted into an outer wall tube whose inner surface is machined and ground. A double-walled tube made has a uniform gap and an excellent thermal conductivity, and is suitable as materials for SG tubes of future FBR.