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.

Date of Patent:
Feb. 28, 2017

Filed:

Jan. 28, 2015
Applicant:

Keihin Thermal Technology Corporation, Oyama-shi, JP;

Inventors:

Youhei Ikawa, Oyama, JP;

Takashi Terada, Oyama, JP;

Hiroshi Otsuki, Oyama, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F28D 21/00 (2006.01); F28F 21/08 (2006.01); C22C 21/00 (2006.01); F28F 19/06 (2006.01); F28D 1/053 (2006.01); B32B 15/01 (2006.01); C22C 21/02 (2006.01); B22F 1/00 (2006.01); C21C 5/00 (2006.01);
U.S. Cl.
CPC ...
F28F 21/084 (2013.01); B22F 1/007 (2013.01); B32B 15/01 (2013.01); C21C 5/005 (2013.01); C22C 21/00 (2013.01); C22C 21/02 (2013.01); F28D 1/05333 (2013.01); F28F 19/06 (2013.01); F28D 2021/0084 (2013.01); F28D 2021/0085 (2013.01); F28D 2021/0094 (2013.01);
Abstract

Heat exchange tubes of a heat exchanger are formed of an alloy containing Mn (0.2 to 0.3 mass %), Cu (0.1 mass % or less), and Fe (0.2 mass % or less), the balance being Al and unavoidable impurities. A Zn diffused layer is formed in an outer surface layer portion of the peripheral wall of each heat exchange tube. T≦200, 0.57≦A≦1.5, D/T≦0.55, and 0.0055≦A/D≦0.025 are satisfied, where T is the thickness [μm] of the peripheral wall of the heat exchange tube, A is the Zn concentration [mass %] at the outermost surface of the outer surface layer portion, and D is the maximum depth [μm] of the Zn diffused layer. The spontaneous potential of the Zn diffused layer is lower than that of a portion of the peripheral wall located on the inner side of the Zn diffused layer.


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