Keihin Thermal Technology Corporation

Youhei Ikawa

Takashi Terada

Hiroshi Otsuki

Kazuyuki Takahashi

A clad material includes a core material, a first skin material covering one side of the core material, and a second skin material covering the other side of the core material. The clad material is brazed in a state in which the first and second skin materials overlap each other. The core material is made of an Al alloy containing Mn (0.6 to 1.5 mass %), Ti (0.05 to 0.25 mass %), Cu (less than 0.05 mass %), Zn (less than 0.05 mass %), Fe (0.2 mass % or less), and Si (0.45 mass % or less) (balance: Al and unavoidable impurities). The first skin material is made of an Al alloy containing Si (6.8 to 11.0 mass %) and Zn (0.05 mass % or less) (balance: Al and unavoidable impurities). The second skin material is made of an Al alloy containing Si (4.0 to 6.0 mass %) and Cu (0.5 to 1.0 mass %) (balance: Al and unavoidable impurities).

Clad material, method of manufacturing brazed pipe, and brazed pipe

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&#x2266;200, 0.57&#x2266;A&#x2266;1.5, D/T&#x2266;0.55, and 0.0055&#x2266;A/D&#x2266;0.025 are satisfied, where T is the thickness [&#x3bc;m] 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 [&#x3bc;m] 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.

Heat exchanger

The anticorrosion treatment method of the invention is carried out on the outer surface of an aluminum extruded heat exchange tube which is formed of an Al alloy containing Mn 0.2 to 0.3 mass %, Cu 0.05 mass % or less, and Fe 0.2 mass % or less, and which has a wall thickness of 200 &#x3bc;m or less. The anticorrosion treatment method includes applying a specific dispersion of a flux powder and a Zn powder onto the outer surface of the heat exchange tube, and vaporizing a liquid component of the dispersion, to thereby deposit the Zn powder and the flux powder on the outer surface of the heat exchange tube, such that the Zn powder deposition amount, the flux powder deposition amount, and the ratio of the flux powder deposition amount to the Zn powder deposition amount are adjusted to specific values.

Growing community of inventors

Oyama, Japan

Youhei Ikawa