Patent ID: 9534851
Date: 2017-01-03
CPC Classifications: B05D,B21D,B23K,B23P,C23C,F28D,F28F,Y10T

Claim:
1. A method for performing an anticorrosion treatment on an outer surface of an aluminum extruded heat exchange tube, the method comprising: providing an aluminum extruded heat exchange tube which is formed of an alloy comprising Mn 0.2 to 0.3 mass %, Cu 0.05 mass % or less, and Fe 0.2 mass % or less, the balance being Al, and unavoidable impurities, and which has a wall thickness of 200 μm or less; applying a dispersion of a flux powder and a Zn powder, the Zn powder having a mean particle size of 3 to 5 μm and a maximum particle size less than 10 μm, in a binder 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 a Zn powder deposition amount is adjusted to 1 to 3 g/m elevating the temperature of the heat exchange tube to thereby melt the Zn powder, and then diffusing Zn to an outer surface portion of the heat exchange tube, to thereby form a Zn diffusion layer in the outer surface portion of the heat exchange tube.