ALUMINUM ALLOY FIN MATERIAL FOR HEAT EXCHANGER, PROCESS FOR MANUFACTURING THE SAME, AND PROCESS FOR MANUFACTURING HEAT EXCHANGER THROUGH BRAZING OF THE FIN MATERIAL

摘要

An aluminum alloy fin material for heat exchanger that facilitates fin forming, having appropriate pre-brazing strength, and that after brazing, exhibits high strength and thermal conductivity (electric conductivity), excelling in sag-proof property, erosion resistance, self-corrosion resistance and sacrificial anode effect; a process for manufacturing the same; and a process for manufacturing a heat exchanger through use of the fin material. There is provided an aluminum alloy fin material comprising 0.7 to 1.4 wt.% Si, 0.5 to 1.4 wt.% Fe, 0.7 to 1.4 wt.% Mn, 0.5 to 2.5 wt.% Zn, impurity Mg limited to 0.05 wt.% or less, and the balance unavoidable impurities and Al, which fin material after brazing has a tensile strength of 130 MPa or greater, a proof strength of 45 MPa or greater, a recrystallization grain diameter of 500 µm or more and an electric conductivity of 47% IACS or higher. Further, there is provided a process for manufacturing a fin material, including subjecting a thin slab obtained by twin-belt continuous casting of a molten metal of the above composition to cold rolling/annealing/cold rolling/annealing/cold rolling under given conditions. Still further, there is provided a process for manufacturing a heat exchanger, including brazing heating of the above fin material and thereafter cooling at a given rate.