Aluminum alloy fin material for heat exchanger and method of production of same and method of production of heat exchanger by brazing fin material

Abstract

An aluminum alloy fin material for a heat exchanger having suitable strength before brazing enabling easy fin formation, having high strength after brazing, having a high thermal conductivity (electrical conductivity) after brazing, and having superior sag resistance, erosion resistance, self corrosion prevention, and sacrificial anode effect, a method of production of the same, and a method of production of a heat exchanger using the fin material are provided, that is, an aluminum alloy fin material having a chemical composition of Si: 0.7 to 1.4 wt %, Fe: 0.5 to 1.4 wt %, Mn: 0.7 to 1.4 wt %, and Zn: 0.5 to 2.5 wt %, Mg as an impurity limited to 0.05 wt % or less, and the balance of unavoidable impurities and Al, and having a tensile strength after brazing of 130 MPa or more, a yield strength after brazing of 45 MPa or more, a recrystallized grain size after brazing of 500 μm or more, and an electrical conductivity after brazing of 47% IACS or more, a method of producing an aluminum alloy fin material comprising cold rolling/annealing/cold rolling/annealing/cold rolling a thin slab continuously cast by a twin-belt system from a melt of the above composition under predetermined conditions, and a method of production of a heat exchanger comprising cooling the fin material at a predetermined rate after brazing heating.