| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat exchanger having excellent corrosion resistance.SOLUTION: The heat exchanger is obtained by brazing a tube to an outer fin. The tube comprises a brazing sheet consisting of a core material, a brazing filler metal and a sacrificial material. The core material consists of an aluminum alloy containing Mn of 1.2-1.8%, Si of 0.4-1.3%, Fe of 0.21-0.5% and Cu of 0.5-1.3%. The brazing filler metal consists of another aluminum alloy containing Si of 6.0-11.0% and Zn of 0.1-5.0%. The sacrificial material consists of a different aluminum alloy containing Zn of 4.0-7.0%, Mg of 1.2-2.5% and Si of 0.1-0.4%. Among the brazing filler metal formed on the surface of the tube, the order of: at the least, potential of the brazing filler metal in the joined part thereof to the outer fin and in the vicinity of the joined part; potential of the core material of the tube; and potential of the outer fin is made, the potential of the outer fin being the lowest and the potential of the brazing filler metal being lower than the potential of the core material. |
