| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat exchanger having excellent corrosion resistance.SOLUTION: The heat exchanger is combined by brazing a tube to an outer fin to form a joined part. The tube comprises: a core material; a brazing filler metal arranged on one surface of the core material to form the outer peripheral surface of the tube; and a sacrificial material arranged on the other surface of the core material to form the inner peripheral surface of the tube. The core material contains Mn of 1.2-1.8 mass%, Si of 0.4-1.3 mass%, Fe of 0.21-0.5 mass%, Cu of 0.5-1.3 mass% and the balance Al and inevitable impurities. The brazing filler metal contains Si of 6.0-11.0 mass%, Zn of 0.1-5.0 mass% and the balance Al and inevitable impurities. When a permutation of: the pitting potential of the brazing filler metal in the joined part; that of the core material; and that of the outer fin is made, that of the outer fin is the lowest and that of the brazing filler metal in the joined part is lower than that of the core material. |
