| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat exchanger made of aluminum alloy having excellent corrosion resistance.SOLUTION: A heat exchanger made of aluminum alloy is constituted of an aluminum alloy brazing sheet including a core material of Al-Mn alloy, and a brazing function imparting sacrificial material of Al-Si-Zn alloy which is cladded on one surface of the core material, and comprises: a tube whose brazing function imparting sacrificial material side is an external surface; and a bare fin which is brazed and bonded to the external surface of the tube. After brazing and bonding, an area ratio of an eutectic structure on the external surface of the tube is 40 to 60%, a natural electric potential difference between the bare fin and the external surface of the tube is ±50 mV or less, the natural electric potential of the external surface of the tube is poorer than the natural electric potential of the core material of the tube by 50 mV or more. There is also provided a method of manufacturing the heat exchanger. |
