| 摘要 |
PROBLEM TO BE SOLVED: To provide a brazing sheet made of an aluminum alloy, which has both high strength and formability even if it is a tube material having a thinner wall and is used for making a brazed tube.SOLUTION: In the aluminum alloy brazing sheet for making a brazed tube, a core material, a sacrificial material, and a brazing filler metal have the following chemical components, wherein the clad thickness is 0.20 mm or less; the tensile strength after brazing heat treatment is 170 MPa or more; the average crystal grain size of the core material after brazing heat treatment is 30 to 120 μm; and the core material before brazing has a fibrous structure. The core material includes 1.2 to 1.8% Mn, 0.4 to 1.3% Si, 0.21 to 0.5% Fe, 0.5 to 1.3% Cu, and the balance Al with inevitable impurities. The sacrificial material includes 4.0 to 7.0% Zn, 1.0 to 1.8% Mn, 0.2 to 1.2% Si, and the balance Al with inevitable impurities. The brazing filler metal is an Al-Si brazing filler metal or an Al-Si-Zn brazing filler metal. |
