| 摘要 |
PROBLEM TO BE SOLVED: To provide a brazing sheet for a heat exchanger which has excellent mechanical strength and external corrosion resistance in a high temperature environment. SOLUTION: The brazing sheet 2 for a heat exchanger comprises a core material 2a composed of an aluminum alloy containing, by mass, 0.5 to 1.2% Si, 0.01 to <1.0% Mn, 0.1 to 1.0% Cu and 0.1 to 0.5% Mg, and a brazing filler metal layer(s) 2b provided at one side or both sides of the core material 2a and composed of an aluminum alloy comprising Zn and Si, wherein the tensile strength when the substantial temperature of the base material after brazing is 150°C is≥80 MPa, a difference in solid solution Si concentration between the primary crystal and theαphase of an eutectic crystal in the brazing filler metal layer(s) 2b is≤0.05 mass%, and, regarding the potential gradient of the brazing filler metal layer(s) 2b, the potential of the outermost surface is the basest, and it is noble by≥0.5 mV/μm from the outermost surface to the thickness direction. COPYRIGHT: (C)2010,JPO&INPIT |
