PURPOSE: To obtain an Al alloy brazing sheet strip by subjecting an ingot clad with prescribed Al alloy materials on both faces of a core material constituted of an Al alloy in which Si, Fe, Cu, Mn or the like are specified to hot rolling and thereafter executing cold rolling and annealing under prescribed conditions.
CONSTITUTION: An alloy constituted of, by weight, 0.05 to 0.8% Si, 0.05 to O.6% Fe, 0.1 to 1% Cu, 0.6 to 1.6% Mn, ≤0.5% Mg, ≤0.3% Cr, ≤0.3% Zr, ≤0.3% Ti and the balance Al is melted. This Al allay is used as a core material, and its one face is clad with an Al-Si alloy brazing filler metal and the other face is clad with an Al alloy material having a sacrificial effect. Next, this Al alloy ingot is subjected to homogenizing treatment and hot rolling and is thereafter subjected to cold rolling at ≥30% draft. Then, it is annealed at 220 to 320°C for 0.5 to 12hr, is successively subjected to cold rolling at 5 to 30% draft and is annealed at 320 to 400°C for 0.5 to 12hr to regulated its strength to prescribed one.
DOKOU TAKENOBU
YAMAGUCHI MOTOYOSHI