METHOD FOR MANUFACTURING HIGH-STRENGTH ALUMINUM-ALLOY BRAZING SHEET FOR HEAT EXCHANGER, HAVING EXCELLENT BRAZABILITY, FORMABILITY AND EROSION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a high-strength aluminum-alloy brazing sheet having excellent brazability, formability and erosion resistance and used for a heat exchanger. SOLUTION: The method for manufacturing the brazing sheet comprises steps of: homogenizing an aluminum-alloy core material containing at least Mn at 560-630 deg.C; superimposing an Al-Si brazing filler metal on one side or both sides of the homogenized aluminum-alloy core material; hot-rolling the resultant superimposed stock to form a hot clad stock in which one side or both sides of the aluminum-alloy core material are clad with a layer of the Al-Si brazing filler metal and which has 360 to 450 deg.C finishing temperature; applying cooling at (10 to 150) deg.C/h cooling rate; cold-rolling the cooled hot clad stock so that 20 to 80% final rolling reduction is reached; and subjecting the cold-rolled clad stock to temperature raising using a continuous annealing furnace up to 200 to 500 deg.C at (2 to 300) deg.C/s temperature-rise rate and holding at this temperature for <=3 min to apply final annealing.