| 摘要 |
PROBLEM TO BE SOLVED: To provide an aluminum alloy brazing fin material for automobile heat exchanger that employs an aluminum tube body with a Zn-coated layer formed thereon and that has no chromate treatment, and to provide also a heat exchanger aluminum alloy brazing fin material that is excellent in formability and suppresses the generation of pitting-corrosion in the aluminum tube body under a severe corrosive environment as well as that has a high corrosive resistance in a fillet portion and can prevent the fin from being released from the aluminum tube body.SOLUTION: There is provided a heat exchanger aluminum alloy brazing sheet characterized in that: it employs an Al alloy that contains Mn by 0.6 to 2.0 mass% (hereinafter mass% is simply denoted as %), Fe by 0.05 to 0.5%, Si by 0.4 to 0.9%, and Zn by 0.02 to 4.0%, and the remainder composed of Al and inevitable impurities, as a core material and employs an Al alloy that contains Si by 6.0% to 13.0%, Fe by 0.05 to 0.80%, and Cu by 0.05 to 0.45%, and the remainder composed of Al and inevitable impurities, as a skin material on both sides of the core material; the ratio A/B of the number density A (number/mm) occupied by the deposition such as Al-Mn-Fe system and Al-Mn-Si system present in the core material having a particle size of 0.1 μm or more and less than 3.0 μm to the number density B (number/mm) occupied by the deposition having a particle size of 3.0 μm or more satisfies 50≤A/B≤500; and further the average crystal grain size in the core material in the longitudinal cross section of the fin after brazing heating is 100 μm or more. |
