Aluminum alloy fin material for heat exchanger and method for manufacturing the same

Abstract

An aluminum alloy fin material for a heat exchanger is made of an aluminum alloy including 0.05 mass % to 0.5 mass % of Si, 0.05 mass % to 0.7 mass % of Fe, 10 mass % to 2.0 mass % of Mn, 0.5 mass % to 1.5 mass % of Cu, and 3.0 mass % to 7.0 mass % of Zn, with the balance being Al and unavoidable impurities. In an L-ST plane thereof, second-phase grains having an equivalent circle diameter equal to or more than 0.030 μm and less than 0.50 μm have a perimeter density of 0.30 μm/μm.sup.2 or more, second-phase grains having an equivalent circle diameter equal to or more than 0.50 μm have a perimeter density of 0.030 μm/μm.sup.2 or more, and specific resistance thereof at 20° C. is 0.030 μΩm or more.

Claims

1. An aluminum alloy fin material for a heat exchanger, the aluminum alloy fin material comprising an aluminum alloy including 0.5 mass % to 1.0 mass % of Si, 0.05 mass % to 0.7 mass % of Fe, 1.0 mass % to 2.0 mass % of Mn, 0.3 mass % to 1.2 mass % of Cu, and 2.2 mass % to 5.8 mass % of Zn, with the balance being Al and unavoidable impurities, wherein in an L-ST plane, second-phase grains having an equivalent circle diameter equal to or more than 0.030 μm and less than 0.50 μm have a perimeter density of 0.30 μm/μm.sup.2 or more, second-phase grains having an equivalent circle diameter equal to or more than 0.50 μm have a perimeter density of 0.030 μm/μm.sup.2 or more, wherein the perimeter density is the sum of the perimeters measured by imaging the second-phase grains divided by the imaging area, and specific resistance thereof at 20° C. is 0.030 μΩm or more.

2. The aluminum alloy fin material according to claim 1, wherein the aluminum alloy further includes at least one selected from 0.05 mass % to 0.3 mass % of Ti, 0.05 mass % to 0.3 mass % of Zr, and 0.05 mass % to 0.3 mass % of Cr.

3. A method for manufacturing the aluminum alloy fin material for a heat exchanger according to claim 1, the method comprising: a casting step of acquiring a sheet-like ingot by a twin-roll type continuous casting rolling method; and a cold rolling step of subjecting the sheet-like ingot to cold rolling with at least one pass, to acquire the aluminum alloy fin material for a heat exchanger, wherein when L (mm) is a contact arc length between a roll and material in cold rolling in the cold rolling step, H (mm) is half of sum of thicknesses on a roller inlet side and a roller outlet side, and L/H is a rolling shape ratio, a minimum value of the rolling shape ratio of each pass of cold rolling in the cold rolling step is 1.0 or more, and at least one annealing is performed before a first pass, between a pass and another pass, or after a final pass in cold rolling in the cold rolling step, and a maximum achievable temperature of annealing performed at highest temperature in the at least one annealing is 370° C. to 520° C.

Description

EXAMPLES

Examples and Comparative Examples

(1) Alloys having the compositions listed in Table 1 to Table 3 were subjected to a twin-roll type continuous casting rolling method to acquire ingots with a thickness of 6 mm. Thereafter, the acquired sheet-like ingots were subjected to cold rolling with two to seven passes under the manufacturing conditions listed in Table 1 to Table 3, and thereafter subjected to annealing in a batch annealing furnace. Thereafter, the ingots were further subjected to cold rolling with two to seven passes to prepare aluminum alloy fin materials with a final thickness of 0.05 mm and temper designation H14.

(2) Thereafter, the acquired aluminum alloy fin materials were used as samples and evaluated with respect to the perimeter density of the second-phase grains and the specific resistance before brazing heating, and the tensile strength after brazing heating, brazability, and corrosion resistance were evaluated. The measurement method and the evaluation method are as follows. Table 4 to Table 6 list results of the evaluation. The examples with the mark “x” in the item “manufacturability” in Table 1 to Table 3 are examples in which no samples could be manufactured, and could not be evaluated.

(3) TABLE-US-00001 TABLE 1 Manufacturing Process Minimum Maximum Value of Chemical Composition (mass %) Achievable Rolling Other Temperature Shape No. Si Fe Mn Cu Zn Compositions Al (° C.) Ratio Manufacturability Example 1 0.05 0.3 1.5 1.0 5.0 — Balance 450 5.0 ◯ 2 0.4 0.3 1.5 1.0 5.0 — Balance 450 5.0 ◯ 3 0.5 0.3 1.5 1.0 5.0 — Balance 450 5.0 ◯ 4 0.3 0.05 1.5 1.0 5.0 — Balance 450 5.0 ◯ 5 0.3 0.5 1.5 1.0 5.0 — Balance 450 5.0 ◯ 6 0.3 0.7 1.5 1.0 5.0 — Balance 450 5.0 ◯ 7 0.3 0.3 1.0 1.0 5.0 — Balance 450 5.0 ◯ 8 0.3 0.3 1.8 1.0 5.0 — Balance 450 5.0 ◯ 9 0.3 0.3 2.0 1.0 5.0 — Balance 450 5.0 ◯ 10 0.3 0.3 1.5 0.5 5.0 — Balance 450 5.0 ◯ 11 0.3 0.3 1.5 1.3 5.0 — Balance 450 5.0 ◯ 12 0.3 0.3 1.5 1.5 5.0 — Balance 450 5.0 ◯ 13 0.3 0.3 1.5 1.0 3.0 — Balance 450 5.0 ◯ 14 0.3 0.3 1.5 1.0 6.2 — Balance 450 5.0 ◯ 15 0.3 0.3 1.5 1.0 7.0 — Balance 450 5.0 ◯ 16 0.3 0.3 1.5 1.0 5.0 Ti: 0.05 Balance 450 5.0 ◯ 17 0.3 0.3 1.5 1.0 5.0 Ti: 0.15 Balance 450 5.0 ◯ 18 0.3 0.3 1.5 1.0 5.0 Ti: 0.3  Balance 450 5.0 ◯ 19 0.3 0.3 1.5 1.0 5.0 Zr: 0.05 Balance 450 5.0 ◯ 20 0.3 0.3 1.5 1.0 5.0 Zr: 0.15 Balance 450 5.0 ◯ 21 0.3 0.3 1.5 1.0 5.0 Zr: 0.3  Balance 450 5.0 ◯ 22 0.3 0.3 1.5 1.0 5.0 Cr: 0.05 Balance 450 5.0 ◯ 23 0.3 0.3 1.5 1.0 5.0 Cr: 0.15 Balance 450 5.0 ◯ 24 0.3 0.3 1.5 1.0 5.0 Cr: 0.3  Balance 450 5.0 ◯ 25 0.3 0.3 1.5 1.0 5.0 — Balance 370 5.0 ◯ 26 0.3 0.3 1.5 1.0 5.0 — Balance 480 5.0 ◯ 27 0.3 0.3 1.5 1.0 5.0 — Balance 520 5.0 ◯ 28 0.3 0.3 1.5 1.0 5.0 — Balance 450 1.0 ◯ 29 0.3 0.3 1.5 1.0 5.0 — Balance 450 3.0 ◯ 30 0.5 0.3 1.5 0.8 4.2 — Balance 450 5.0 ◯ 31 0.9 0.3 1.5 0.8 4.2 — Balance 450 5.0 ◯ 32 1.0 0.3 1.5 0.8 4.2 — Balance 450 5.0 ◯ 33 0.8 0.05 1.5 0.8 4.2 — Balance 450 5.0 ◯ 34 0.8 0.5 1.5 0.8 4.2 — Balance 450 5.0 ◯ 35 0.8 0.7 1.5 0.8 4.2 — Balance 450 5.0 ◯ 36 0.8 0.3 1.0 0.8 4.2 — Balance 450 5.0 ◯ 37 0.8 0.3 1.8 0.8 4.2 — Balance 450 5.0 ◯ 38 0.8 0.3 2.0 0.8 4.2 — Balance 450 5.0 ◯ 39 0.8 0.3 1.5 0.3 4.2 — Balance 450 5.0 ◯ 40 0.8 0.3 1.5 1.0 4.2 — Balance 450 5.0 ◯ 41 0.8 0.3 1.5 1.2 4.2 — Balance 450 5.0 ◯ 42 0.8 0.3 1.5 0.8 2.2 — Balance 450 5.0 ◯ 43 0.8 0.3 1.5 0.8 5.0 — Balance 450 5.0 ◯ 44 0.8 0.3 1.5 0.8 5.8 — Balance 450 5.0 ◯ 45 0.8 0.3 1.5 0.8 4.2 Ti: 0.05 Balance 450 5.0 ◯ 46 0.8 0.3 1.5 0.8 4.2 Ti: 0.15 Balance 450 5.0 ◯ 47 0.8 0.3 1.5 0.8 4.2 Ti: 0.3  Balance 450 5.0 ◯

(4) TABLE-US-00002 TABLE 2 Manufacturing Process Minimum Maximum Value of Chemical Composition (mass %) Achievable Rolling Other Temperature Shape No. Si Fe Mn Cu Zn Compositions Al (° C.) Ratio Manufacturability Example 48 0.8 0.3 1.5 0.8 4.2 Zr: 0.05 Balance 450 5.0 ◯ 49 0.8 0.3 1.5 0.8 4.2 Zr: 0.15 Balance 450 5.0 ◯ 50 0.8 0.3 1.5 0.8 4.2 Zr: 0.3  Balance 450 5.0 ◯ 51 0.8 0.3 1.5 0.8 4.2 Cr: 0.05 Balance 450 5.0 ◯ 52 0.8 0.3 1.5 0.8 4.2 Cr: 0.15 Balance 450 5.0 ◯ 53 0.8 0.3 1.5 0.8 4.2 Cr: 0.3  Balance 450 5.0 ◯ 54 0.8 0.3 1.5 0.8 4.2 — Balance 370 5.0 ◯ 55 0.8 0.3 1.5 0.8 4.2 — Balance 480 5.0 ◯ 56 0.8 0.3 1.5 0.8 4.2 — Balance 520 5.0 ◯ 57 0.8 0.3 1.5 0.8 4.2 — Balance 450 1.0 ◯ 58 0.8 0.3 1.5 0.8 4.2 — Balance 450 3.0 ◯ 59 1.0 0.3 1.5 0.3 2.2 — Balance 450 5.0 ◯ 60 1.4 0.3 1.5 0.3 2.2 — Balance 450 5.0 ◯ 61 1.5 0.3 1.5 0.3 2.2 — Balance 450 5.0 ◯ 62 1.3 0.05 1.5 0.3 2.2 — Balance 450 5.0 ◯ 63 1.3 0.5 1.5 0.3 2.2 — Balance 450 5.0 ◯ 64 1.3 0.7 1.5 0.3 2.2 — Balance 450 5.0 ◯ 65 1.3 0.3 1.0 0.3 2.2 — Balance 450 5.0 ◯ 66 1.3 0.3 1.8 0.3 2.2 — Balance 450 5.0 ◯ 67 1.3 0.3 2.0 0.3 2.2 — Balance 450 5.0 ◯ 68 1.3 0.3 1.5 0.05 2.2 — Balance 450 5.0 ◯ 69 1.3 0.3 1.5 0.4 2.2 — Balance 450 5.0 ◯ 70 1.3 0.3 1.5 0.5 2.2 — Balance 450 5.0 ◯ 71 1.3 0.3 1.5 0.3 0.5 — Balance 450 5.0 ◯ 72 1.3 0.3 1.5 0.3 2.6 — Balance 450 5.0 ◯ 73 1.3 0.3 1.5 0.3 3.0 — Balance 450 5.0 ◯ 74 1.3 0.3 1.5 0.3 2.2 Ti: 0.05 Balance 450 5.0 ◯ 75 1.3 0.3 1.5 0.3 2.2 Ti: 0.15 Balance 450 5.0 ◯ 76 1.3 0.3 1.5 0.3 2.2 Ti: 0.3  Balance 450 5.0 ◯ 77 1.3 0.3 1.5 0.3 2.2 Zr: 0.05 Balance 450 5.0 ◯ 78 1.3 0.3 1.5 0.3 2.2 Zr: 0.15 Balance 450 5.0 ◯ 79 1.3 0.3 1.5 0.3 2.2 Zr: 0.3  Balance 450 5.0 ◯ 80 1.3 0.3 1.5 0.3 2.2 Cr: 0.05 Balance 450 5.0 ◯ 81 1.3 0.3 1.5 0.3 2.2 Cr: 0.15 Balance 450 5.0 ◯ 82 1.3 0.3 1.5 0.3 2.2 Cr: 0.3  Balance 450 5.0 ◯ 83 1.3 0.3 1.5 0.3 2.2 — Balance 370 5.0 ◯ 84 1.3 0.3 1.5 0.3 2.2 — Balance 480 5.0 ◯ 85 1.3 0.3 1.5 0.3 2.2 — Balance 520 5.0 ◯ 86 1.3 0.3 1.5 0.3 2.2 — Balance 450 1.0 ◯ 87 1.3 0.3 1.5 0.3 2.2 — Balance 450 3.0 ◯

(5) TABLE-US-00003 TABLE 3 Manufacturing Process Minimum Maximum Value of Chemical Composition (mass %) Achievable Rolling Other Temperature Shape No. Si Fe Mn Cu Zn Compositions Al (° C.) Ratio Manufacturability Comparative 1 0.3 0.01 1.5 1.0 5.0 — Balance 450 5.0 ◯ Example 2 0.3 1.0 1.5 1.0 5.0 — Balance 450 5.0 ◯ 3 0.3 0.3 0.8 1.0 5.0 — Balance 450 5.0 ◯ 4 0.3 0.3 2.2 1.0 5.0 — Balance 450 5.0 X 5 0.05 0.3 1.5 1.7 7.8 — Balance 450 5.0 ◯ 6 0.4 0.3 1.5 0.4 2.6 — Balance 450 5.0 ◯ 7 0.3 0.3 1.5 1.0 5.0 Ti: 0.4 Balance 450 5.0 X 8 0.3 0.3 1.5 1.0 5.0 Zr: 0.4 Balance 450 5.0 X 9 0.3 0.3 1.5 1.0 5.0 Cr: 0.4 Balance 450 5.0 X 10 0.3 0.3 1.5 1.0 5.0 — Balance 350 5.0 ◯ 11 0.3 0.3 1.5 1.0 5.0 — Balance 540 5.0 ◯ 12 0.3 0.3 1.5 1.0 5.0 — Balance 450 0.8 ◯ 13 0.8 0.01 1.5 0.8 4.2 — Balance 450 5.0 ◯ 14 0.8 1.0 1.5 0.8 4.2 — Balance 450 5.0 ◯ 15 0.8 0.3 0.8 0.8 4.2 — Balance 450 5.0 ◯ 16 0.8 0.3 2.2 0.8 4.2 — Balance 450 5.0 X 17 0.6 0.3 1.5 1.3 6.2 — Balance 450 5.0 ◯ 18 0.9 0.3 1.5 0.2 1.8 — Balance 450 5.0 ◯ 19 0.8 0.3 1.5 0.8 4.2 Ti: 0.4 Balance 450 5.0 X 20 0.8 0.3 1.5 0.8 4.2 Zr: 0.4 Balance 450 5.0 X 21 0.8 0.3 1.5 0.8 4.2 Cr: 0.4 Balance 450 5.0 X 22 0.8 0.3 1.5 0.8 4.2 — Balance 350 5.0 ◯ 23 0.8 0.3 1.5 0.8 4.2 — Balance 540 5.0 ◯ 24 0.8 0.3 1.5 0.8 4.2 — Balance 450 0.8 ◯ 25 1.3 0.01 1.5 0.3 2.2 — Balance 450 5.0 ◯ 26 1.3 1.0 1.5 0.3 2.2 — Balance 450 5.0 ◯ 27 1.3 0.3 0.8 0.3 2.2 — Balance 450 5.0 ◯ 28 1.3 0.3 2.2 0.3 2.2 — Balance 450 5.0 X 29 1.2 0.3 1.5 0.7 3.8 — Balance 450 5.0 ◯ 30 1.6 0.3 1.5 0.05 1.0 — Balance 450 5.0 ◯ 31 1.3 0.3 1.5 0.3 2.2 Ti: 0.4 Balance 450 5.0 X 32 1.3 0.3 1.5 0.3 2.2 Zr: 0.4 Balance 450 5.0 X 33 1.3 0.3 1.5 0.3 2.2 Cr: 0.4 Balance 450 5.0 X 34 1.3 0.3 1.5 0.3 2.2 — Balance 350 5.0 ◯ 35 1.3 0.3 1.5 0.3 2.2 — Balance 540 5.0 ◯ 36 1.3 0.3 1.5 0.3 2.2 — Balance 450 0.8 ◯

(6) In the chemical composition tables of Table 1 to Table 3, the mark “-” means that the content was less than the detection limit of the spark discharge optical emission spectrometer, and the term “balance” means that the balance is formed of Al and unavoidable impurities. The term “maximum achievable temperature” in the manufacturing process indicates the maximum achievable temperature of annealing, and the term “minimum value of the rolling shape ratio” indicates the minimum value of the rolling shape ratio of cold rolling.

Perimeter Density of Second-phase Grains

(7) An L-ST plane (plane including the rolling direction and the thickness direction) in the center of the thickness of each of the samples was imaged with a field emission scanning electron microscope (FE-SEM) with 20,000 magnifications, the perimeter (μm) for second-phase grains with an equivalent circle diameter equal to or more than 0.030 μm and less than 0.50 μm was measured with image analysis software, and the sum of the perimeters was divided by the imaging area to calculate the perimeter density. In the same manner, the L-ST plane in the center of the thickness was imaged with a field emission scanning electron microscope (FE-SEM) with 3,000 magnifications, the perimeter (μm) for second-phase grains with an equivalent circle diameter equal to or more than 0.50 μm was measured with image analysis software, and the sum of the perimeters was divided by the imaging area to calculate the perimeter density. The perimeter density was calculated with five fields of view for the same sample, and the arithmetic mean value of the values was calculated as the perimeter density.

Specific Resistance

(8) In accordance with JIS-H0505, the electrical resistance of each of the samples was measured in a thermostatic chamber at 20° C. to calculate the specific resistance.

Strength after Brazing Heating

(9) Each of the samples was subjected to brazing heating, thereafter cooled at cooling speed of 50° C./min, and thereafter left at a room temperature for one week, to acquire samples. Brazing heating was performed by heating each of the samples in a nitrogen-gas-atmosphere furnace, and maintained at 590° C. for three minutes. Each of the samples was subjected to tensile test in accordance with JIS Z2241. The samples with the tensile strength of 145 MPa or more were expressed with the symbol “O”.

Brazability

(10) Miniature cores of a heat exchanger were prepared by corrugating the individual fin materials, assembling the individual fin materials with a tube formed of a sheet material formed in a flat shape, having a thickness of 0.20 mm, and formed of a core material of JIS-A3003 alloy and a brazing material of JIS-A4045 alloy, applying a fluoride-based flux with a concentration of 3% onto the brazing-material side surface of the tube material, and performing brazing heating in a nitrogen-gas atmosphere at 590° C. for three minutes. With respect to each of the miniature cores, brazability was evaluated on the basis of presence/absence of buckling and melting of the fin, by observing the bonded portion between the fin material and the tube material by visual inspection. The symbol “O” indicates the case where neither buckling nor melting occurred, and the symbol “x” indicates the case where buckling or melting occurred.

Corrosion Resistance

(11) Miniature cores prepared in the same manner as the miniature cores for evaluating brazability were subjected to corrosion test conforming to copper accelerated acetic acid salt spray (CASS) test of JIS-H8681 for two weeks. Evaluation was performed on the corrosion state on the brazing material side of the tube and the corrosion state of the fin after the test. The symbol “O” indicates the case where no through hole was generated in the tube, and the symbol “x” indicates the case where a through hole was generated in the tube. The symbol “O” indicates the case with small self-corrosion of the fin, and the symbol “x” indicates the case with large self-corrosion of the fin.

(12) TABLE-US-00004 TABLE 4 Metal Structure Before Brazing Heating Perimeter Density of Perimeter Density of Second-Phase Grains Second-Phase Grains with Equivalent with Equivalent Circle Diameter Circle Diameter Properties After Brazing Heating Equal to or More Equal to or More Specific Tensile Than 0.030 μm and Than 0.50 μm Resistance Strength Corrosion No. Less Than 0.50 μm (μm/μm.sup.2) (μΩm) (MPa) Brazability Resistance Example 1 0.40 0.100 0.036 149 ◯ ◯ 2 1.10 0.102 0.035 163 ◯ ◯ 3 1.17 0.105 0.034 165 ◯ ◯ 4 1.16 0.039 0.036 157 ◯ ◯ 5 0.63 0.109 0.035 160 ◯ ◯ 6 0.37 0.115 0.034 159 ◯ ◯ 7 0.43 0.041 0.033 151 ◯ ◯ 8 1.05 0.113 0.035 162 ◯ ◯ 9 1.24 0.116 0.036 165 ◯ ◯ 10 0.36 0.096 0.033 149 ◯ ◯ 11 1.15 0.105 0.035 164 ◯ ◯ 12 1.19 0.096 0.036 164 ◯ ◯ 13 1.00 0.096 0.032 159 ◯ ◯ 14 1.03 0.097 0.036 159 ◯ ◯ 15 1.00 0.097 0.037 160 ◯ ◯ 16 1.01 0.102 0.035 161 ◯ ◯ 17 1.01 0.096 0.035 162 ◯ ◯ 18 0.95 0.097 0.035 163 ◯ ◯ 19 0.96 0.099 0.035 161 ◯ ◯ 20 1.00 0.102 0.035 162 ◯ ◯ 21 0.95 0.105 0.035 163 ◯ ◯ 22 1.00 0.103 0.035 161 ◯ ◯ 23 0.98 0.099 0.035 162 ◯ ◯ 24 1.02 0.102 0.035 163 ◯ ◯ 25 0.38 0.057 0.036 151 ◯ ◯ 26 0.73 0.081 0.035 156 ◯ ◯ 27 0.36 0.062 0.036 150 ◯ ◯ 28 0.43 0.035 0.035 148 ◯ ◯ 29 0.75 0.072 0.035 155 ◯ ◯ 30 0.39 0.097 0.035 148 ◯ ◯ 31 1.05 0.099 0.034 164 ◯ ◯ 32 1.16 0.102 0.033 166 ◯ ◯ 33 1.24 0.042 0.035 158 ◯ ◯ 34 0.55 0.112 0.034 161 ◯ ◯ 35 0.38 0.115 0.033 161 ◯ ◯ 36 0.39 0.044 0.032 149 ◯ ◯ 37 1.13 0.115 0.034 163 ◯ ◯ 38 1.19 0.118 0.035 166 ◯ ◯ 39 0.43 0.096 0.032 148 ◯ ◯ 40 1.13 0.098 0.034 164 ◯ ◯ 41 1.18 0.098 0.035 164 ◯ ◯ 42 1.02 0.096 0.031 161 ◯ ◯ 43 1.01 0.101 0.035 159 ◯ ◯ 44 0.96 0.099 0.036 160 ◯ ◯ 45 1.03 0.101 0.034 161 ◯ ◯ 46 0.96 0.104 0.034 162 ◯ ◯ 47 1.04 0.102 0.034 163 ◯ ◯

(13) TABLE-US-00005 TABLE 5 Metal Structure Before Brazing Heating Perimeter Density of Second-Phase Grains Perimeter Density of with Equivalent Second-Phase Grains Circle Diameter with Equivalent Equal to or More Circle Diameter Properties After Brazing Heating Than 0.030 μm and Equal to or More Specific Tensile Less Than 0.50 μm Than 0.50 μm Resistance Strength Corrosion No. (μm/μm.sup.2) (μm/μm.sup.2) (μΩm) (MPa) Brazability Resistance Example 48 0.97 0.105 0.034 161 ◯ ◯ 49 0.96 0.102 0.034 162 ◯ ◯ 50 0.99 0.096 0.034 163 ◯ ◯ 51 0.98 0.097 0.034 161 ◯ ◯ 52 0.97 0.099 0.034 162 ◯ ◯ 53 1.03 0.102 0.034 163 ◯ ◯ 54 0.43 0.064 0.035 148 ◯ ◯ 55 0.71 0.085 0.034 155 ◯ ◯ 56 0.40 0.062 0.035 152 ◯ ◯ 57 0.37 0.039 0.034 151 ◯ ◯ 58 0.66 0.067 0.034 154 ◯ ◯ 59 0.44 0.095 0.034 151 ◯ ◯ 60 1.05 0.102 0.033 163 ◯ ◯ 61 1.23 0.104 0.032 165 ◯ ◯ 62 1.16 0.043 0.034 156 ◯ ◯ 63 0.65 0.109 0.033 159 ◯ ◯ 64 0.44 0.122 0.032 160 ◯ ◯ 65 0.45 0.040 0.031 152 ◯ ◯ 66 1.14 0.105 0.033 162 ◯ ◯ 67 1.19 0.121 0.034 164 ◯ ◯ 68 0.43 0.099 0.031 150 ◯ ◯ 69 1.14 0.102 0.033 164 ◯ ◯ 70 1.22 0.100 0.034 165 ◯ ◯ 71 0.96 0.102 0.030 161 ◯ ◯ 72 0.96 0.099 0.034 160 ◯ ◯ 73 1.05 0.103 0.035 160 ◯ ◯ 74 0.98 0.101 0.033 161 ◯ ◯ 75 1.03 0.095 0.033 162 ◯ ◯ 76 1.02 0.101 0.033 163 ◯ ◯ 77 1.05 0.103 0.033 161 ◯ ◯ 78 0.99 0.099 0.033 162 ◯ ◯ 79 0.97 0.098 0.033 163 ◯ ◯ 80 1.04 0.096 0.033 161 ◯ ◯ 81 1.00 0.102 0.033 162 ◯ ◯ 82 0.99 0.100 0.033 163 ◯ ◯ 83 0.35 0.062 0.034 149 ◯ ◯ 84 0.70 0.084 0.033 155 ◯ ◯ 85 0.39 0.060 0.034 150 ◯ ◯ 86 0.35 0.035 0.033 150 ◯ ◯ 87 0.72 0.069 0.033 154 ◯ ◯

(14) TABLE-US-00006 TABLE 6 Metal Structure Before Brazing Heating Perimeter Density of Second-Phase Grains Perimeter Density of with Equivalent Second-Phase Grains Circle Diameter with Equivalent Equal to or More Circle Diameter Properties After Brazing Heating Than 0.030 μm and Equal to or More Specific Tensile Less Than 0.50 μm Than 0.50 μm Resistance Strength Corrosion No. (μm/μm.sup.2) (μm/μm.sup.2) (μΩm) (MPa) Brazability Resistance Comparative 1 1.30 0.029 0.036 141 ◯ ◯ Example 2 0.31 0.125 0.033 161 X ◯ 3 0.29 0.026 0.032 144 ◯ ◯ 4 — — — — — — 5 1.03 0.097 0.038 161 X X 6 0.29 0.098 0.029 143 ◯ X 7 — — — — — — 8 — — — — — — 9 — — — — — — 10 0.29 0.096 0.037 143 ◯ ◯ 11 0.27 0.099 0.037 140 ◯ ◯ 12 0.25 0.026 0.035 144 ◯ ◯ 13 1.33 0.025 0.035 140 ◯ ◯ 14 0.32 0.125 0.032 159 X ◯ 15 0.28 0.029 0.031 143 ◯ ◯ 16 — — — — — — 17 1.05 0.099 0.037 159 X X 18 0.26 0.104 0.029 140 ◯ X 19 — — — — — — 20 — — — — — — 21 — — — — — — 22 0.28 0.103 0.036 140 ◯ ◯ 23 0.26 0.101 0.036 144 ◯ ◯ 24 0.27 0.029 0.034 143 ◯ ◯ 25 1.30 0.025 0.034 142 ◯ ◯ 26 0.31 0.134 0.031 159 X ◯ 27 0.29 0.025 0.030 140 ◯ ◯ 28 — — — — — — 29 1.04 0.096 0.036 160 X X 30 0.29 0.103 0.029 141 ◯ ◯ 31 — — — — — — 32 — — — — — — 33 — — — — — — 34 0.28 0.097 0.030 142 ◯ ◯ 35 0.28 0.105 0.030 142 ◯ ◯ 36 0.28 0.026 0.033 143 ◯ ◯

(15) In Examples 1 to 87, the chemical compositions fall within the range provided in the present invention, and the manufacturing conditions thereof satisfy the conditions provided in the present invention. These examples of the present invention exhibited good manufacturability, and had metal structures satisfying the conditions provided in the present invention. In addition, these examples of the present invention passed the test in each of strength after brazing heating, brazability, and corrosion resistance.

(16) In Comparative Examples 1 to 9, the chemical compositions fell out of the range provided in the present invention, and the following results were obtained.

(17) In Comparative Example 1, the Fe content was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 1 failed in strength after brazing heating.

(18) In Comparative Example 2, the Fe content was too high, and the grain size after brazing heating was minute. For this reason, Comparative Example 2 failed in brazability.

(19) In Comparative Example 3, the Mn content was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 3 failed in strength after brazing heating.

(20) In Comparative Example 4, the Mn content was too high, cracks occurred during cold rolling, and no fin material could be manufactured.

(21) In Comparative Example 5, the Cu content and the Zn content were too high, and the melting point of the material was low. For this reason, Comparative Example 5 failed in brazability. In addition, because the self-corrosion speed increased, Comparative Example 5 failed in corrosion resistance.

(22) In Comparative Example 6, the Cu content and the Zn content were too low, and the perimeter density of the second-phase grains and the specific resistance were too low. For this reason, Comparative Example 6 failed in strength after brazing heating. In addition, because it had a noble spontaneous potential, Comparative Example 6 failed in corrosion resistance.

(23) Comparative Examples 7 included an excessive Ti content, Comparative Example 8 included an excessive Zr content, and Comparative Example 9 included an excessive Cr content. For this reason, in Comparative Examples 7 to 9, cracks occurred during cold rolling, and no fin materials could be manufactured.

(24) Comparative Examples 10 to 12 included the manufacturing conditions falling out of the conditions provided in the present invention, and produced the following results.

(25) In Comparative Example 10, the maximum achievable temperature of annealing in which annealing was performed at the highest temperature was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 10 failed in strength after brazing heating.

(26) In Comparative Example 11, the maximum achievable temperature of annealing in which annealing was performed at the highest temperature was too high, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 11 failed in strength after brazing heating.

(27) In Comparative Example 12, the minimum value of the rolling shape ratio in the cold rolling step was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 12 failed in strength after brazing heating.

(28) Comparative Examples 13 to 21 included the chemical compositions falling out of the range provided in the present invention, and produced the following results.

(29) In Comparative Example 13, the Fe content was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 13 failed in strength after brazing heating.

(30) In Comparative Example 14, the Fe content was too high, and the grain size after brazing heating was minute. For this reason, Comparative Example 14 failed in brazability.

(31) In Comparative Example 15, the Mn content was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 15 failed in strength after brazing heating.

(32) In Comparative Example 16, the Mn content was too high, cracks occurred during cold rolling, and no fin material could be manufactured.

(33) In Comparative Example 17, the Cu content and the Zn content were too high, and the melting point of the material was low. For this reason, Comparative Example 17 failed in brazability. In addition, because the self-corrosion speed increased, Comparative Example 17 failed in corrosion resistance.

(34) In Comparative Example 18, the Cu content and the Zn content were too low, and the perimeter density of the second-phase grains and the specific resistance were too low. For this reason, Comparative Example 18 failed in strength after brazing heating. In addition, because it had a noble spontaneous potential, Comparative Example 18 failed in corrosion resistance.

(35) Comparative Examples 19 included an excessive Ti content, Comparative Example 20 included an excessive Zr content, and Comparative Example 21 included an excessive Cr content. For this reason, in Comparative Examples 19 to 21, cracks occurred during cold rolling, and no fin materials could be manufactured.

(36) Comparative Examples 22 to 24 included the manufacturing conditions falling out of the conditions provided in the present invention, and produced the following results.

(37) In Comparative Example 22, the maximum achievable temperature of annealing in which annealing was performed at the highest temperature was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 22 failed in strength after brazing heating.

(38) In Comparative Example 23, the maximum achievable temperature of annealing in which annealing was performed at the highest temperature was too high, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 23 failed in strength after brazing heating.

(39) In Comparative Example 24, the minimum value of the rolling shape ratio in the cold rolling step was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 24 failed in strength after brazing heating.

(40) Comparative Examples 25 to 33 included the chemical compositions falling out of the range provided in the present invention, and produced the following results.

(41) In Comparative Example 25, the Fe content was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 25 failed in strength after brazing heating.

(42) In Comparative Example 26, the Fe content was too high, and the grain size after brazing heating was minute. For this reason, Comparative Example 26 failed in brazability.

(43) In Comparative Example 27, the Mn content was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 27 failed in strength after brazing heating.

(44) In Comparative Example 28, the Mn content was too high, cracks occurred during cold rolling, and no fin material could be manufactured.

(45) In Comparative Example 29, the Cu content and the Zn content were too high, and the melting point of the material was low. For this reason, Comparative Example 29 failed in brazability. In addition, because the self-corrosion speed increased, Comparative Example 29 failed in corrosion resistance.

(46) In Comparative Example 30, the Si content was too low, and the perimeter density of the second-phase grains and the specific resistance were too low. For this reason, Comparative Example 30 failed in strength after brazing heating.

(47) Comparative Examples 31 included an excessive Ti content, Comparative Example 32 included an excessive Zr content, and Comparative Example 33 included an excessive Cr content. For this reason, in Comparative Examples 31 to 33, cracks occurred dining cold rolling, and no fin materials could be manufactured.

(48) Comparative Examples 34 to 36 included the manufacturing conditions falling out of the conditions provided in the present invention, and produced the following results.

(49) In Comparative Example 34, the maximum achievable temperature of annealing in which annealing was performed at the highest temperature was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 34 failed in strength after brazing heating.

(50) In Comparative Example 35, the maximum achievable temperature of annealing in which annealing was performed at the highest temperature was too high, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 35 failed in strength after brazing heating.

(51) In Comparative Example 36, the minimum value of the rolling shape ratio in the cold rolling step was too low, and the perimeter density of the second-phase grains was too low. For this reason, Comparative Example 36 failed in strength after brazing heating.

INDUSTRIAL APPLICABILITY

(52) The aluminum alloy fin material for a heat exchanger according to the present invention has high strength after brazing heating and excellent brazability, and enables reduction in thickness compared to conventional aluminum alloy fin materials. For this reason, the aluminum alloy fin material according to the present invention is useful, in particular, for heat exchangers of automobiles.