JP2000038631A - Aluminum alloy material for heat exchanger, composite material for heat exchanger using the aluminum alloy material and production of the aluminum alloy material or the composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy material for a heat exchanger that the erosion of a brazer is suppressed at the time of brazing heating to have excellent corrosion-resistance and required strength. SOLUTION: This invention relates to a finish annealing material after the cold rolling of an Al alloy contg., by weight, 0.4 to 2.0% Fe, 0.3 to 2.0% Cu, 0.5 to 2.0% Mn, <0.03% (including 0%) Ti, and the balance Al with inevitable impurities, and the average grain size in the face rectangular to the rolling direction of the finish annealing material is <=40 μm. Since Fe, Cu and Mn are contained in suitable amount, strength required for a heat exchanger core can be obtd., and, furthermore, by controlling the recrystallized grain size in the face rectangular to the rolling direction of the Al alloy to <=40 μm, the Al alloy material is perfectly recrystallized at the time of brazing heating after its working into a refrigerant passage shaped body 1, and the erosion of a brazer can be suppressed. Moreover, by the incorporation of a suitable amt. of Ti, its corrosion resistance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aluminum alloy material for a heat exchanger, which is suitable for a refrigerant passage tube or a refrigerant passage shape body through which a refrigerant of an automotive heat exchanger is assembled by brazing, and the aluminum alloy material. The present invention relates to an aluminum alloy composite material for a heat exchanger used and a method for producing the aluminum alloy material or the composite material.

[0002]

2. Description of the Related Art Conventionally, a core of a heat exchanger such as an evaporator or a condenser is assembled by brazing a fin 2 to a refrigerant passage-shaped body 1 through which a refrigerant passes in a longitudinal direction as shown in FIG. It is a thing. In FIG. 1, reference numeral 3 denotes a vertical refrigerant passage. The coolant passage-shaped body 1 is, for example, a core material (A
1 (alloy material) is coated with a brazing material on one side, and a composite material (brazing sheet) 4 is press-formed into an uneven shape. It is manufactured by overlapping the refrigerant passages 5 so as to form them and brazing (placing) the inner surface of the joint portion (flat portion) 6. As the coolant passage 4, in addition to the coolant passage shaped body 1, a coolant passage tube (tube) in which a composite material is roll-formed into a tubular shape and an end portion is subjected to an electric resistance welding, or an extruded multi-hole tube of an Al alloy material is used. By the way, in the heat exchanger of the type to be assembled by brazing, the thickness of each member is being reduced for the purpose of cost reduction and weight reduction. Therefore, the Al alloy material and the composite material have improved strength and corrosion resistance. It has been strongly demanded, and conventionally, improvement in strength by alloy elements such as Si, Cu, and Mg, and improvement in corrosion resistance by addition of Ti have been attempted.

[0003]

By the way, the Al alloy material or the core material is eroded by the heating at the time of brazing, and the corrosion resistance and strength of the Al alloy material or the core material are reduced. This problem has become more serious with the thinning of the Al alloy material or the core material. Accordingly, the present inventors have conducted intensive studies on the prevention of brazing of the core material and the like, and if the core material does not completely recrystallize during brazing and a fine subcrystal grain structure remains, the brazing material will erode. Cu promotes erosion, but Fe
It was found that co-presence of a suitable amount mitigates the promoting action thereof, and based on these findings, the research was advanced to complete the present invention. The present invention relates to an Al alloy material for a heat exchanger or a composite material for a heat exchanger using the Al alloy material, in which erosion of the brazing is suppressed during brazing and excellent corrosion resistance and required high strength are obtained, and the Al alloy It is an object of the present invention to provide a method for producing a material or the composite material.

[0004]

According to the first aspect of the present invention,
0.4 to 2.0% by weight of Fe (hereinafter abbreviated as%), C
u is 0.3 to 2.0%, Mn is 0.5 to 2.0%, Ti
Is less than 0.03% (including 0%), and the balance is a finish-annealed material after cold-rolling of an Al alloy composed of Al and inevitable impurities, the surface being perpendicular to the rolling direction of the finish-annealed material. An aluminum alloy material for a heat exchanger, having an average crystal grain size of 40 μm or less.

The invention according to claim 2 is characterized in that Fe is set to 0.4 to 0.4.
2.0%, Cu 0.3-2.0%, Mn 0.5-
2.0%, Zn 0.005 to 0.2%, Ti 0.02%
An average crystal grain of a surface of the Al alloy containing less than 3% (including 0%) and the balance being Al and unavoidable impurities after cold rolling, the plane being perpendicular to the rolling direction of the finish annealed material. An aluminum alloy material for a heat exchanger having a diameter of 40 μm or less.

According to a third aspect of the present invention, the content of Fe is set to 0.4 to
2.0%, Cu 0.3-2.0%, Mn 0.5-
2.0%, contains less than 0.03% (including 0%) of Ti, and further contains 0.03% to 1.0% of Mg, 0.03%
A finish-annealed material after cold rolling of an Al alloy containing one or more of 0.3% and Zr of 0.03 to 0.3%, with the balance being Al and unavoidable impurities, The average grain size of the surface perpendicular to the rolling direction of the finish-annealed material is 40 μm
An aluminum alloy material for a heat exchanger, characterized in that:

According to a fourth aspect of the present invention, when Fe is set to 0.4 to
2.0%, Cu 0.3-2.0%, Mn 0.5-
2.0%, Zn 0.005 to 0.2%, Ti 0.02%
Less than 3% (including 0%)
1.0%, Cr 0.03-0.3%, Zr 0.03-
A finish-annealed material after cold rolling of an Al alloy containing one or more of 0.3% and the balance being Al and unavoidable impurities, wherein the finish is perpendicular to the rolling direction of the finish-annealed material. An aluminum alloy material for a heat exchanger, wherein the average crystal grain size of the surface is 40 μm or less.

According to a fifth aspect of the present invention, there is provided an Al alloy according to any one of the first to fourth aspects as a core material, and Al-S
It is a finish-annealed material after cold rolling of a composite material clad with an i-type brazing alloy, wherein an average crystal grain size of a surface perpendicular to a rolling direction of a core portion of the finish-annealed material is 40 μm or less. A composite material for a heat exchanger.

According to a sixth aspect of the present invention, there is provided an Al alloy cold-rolled material according to any one of the first to fourth aspects, wherein the cold-rolled material is heated at a temperature rising rate of 30 ° C./min or more. 1-6
This is a method for producing an aluminum alloy material for a heat exchanger, wherein the aluminum alloy material is held for 0 second and then subjected to finish annealing under conditions of lowering the temperature at a rate of 30 ° C./min or more.

According to a seventh aspect of the present invention, the cold-rolled material of the Al alloy according to the first to fourth aspects is heated at a rate of 30 ° C./min or more, and is heated at a temperature of 300 to 550 ° C. A method for producing an aluminum alloy material for a heat exchanger, comprising: holding for 60 seconds, performing finish annealing under a condition of lowering the temperature at a rate of 30 ° C./min or more, and then applying a prestrain of 1 to 5%. .

[0011] According to an eighth aspect of the present invention, a cold-rolled material of the composite material according to the fifth aspect is heated at a heating rate of 30 ° C / min or more, and at a temperature of 300 to 550 ° C for 1 to 60 seconds. Hold and
A method for producing an aluminum alloy composite material for a heat exchanger, comprising: performing finish annealing under a condition of lowering the temperature at a rate of 30 ° C./min or more.

According to a ninth aspect of the present invention, the cold-rolled material of the composite material according to the fifth aspect is heated at a rate of 30 ° C./min or more at a temperature of 300 to 550 ° C. for 1 to 60 seconds. Hold and
A method for producing an aluminum alloy composite material for a heat exchanger, comprising: performing finish annealing under a condition of lowering the temperature at a rate of 30 ° C./min or more, and then applying a prestrain of 1 to 5%.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The alloy elements of the Al alloy described in claim 1 will be described below. Fe and Cu are effective in improving the strength and accelerating the recrystallization. Due to the recrystallization accelerating effect, the recrystallization is appropriately performed by heating at the time of brazing to the core material of the composite material, and the erosion of the wax is suppressed. Fe content of 0.4 to
The reason for setting the content to 2.0% is that if the content is less than the lower limit, the effect cannot be sufficiently obtained, and if the content exceeds the upper limit, the corrosion resistance is reduced. Desirable content of Fe is 0.5-1.5%,
Furthermore, it is 0.7 to 1.1%.

The reason why the content of Cu is limited to 0.3 to 2.0% is that if the Cu content is less than the lower limit, the effect cannot be sufficiently obtained.
If the upper limit is exceeded, the base material (matrix) may be melted. Desirable content of Cu is 0.5 to
1.5%, and further 0.7 to 1.3%. Although Cu has an action of accelerating the erosion of the wax, the erosion action is suppressed by coexisting an appropriate amount of Fe (0.4 to 2.0%).

Mn contributes to the improvement of strength by forming a solid solution in the Al matrix during brazing. 0.5-
The reason for setting the content to 2.0% is that if the content is less than 0.5%, the effect cannot be sufficiently obtained, and if the content exceeds 2.0%, the rolling workability and the formability are reduced. A particularly desirable content of Mn is 0.9 to 1.6%. Ti contributes to improvement of corrosion resistance. The reason for defining the content to be less than 0.03% (including 0%) is that if the content is 0.03% or more, recrystallization of the core material (Al alloy) during brazing is suppressed.

In the first aspect of the present invention, the average grain size of the plane perpendicular to the rolling direction of the finish-annealed material after the cold rolling of the Al alloy is specified to be 40 μm or less. The reason is 40 μm
Is exceeded, the core material (Al alloy) is not completely recrystallized by heating at the time of brazing, and a fine sub-crystal grain structure remains.

According to the second aspect of the present invention, there is provided the first aspect of the present invention.
1 alloy contains Zn in an appropriate amount. Zn is taken into the segregated portion of Cu at the crystal grain boundary, lowers the potential near the crystal grain boundary, suppresses intergranular corrosion, and contributes to improvement of corrosion resistance.
The reason why the content of Zn is defined to be 0.005 to 0.2% in the present invention is that if the content is less than 0.005%, the effect is not sufficiently obtained, and if it exceeds 0.2%, the corrosion resistance is rapidly reduced. That's why. The content of Zn is particularly preferably 0.02 to 0.13%.

The invention according to claim 3 is the invention according to claim 1,
One of the alloys contains one or more of Mg, Cr, and Zr to further improve the strength. M
The reason for defining the content of g to be 0.03 to 1.0% is as follows.
If it is less than 0.03%, the effect cannot be obtained sufficiently, and
%, The brazing property is reduced. Also C
The reason that the content of each of r and Zr is specified to be 0.03 to 0.3% is that, when the content is 0.03%, the effect is not sufficiently obtained. This is because cracks occur.

The invention according to claim 4 is the invention according to claim 2,
1 alloy containing one or more of Mg, Cr, and Zr to further improve the strength.
The effects of g, Cr, and Zr and the reasons for defining their contents are the same as those of the third aspect of the invention.

According to a fifth aspect of the present invention, there is provided a composite material comprising the Al alloy according to the first to fourth aspects as a core material, and an Al-based alloy on one or both surfaces thereof.
It is a two-layer or three-layer clad material in which a brazing material of a Si-based alloy is clad.

The Al alloy material according to claims 1 to 4 or the core material of the composite material according to claim 5 may contain other elements such as impurity elements as long as various properties are not reduced. Absent. Specifically, Si 0.4% or less, Ni
0.3% or less, Ge 0.2% or less, Ga 0.2% or less,
If the Li is 0.1% or less, there is no problem.

The Al alloy material according to the first to fourth aspects of the present invention
For example, a DC casting method of the Al alloy according to claims 1 to 4,
It is manufactured by homogenization, hot rolling, cold rolling and finish annealing of an ingot cast by a conventional method such as a caster (twin-roll caster). The invention according to claim 6 is that the finish annealing is heated at a heating rate of 30 ° C./min or more, and the finish annealing is performed at 300 to 550.
The temperature is maintained for 1 to 60 seconds, and then the temperature is reduced at a rate of 30 ° C./min or more. The reason for defining the conditions in this way is that either the rate of temperature increase or the rate of temperature decrease is 30 ° C.
/ Minute, the holding temperature exceeds 550 ° C., and the holding time exceeds 60 seconds, the crystal grain size of the Al alloy material exceeds 40 μm. This is because recrystallization is incomplete even in less than a second, and in any case, the erosion of the brazing material into the core material (Al alloy) during the heating by brazing is not sufficiently suppressed.

According to a seventh aspect of the present invention, there is provided a manufacturing method in which a pre-strain of 1 to 5% is imparted after the finish annealing performed in the sixth aspect of the invention to facilitate recrystallization. By applying the pre-strain in this way, recrystallization proceeds more reliably during brazing even in a portion such as a flat portion (see FIG. 1) of the coolant passage shape where almost no strain is introduced by press forming. Wax erosion is suppressed. The pre-strain is given by an ordinary method using a tension leveler, a stretcher, or the like.

[0024] According to an eighth aspect of the present invention, there is provided an Al alloy according to any one of the first to fourth aspects as a core material, and Al-S
The finish annealing after the cold-rolled material of the composite material clad with the i-type brazing alloy is raised at a rate of 30 ° C./min or more.
Hold at a temperature of 0 to 550 ° C. for 1 to 60 seconds, then 30
In the method for producing an aluminum alloy composite for a heat exchanger performed at a temperature lowering rate of not less than ° C./min, the reason for specifying the finish annealing conditions is the same as that of the invention according to claim 6.

According to a ninth aspect of the present invention, there is provided a manufacturing method for imparting 1 to 5% of strain after the finish annealing performed in the eighth aspect of the present invention. This is the same as the case of the invention of the above.

When the Al alloy material or the composite material of the present invention is assembled to a heat exchanger core, the brazing material includes Al-Si based J
IS4343 alloy, JIS4045 alloy, or JIS
4004 alloy or the like can be used. The melting point of the brazing material may be lowered by adding about 0.1 to 5% of Cu and about 0.5 to 10% of Zn to the Al-Si alloy. In addition, other elements may be added as long as the brazing property is not reduced.

In the invention according to claim 8 or 9, any method such as a rolling method, a method of applying a mixture of a brazing material powder and a binder, and a thermal spraying method can be applied to clad the brazing material on the core material. In the above-mentioned method, it is desirable to apply or braze a brazing material after the core material is strained.

The Al alloy material and the composite material of the present invention can be used not only for a refrigerant passage tube of a heat exchanger such as an evaporator and a radiator, but also for a header plate and a tank. In addition, it can be used for any member that requires strength, corrosion resistance, and wax erosion resistance other than the heat exchanger, such as a heater tube and a condenser tube.

[0029]

The present invention will be described below in detail with reference to examples. (Example 1) Both sides of a die casting ingot of an Al alloy for a core material having the specified composition of the present invention (No. 1 to 10) shown in Table 1 were cut to a thickness of 40 mm and then homogenized at 600 ° C. for 8 hours. This was processed to produce a core material. JIS4343 alloy (Al-Si alloy)
Was cast on both sides, and then hot-rolled and cold-rolled in this order to produce a brazing material having a thickness of 5 mm. next,
The brazing material, the core material, and the brazing material are stacked in this order and hot-rolled at a starting temperature of 520 ° C. to form a three-layer clad material having a thickness of 3.5 mm, which is cold-rolled to a thickness of 0.6 mm. Then, the cold-rolled material is intermediately annealed at 360 ° C. for 2 hours, further cold-rolled to a thickness of 0.35 mm, and then maintained at a temperature rising rate of 80 ° C./min at a temperature of 480 ° C. for 10 seconds.
Finish annealing by cooling at a cooling rate of 0 ° C / min.
Material.

Example 2 A 2% strain was applied to the tempered O material obtained in Example 1 using a tension leveler to produce a pre-strained material.

(Comparative Example 1) Non-specified composition of the present invention shown in Table 2
A tempered O material or a pre-strained material was produced in the same manner as in Example 1 or Example 2 except that the Al alloys (Nos. 11 to 13) were used.

(Comparative Example 2) An aluminum alloy having the composition specified in the present invention (No. 5) shown in Table 2 was used, and retained during finish annealing at 550.
A tempered O material or a pre-strained material was produced in the same manner as in Example 1 or Example 2 except that the temperature was changed to 100 ° C. for 100 seconds.

A refrigerant passage tube or a refrigerant passage shape A was prepared using each of the tempered O materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2, and a refrigerant passage shape was formed using a pre-strained material. A body B was prepared, and a heat exchanger core was assembled by brazing using the refrigerant passage tubes or the refrigerant passage shaped bodies A and B. For the assembly of the heat exchanger core, a 0.1 mm thick Al-0.5% Si-0.2% Cu-1.0% Mn-
A fin obtained by corrugating a 2.0% Zn alloy strip was used.

From each of the heat exchanger cores, the refrigerant passage tubes or the refrigerant passage shapes A and B were cut out, and the crystal grain size of the surface perpendicular to the rolling direction of the core material and the degree of erosion of the wax were examined. Regarding the crystal grain size, a crystal structure was revealed by an electrolytic polishing method (Barker method), and the average crystal grain size was measured by an ASTM method. The degree of wax erosion was examined by observing a cross section of the refrigerant passage tube or the refrigerant passage shape body. Further, the corrosion resistance of the heat exchanger core was examined. The corrosion resistance was evaluated by performing a corrosion test under the following conditions, and measuring a maximum pit depth generated on the outer surface of the refrigerant passage tube or the refrigerant passage-shaped body after the corrosion test.
The corrosion test was performed by spraying 5% saline for 4 hours (40 ° C., 9
8% RH) → 4hr drying (55 ° C, 30% RH) → 4h
The cycle of r-wet (50 ° C., 98% RH) was repeated for one month. The results are shown in Tables 3 and 4.

[0035]

[Table 1] (Note) Unit wt%.

[0036]

[Table 2] (Note) Unit wt%.

[0037]

[Table 3] (Note) Erosion: wax erosion, ◎ no erosion, ○ slight erosion. Pitting depth: Pitting depth after corrosion test. Refrigerant passage shape body A: no pre-strain, B: pre-strain.

[0038]

[Table 4] (Note) Erosion: wax erosion, ◎ no erosion, ○ slight erosion, × erosion. Pitting depth: Pitting depth after corrosion test. Refrigerant passage shape body A: no pre-strain, B: pre-strain.

As is clear from Tables 3 and 4, all of the alloys Nos. 1 to 10 of the present invention exhibited little wax erosion. This is because Fe and Cu were contained in appropriate amounts, and the crystal grains of the core material were as small as 40 μm or less, so that the core material had a completely recrystallized structure by heating with brazing. Erosion was slightly observed in the refrigerant passage-shaped body A without pre-strain, but it was practically acceptable. In Nos. 4, 5, 6, and 9 containing an appropriate amount of Zn, the high potential of the grain boundary due to Cu was relaxed, and the corrosion resistance (pitting corrosion) was significantly improved. The strength was separately measured, and it was confirmed that each had the necessary strength for the heat exchanger core. On the other hand, No. 11 of the comparative example had less Fe, and
No. 13 has less Fe and Cu,
Because of the large amount of Ti, No. 14 had large recrystallized grains of the core material, so that the core material did not have a completely recrystallized structure by heating during brazing, so that the core material was eroded by the wax. Corrosion resistance (pitting depth) also decreased with the erosion of the wax.
In No. 13, the large amount of Zn also affects the reduction in corrosion resistance.

[0040]

As described above, since the Al alloy material or the core material of the composite material of the present invention contains an appropriate amount of Fe, Cu and Mn, the strength required for the heat exchanger core can be obtained. In addition, the action of the Fe and Cu, and the recrystallized grain size of a plane perpendicular to the rolling direction of the Al alloy material or the core material is 40 μm.
m or less, the core material of the Al alloy material or the composite material will have a completely recrystallized structure at the time of brazing and heating after processing the Al alloy material or the composite material into the refrigerant passage tube or the refrigerant passage shape body. Erosion is suppressed. In addition, by adding an appropriate amount of Ti, the corrosion resistance is improved. Also Z
By containing n in an appropriate amount, the decrease in corrosion resistance due to Cu is improved. The strength is further improved by adding one or more of Mg, Cr and Zr in an appropriate amount. The Al alloy material or the composite material of the present invention can be manufactured by a conventional method including cold rolling and finish annealing, and by defining the finish annealing conditions, the Al alloy material or the composite material is perpendicular to the rolling direction of the core material. The recrystallized grain size of the surface can be more reliably reduced to 40 μm or less. By applying a pre-strain after the finish annealing, a complete recrystallized structure can be more reliably obtained during brazing. Therefore, an industrially remarkable effect is achieved.

[Brief description of the drawings]

FIG. 1 is a partial perspective explanatory view of a heat exchanger (radiator) for an automobile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerant-passage-shaped body through which a refrigerant passes in the longitudinal direction 2 Fin 3 Vertical refrigerant passage 4 Composite material (brazing sheet) 5 Longitudinal refrigerant passage 6 Joint (flat part)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (reference) // C22F 1/00 601 C22F 1/00 601 604 604 623 623 623 627 627 630 630M 651 651A 685 685Z 691 691A 691B 691C 692 692A 694 694A

Claims (9)

[Claims] 1. Fe is 0.4 to 2.0% by weight (hereinafter abbreviated as%), Cu is 0.3 to 2.0%, and Mn is 0.5 to 2.0% by weight.
A finish-annealed material after cold rolling of an Al alloy containing 2.0% and less than 0.03% (including 0%) of Ti and the balance being Al and unavoidable impurities, wherein the finish-annealed material is rolled. An aluminum alloy material for a heat exchanger, wherein an average crystal grain size of a plane perpendicular to the direction is 40 μm or less. 2. An alloy containing 0.4 to 2.0% of Fe and 0.3% of Cu.
~ 2.0%, Mn is 0.5 ~ 2.0%, Zn is 0.00
A finish-annealed material after cold rolling of an Al alloy containing 5 to 0.2% and less than 0.03% (including 0%) of Ti, with the balance being Al and unavoidable impurities, wherein the finish-annealed material is An aluminum alloy material for a heat exchanger, wherein the average crystal grain size of a plane perpendicular to the rolling direction is 40 μm or less. 3. An alloy containing 0.4 to 2.0% of Fe and 0.3% of Cu.
~ 2.0%, Mn 0.5 ~ 2.0%, Ti 0.03%
% (Including 0%).
1.0%, Cr 0.03-0.3%, Zr 0.03-
A finish-annealed material after cold rolling of an Al alloy containing one or more of 0.3% and the balance being Al and unavoidable impurities, wherein the finish is perpendicular to the rolling direction of the finish-annealed material. An aluminum alloy material for a heat exchanger, wherein the average crystal grain size of the surface is 40 μm or less. 4. An alloy containing 0.4 to 2.0% of Fe and 0.3% of Cu.
~ 2.0%, Mn is 0.5 ~ 2.0%, Zn is 0.00
5 to 0.2%, contains less than 0.03% (including 0%) of Ti, and further contains 0.03 to 1.0% of Mg, 0.03 to
A finish-annealed material after cold rolling of an Al alloy containing one or more of 0.3% and Zr of 0.03 to 0.3%, with the balance being Al and unavoidable impurities, The average grain size of the surface perpendicular to the rolling direction of the finish-annealed material is 40 μm
An aluminum alloy material for a heat exchanger, comprising: 5. A finish-annealed material after cold rolling of a composite material comprising the Al alloy according to claim 1 as a core material and an Al—Si-based brazing alloy clad on one or both surfaces thereof, A composite material for a heat exchanger, wherein the average crystal grain size of a surface of a core portion of a finish annealing material perpendicular to a rolling direction is 40 μm or less. 6. The cold-rolled material of any one of claims 1 to 4 is heated at a heating rate of 30 ° C./min or more,
A method for producing an aluminum alloy material for a heat exchanger, comprising: holding at a temperature of 300 to 550 ° C. for 1 to 60 seconds, and thereafter performing finish annealing under a condition of lowering the temperature at a rate of 30 ° C./min or more. 7. The cold-rolled material of the Al alloy according to claim 1 is heated at a heating rate of 30 ° C./min or more to obtain a temperature of 300-5.
Hold at a temperature of 50 ° C. for 1 to 60 seconds, then finish annealing at a temperature lowering rate of 30 ° C./min or more,
A method for producing an aluminum alloy material for a heat exchanger, wherein a prestrain of up to 5% is provided. 8. The cold-rolled material of the composite material according to claim 5, which is heated at a heating rate of 30 ° C./min or more, and is heated to 300 to 55 ° C.
A method for producing an aluminum alloy composite material for a heat exchanger, comprising: holding at a temperature of 0 ° C. for 1 to 60 seconds; and thereafter, performing finish annealing under conditions of lowering the temperature at a rate of 30 ° C./min or more. 9. The cold-rolled material of the composite material according to claim 5, which is heated at a heating rate of 30 ° C./min or more to 300 to 55.
Hold at a temperature of 0 ° C. for 1 to 60 seconds, then finish annealing at a temperature lowering rate of 30 ° C./min or more,
A method for producing an aluminum alloy composite for a heat exchanger, wherein a prestrain of 5% is imparted.