JP2000204427A - Aluminum alloy clad material for heat exchanger excellent in brazing property and corrosion resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aluminum alloy clad material for heat exchangers excellent in brazing property and corrosion resistance and capable of being suitably used for a radiator, heater core, or the like, as a tube material of a heat exchanger for automobile. SOLUTION: This material is obtained by cladding a sacrificial anode material having the composition containing one or more metals of 0.5-4.0% Zn, 0.005-0.1% In and 0.01-0.1% Sn and regulated to <=0.3% Si, <=0.5% Fe and <=0.04% Mg and the balance Al with impurities on one surface of aluminum alloy core material containing 0.6-2.0% Mn, 0.3-1.0% Cu and 0.06-1.0% Si and regulated to <=0.4% Fe and <=0.04% Mg and the balance Al with impurities, and cladding a brazing filler metal containing 6-14% Si and 0.06-0.7% Fe and regulated to <=0.04% Mg and <=0.006% Ca and the balance Al with impurities on another surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy clad material for a heat exchanger having excellent brazing properties and corrosion resistance, and more particularly to a heat exchanger for automobiles, such as a radiator or a heater core, which is joined by brazing. Suitable for fluid passage components (tube material), header plate material,
The present invention relates to an aluminum alloy clad material for a heat exchanger having excellent brazing properties and corrosion resistance in brazing using a fluoride-based flux.

[0002]

2. Description of the Related Art Tube materials and header plate materials for automotive heat exchangers, such as radiators and heater cores, include J
Al-Mn alloy such as IS3003 alloy as the core material,
One surface of the core material is clad with an Al-Si brazing material,
A three-layer clad material of an aluminum alloy clad with a sacrificial anode material made of an Al-Zn-based alloy or an Al-Zn-Mg-based alloy on the other surface is used.

An Al-Si brazing material is clad for joining a tube to a fin and for brazing a tube to a header plate. The brazing is generally performed in an inert gas atmosphere. In the above, brazing using a fluoride-based flux is applied, but vacuum brazing may be performed in some cases. The sacrificial anode material constitutes the inner surface of the tube and contacts the working fluid during use of the heat exchanger to exert a sacrificial anode effect, thereby preventing pitting and crevice corrosion of the core material. The fin bonded to the outer surface of the tube exerts a sacrificial anode effect to prevent corrosion of the core material.
An aluminum alloy to which Zn, Sn, In, or the like is added is applied.

In recent years, from the viewpoint of reducing the weight of automobiles, there has been a strong demand for reducing the weight and cost of heat exchangers for automobiles.
It is necessary to further reduce the thickness of a heat exchanger constituent material such as a tube material. For this reason, it has been attempted to increase the strength by adding various elements to the tube material and the header plate material. However, the inclusion of the added components causes the corrosion resistance to decrease, and the brazing is accompanied by the thinning of the material. Therefore, there arises a problem in the productivity and durability of the heat exchanger. Therefore, there is a strong demand for the development of a heat exchanger material having excellent brazing properties and corrosion resistance.

[0005]

SUMMARY OF THE INVENTION The present invention provides a composition of a core material, a sacrificial anode material and a brazing material in a three-layer clad material, and a composition thereof, in order to obtain an aluminum alloy material for a heat exchanger satisfying the above-mentioned requirements. The relationship between brazing properties and corrosion resistance in brazing using a combination of fluorides and fluxes in particular was made as a result of repeated experiments and studies from various angles. In particular, it is an object of the present invention to provide an aluminum alloy clad material for a heat exchanger having excellent brazing properties and corrosion resistance which can be suitably used as a tube material and a header plate material for a heat exchanger for an automobile.

[0006]

According to the present invention, there is provided an aluminum alloy clad material for a heat exchanger having excellent brazing properties and corrosion resistance according to the first aspect of the present invention. Material is clad and the other surface is Al-S
An aluminum alloy clad material clad with an i-type brazing material, wherein the core material is Mn: 0.6-2.0%, Cu: 0.3-1.
0%, Si: 0.06 to 1.0%, and the Fe content is 0.1%.
4% or less, the content of Mg is regulated to 0.04% or less, and the balance is made of an aluminum alloy composed of aluminum and unavoidable impurities. The sacrificial anode material is Zn: 0.5 to 4.0%,
n: 0.005 to 0.1%, Sn: one or more of 0.01 to 0.1%, the content of Si is 0.3% or less,
The content of e is controlled to 0.5% or less, the content of Mg is controlled to 0.04% or less, and the balance is made of an aluminum alloy composed of aluminum and impurities.
e: contains 0.06 to 0.7%, regulates the content of Mg to 0.04% or less, the content of Ca to 0.006% or less, and is composed of an aluminum alloy containing the balance of Al and inevitable impurities. .

According to a second aspect of the present invention, there is provided the aluminum alloy clad material according to the first aspect, wherein the brazing material further comprises
i: 0.01 to 0.4%, wherein the aluminum alloy clad material according to claim 3 of the present invention is characterized in that, in claim 1 or 2, the core material further comprises Ti: 0.06 to 0.35.
%.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The significance of alloy components of a core material, a sacrificial anode material and a brazing material in an aluminum alloy clad material of the present invention and reasons for limiting the components will be described. (1) Core Material Mn in the core material functions to improve the strength, increase the potential of the core material, increase the potential difference from the sacrificial anode material, and increase the corrosion resistance. The preferred content range is 0.6 to 2.
0%, the effect is small at less than 0.6%, 2.0%
If contained in excess of the above, a coarse compound is formed during casting,
As a result of impairing the rolling processability, it is difficult to obtain a sound plate.

[0009] Cu functions to improve the strength, increase the potential of the core material, increase the potential difference between the sacrificial anode material and the brazing material, and increase the corrosion resistance. Further, Cu in the core material diffuses into the sacrificial anode material and the brazing material at the time of brazing heating, and forms a gentle concentration gradient. As a result, the potential on the core material side becomes noble, the potential on the surface side of the sacrificial anode material and the surface side of the brazing material become low, and a gentle potential gradient is formed in the sacrificial anode material and the brazing material, resulting in corrosion. The form is a horizontal spread general corrosion type. The preferable content of Cu is in the range of 0.3 to 1.0%. If the content is less than 0.3%, the effect is small, and if it exceeds 1.0%, the corrosion resistance of the core material is lowered, and the melting point is lowered, so that the local content during brazing is reduced. Melting is likely to occur. The more preferred content of Cu is 0.3 to
It is in the range of 1.0%.

[0010] Si has the effect of improving the strength.
The preferable content range of Si is 0.06 to 1.0%, and 0.06%
If it is less than 1.0%, the effect is not sufficient, and if it exceeds 1.0%, the corrosion resistance is lowered, and the melting point is lowered, so that local melting tends to occur.

[0011] Fe as an impurity serves as a cathode with respect to the aluminum base material and lowers corrosion resistance.
It is preferable to regulate it to 4% or less. Further, since a high-purity aluminum ingot having an extremely low Fe content is expensive and impractical, a more preferable Fe content is 0.
01 to 0.4%.

Mg is added in an amount of 0.04% from the viewpoint of reducing the brazing property.
It is preferable to limit to the following. If the content exceeds 0.04%, in the case of an inert gas atmosphere brazing using a fluoride-based flux, Mg reacts with the flux to form MgF.
_Since a compound such as ₂ is generated, the absolute amount of the flux is insufficient, and the brazing property is reduced. The more preferred content of Mg is in the range of 0.02% or less.

[0013] Ti has the effect of further improving the corrosion resistance of the core material. That is, Ti is divided into a high-concentration region and a low-concentration region, and they are alternately distributed in the plate thickness direction to form a layer. As a result, the progress of corrosion in the sheet thickness direction is hindered, and the pitting resistance is improved. The preferable content of Ti is in the range of 0.06 to 0.35%. If the content is less than 0.06%, the effect is not sufficient. If the content is more than 0.35%, a coarse compound is formed at the time of casting, which hinders the rolling of the material, resulting in a sound cladding. It becomes difficult to obtain wood.

In the core material, Zn,
Components such as Cr and Zr may be included. Where Z
Since n makes the potential of the core material low and reduces the potential difference between the sacrificial anode material and the brazing material and lowers the corrosion resistance, it is preferable to limit the content to 0.2% or less. Although it can be added for the purpose, it is preferable to limit each to 0.3% or less because it impairs processability.

(2) Sacrificial anode material Zn in the sacrificial anode material makes the potential of the sacrificial anode material low, maintains the sacrificial anode effect on the core material, makes the clad material corroded completely by corrosion, and It functions to prevent pitting and crevice corrosion. The preferred range of Zn content is 0.5-4.0%. If the Zn content is less than 0.5%, the effect is not sufficient, and if it exceeds 4.0%, the self-corrosion resistance is reduced and the sacrificial anode material is greatly consumed by corrosion. In addition, the sacrificial anode effect is not maintained for a long time. If the content exceeds 0.4%, the effect is saturated.

In lowers the potential of the sacrificial anode material and helps the sacrificial anode effect to the core material. In
Is preferably in the range of 0.005 to 0.1%,
If the content is less than 5%, the effect is small. If the content exceeds 0.1%, the effect is saturated, the self-corrosion resistance of the sacrificial anode material is reduced, and the rolling processability is deteriorated.

Sn serves to make the potential of the sacrificial anode material low and to surely impart the sacrificial anode effect to the core material. Sn
Is preferably in the range of 0.01 to 0.1%, and 0.01%
If the content is less than 0.1%, the effect is small. If the content exceeds 0.1%, the effect is saturated, the self-corrosion resistance of the sacrificial anode material is reduced, and the rolling processability is deteriorated.

Since both Si and Fe as impurities serve as cathodes for the aluminum base material and lower the self-corrosion resistance, the content of Si is 0.3% or less, and
Is preferably regulated to 0.5% or less. Also,
Since high-purity aluminum ingot with extremely small amounts of Si and Fe is expensive and impractical, Si: 0.01 to 0.3%,
Fe: More preferably in the range of 0.01 to 0.5%.

Mg in the sacrificial anode material reacts with fluorine (F) as a flux component to generate a compound such as MgF ₂ when brazing is performed using a fluoride-based flux. Since the amount is insufficient and the brazing property is reduced, it is preferable to regulate the amount to 0.04% or less.
It is more preferably regulated to 0.02% or less.

In the sacrificial anode material, Mn, Cu, C
Elements such as r, Zr, and Ti may be contained in small amounts as long as the effects of the invention are not impaired.
Since the potential of the sacrificial anode material is made noble and the potential difference from the core material is reduced to reduce the sacrificial anode effect, it is preferable to limit each to 0.3% or less. In addition, Cr, Zr and Ti
May be added for the purpose of refining the crystal grains, etc., but it impairs the processability, so it is preferable to limit each to 0.3% or less.

(3) Brazing material Si in the brazing material functions to lower the melting point of the brazing material and increase the fluidity of the brazing material. The preferred content of Si is 6-14.
%, And less than 6% is not effective enough.
If it exceeds 14%, the melting point of the brazing material will be high, and workability during the production of the brazing material will be reduced.

Fe has the effect of refining the structure of the brazing material and increasing the fluidity of the brazing material. The preferred content of Fe is
When the content is less than 0.06%, the effect is small, and when the content exceeds 0.7%, the effect is saturated, and the cathode becomes a cathode with respect to the aluminum base material to form an Al-Fe-based compound. The amount increases and the corrosion resistance decreases.

When brazing is performed using a fluoride-based flux, Mg in the brazing material is easily concentrated on the surface of the brazing material during the brazing heating process, and reacts with fluorine (F) as a flux component. Since a compound such as MgF ₂ is generated, the absolute amount of the flux is insufficient, and the brazing property is deteriorated. It is more preferably regulated to 0.02% or less.

Since Ca forms a dense oxide on the surface of the brazing material, the wettability and spreadability of the brazing material are reduced, and the brazing property is impaired. Since the decrease in brazing property becomes significant when the Ca content exceeds 0.006%, the Ca content is preferably regulated to 0.006% or less. More preferably, it is 0.004% or less.

Bi lowers the melting point of the brazing material and improves the wettability and spreadability of the brazing material. The preferred content of Bi is
If it is less than 0.01%, the effect is small, and if it exceeds 0.4%, the effect is saturated and the self-corrosion resistance of the brazing material is reduced. The more preferable content range of Bi is 0.1 to 0.4%.

In order to improve the brazing property, a small amount of, for example, 0.1% or less of Be, Sr, Li, Na
One or more of the above may also be contained. In order to make the potential of the brazing material low, to give the brazing material a sacrificial anode effect on the core material, and to improve the corrosion resistance of the clad material, Zn,
One or more of In and Sn may be contained. However, when the contents of Zn, In, and Sn are large, the self-corrosion resistance is reduced, and the corrosion consumption of the brazing material becomes severe,
Since the sacrificial anode effect is not maintained for a long time, the content of Zn is 4% or less, and the content of In and Sn is 0.1% each.
It is preferable to regulate it to 1% or less. Also, Mn, Cu,
Ti, Cr, Zr, Ni, and the like may be added in a range that does not impair the effects of the present invention in order to improve the strength of the brazing filler metal. However, if the added amount increases, the self-corrosion resistance decreases. % Is preferred.

The aluminum alloy clad material for a heat exchanger of the present invention is obtained by agglomerating an aluminum alloy constituting a core material, a sacrificial anode material and a brazing material by, for example, semi-continuous casting and, if necessary, homogenizing. Each is hot-rolled to a predetermined thickness, then each material is combined, and in accordance with a conventional method, a clad material is formed by hot-rolling, finally cold-rolled to a predetermined thickness, and if necessary, manufactured through a process of annealing. You.

The aluminum alloy clad material of the present invention is
In order to form a tube material for a heat exchanger for an automobile, such as a radiator or a heater core, a clad plate is bent and a butt portion is welded or brazed to form a tube. The sacrificial anode material layer constitutes the endothelial layer and contacts the working fluid,
The brazing material layer becomes the outer skin layer. The heat exchanger is assembled by brazing an aluminum alloy fin material to the outer skin layer.

[0029]

Example 1 An aluminum alloy for a core material having the composition shown in Table 1 was ingoted by continuous casting, and after homogenization treatment, a 25 mm-thick surface was chamfered to obtain a core material. Further, an alloy for a brazing filler metal having a composition shown in Table 2 and an alloy for a sacrificial anode material having a composition shown in Table 3 were ingoted in the same manner as the alloy for the core material, and after face milling,
Hot rolling was performed to obtain a plate material having a thickness of 3 mm.
The brazing material and the sacrificial anode material were superimposed on both sides of the core material and hot rolled to obtain a clad material having a thickness of 3 mm. Thereafter, cold rolling, intermediate annealing and final cold rolling were performed to obtain a three-layer clad material (temper H14) having a thickness of 0.25 mm.

With respect to the obtained aluminum alloy clad material (test material), the strength after brazing was measured according to the following method, and the brazing property and the corrosion resistance were evaluated. The results are shown in Tables 4 and 5. (1) Strength after brazing A fluoride flux (concentration: 1%) is applied to the clad material in the same manner as the brazing condition, and heated to 600 ° C. (material temperature) of the brazing temperature in nitrogen gas for 5 minutes. After cooling, a tensile test was performed to measure the tensile strength.

(2) Brazing properties The clad material was cut into a width of 20 mm and a length of 40 mm, and as shown in FIG.
Clad material 2 made of 3003 alloy material (thickness 1 mm,
(Width 25 mm, length 40 mm) 3, combined with the inverted T-shaped joint 1, and applied a fluoride-based flux in the same manner as the brazing condition, and then heated to a temperature of 600 ° C. in a nitrogen gas atmosphere. 2 minutes, and as shown in FIG. 2, the cross-sectional areas A ₁ and A ₂ of the fillet portions 7 and 8 melt-formed at the corners of the inverted T-shaped joint 1 by heating were measured, and before the brazing heating, From the ratio to the cross-sectional area A ₀ of the brazing material, the flow coefficient K (K =
(A ₁ + A ₂ ) / A ₀ ) is obtained. The larger the flow coefficient K, the higher the ratio of the molten brazing material, the better the flowability of the braze, and the more excellent the brazeability. In the brazing of a three-layer clad material for an ordinary heat exchanger for an automobile, if the flow coefficient K is less than 0.20, poor brazing such as breakage of a fillet (formation of a fillet unformed portion) tends to occur. Is less than 0.20 or the one where the fillet is actually cut was evaluated as insufficient brazing (x), and the flow coefficient K of 0.20 or more was evaluated as good brazing.

(3) Corrosion Resistance The corrosion resistance on the outer surface side (the brazing material side) of the clad material is determined according to JIS H8681 after sealing the inner surface side (the sacrificial anode material side) of the inverted T-shaped joint after the brazing and heating. C
The ASS test was performed for 2 weeks, and the maximum corrosion depth of the general portion (the portion other than the fillet portion) of the clad material after the test was measured. In the fillet portion, 50% or more of the fillet area disappeared due to corrosion. Those having poor corrosion resistance (x) were evaluated as having poor corrosion resistance, and those having disappearance areas of less than 50% of the fillet area were evaluated as having good corrosion resistance.

The corrosion resistance on the inner surface side (the sacrificial anode material side) is determined by applying a fluoride-based flux (concentration: 1%) to a clad veneer and applying a brazing temperature of 600 ° C. (material temperature) in nitrogen gas. After heating for one minute, the outer surface side (the brazing material side) was sealed, and Cl ⁻ : 100 ppm, SO ₄ ²⁻ : 100 ppm,
After repeating a cycle of immersing in an aqueous solution containing HCO ₃ ⁻ : 100 ppm and Cu ²⁺ : 10 ppm, maintaining the temperature at 80 ° C. for 8 hours, and then allowing it to stand for 16 hours while allowing to cool to room temperature, for 2 months The maximum corrosion depth was measured.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

As can be seen from Tables 4 and 5, the test materials according to the present invention all show excellent tensile strength of 138 MPa or more after brazing, and the maximum corrosion depth on the inner surface side in the corrosion test is 0. It is 0.5 to 0.13 mm and has excellent corrosion resistance. As for brazing properties, good joints were formed. In addition, the clad material of the present invention had good workability and did not cause any problem in production.

Comparative Example 1 By continuous casting, an aluminum alloy for a core material having a composition shown in Table 6, an aluminum alloy for a brazing material having a composition shown in Table 7, and an aluminum alloy for a sacrificial anode material having a composition shown in Table 8 were obtained by continuous casting. Under the same conditions as in Example 1, a 0.25 mm thick aluminum alloy clad material (H14) was produced. Obtained clad material (test material)
, The tensile strength after brazing was measured according to the method of Example 1, and the brazing property and the corrosion resistance were evaluated. The results are shown in Tables 9 to 10.

[0041]

[Table 6]

[0042]

[Table 7]

[0043]

[Table 8]

[0044]

[Table 9] << Table note >> Flow coefficient *: Fillet cut

[0045]

[Table 10]

As can be seen from Tables 9 to 10, the test materials which did not satisfy the conditions of the present invention exhibited strength after brazing, brazing property,
One of the corrosion resistance is inferior. Test material No.34 and N
In o.41, the strength after brazing is low because the Mn content of the core material is small. Test materials No. 35 and No. 42 were inferior in workability and could not produce sound plate materials because of the large amount of Mn in the core material. Test materials No. 36 and No. 43 were each made of Cu
Since the amount is small, the strength after brazing is low, and in the corrosion test, a through hole is formed on the outer surface side, and the maximum corrosion depth on the inner surface side is large. Test materials No. 37 and No. 44 each had a large amount of Cu in the core material, so that local melting occurred in the core material during heating during brazing. Test materials No. 38 and No. 45 have low strength after brazing because the amount of Si in the core material is small. Test materials No. 39 and No. 46 have a large amount of Si in the core material,
Upon heating during brazing, local melting occurred in the core material.
In Test materials No. 40 and No. 50, since the amount of Mg in the core material was large, the brazing properties were inferior, and sufficient fillets were not formed during brazing, and the fillets were cut. Further, in Test Material No. 40, since the amount of Fe in the core material was large, the corrosion resistance was poor, and a through hole was formed on the inner surface side.

In Test Material No. 47, since the amount of Fe in the core material was large, the corrosion resistance was poor, and a through hole was formed on the outer surface side. Test material N
In o.48, since the amount of Ti in the core material is small, the maximum corrosion depth on the outer surface side and the inner surface side is larger than that of the clad material comprising the Ti-containing core material of the present invention. Test material No.49
Since the content of Ti in the core material was large, rolling became difficult, and a sound clad material could not be produced. Test material No.50 is
Since the core material corresponds to JIS3003 alloy and has a low Cu content, the strength after brazing is low. Further, since the amount of Fe was large, the corrosion resistance was poor, and a through hole was formed on the inner surface side. And M
Due to the large amount of g, the brazing property was inferior and the fillet was broken during brazing.

Test material No. 51 has a low flow coefficient and a low brazing property because the amount of Si in the brazing material is small. Test material N
In No. 52, since the amount of Si in the brazing material was large, rolling workability was poor, and a sound clad material could not be produced. Test material N
o.53 has a low flow coefficient due to the low Fe content of the brazing material, and has poor brazing properties.
Due to the large amount of e, the corrosion resistance was poor and the corrosion of the fillet portion on the outer surface side was remarkable. Test material No. 55 was made of Mg
The test material No. 56 was inferior in brazing property due to a large amount of Ca and a large amount of Ca in the brazing material.

Test material No. 57 has a smaller flow coefficient and lower brazing properties than the clad material of the present invention containing Bi because the amount of Bi in the brazing material is small. In test material No. 58, since the amount of Bi in the brazing material was large, self-corrosion of the fillet portion on the outer surface side was severe. Test materials No. 59 and No. 60 each had a large amount of Si and Fe in the sacrificial anode material, and test material No. 62 had a large amount of Zn in the sacrificial anode material.
No. 3 has a large amount of In in the sacrificial anode material, and test material No. 64 has a large amount of Sn in the sacrificial anode material.
Corrosion of the sacrificial anode material on the inner surface side is severe, and the sacrificial anode effect is not maintained for a long time. Test material No.61 is M of sacrificial anode material.
Due to the large amount of g, no fillet was formed at the time of brazing, resulting in an unjoined state. The sacrificial anode material Z
Since the contents of n, In, and Sn were small, the sacrificial anode effect was not sufficiently exhibited, and a through hole was formed on the inner surface side.

[0050]

According to the present invention, there is provided an aluminum alloy clad material for a heat exchanger having high strength after brazing, excellent brazing properties and corrosion resistance. This clad material can be particularly suitably used as a tube material constituting a fluid passage of a heat exchanger made of an aluminum alloy for automobiles.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an inverted T-shaped joint (before the test) used in an evaluation test of brazeability of the present invention.

FIG. 2 is a cross-sectional view showing an inverted T-shaped joint (after the test) used in an evaluation test of brazing property of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 inverted T-shaped joint 2 aluminum alloy clad material (high-strength aluminum alloy clad material for heat exchanger with excellent corrosion resistance) 3 3003 alloy material 4 brazing material 5 sacrificial anode material 6 core material 7, 8 fillet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 15/01 B32B 15/01 Z F28F 19/06 F28F 19/06 A // B23K 101: 14 103: 10 (72) Inventor Hirokazu Tanaka 5-11-3, Shimbashi, Minato-ku, Tokyo Sumitomo Light Metal Industries, Ltd. F-term (reference) AB31B AB31C AB40B AB40C BA03 BA07 BA10A BA10C BA14 EC01 GB90 JB02 JL12

Claims (3)

[Claims] An aluminum alloy clad material in which a sacrificial anode material is clad on one surface of a core material and an Al-Si brazing material is clad on the other surface, wherein the core material has Mn: 0.6.
~ 2.0% (wt%, the same applies hereinafter), Cu: 0.3 ~ 1.0%, S
i: contains 0.06 to 1.0%, regulates the content of Fe to 0.4% or less and the content of Mg to 0.04% or less, and is composed of an aluminum alloy consisting of the remaining aluminum and unavoidable impurities. Zn: 0.5 to 4.0%, In: 0.0
05-0.1%, Sn: one or two of 0.01-0.1%
Containing at least one species, the content of Si is limited to 0.3% or less, the content of Fe is regulated to 0.5% or less, and the content of Mg is regulated to 0.04% or less. The brazing material is Si: 6-14%,
Fe: 0.06 to 0.7%, the content of Mg is regulated to 0.04% or less, the content of Ca is regulated to 0.006% or less, and the balance is made of aluminum alloy consisting of Al and unavoidable impurities. Aluminum alloy clad material for heat exchangers with excellent brazing and corrosion resistance. 2. The aluminum alloy clad material for heat exchangers according to claim 1, wherein the brazing material further contains Bi: 0.01 to 0.4%. 3. The aluminum alloy clad material for heat exchangers according to claim 1, wherein the core material further contains 0.06 to 0.35% of Ti.