JP4266919B2 - Aluminum alloy clad material for heat exchangers with excellent erosion / corrosion resistance and general corrosion resistance - Google Patents

Description

  The present invention relates to an aluminum alloy clad material used in heat exchangers, particularly automotive heat exchangers, in particular radiators, heaters, and oils joined by brazing in an inert gas atmosphere using fluoride or cesium fluxes. The present invention relates to an aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance, which is suitable as a tube material for an aluminum alloy automotive heat exchanger such as a cooler.

  2. Description of the Related Art An automobile heat exchanger, for example, a radiator, includes a tube and a header that have fins on the outer surface and whose inner surface serves as a passage for a working fluid (refrigerant). As a tube material for such an automobile radiator or a heater core, an aluminum alloy having a two-layer structure in which an Al—Mn alloy such as JIS A3003 is used as a core and an Al—Si alloy brazing material is clad on one side of the core. A three-layer aluminum alloy clad material is used in which a brazing material is clad on one surface of a clad material and a core material, and a sacrificial anode material of an Al—Zn alloy is clad on the other surface.

  Aluminum alloy heat exchangers are often joined by brazing with an inert gas atmosphere using a fluoride flux or a cesium flux, and the Al-Si brazing filler metal is an aluminum alloy heat exchanger. When the tube is manufactured, it is clad for joining the tube and the fin, joining the tube and the header plate, or brazing when manufacturing the tube from the clad plate. The sacrificial anode material is used, for example, on the inner surface side of the tube, and exerts a sacrificial anode action in contact with the working fluid to prevent the occurrence of pitting corrosion and crevice corrosion of the core material.

  As a working fluid for these heat exchangers and piping materials, neutral to weakly alkaline solutions in which an antifreeze mainly composed of ethylene glycol, which is commercially available as a coolant, is diluted to 0 to 50% by volume with water are used. However, depending on the region, neutral to weakly acidic working fluid containing chlorine ions may be used. Depending on the type of working fluid, the aluminum alloy clad material constituting the tube material or piping material may be used. It is often experienced that erosion / corrosion can cause corrosion to penetrate the core and impair the heat exchange function.

  A sacrificial anode layer of an Al-Zn or Al-Zn-Mn alloy is provided on one side of a core material of an Al-Mn alloy as one that is neutral to weakly acidic and has corrosion resistance to a working fluid containing chlorine ions. An aluminum alloy clad material is proposed which is clad and clad with an Al—Si alloy brazing material on the sacrificial anode layer and used as a radiator or an oil cooler for automobiles (see Patent Document 1). The clad material has a problem that the corrosion resistance against a neutral to weak alkaline working fluid is not sufficient.

  In addition, an aluminum alloy clad material for a tube material that has excellent corrosion resistance against a neutral to weakly alkaline working fluid and has corrosion resistance against a neutral to weakly acidic working fluid has also been proposed (see Patent Documents 2 and 3). However, these aluminum alloy clad materials have a small corrosion depth against neutral to weakly acidic working fluid and have good corrosion resistance, but the self-corrosion resistance of the sacrificial anode material is inferior, and it is used when used as a tube. There is a problem that the corrosion weight loss is large, and a large amount of corrosion products are generated, so that the tube is easily clogged.

  On the other hand, in recent years, with the demand for reducing the weight of automobiles, the heat exchangers for automobiles are also required to be thinner from the viewpoint of energy saving and resource saving, and the thinning of tube materials is also progressing. In order to reduce the thickness of the tube material, it is necessary to further increase the strength of the material, and the core material contains a large amount of Mn, Cu, Si, etc., but the inclusion of these elements reduces the corrosion resistance of the core material. Therefore, a material structure is adopted in which a large amount of Zn is added to the sacrificial anode material to ensure a potential difference from the core material and the sacrificial anode effect is reliably obtained, and Mg is added to the core material and sacrificial anode material. Addition has also been made to further increase the strength.

However, when Mg is added to the core material or sacrificial anode material, Mg diffuses to the surface of the brazing material in the brazing process and reacts with the flux to form a compound such as MgF ₂ , which functions as a flux. There is a problem that a sufficient strength cannot be obtained because it is damaged and a brazing defect occurs or Mg in the material decreases.

This problem also arises when the aluminum alloy clad material having the three-layer structure is bent and welded to form a flat tube, and a header plate is assembled to this and integrally brazed. However, in recent years, energy saving and work efficiency have been improved. From the point of view, the plate material that is increasing in use is formed into a tube shape without being welded only by bending, that is, as shown in FIGS. 5 and 6, the brazing material 3 on one side of the core material 1, and the other single side A B-type tube can be obtained by bending the both ends 6 of the aluminum alloy clad material clad with the sacrificial anode material 5 or the brazing material 3 at both ends 6 and both ends 7 so as to contact the sacrificial anode material 5. This is a particular problem in brazing dies that are shaped A or B and are assembled to the header plate and integrally brazed.
JP 9-316579 A JP 2000-190089 A JP 2000-309837 A

  The inventors have solved the above-mentioned problems in a three-layer aluminum alloy clad material for a heat exchanger used as a tube material for automobile radiators, heaters and oil coolers, and have improved erosion / corrosion resistance and general corrosion resistance. Even when using a neutral to weakly alkaline and high-speed solution flowing through the heat exchanger as a working fluid with excellent strength for thinning, a neutral to weakly acidic solution containing chlorine ions In order to obtain an aluminum alloy clad having sufficient corrosion resistance even when used, a combination of a core material, a sacrificial anode layer and a brazing material was examined.

  As a result of repeated tests and examinations, in an aluminum alloy clad material having a three-layer structure in which a brazing material having erosion / corrosion resistance is clad on one side of an Al-Mn alloy core material via an intermediate material, Mn is used as an intermediate material. By applying an aluminum alloy containing Zn and further containing specific amounts of Fe and Si, sufficient strength can be achieved even in a thinned cladding material, and the working fluid is neutral to weak. It has been found that erosion / corrosion resistance in the case of alkali and pitting corrosion resistance and clogging resistance in the case where the working fluid is neutral to weakly acidic can be achieved.

  The present invention was made as a result of further investigation based on the above knowledge, and its purpose is excellent in erosion / corrosion resistance and general corrosion resistance, having high strength for thinning, and as a working fluid. As a tube material, it has sufficient corrosion resistance both when using a solution that is neutral to weakly alkaline and flows through the heat exchanger at high speed, and also when using a solution that is neutral to weakly acidic and contains chlorine ions. When applied, there is no problem that the corrosion product is generated and the tube is clogged, and Mg diffuses from the core material to the surface of the brazing material in the brazing process, and it reacts with the flux to impair the brazing property. Inert gas atmosphere using aluminum alloy cladding material used in heat exchangers, especially automotive heat exchangers, especially fluoride flux and cesium flux A radiator to be joined by cormorants with the heater to provide a suitable aluminum alloy clad material as tube material of the heat exchanger made of aluminum alloy car such as an oil cooler.

  The present invention further provides a three-layered aluminum alloy clad material obtained by clad a brazing material on one surface of a core material via an intermediate material, and a sacrificial anode material or brazing material on the other surface of the core material. Another object of the present invention is to provide an aluminum alloy clad material having a four-layer structure.

The aluminum alloy clad material for heat exchangers excellent in erosion / corrosion resistance and general corrosion resistance according to claim 1 for achieving the above object will have erosion / corrosion resistance through an intermediate material on one side of the core material. It is a three-layer clad material of an aluminum alloy clad with a material, the core material comprising Mn : 0.8 to 1.8%, composed of an aluminum alloy composed of the balance Al and inevitable impurities , Material: Mn : 0.6 to 1.8%, Fe: more than 0.5% to 1.5% or less, Si: more than 0.6% to 1.1% or less, Zn: 0.5 to 10% contains, consists of an aluminum alloy and the balance Al and impurities, a brazing material having a resistance to erosion-corrosion resistance, Si: containing from 3 to 13% the balance being Al and impurities aluminum Characterized in that it is constituted by an alloy. In addition, by arranging a brazing material having erosion / corrosion resistance on the working fluid (water) side, a tube material with excellent inner surface corrosion resistance is constructed, but a brazing material having erosion / corrosion resistance is arranged on the outside air side. Then, the tube material excellent in outer corrosion resistance is configured.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 2 is characterized in that the core material is Mn: 0.8 to 1.8%, Mg: 0.1 It is characterized by being composed of an aluminum alloy containing -1.0% and the balance Al and impurities.

Aluminum alloy clad material having excellent erosion-corrosion resistance and general corrosion resistance according to claim 3, in claim 1, wherein the core material, Mn: 0.8~1.8%, Mg: 0.1 -1.0%, Si: 0.7-1.1%, Fe: 0.5-1.0%, Cu: 0.8% or less, Ni: 0.1-1.0 %, Cr: 0.02 to 0.3%, Zr: 0.02 to 0.3%, Ti: 0.05 to 0.35%, or a balance of Al and It is composed of an aluminum alloy made of impurities.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 5 is any one of claims 1 to 4, wherein the intermediate material is Mn: 0.6 to 1.8%, Fe: more than 0.5% and 1.5 % or less, Si: more than 0.6% and 1.1% or less, Zn: 0.5 to 10%, Ni: 0.1 to 1%. 1% or more of 0%, Cr: 0.02-0.3%, Zr: 0.02-0.3%, Ti: 0.05-0.35%, the balance being Al And an aluminum alloy made of impurities.

The aluminum alloy clad material for a heat exchanger having excellent erosion / corrosion resistance and general corrosion resistance according to claim 8 is the aluminum alloy clad material for heat exchanger according to any one of claims 1 to 7 , wherein the brazing material having erosion / corrosion resistance is Si: 3 to 3. Containing 13%, Fe: 0.15-2.0%, Zn: 0.5-5.0%, Cu: 0.5-5.0%, Sr: 0.005-0.1 % Or more, and is made of an aluminum alloy composed of the remaining Al and impurities.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 10 is the sacrificial anode on the other surface of the core material in the aluminum alloy clad material according to any one of claims 1 to 9. The material is clad to form a four-layer clad material, and the sacrificial anode material contains Zn: 0.5 to 10%, and is composed of an aluminum alloy composed of the balance Al and impurities.

Aluminum alloy clad material having excellent erosion-corrosion resistance and general corrosion resistance according to claim 11, in claim 10, wherein the sacrificial anode material, Zn: 0.5~10%, Mn: 0.8~ It is characterized by being composed of an aluminum alloy containing 1.8% and the balance Al and impurities.

Aluminum alloy clad material having excellent erosion-corrosion resistance and general corrosion resistance according to claim 12, in claim 10, wherein the sacrificial anode material, Zn: 0.5~10%, Mn: 0.8~ It contains 1.8%, Si: 0.7-1.1%, Fe: 0.5-1.0%, Ni: 0.1-1.0%, Cr: 0.02-0 .3%, Zr: 0.02 to 0.3%, Ti: 0.05 to 0.35%, or one or more of them, and the balance is composed of an aluminum alloy composed of Al and impurities. It is characterized by that.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 15 is the aluminum alloy clad material according to any one of claims 1 to 9 , wherein the brazing material is provided on the other surface of the core material. Is a four-layer clad material, and the brazing material is composed of an aluminum alloy containing Si: 6 to 13% and the balance Al and impurities.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 16 is characterized in that, in claim 15 , the brazing material contains Si: 6 to 13%, and further Fe: 0.00. Contains one or more of 8-2.0%, Zn: 0.5-5.0%, Cu: 0.5-5.0%, Sr: 0.005-0.1% And it is comprised with the aluminum alloy which consists of remainder Al and an impurity.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 6 is any one of claims 1 to 5 , wherein the intermediate material is further In: 0.05% or less, Sn: It contains 0.05% or less of 1 type or 2 types.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 9 is the alloy according to any one of claims 1 to 8 , wherein the brazing material having erosion / corrosion resistance is further In: 0. 0.05% or less and Sn: 0.05% or less are contained.

Aluminum alloy clad material having excellent erosion-corrosion resistance and general corrosion resistance according to claim 13, in any one of claims 10 to 12, wherein the sacrificial anode material is further an In: 0.05% or less, Sn : It contains 0.05% or less of 1 type or 2 types.

The aluminum alloy clad material for heat exchangers excellent in erosion / corrosion resistance and general corrosion resistance according to claim 17 is the aluminum alloy clad material for heat exchanger according to claim 15 or 16 , wherein the brazing material further contains In: 0.05% or less, Sn: 0.05. % Or less of 1 type or 2 types.

The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 4 is the heat-treatable aluminum alloy clad material according to any one of claims 1 to 3 , wherein the core material further includes V: 0.01 to 0.3%. B: One or two of 0.01 to 0.3% are contained.

Aluminum alloy clad material having excellent erosion-corrosion resistance and general corrosion resistance according to claim 7, in any one of claims 1 to 6, wherein the intermediate member further V: 0.01 to 0.3% B: One or two of 0.01 to 0.3% are contained.

The aluminum alloy clad material for heat exchangers excellent in erosion / corrosion resistance and general corrosion resistance according to claim 14 is the sacrificial anode material according to any one of claims 10 to 13 , further comprising V: 0.01 to 0.3. %, B: One or two of 0.01 to 0.3% are contained.

  According to the present invention, it is excellent in erosion / corrosion resistance and general corrosion resistance, has high strength for thinning, and is used as a working fluid in a neutral to weak alkaline and high-speed solution flowing in a heat exchanger. However, it has sufficient corrosion resistance even when using a neutral to weakly acidic solution containing chlorine ions, and when applied as a tube material, there is no problem that the corrosion product is generated and the tube is clogged. In the brazing process, Mg diffuses from the core material to the brazing material surface and does not harm the brazing property by reacting with the flux, and especially aluminum alloy clad materials used in heat exchangers for automobiles, Aluminum such as radiators, heaters and oil coolers that are joined by brazing in an inert gas atmosphere using fluoride or cesium flux Suitable aluminum alloy clad sheet is provided as a tube material of gold automobile heat exchanger.

The form in the case of applying the aluminum alloy clad material by this invention as a tube material is as follows.
(1) A mode in which the core material 1 is on the outside air side, and the brazing material 2 having erosion / corrosion resistance is disposed on the working fluid side via the intermediate material 4 (see FIG. 1).
(2) In (1), the sacrificial anode material 5 is disposed on the other surface of the core material 1 to enhance the outer surface corrosion resistance, or the brazing material 3 is disposed to enhance the bondability with the fin (see FIG. 2). .
(3) A configuration in which the core material 1 is on the working fluid side, and the brazing material 2 having erosion / corrosion resistance is disposed on the outside air side (the working fluid side in the oil cooler) via the intermediate material 4 (see FIG. 3).
(4) In (3), the brazing material 3 is disposed on the other surface of the core material 1 to enhance the bondability with the inner fin (see FIG. 4).

Hereinafter, the components of the core material 1, the intermediate material 4, the erosion / corrosion resistance brazing material 2, the sacrificial anode material 5 and the brazing material 3 in the aluminum alloy clad material of the present invention and the reasons for limitation thereof will be described.
(Core material)
Mn: 0.8 to 1.8%
Mn functions to improve the corrosion resistance by improving the strength of the core material and making the potential of the core material noble and increasing the potential difference from the sacrificial anode material. The preferable content of Mn is in the range of 0.8 to 1.8%. If the content is less than 0.8%, the effect is small. If the content exceeds 1.8%, a coarse compound is produced during casting, and the rolling processability is low. It decreases and it becomes difficult to obtain a healthy plate (core material). A more preferable content range of Mn is 1.0 to 1.3%.

Mg: 0.1 to 1.0%
Mg improves the strength of the core material. The preferable content of Mg is in the range of 0.1 to 1.0%. If the content is less than 0.1%, the effect is small. If the content exceeds 1.0%, an inert gas is used using a fluoride-based flux. When performing brazing heating in an atmosphere, even if an intermediate material is provided, Mg diffuses to the brazing material surface during brazing and reacts with the fluoride-based flux, so that brazing properties are easily hindered, and Mg fluoride. Are likely to form brazing defects. A more preferable content range of Mg is 0.1 to 0.6%.

Si: 0.7 to 1.1%
Si has the effect of improving the strength of the core material. The preferable content of Si is in the range of 0.7 to 1.1%. If the content is less than 0.7%, the effect is small. If the content exceeds 1.1%, the corrosion resistance of the core material decreases, and The melting point is lowered, and local melting is likely to occur during brazing heating. The more preferable content range of Si is 0.8 to 1.0%.

Fe: 0.5 to 1.0%
Fe has the effect of improving the strength of the core material. The preferable content of Fe is in the range of 0.5 to 1.0%. If the content is less than 0.5%, the effect is small, and if it exceeds 1.0%, the self-corrosion property of the core material increases. The more preferable content range of Fe is 0.5 to 0.8%.

Cu: 0.8% or less Cu functions to improve the corrosion resistance by improving the strength of the core material, making the potential of the core material noble, and increasing the potential difference from the sacrificial anode material. Further, Cu in the core material diffuses into the sacrificial anode material and the intermediate material during brazing heating, and forms a gentle Cu concentration gradient in the thickness direction of the sacrificial anode material and the intermediate material. The potential on the side becomes noble, the potential on the surface side of the sacrificial anode material and the surface side of the intermediate material becomes base, and a gentle potential gradient is formed in the thickness direction of the sacrificial anode material and intermediate material. Becomes a full corrosive type. The preferable content of Cu is in the range of 0.8% or less. If it exceeds 0.8%, the corrosion resistance of the core material is lowered, and the melting point is lowered, so that local melting is likely to occur during heat brazing. The more preferable content range of Cu is 0.4 to 0.6%.

Ni: 0.1 to 1.0%
Ni functions to improve the strength of the core material. The preferable content of Ni is in the range of 0.1 to 1.0%. If the content is less than 0.1%, the effect is small, and if it exceeds 1.0%, the self-corrosion property of the core material increases. A more preferable content range of Ni is 0.5 to 0.8%.

Cr: 0.02-0.3%, Zr: 0.02-0.3%
When Cr and Zr are contained within the above range, the crystal grain size of the core material is coarsened, and Mg grain boundary diffusion during brazing heating is suppressed. If the content is less than 0.02%, the effect is small. If the content exceeds 0.3%, the effect is saturated, and no further effect can be expected. The more preferable content ranges of Cr and Zr are each 0.05 to 0.2%.

Ti: 0.05 to 0.35%
Ti is divided into a high concentration region and a low region in the thickness direction of the core material, and these regions are alternately distributed in a layered manner, and the low Ti concentration region corrodes preferentially compared to the high region. It has the effect of layering the corrosion form, and this effect prevents the progress of intergranular corrosion in the plate thickness direction and improves the pitting corrosion resistance of the material. The preferable content of Ti is in the range of 0.05 to 0.35%. If it is less than 0.05%, the effect is small, and if it exceeds 0.35%, casting becomes difficult and workability is reduced. It becomes difficult to produce sound materials. A more preferable content range of Ti is 0.1 to 0.2%.

V: 0.01 to 0.3%, B: 0.01 to 0.3%
When V and B are contained within the above range, the crystal grain size of the core material is coarsened, and Mg grain boundary diffusion during brazing heating is suppressed. If the content is less than 0.01%, the effect is small. If the content exceeds 0.3%, the effect is saturated, and no further effect can be expected.

(Intermediate material)
Mn: 0.6 to 1.8%
Mn improves the strength of the intermediate material and increases the deformation resistance of the intermediate material during hot rolling (temperature: 400 to 500 ° C.) together with Fe, and the deformation resistance with other constituent materials such as core material and brazing material. The difference is reduced (adjusted in the range of 0.7 to 1.4) to improve hot rollability. In addition, when the corrosion reaches the intermediate material beyond the brazing material having erosion / corrosion resistance, the working fluid is weakly alkaline, particularly when an Al—Zn alloy such as an ordinary 7072 alloy is used as the intermediate material. When flowing in a heat exchanger at high speed, the corrosion progresses in a pitting corrosion manner and relatively early penetration corrosion occurs. By adding Mn, Al-Mn and Al-Mn-Fe compounds Since this compound disperses corrosion, the progress of pitting corrosion is suppressed. The preferable content of Mn is in the range of 0.6 to 1.8%. If the content is less than 0.6%, the effect is small. If the content exceeds 1.8%, a coarse compound is produced during casting, and the rolling processability is low. It becomes difficult to obtain a healthy plate material. A more preferable content range of Mn is 1.0 to 1.4%.

Fe: more than 0.5% and 1.5% or less Fe improves the strength of the intermediate material. In addition, the deformation resistance of the intermediate material during hot rolling (temperature: 400 to 500 ° C.) is increased together with Mn, and the difference in deformation resistance from other constituent materials such as the core material and brazing material is reduced (0.7 to Adjusted to a range of 1.4) to improve hot rollability. Furthermore, when the corrosion reaches the intermediate material beyond the brazing material having erosion / corrosion resistance, the working fluid is weakly alkaline, especially when an Al—Zn alloy such as a normal 7072 alloy is used as the intermediate material. When flowing in a heat exchanger at high speed, corrosion progresses in a pitting corrosion manner and relatively early penetration corrosion occurs, but by adding Fe, an Al-Fe-based compound, an Al-Fe-Si-based compound Since this compound disperses corrosion, the progress of pitting corrosion is suppressed. The preferable content of Fe is in the range of more than 0.5% and 1.5% or less. If the content is less than 0.5%, the effect is small, and if it exceeds 1.5%, the corrosion resistance of the outer surface is lowered. A more preferable content range of Fe is more than 0.6% and 1.0% or less.

Si: more than 0.6% and 1.1% or less Si functions as a solid solution in the Al matrix and reduces the solubility of the Al matrix in a weak alkaline environment. Moreover, Si deposits on the surface of the brazing material and intermediate material having erosion / corrosion resistance as a hydrated oxide film, and protects the brazing material and intermediate material having erosion / corrosion resistance. Further, Si improves the strength of the intermediate material, increases the deformation resistance of the intermediate material during hot rolling, and reduces the difference in deformation resistance from other constituent materials such as a core material and brazing material. The preferable content of Si is in the range of more than 0.6% and not more than 1.1%. If the content is less than 0.6%, the effect is small. If the content exceeds 1.1%, the corrosion resistance of the intermediate material is lowered. The melting point of the intermediate material is lowered, and local melting is likely to occur during brazing heating. The more preferable content range of Si is 0.8 to 1.0%.

Zn: 0.5 to 10.0%
Zn lowers the potential of the intermediate material, maintains the sacrificial anode effect on the core material, and prevents pitting corrosion and crevice corrosion of the core material. The preferable content of Zn is in the range of 0.5 to 10.0%. If the content is less than 0.5%, the effect is small, and if it exceeds 10.0%, the self-corrosion property of the intermediate material increases. A more preferable content range of Zn is 2.0 to 5.0%.

Ni: 0.1 to 1.0%
Ni functions to improve the strength of the intermediate material, increase the deformation resistance during hot rolling, and reduce the difference in deformation resistance between the core material, the sacrificial anode material and the brazing material. The preferable content of Ni is in the range of 0.1 to 1.0%. If the content is less than 0.1%, the effect is small, and if it exceeds 1.0%, the self-corrosion property of the intermediate material increases. A more preferable content range of Ni is 0.5 to 0.8%.

Cr: 0.02-0.3%, Zr: 0.02-0.3%
When Cr and Zr are contained within the above range, the crystal grain size of the intermediate material is coarsened, and when Mg is contained in the core material, the grain boundary diffusion of Mg during brazing heating is suppressed. If the content is less than 0.02%, the effect is small. If the content exceeds 0.3%, the effect is saturated, and no further effect can be expected. The more preferable content ranges of Cr and Zr are each 0.05 to 0.2%.

Ti: 0.05 to 0.35%
Ti is divided into a high concentration region and a low region in the thickness direction of the intermediate material, and these regions are alternately distributed in layers, and the low Ti concentration region corrodes preferentially compared to the high region. It has the effect of layering the corrosion form, and this effect prevents the progress of intergranular corrosion in the plate thickness direction and improves the pitting corrosion resistance of the material. The preferable content of Ti is in the range of 0.05 to 0.35%. If it is less than 0.05%, the effect is small, and if it exceeds 0.35%, casting becomes difficult and workability is reduced. It becomes difficult to produce sound materials. A more preferable content range of Ti is 0.1 to 0.2%.

V: 0.01 to 0.3%, B: 0.01 to 0.3%
When V and B are contained within the above range, the crystal grain size of the core material is coarsened, and when the core material contains Mg, the grain boundary diffusion of Mg during brazing heating is suppressed. If the content is less than 0.01%, the effect is small. If the content exceeds 0.3%, the effect is saturated, and no further effect can be expected.

In: 0.05% or less, Sn: 0.05% or less The addition of In and Sn lowers the potential of the intermediate material, ensures the sacrificial anode effect on the core material, and prevents pitting corrosion and crevice corrosion of the core material. It works as follows. The preferred content is in the range of 0.05% or less, and if it exceeds 0.05%, the self-corrosion property of the intermediate material increases. More preferable content ranges of In and Sn are 0.01 to 0.03%, respectively.

(Brazing material with erosion / corrosion resistance)
Si: 3.0 to 13.0%
Si dissolves in the Al matrix and functions to reduce the solubility of the Al matrix in a weak alkaline environment. Further, Si is deposited on the surface of the brazing material having erosion / corrosion resistance as a hydrated oxide film to protect the brazing material having erosion / corrosion resistance. Further, eutectic Si is harder than the primary crystal α phase and the eutectic α phase, and has an effect of improving erosion resistance. In addition, it lowers the melting point and functions effectively as a brazing material. The preferable content of Si is in the range of 3.0 to 13.0%. If the content is less than 3.0%, the effect is small, and if it exceeds 13.0%, ingot formation becomes difficult.

Zn: 0.5 to 5.0%
Zn lowers the potential of the brazing material having erosion and corrosion resistance, maintains the sacrificial anode effect on the intermediate material and the core material, and prevents pitting corrosion and crevice corrosion of the core material and intermediate material. Moreover, it coexists with Cu and lowers the melting point of the brazing material. The preferable content of Zn is in the range of 0.5 to 5.0%. When the content is less than 0.5%, the effect is small. When the content exceeds 5.0%, the self-corrosion of the brazing material having erosion / corrosion resistance. Increase. A more preferable content range of Zn is 1.0 to 3.0%.

Fe: 0.15-2.0%
Fe forms an Al-Fe-based or Al-Fe-Si-based compound, and these compounds serve as a starting point for corrosion and disperse pitting corrosion, thereby improving corrosion resistance. The preferable content of Fe is in the range of 0.15 to 2.0%. If the content is less than 0.15%, the effect is small, and if it exceeds 2.0%, the self-corrosion property of the brazing material having erosion / corrosion resistance. Will increase. The more preferable content range of Fe is 0.8 to 1.5%.

Cu: 0.5 to 5.0%
Cu coexists with Zn and lowers the melting point of the brazing material having erosion / corrosion resistance. The preferable content of Cu is in the range of 0.5 to 5.0%. If the content is less than 0.5%, the effect is small, and if it exceeds 5.0%, the self-corrosion property of the brazing material having erosion / corrosion resistance. Will increase. A more preferable content range of Cu is 1 to 3%.

Sr: 0.005 to 0.1%
Sr has the effect of making the existence form of Si particles finer and uniform. As a result, the melting of the brazing material having erosion / corrosion resistance becomes uniform, and the brazing property is improved. Moreover, since the presence form of the Si particles after brazing becomes fine and uniform, the corrosion resistance is improved. The preferable content of Sr is in the range of 0.005 to 0.1%. If the content is less than 0.005%, the effect is small, and if the content exceeds 0.1%, the effect is saturated, and further effects are expected. Can not. A more preferable content range of Sr is 0.01 to 0.03%. Even when Na: 1 to 100 ppm and Sb: 0.001 to 0.5% are added, the same effect as that obtained when Sr is added can be obtained.

In: 0.05% or less, Sn: 0.05% or less In and Sn make the potential of the brazing material having erosion / corrosion resistance low, and reliably maintain the sacrificial anode effect on the intermediate material and the core material, It functions to prevent pitting corrosion and crevice corrosion of the core material. The preferable content is in the range of 0.05% or less, and when it exceeds 0.05%, the self-corrosion property of the brazing material increases. More preferable content ranges of In and Sn are 0.01 to 0.03%, respectively.

(Sacrificial anode material)
Zn: 0.5 to 10.0%
Zn lowers the potential of the sacrificial anode material, maintains the sacrificial anode effect on the core material, and prevents pitting corrosion and crevice corrosion of the core material. The preferable content of Zn is in the range of 0.5 to 10.0%. If the content is less than 0.5%, the effect is small, and if it exceeds 10.0%, the self-corrosion property of the sacrificial anode material increases. A more preferable content range of Zn is 2.0 to 5.0%.

Mn: 0.8 to 1.8%
Mn improves the strength of the sacrificial anode material. Further, as a result of the pitting corrosion being dispersed by the Al—Mn compound as a starting point of corrosion, the corrosion resistance is improved. The preferable content of Mn is in the range of 0.8 to 1.8%. If the content is less than 0.8%, the effect is small. If the content exceeds 1.8%, a coarse compound is produced during casting, and the rolling processability is low. It becomes difficult to obtain a healthy plate material. A more preferable content range of Mn is 1.0 to 1.3%.

Si: 0.7 to 1.1%
Si improves the strength of the sacrificial anode material. In addition, as a result of the Al—Mn—Fe—Si based compound becoming a starting point of corrosion and the corrosion being dispersed, the corrosion resistance is improved. The preferable content of Si is in the range of 0.7 to 1.1%. If the content is less than 0.7%, the effect is small. If the content exceeds 1.1%, the corrosion resistance of the sacrificial anode material is lowered. The more preferable content range of Si is 0.8 to 1.0%.

Fe: 0.5 to 1.0%
Fe improves the strength of the sacrificial anode material. In addition, as a result of the Al—Mn—Fe—Si based compound becoming a starting point of corrosion and the corrosion being dispersed, the corrosion resistance is improved. The preferable content of Fe is in the range of 0.5 to 1.0%. If the content is less than 0.5%, the effect is small, and if it exceeds 1.0%, the self-corrosion property of the sacrificial anode material increases. The more preferable content range of Fe is 0.5 to 0.8%.

Ni: 0.1 to 1.0%
Ni improves the strength of the sacrificial anode material. The preferable content of Ni is in the range of 0.1 to 1.0%. If the content is less than 0.1%, the effect is small, and if it exceeds 1.0%, the self-corrosion property of the sacrificial anode material increases. A more preferable content range of Ni is 0.5 to 0.8%.

Cr: 0.02-0.3%, Zr: 0.02-0.3%
When Cr and Zr are contained within the above range, the grain size of the sacrificial anode material is coarsened, and Mg grain boundary diffusion during brazing heating is suppressed. If the content is less than 0.02%, the effect is small. If the content exceeds 0.3%, the effect is saturated, and no further effect can be expected. The more preferable content ranges of Cr and Zr are each 0.05 to 0.2%.

Ti: 0.01 to 0.35%
Ti is divided into high-concentration regions and low-concentration regions in the thickness direction of the sacrificial anode material, and these regions are alternately distributed in layers, and the low-Ti concentration regions corrode preferentially over the high regions. This has the effect of making the corrosion form into a layer, and this effect prevents the progress of intergranular corrosion in the plate thickness direction and improves the pitting corrosion resistance of the material. The preferable content of Ti is in the range of 0.01 to 0.35%. If the content is less than 0.01%, the effect is small, and if it exceeds 0.35%, casting becomes difficult and workability is reduced. It becomes difficult to produce sound materials. A more preferable content range of Ti is 0.1 to 0.2%.

In: 0.05% or less, Sn: 0.05% or less In and Sn lower the potential of the sacrificial anode material, ensure the sacrificial anode effect on the core material, and prevent pitting corrosion and crevice corrosion of the core material. It works as follows. The preferred content is in the range of 0.05% or less, and if it exceeds 0.05%, the self-corrosion property of the sacrificial anode material increases. More preferable content ranges of In and Sn are 0.01 to 0.03%, respectively.

V: 0.01 to 0.3%, B: 0.01 to 0.3%
V and B, when contained within the above range, make the grain size of the sacrificial anode material coarse and suppress Mg grain boundary diffusion during brazing heating. If the content is less than 0.01%, the effect is small. If the content exceeds 0.3%, the effect is saturated, and no further effect can be expected.

(Brazing material)
Si: 6-13%
As the brazing material, a commonly used Al—Si alloy containing 6 to 13% of Si is applied. If Si is less than 6%, the fluidity is lowered and does not act effectively as a wax. If Si exceeds 13%, it is difficult to produce a sound material.

Zn: 0.5 to 5.0%
Zn lowers the potential of the brazing material, maintains the sacrificial anode effect on the core material, and prevents pitting corrosion and crevice corrosion of the core material from the outer surface. Further, the coexistence with Cu lowers the melting point of the brazing material. The preferable content of Zn is in the range of 0.5 to 5.0%. If the content is less than 0.5%, the effect is small, and if it exceeds 5.0%, the self-corrosion of the brazing material increases. A more preferable content range of Zn is 1.0 to 4.0%.

Fe: 0.8 to 2.0%
Fe forms an Al-Fe-based or Al-Fe-Si-based compound, and these compounds serve as a starting point for corrosion to disperse the corrosion. As a result, the corrosion resistance of the outer surface (the brazing filler metal side) is improved. The preferable content of Fe is in the range of 0.8 to 2.0%. If the content is less than 0.8%, the effect is small, and if it exceeds 2.0%, the corrosion resistance of the outer surface is lowered. A more preferable content range of Fe is 0.8 to 1.0%.

Cu: 0.5 to 5.0%
Cu coexists with Zn to lower the melting point of the brazing material. The preferable content of Cu is in the range of 0.5 to 5.0%. If the content is less than 0.5%, the effect is small. If the content exceeds 5.0%, the self-corrosion resistance of the brazing material increases. A more preferable content range of Cu is 1 to 3%.

Sr: 0.005 to 0.1%
Sr has the effect of making the existence form of Si particles finer and uniform, and as a result, the melting of the brazing becomes uniform and the brazing property is improved. Moreover, since the presence form of the Si particles after brazing becomes fine and uniform, the corrosion resistance of the outer surface is improved. The preferable content of Sr is in the range of 0.005 to 0.1%. If the content is less than 0.005%, the effect is small, and even if the content exceeds 0.1%, the effect is saturated. The effect cannot be expected. A more preferable content range of Sr is 0.01 to 0.03%. In addition, an equivalent effect is acquired also by containing Na: 1-100 ppm and Sb: 0.001-0.5%.

In: 0.05% or less, Sn: 0.05% or less In and Sn make the sacrificial anode effect on the intermediate material and the core material reliable by lowering the potential of the brazing material, and pitting corrosion and gaps in the core material. Functions to prevent corrosion. The preferable content is in the range of 0.05% or less, and when it exceeds 0.05%, the self-corrosion property of the brazing material increases. More preferable content ranges of In and Sn are 0.01 to 0.03%, respectively.

  The aluminum alloy clad material of the present invention is based on a combination of a core material, an intermediate material, and a brazing material having erosion / corrosion resistance, and an aluminum material constituting them, and if necessary, a sacrificial anode material and a brazing material. For example, the ingot of the aluminum material to be formed is ingoted by, for example, continuous casting and, if necessary, homogenized, for example, intermediate material, brazing material having erosion / corrosion resistance, sacrificial anode material and brazing material ingot. , Each of which is hot-rolled to a predetermined thickness, then combined with an ingot of the core material, and made into a clad material by hot rolling according to a conventional method, and then made into a predetermined thickness by cold rolling, intermediate annealing, and cold rolling Manufactured by. The ingot of the core material is also hot-rolled to a predetermined thickness, several hot-rolled core materials are stacked, combined with an intermediate material and a brazing material having erosion / corrosion resistance, and a sacrificial anode material and brazing material Hot clad rolling can also be performed in combination with a hot rolled material.

  Examples of the present invention will be described below in comparison with comparative examples. These examples show one embodiment of the present invention, and the present invention is not limited to these examples.

Example 1
Alloys for core materials having compositions shown in Tables 1 and 2 by continuous casting, alloys for intermediate materials having compositions shown in Tables 3 to 4, and brazing materials having erosion / corrosion resistance having compositions shown in Tables 5 to 6 An alloy, a sacrificial anode material alloy having a composition shown in Tables 7 to 8, and a brazing material alloy having a composition shown in Tables 9 to 10 are ingot, and among the obtained ingots, an alloy for a core material, an intermediate material The ingots of the alloy for the material and the alloy for the sacrificial anode material were homogenized.

  Subsequently, the ingot of the intermediate material alloy, the erosion-corrosion resistant brazing material alloy, the sacrificial anode material alloy and the brazing material alloy is hot-rolled to a predetermined thickness, and these hot-rolled sheet and core A clad material was obtained by hot rolling with the ingot of the alloy for the material as a combined material. Thereafter, a plate material (cladding material, tempered H14) having a thickness of 0.20 mm was obtained by cold rolling, intermediate annealing, and cold rolling. The structure of the clad material is as shown in FIGS. 7 to 9. The brazing material having erosion and corrosion resistance is 0.010 to 0.030 mm, the intermediate material is 0.020 to 0.040 mm, and the sacrificial anode material is 0. 0.010 to 0.040 mm, brazing material was set to 0.010 to 0.040 mm, and the remainder was used as a core material.

  Using the obtained aluminum alloy clad material as a test material, applying a fluoride-based flux in nitrogen gas and heating to brazing temperature (600 ° C: material temperature) A fluid side) corrosion test was conducted. The results are shown in Tables 11-18.

Corrosion test 1 (corrosion test simulating the case where the working fluid is weakly alkaline and flows in the heat exchanger at high speed):
Corrosion solution: SiO ₃ ^2- (HSiO ₃ ^2- ): 150 ppm, B ₄ O ₇ ^2- : 7000 ppm (adjusted to pH 9 with sodium hydroxide solution)
Specific liquid volume: 200 to 2000 mL / cm ²
Seal: The brazing filler metal surface and the end surface were sealed with silicon resin.
Temperature: 88 ° C continuous Nozzle flow rate: 10m / s (by jet test)
Test method: Corrosion solution is discharged from a hole with a nozzle diameter of 2 mm, and the nozzle corrodes as shown in FIG. 10 on the brazing material surface having erosion / corrosion resistance of the test material placed at a position 2 mm away from the nozzle tip. In the state completely immersed in the liquid, the corrosive liquid was collided for 96 hours, and the maximum corrosion depth was measured.

Corrosion test 2 (corrosion test simulating the case where the working fluid is neutral to weakly acidic and contains chlorine ions):
Corrosion solution: Cl ⁻ : 300 ppm, SO ₄ ²⁻ : 100 ppm, Cu ²⁺ : 10 pm
Specific liquid volume: 5 mL / cm ²
Seal: The brazing filler metal surface and the end surface were sealed with silicon resin.
Test method: After immersing in a caustic solution heated to 88 ° C. for 8 hours, a cycle of cooling and holding at 25 ° C. for 16 hours was repeated for 4 months, and the maximum corrosion depth and weight loss were measured.

  As seen in Tables 11-18, test material No. 1 to 150 all have good erosion / corrosion resistance, and also in corrosion test 2 (corrosion test simulating the case where the working fluid is relatively low temperature, neutral to weakly acidic and contains chlorine ions). It has excellent properties with little weight loss.

In addition, as a method for improving the brazing property, when Mg is contained in the core material, the amount of Mg in the core material that diffuses through the intermediate material to the brazing material side having erosion / corrosion resistance is controlled. Therefore, the heat pattern at the time of brazing is expressed as the time integral of the diffusion coefficient of Mg, ∫D (t) dt = D ₀ exp {−Q / RT (t)} (where D ₀ : frequency term (1.24) × 10 ⁻⁴ m ² / s), Q: activation energy (131000 J / mol), gas constant (8.3145 J / mol · K), T: temperature (K), t: time (s)) is 3. It is effective that the Mg concentration at the interface between the intermediate material and the brazing material having erosion / corrosion resistance is controlled to 0.1 × 10 ⁻¹⁰ (m ² ) or less, and Mg is contained. When using a core material with a diffusion coefficient at the time of brazing As a result of obtaining the inter-integration, it was 2 × 10 ⁻¹⁰ for all the test materials.

Comparative Example 1
The brazing material A7, core material C22 and brazing material E2 having the erosion / corrosion resistance of Example 1 are combined in this order and hot rolled to form a clad material, and then thickened by cold rolling, intermediate annealing, and cold rolling. A plate material (cladding material, tempered H14) having a thickness of 0.20 mm was obtained. The structure of the clad material was the same as in Example 1, with the brazing material having erosion / corrosion resistance being 0.020 mm, the brazing material being 0.020 mm, and the remainder being the core material.

  Using the obtained clad material as a test material, the same as in Example 1, after applying a fluoride flux in nitrogen gas and heating to brazing temperature (600 ° C .: material temperature) The inner surface side (working fluid side) corrosion test was conducted by the method. The results are shown in Table 19.

  As shown in Table 19, the test material No. No. 151 has a conventional structure in which an Al—Zn—Si based sacrificial anode layer is clad on one surface of an Al—Mn alloy core material and an Al—Si alloy brazing material is clad on the other surface. In the corrosion test 2 (corrosion test simulating a case where the working fluid is relatively low temperature, neutral to weakly acidic and contains chlorine ions), the weight reduction amount is large.

It is sectional drawing which shows the Example of the tube material (B type tube shape) manufactured from the aluminum alloy clad material by this invention. In the thing of FIG. 1, it is sectional drawing which shows the case where a brazing material or a sacrificial anode material is clad with the core material. It is sectional drawing which shows the other Example of the tube material (B type tube shape) manufactured from the aluminum alloy clad material by this invention. FIG. 4 is a cross-sectional view showing a case where a brazing material is clad on a core material in FIG. 3. It is sectional drawing which shows the example of the tube material (B type tube shape) manufactured from the conventional aluminum alloy clad material. It is sectional drawing which shows the other example of the tube material (B type tube shape) manufactured from the conventional aluminum alloy clad material. It is sectional drawing which shows the structure of the aluminum alloy clad material in the Example of this invention. It is sectional drawing which shows the other structure of the aluminum alloy clad material in the Example of this invention. It is sectional drawing which shows the further another structure of the aluminum alloy clad material in the Example of this invention. It is a figure which shows the outline | summary of the corrosion test 1 in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core material 2 Brazing material which has erosion resistance and corrosion resistance 3 Brazing material 4 Intermediate material 5 Sacrificial anode material 6 Both ends 7 Both end surfaces A B type tube shape B B type tube shape

Claims (17)

An aluminum alloy three-layer clad material obtained by clad a brazing material having erosion / corrosion resistance via an intermediate material on one side of a core material, and the core material has Mn : 0.8 to 1.8% ( It is composed of an aluminum alloy containing the balance Al and inevitable impurities (hereinafter referred to as impurities) , and the intermediate materials are Mn : 0.6 to 1.8%, Fe: 0.5% 1.5% or less, Si: more than 0.6% and 1.1% or less, Zn: 0.5 to 10%, composed of an aluminum alloy composed of the balance Al and impurities , and is resistant to erosion and corrosion. brazing material having sex, Si: containing from 3 to 13% heat exchanger having excellent erosion-corrosion resistance and general corrosion resistance, characterized in that it is made of aluminum alloy and the balance Al and impurities Aluminum alloy cladding material. 2. The core material according to claim 1, wherein the core material contains Mn: 0.8 to 1.8%, Mg: 0.1 to 1.0%, and an aluminum alloy composed of the balance Al and impurities. Aluminum alloy clad material for heat exchangers with excellent erosion / corrosion resistance and general corrosion resistance. The core material contains Mn: 0.8 to 1.8%, Mg: 0.1 to 1.0%, Si: 0.7 to 1.1%, Fe: 0.5 to 1 0.0%, Cu: 0.8% or less, Ni: 0.1-1.0%, Cr: 0.02-0.3%, Zr: 0.02-0.3%, Ti: 0.05 It is excellent in erosion / corrosion resistance and general corrosion resistance according to claim 1, characterized in that it comprises one or more of ˜0.35% and is composed of an aluminum alloy consisting of the balance Al and impurities. Aluminum alloy clad material for heat exchanger. The core further V: from 0.01 to 0.3 percent, B: one of the claims 1 to 3, characterized in that it contains from 0.01 to 0.3 percent of one or two of An aluminum alloy clad material for heat exchangers having excellent erosion / corrosion resistance and general corrosion resistance. The intermediate material is Mn: 0.6 to 1.8%, Fe: more than 0.5% to 1.5% or less, Si: more than 0.6% to 1.1% or less, Zn: 0.5 to 10%, Ni: 0.1-1.0%, Cr: 0.02-0.3%, Zr: 0.02-0.3%, Ti: 0.05-0.35 The erosion / corrosion resistance and general corrosion resistance according to any one of claims 1 to 4, wherein the erosion / corrosion resistance and general corrosion resistance are one or more of Excellent aluminum alloy clad material for heat exchangers. Wherein the intermediate member further an In: 0.05% or less, Sn: erosion-corrosion according to claim 1, characterized in that it contains one or more than 0.05% Aluminum alloy clad material for heat exchangers with excellent heat resistance and general corrosion resistance. Wherein the intermediate member further V: from 0.01 to 0.3%, B: one of the claims 1 to 6, characterized in that it contains from 0.01 to 0.3% one or two of An aluminum alloy clad material for heat exchangers having excellent erosion / corrosion resistance and general corrosion resistance. The brazing material having erosion / corrosion resistance contains Si: 3 to 13%, Fe: 0.15 to 2.0%, Zn: 0.5 to 5.0%, Cu: 0.00. from 5 to 5.0%, Sr: containing 0.005% to 0.1% one or more of, claims, characterized in that it is made of aluminum alloy and the balance Al and impurities 1 The aluminum alloy clad material for heat exchangers having excellent erosion / corrosion resistance and general corrosion resistance according to any one of 7 to 7 . Brazing material having a resistance to erosion-corrosion resistance is further an In: 0.05% or less, Sn: any of claims 1 to 8 characterized in that it contains one or more than 0.05% Aluminum alloy clad material for heat exchangers with excellent erosion / corrosion resistance and general corrosion resistance. The aluminum alloy clad material according to any one of claims 1 to 9 , wherein the sacrificial anode material is clad on the other surface of the core material to form a four-layer clad material, and the sacrificial anode material is made of Zn: 0.5 to 10 An aluminum alloy clad material for heat exchangers that is excellent in erosion / corrosion resistance and general corrosion resistance , characterized in that it is made of an aluminum alloy containing the remaining Al and impurities. The sacrificial anode material, Zn: 0.5 to 10% Mn: contains from 0.8 to 1.8%, according to claim 10, wherein a is made of aluminum alloy and the balance Al and impurities Aluminum alloy clad material for heat exchangers with excellent erosion / corrosion resistance and general corrosion resistance. The sacrificial anode material contains Zn: 0.5 to 10%, Mn: 0.8 to 1.8%, Si: 0.7 to 1.1%, Fe: 0.5 to 1.%. 1% of 0%, Ni: 0.1-1.0%, Cr: 0.02-0.3%, Zr: 0.02-0.3%, Ti: 0.05-0.35% The aluminum alloy clad material for a heat exchanger excellent in erosion / corrosion resistance and general corrosion resistance according to claim 10, wherein the aluminum alloy clad material contains at least one species or two or more species and is composed of an aluminum alloy composed of the balance Al and impurities. The erosion-resistant material according to any one of claims 10 to 12 , wherein the sacrificial anode material further contains one or two of In: 0.05% or less and Sn: 0.05% or less. Aluminum alloy clad material for heat exchangers with excellent corrosion and general corrosion resistance. The sacrificial anode material further V: 0.01 to 0.3%, B: of claim 10 to 13, characterized in that it contains one or two of 0.01 to 0.3% Aluminum alloy clad material for heat exchangers having excellent erosion / corrosion resistance and general corrosion resistance. The aluminum alloy clad material according to any one of claims 1 to 9 , wherein a brazing material is clad on the other surface of the core material to form a four-layer clad material, and the brazing material contains Si: 6 to 13%. An aluminum alloy clad material for heat exchangers having excellent erosion / corrosion resistance and general corrosion resistance , characterized by comprising an aluminum alloy composed of the balance Al and impurities. The brazing material contains Si: 6-13%, Fe: 0.8-2.0%, Zn: 0.5-5.0%, Cu: 0.5-5.0%, The erosion / corrosion resistance according to claim 15 , wherein the erosion / corrosion resistance is composed of an aluminum alloy containing one or more of Sr: 0.005 to 0.1% and the balance being Al and impurities. Aluminum alloy clad material for heat exchangers with excellent general corrosion resistance. The erosion / corrosion resistance and general corrosion resistance according to claim 15 or 16 , wherein the brazing material further contains one or two of In: 0.05% or less and Sn: 0.05% or less. Excellent aluminum alloy clad material for heat exchangers.

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