JP4220410B2 - Aluminum alloy clad material for heat exchanger - Google Patents

Description

  The present invention is an aluminum alloy clad material for a heat exchanger, in particular, a tube of an aluminum alloy heat exchanger such as a radiator or a heater core joined by brazing or vacuum brazing using a fluoride flux in an inert gas atmosphere, The present invention relates to an aluminum alloy clad material for a heat exchanger having a three-layer structure suitable as a material for a fluid passage constituent member such as a header.

  2. Description of the Related Art A heat exchanger, for example, an automobile radiator, includes a tube (having a clad plate formed into a tube shape by welding or brazing) and a header having fins on the outer surface and the inner surface serving as a passage for a working fluid (refrigerant). . As a tube material and header plate material such as an automobile radiator or heater core, an Al-Mn alloy such as JIS A3003 is used as a core material, and an Al-Si alloy brazing material is clad on one side of the core material. Aluminum alloy clad material with a structure, aluminum alloy clad material with a three-layer structure in which a brazing material is clad on both sides of the core material, or a brazing material is clad on one surface of the core material, and an Al-Zn alloy or An aluminum alloy clad material having a three-layer structure in which a sacrificial anode material of an Al—Zn—Mg alloy is clad is used.

  When manufacturing an aluminum alloy heat exchanger, the clad Al-Si brazing material is used when a tube is manufactured by joining the outer surface of the tube and the fin, joining the tube and the header plate, or brazing from the clad plate. Clad for brazing joints. For these brazings, inert gas atmosphere brazing using a fluoride flux and vacuum brazing are applied.

  The sacrificial anode material of the aluminum alloy clad material having a three-layer structure is used on the inner surface side of the tube, for example, 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. The fin material joined to the outer surface of the tube exhibits a sacrificial anodic action during use to prevent the occurrence of pitting corrosion of the core material.

  In recent years, from the viewpoint of reducing the weight of automotive heat exchangers in response to demands for reducing the weight of automobiles, cladding has been improved so far by improving the composition of the core material or sacrificial anode material in order to reduce the thickness of the tube material. Various materials have been proposed, and recently, a technique for improving the strength by adding Mn and Si to the sacrificial anode material has been proposed.

  For example, a high-strength aluminum alloy composite (see Patent Documents 1 and 2) whose corrosion resistance is improved by adding Mn, Mn, or Si to the sacrificial anode material and controlling the distribution of Al-Mn intermetallic compounds, sacrificial anode In addition to adding Mn and Si to the material, the amount of simple Si precipitates, Si-containing crystallized substances, and precipitates is controlled to make it difficult to produce grain boundary precipitates, thereby improving the corrosion resistance. Further, Si in the sacrificial anode material A high-strength aluminum alloy composite has been proposed in which the ratio between the content and the Zn content is adjusted to obtain a balance between strength and corrosion resistance (see Patent Documents 3 and 4).

However, regarding the corrosion resistance of the sacrificial anode material that forms the inner surface of the tube, when Mn and Si are contained in a large amount, the intergranular corrosion susceptibility tends to increase. However, there is a problem that it reaches the core material and leads to early penetration. On the other hand, with respect to brazeability, when Mn or Si is added to the sacrificial anode material, the tube is joined not by welding but by brazing, and when the brazing material and sacrificial anode material are brazed, Depending on the dispersion state, the sacrificial anode material having a processed structure does not recrystallize during brazing, and subcrystalline grains remain, and the brazing material erodes (eroses) in the sacrificial anode material, and the pressure resistance at the erosion part Problems such as reduced strength and corrosion resistance occur.
Japanese Patent Laid-Open No. 11-61305 JP-A-11-61306 JP 2003-293060 A JP 2003-268470 A

  In order to solve the above problems in the method of improving the strength by adding Mn, Si to the sacrificial anode material to achieve thinning of the aluminum alloy cladding material, the occurrence of intergranular corrosion, As a result of reexamination of the relationship between brazing metal erosion and dispersion of additive elements and intermetallic compounds, the addition of Ti to the sacrificial anode material can suppress intergranular corrosion susceptibility, and together with Si-based compounds and Fe-based compounds It has been found that erosion of the brazing material can be suppressed by suppressing fine precipitation of Mn-based compounds and controlling the particle size and distribution of these compounds.

  The present invention has been made as a result of further studies based on the above knowledge, and the object thereof is a tube material and a header plate material of a heat exchanger made of aluminum alloy such as a radiator, particularly a radiator mounted on an automobile and a heater core. It is an object to provide an aluminum alloy clad material for a heat exchanger that is excellent in brazing properties, corrosion resistance, and strength properties after brazing, which can be suitably used.

  In order to achieve the above object, an aluminum alloy clad material for a heat exchanger according to claim 1 has an aluminum alloy three-layer structure in which a sacrificial anode material is clad on one surface of a core material and a brazing material is clad on the other surface. It is a cladding material, and the core material is Mn: 0.6-2.0%, Cu: 0.3-1.0%, Si: 0.3-1.2%, Fe: 0.01-0. 4%, Ti: 0.06 to 0.35%, an aluminum alloy composed of the balance Al and impurities. Sacrificial anode material is Zn: 2.0 to 6.0%, Mn: 1.2 to 2 0.0%, Si: 0.4 to 1.2%, Fe: 0.01 to 0.3%, Ti: 0.01 to 0.3%, an aluminum alloy composed of the balance Al and impurities The brazing material is an Al—Si alloy brazing material.

  The aluminum alloy clad material for heat exchanger according to claim 2 is characterized in that, in claim 1, the core material further contains Mg: 0.5% or less.

  The aluminum alloy clad material for a heat exchanger according to claim 3 is the aluminum alloy clad material according to claim 1 or 2, wherein the core material is further Cr: 0.5% or less, Zr: 0.3% or less, and B: 0.1% or less. 1 type or 2 types or more are contained.

  The aluminum alloy clad material for a heat exchanger according to claim 4 is any one of claims 1 to 3, wherein the sacrificial anode material is further In: 0.005 to 0.05%, Sn: 0.005 to 0.05%. It contains 1 type or 2 types of these, It is characterized by the above-mentioned.

  The aluminum alloy clad material for heat exchanger according to claim 5 is characterized in that in any one of claims 1 to 4, the sacrificial anode material further contains Mg: 2.5% or less.

  The aluminum alloy clad material for a heat exchanger according to claim 6 is any one of claims 1 to 5, wherein the sacrificial anode material is further Cu: 0.2% or less, Cr: 0.3% or less, Zr: 0.3 % Or less, and B: 0.1% or less.

  An aluminum alloy clad material for a heat exchanger according to claim 7 is any one of claims 1 to 6, wherein the brazing material is an Al-Si based alloy brazing material containing Sr: 0.005 to 0.1%. Features.

  According to the present invention, radiators joined by brazing or vacuum brazing using a fluoride flux in an inert gas atmosphere, especially tubes for aluminum heat exchangers such as radiators for automobiles and heater cores, headers, etc. An aluminum alloy clad material for a heat exchanger having a three-layer structure excellent in brazing property, corrosion resistance, and strength properties after brazing, which is suitable as a material for a fluid passage constituent member is provided.

The composition of the aluminum alloy clad material of the present invention and the reason for limitation will be described.
(Sacrificial anode material)
Zn: 2.0-6.0%
Zn lowers the potential of the sacrificial anode material, exhibits the sacrificial anode effect on the core material, and prevents the occurrence of pitting corrosion or crevice corrosion of the core material. The preferable content of Zn is in the range of 2.0 to 6.0%. If the Zn content is less than 2.0%, the effect is small, and if the content exceeds 6.0%, the self-corrosion resistance of the sacrificial anode material Decreases.

Mn: 1.2 to 2.0%
Mn has an effect of improving the cladability by improving the strength, improving the deformation resistance of the sacrificial anode material during clad rolling, and suppressing the preferential elongation of the sacrificial anode material. In particular, Si and a Mn-Si compound are formed to contribute to strength improvement. Mn forms a Mn-based compound in the sacrificial anode material, adjusts the fine particle distribution of the compound together with the particle distribution of the Si-based compound and Fe compound described later, and has a particle size of 0.01 to 0 in the sacrificial anode material. When the total of 1 μm compound particles is 2 × 10 ⁷ or less per 1 mm ² , erosion of the brazing material to the sacrificial anode material during brazing can be suppressed. The preferable content of Mn is in the range of 1.2 to 2.0%. If it is less than 1.2%, the effect of improving the strength is not sufficient, and if it exceeds 2.0%, a coarse compound is produced during casting. Self-corrosion resistance is reduced. A more preferable content range of Mn is 1.2 to 1.8%.

Si: 0.4-1.2%
Si produces a Si-based compound in the matrix of the sacrificial anode material, and adjusts the particle distribution of the compound together with the particle distribution of the Mn-based compound and the Fe-based compound described later, thereby sacrificing the sacrificial anode of the brazing material at the time of brazing Erosion to the material can be suppressed. In particular, the strength improvement effect is increased by forming a Mn-Si compound together with Mn. The preferable content of Si is in the range of 0.4 to 1.2%. When the content is less than 0.4%, the effect of improving the strength is small. When the content exceeds 1.2%, the number of large Si compound particles increases. Since the self-corrosion resistance of the sacrificial anode material is lowered, the sacrificial anode effect is inferior. The more preferable content range of Si is 0.6 to 1.1%.

Fe: 0.01 to 0.3%
Fe can control the erosion of the brazing material to the sacrificial anode material during brazing by adjusting the particle distribution of the Fe-based compound together with the particle distribution of the Mn-based compound and the Si-based compound. If the Fe content exceeds 0.3%, the self-corrosion resistance of the sacrificial anode material decreases. The preferable content of Fe is in the range of 0.01 to 0.3%, and if it is less than 0.01%, the metal cost increases, which is not preferable. A more preferable content range of Fe is 0.01 to 0.2%.

Ti: 0.01 to 0.3%
Ti is divided into a high concentration region and a low region in the thickness direction of the 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 0.01 to 0.3%. If the content is less than 0.01%, the effect is small, and if it exceeds 0.3%, a huge crystallized product is produced during casting. The processability is lowered and it is difficult to produce a sound material. A more preferable content range of Ti is 0.06 to 0.3%.

In: 0.005 to 0.05%
In makes the potential of the sacrificial anode material base by adding a small amount, and prevents the occurrence of pitting corrosion and crevice corrosion of the core material by the sacrificial anode effect. The preferable content of In is in the range of 0.005 to 0.05%. If it is less than 0.005%, the effect is not sufficient, and if it exceeds 0.05%, the self-corrosion resistance and the rolling workability are lowered. A more preferable content range of In is 0.01 to 0.02%.

Sn: 0.05-0.05%
Sn has the effect of preventing the occurrence of pitting corrosion and crevice corrosion of the core material by the sacrificial anode effect by making the potential of the sacrificial anode material base by adding a small amount, and reliably exhibits the sacrificial anode effect on the core material. It works as follows. The preferable content of Sn is in the range of 0.005 to 0.05%. If it is less than 0.005%, the effect is not sufficient, and if it exceeds 0.05%, the self-corrosion resistance and the rolling processability are lowered. A more preferable content range of Sn is 0.01 to 0.02%.

Mg: 2.5% or less Mg is diffused into the core material during brazing heating during brazing assembly of a heat exchanger or the like, and functions to increase the strength together with Si and Cu in the core material. Mg remaining in the sacrificial anode material increases the strength of the sacrificial anode material together with Si, and improves the strength of the clad material by these effects. The preferable content of Mg is in the range of 2.5% or less. If it exceeds 2.5%, the rolling processability is lowered. A more preferable content range of Mg is 0.5 to 2.5%.

Cu: 0.2% or less, Cr: 0.3% or less, Zr: 0.3% or less, B: 0.1% or less Cu, Cr, Zr and B can be contained in the above ranges. When Cu exceeds 0.2%, a sufficient potential difference between the sacrificial anode material and the core material is not secured, and the sacrificial anode effect on the core material is lowered. If Cr, Zr, and B are contained in amounts exceeding 0.3%, 0.3%, and 0.1%, respectively, huge crystallized products are generated during casting, and it becomes difficult to produce a sound plate material.

(Core material)
Mn: 0.6 to 2.0%
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 0.6 to 2.0%. If the content is less than 0.3%, the effect is small. If the content exceeds 2.0%, a coarse compound is produced during casting, and the rolling processability is reduced. Decreases and it becomes difficult to obtain a sound plate material (core material). A more preferable content range of Mn is 1.2 to 1.8%.

Cu: 0.3 to 1.0%
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 with the sacrificial anode material and the potential difference with the brazing material. Further, when the tube is assembled as a radiator, it diffuses into the sacrificial anode material and the brazing material at the time of heat brazing to form a gentle Cu concentration gradient in the thickness direction of the sacrificial anode material and the brazing 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 brazing material becomes base, and a gentle potential gradient is formed in the thickness direction of the sacrificial anode material and brazing material. Becomes a full corrosive 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. If the content exceeds 1.0%, the corrosion resistance of the core material is lowered, and the melting point is lowered. Thus, local melting is likely to occur during heat brazing. The more preferable content range of Cu is 0.4 to 0.7%.

Si: 0.3-1.2%
Si has the effect of improving the strength of the core material. In particular, when Mg is contained in the sacrificial anode material, Si coexists with Mg diffusing from the sacrificial anode material during the heat brazing to bond with Mg to form Mg ₂ Si, thereby aging after brazing. Curing occurs and the strength is further improved. The preferable content of Si is in the range of 0.3 to 1.2%. When the content is less than 0.3%, the effect is small. When the content exceeds 1.2%, the corrosion resistance of the core material decreases, and The melting point is lowered, and local melting tends to occur during brazing with heating. The more preferable content range of Si is 0.6 to 1.1%.

Ti: 0.06-0.35%
Ti is divided into a high concentration region and a low region in the thickness direction of the 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 0.06 to 0.35%. If the content is less than 0.06%, the effect is small, and if it exceeds 0.35%, casting becomes difficult and workability decreases. It becomes difficult to produce sound materials.

Mg: 0.5% or less Mg improves the strength of the core material. The preferable content of Mg is in the range of 0.05 to 0.5%. If the content is less than 0.05%, the effect is small. If the content exceeds 0.5%, an inert gas is used using a fluoride-based flux. When heat brazing is performed in an atmosphere, Mg reacts with a fluoride-based flux during brazing to produce Mg fluoride, which lowers the brazeability and deteriorates the appearance of the brazed portion. A more preferable content range of Mg is 0.05 to 0.15%.

Cr: 0.5% or less, Zr: 0.3% or less, B: 0.1% or less Cr, Zr and B can be contained within the above ranges. If the contents of Cr, Zr, and B exceed 0.5%, 0.3%, and 0.1%, respectively, giant crystals are generated during casting, making it difficult to produce a sound plate material.
(Brazing material)
As the brazing material, a commonly used Al—Si alloy, for example, an alloy containing Si: 6 to 13% is used. In the case where brazing performed to constitute a radiator or the like is vacuum brazing, an Al-Si-1.0 to 2.0% Mg-based alloy or the like is used. These Al—Si based alloys and Al—Si—Mg based alloys include Bi: 0.2% or less, Be: 0.1% or less, Ca: 1.0% or less, Li: 1, as necessary. 0.0% or less may be added.

Sr: 0.005 to 0.1%
Sr has an effect of finely and uniformly dispersing Si particles in the brazing material. When the Si particles are finely and uniformly dispersed, the melting of the brazing becomes uniform and the brazing property is improved. The preferable content of Sr is in the range of 0.005 to 0.1%. If it is less than 0.005%, the effect is small, and if it exceeds 0.1%, the effect is saturated. A more preferable content range of Sr is 0.01 to 0.03%.

The aluminum alloy clad material of the present invention contains Mn and Si in addition to Zn in the sacrificial anode material to improve the strength and suppresses the increase in intergranular corrosion sensitivity due to the inclusion of Mn and Si by containing Ti. Thus, intergranular corrosion resistance is ensured. Another feature of the aluminum alloy clad material according to the present invention is that the total of compounds having a particle diameter of 0.01 to 0.1 μm is 2 × 10 ⁷ per 1 mm ² among Mn-based compounds, Si-based compounds, and Fe-based compounds. By adjusting to the number of pieces or less, it is to suppress the erosion of the brazing material to the sacrificial anode material during brazing. When the total of the compounds having a particle diameter of 0.01 to 0.1 μm exceeds 2 × 10 ⁷ per 1 mm ² , the brazing material is easily eroded into the sacrificial anode material at the time of brazing, and the brazing property is lowered.

In order to obtain the above compound distribution, particularly in the production of the sacrificial anode material, the material having the above composition is kept at a temperature of 450 to 610 ° C, more preferably 530 to 600 ° C for 2 to 20 hours. It is desirable to do. When the homogenization treatment temperature is less than 450 ° C., many fine compounds of 0.01 to 0.1 μm are likely to precipitate, and when it exceeds 610 ° C., the coarsened compound is precipitated and the self-corrosion resistance of the sacrificial anode material is lowered. The same applies when the homogenization time exceeds 20 hours. If the homogenization treatment time is less than 2 hours, the self-corrosion resistance is lowered by the crystallized material segregated during casting.

  The aluminum alloy clad material of the present invention comprises a core material, a sacrificial anode material, and an aluminum alloy constituting an Al—Si brazing material, for example, ingot by continuous casting, and after homogenization treatment as necessary, a sacrificial anode material The aluminum alloy ingots for solder and brazing material are each hot-rolled to a predetermined thickness, and then the aluminum alloy ingot for core material is combined with the aluminum alloy for sacrificial anode and the aluminum alloy for brazing material. Accordingly, the clad material is manufactured by hot rolling, and then is made to have a predetermined thickness by cold rolling, intermediate annealing, and cold rolling.

  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
An ingot obtained by ingoting a core material alloy having the composition shown in Table 1, a sacrificial anode material alloy having the composition shown in Table 2, and a brazing alloy having the composition shown in Table 3 by continuous casting. Among these, the ingots of the core material alloy and the sacrificial anode material alloy were subjected to a homogenization treatment. The ingot of the alloy for the sacrificial anode material was subjected to a homogenization treatment under the condition of maintaining the temperature at 530 to 580 ° C. for 10 hours in order to uniformly distribute the additive elements and suppress the precipitation of fine compound particles.

  Next, the ingot of the sacrificial anode material alloy and the brazing material alloy is hot-rolled to a predetermined thickness, and the hot-rolled plate and the core alloy ingot (thickness 30 mm) are combined and heated. Cold rolling was performed to obtain a clad material having a three-layer structure (thickness: 3 mm). 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 0.025 to 0.05 mm for the sacrificial anode material and 0.030 mm for the brazing material.

  About the obtained clad material, (1) clad property, (2) erodibility of sacrificial anode material, (3) tensile strength, (4) number of compound particles of 0.1 μm or less in sacrificial anode material by the following methods (5) Corrosion resistance of the sacrificial anode material and (6) Corrosion resistance of the outer surface were evaluated. The results are shown in Table 4.

  Cladity: In the production of sacrificial anode material, the rolling processability is poor and it is difficult to produce a sacrificial anode plate material. The material obtained is defined as having good cladding properties (◯).

  Erosion of sacrificial anode material: As shown in FIG. 1, two clad materials 1 and 2 (width 30 mm, length 30 mm, thickness 0.20 mm) (3 is a core material, 4 is a sacrificial anode material, and 5 is a brazing material. Material) with the sacrificial anode side facing up and fixed. At this time, a fluoride-based flux is applied to the brazing material surface side of the clad material 1. In a superposed state, the substrate is cooled to a temperature of 595 ° C. (material temperature) in a nitrogen gas atmosphere for 3 minutes and then cooled. As shown in FIG. 2, the molten brazing filler 6 is filled in the gap between the clad materials 1 and 2 by heating. Observe the filling state of the molten solder 6, good if the brazing material is not eroded by the sacrificial anode material and the core material (○), bad if the brazing material erosion to the sacrificial anode material and the core material is not good ( X).

  Tensile strength: The aluminum alloy clad material after brazing and heating is subjected to a tensile test, and those having a tensile strength of 170 MPa or more are accepted.

The number of compound particles of 0.1 μm or less in the sacrificial anode material: The compound distribution in the sacrificial anode material is observed by TEM (JEM-200CX) at 10 magnifications (total area 2.4 mm ² ) at a magnification of 20000, and photographed. . The imaging conditions are an exposure condition with an acceleration voltage of 200 kV and a sensitivity of 5 in order to equalize the transmission thickness. The compound particle diameter and the number of compounds are measured by an image analyzer after marking the compound particles (particle diameter: 0.01 μm or more) on the photograph within a range that can be visually observed.

Corrosion resistance of sacrificial anode material: Using the clad sacrificial anode material (shown in FIG. 2) after heat brazing as a test material, the following two types of corrosion tests were performed.
(Corrosion test 1)
According to the intergranular corrosion test (ISO11846 (Method B)). The liquid composition is 30 g / l NaCl + 10 ml / l HCl. In the standard, the test time is 24 hours, but the occurrence of intergranular corrosion was examined by microscopic observation of the cross section of the test material 10 hours after the test. No intergranular corrosion or slight intergranular corrosion that can act satisfactorily as a sacrificial anode layer is good (○), intergranular corrosion is remarkable, and it acts satisfactorily as a sacrificial anode layer due to degranulation. Those that could not be obtained were judged as defective (x).
(Corrosion test 2)
Etchant heated to ^{88 ℃ (Cl - 100ppm, SO} 4 2- 100ppm, HCO 3- 100ppm) To 336 hours of continuous immersion, the maximum corrosion depth of the test material is measured, the maximum corrosion depth is less 0.09mm Was accepted. The specific liquid amount was 5 ml / cm ² .

  Corrosion resistance of outer surface (corrosion test 3): As shown in FIG. 3, the thickness of the cladding material 1 on the brazing material 5 side is made of an Al-1.2% Mn-0.15% Cu-1.0% Zn alloy. A 0.06 mm corrugated fin 7 is placed, and brazing is performed at a brazing temperature of 600 ° C. using a fluoride-based flux in a nitrogen gas atmosphere. The outer surface of the obtained test material is subjected to a two-week corrosion test in accordance with the CASS test method of JIS8861, and the maximum corrosion depth is measured on the brazing material side (outer surface) of the test material after the test. If the length is 0.10 mm or less, the test is accepted.

  As seen in Table 4, the test material No. All of Nos. 1 to 29 have good clad properties, no erosion of the brazing material, tensile strength of 170 MPa or more, excellent corrosion resistance such as intergranular corrosion resistance, and good corrosion resistance on the outer surface. showed that.

Comparative Example 1
A core material alloy having the composition shown in Table 5 and a sacrificial anode material alloy having the composition shown in Table 6 were ingoted by continuous casting, and the resulting ingot was homogenized. The ingot of the alloy for the sacrificial anode material was subjected to a homogenization treatment under the condition of maintaining the temperature at 530 to 580 ° C. for 10 hours in order to completely dissolve the additive element and suppress the precipitation of fine compound particles. .

  Subsequently, the ingot of the alloy for sacrificial anode material and the ingot of the alloy for brazing material ingoted in Example 1 were hot-rolled to a predetermined thickness, and the ingot of these hot-rolled plate and core material alloy ( And a three-layer clad material (thickness 3 mm). Thereafter, a plate material (clad material, tempered H14) having a thickness of 0.25 mm was obtained by cold rolling, intermediate annealing, and cold rolling. The structure of the clad material is 0.025 to 0.05 mm for the sacrificial anode material and 0.030 mm for the brazing material. In Tables 5 and 6, those outside the conditions of the present invention are underlined.

  With respect to the obtained clad material, (1) clad property, (2) erodibility of the sacrificial anode material, (3) tensile strength, and (4) 0.1 μm or less in the sacrificial anode material by the same method as in Example 1. The number of compound particles, (5) corrosion resistance of the sacrificial anode material, and (6) corrosion resistance of the outer surface were evaluated. The results are shown in Table 7.

  As shown in Table 7, the test material No. No. 30 has a large amount of Mn in the sacrificial anode material, so that a coarse compound is generated during casting, the self-corrosion resistance is lowered, and the corrosion resistance is inferior. Test material No. No. 31 is inferior in tensile strength after heat brazing because the amount of Mn in the sacrificial anode material is small. Test material No. No. 32 has a large amount of Zn in the sacrificial anode material, so that the sacrificial anode material is quickly consumed and the corrosion resistance is lowered. Test material No. No. 33 has a small amount of Zn in the sacrificial anode material, so that the sacrificial anode effect is not sufficient and the corrosion resistance (pitting corrosion resistance) is poor.

  Test material No. No. 34 has a large amount of Si in the sacrificial anode material, so that the number of Si-based compound particles increases, and the self-corrosion resistance is lowered and the corrosion resistance is inferior. Test material No. No. 35 is inferior in tensile strength after heat brazing because the amount of Si in the sacrificial anode material is small. Test material No. In No. 36, since the amount of Fe in the sacrificial anode material is large, the compound of 0.1 μm or less in the sacrificial anode material is increased, and the sacrificial erosion of the sacrificial anode material occurs. Test material No. 37 and test material No. Since each of No. 38 has a large amount of In and Sn in the sacrificial anode material, both have poor rolling processability in the production of the sacrificial anode material, and as a result, it became difficult to produce a sound sacrificial anode material, resulting in poor cladding properties. It was.

  Test material No. In No. 39, the sacrificial anode material had a large amount of Mg, so that the brazing property was poor and poor bonding occurred. Test material No. No. 40 has low intergranular corrosion resistance because the amount of Ti in the sacrificial anode material is small. Test material No. No. 41 had a high amount of Ti in the sacrificial anode material, so that rolling processability was poor in the production of the sacrificial anode material, and it became difficult to produce a sound sacrificial anode material, resulting in poor cladness. Test material No. Since No. 42 has a large amount of Mn in the core material, rolling processability is deteriorated in the production of the core material, and as a result, it is difficult to produce a sound core material. Test material No. No. 43 is inferior in tensile strength after heat brazing because the amount of Mn in the core material is small.

  Test material No. In No. 44, since the amount of Cu in the core material is large, local melting occurred in the core material at the time of heat brazing, and the brazing property was lowered. Test material No. 45. Since the amount of Cu in the core material is small, the tensile strength after heat brazing is inferior. Test material No. No. 46 had a large amount of Si in the core material, so that local melting occurred in the core material at the time of heat brazing, and the brazing performance was lowered. Test material No. 47. Since the amount of Si in the core material is small, the tensile strength after heat brazing is inferior. Test material No. In No. 48, the amount of Mg in the core material was large, so that the brazing property was poor and a bonding failure occurred. Test material No. In No. 49, since the amount of Ti in the core material was large, rolling workability was poor in the production of the core material, and as a result, it was difficult to produce a sound core material. Test material No. Since 50 has a large amount of Fe in the core material, the outer surface corrosion resistance is lowered.

It is a schematic sectional drawing which shows the combination of the clad material in the erodibility test of the brazing material in an Example. It is a schematic sectional drawing of the clad material after the brazing material erosion test. It is sectional drawing which shows the outline of the outer surface corrosion test of a clad material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cladding material 2 Cladding material 3 Core material 4 Sacrificial anode material 5 Brazing material 6 Melting brazing 7 Corrugated fin

Claims (7)

A clad material having an aluminum alloy three-layer structure in which a sacrificial anode material is clad on one surface of a core material and a brazing material is clad on the other surface, and the core material is Mn: 0.6 to 2.0% (mass) %, The same applies hereinafter), Cu: 0.3-1.0%, Si: 0.3-1.2%, Fe: 0.01-0.4%, Ti: 0.06-0.35% It is an aluminum alloy containing the balance Al and impurities, and the sacrificial anode material is Zn: 2.0-6.0%, Mn: 1.2-2.0%, Si: 0.4-1.2% Fe: 0.01 to 0.3%, Ti: 0.01 to 0.3%, the balance being an aluminum alloy composed of Al and impurities, and the brazing material being an Al-Si alloy brazing material Aluminum alloy clad material for heat exchanger. The aluminum alloy clad material for a heat exchanger according to claim 1, wherein the core material further contains Mg: 0.5% or less. The core material further contains one or more of Cr: 0.5% or less, Zr: 0.3% or less, and B: 0.1% or less. The aluminum alloy clad material for heat exchangers as described. The sacrificial anode material further contains one or two of In: 0.005 to 0.05% and Sn: 0.005 to 0.05%. The aluminum alloy clad material for heat exchangers according to claim 1. The aluminum alloy clad material for a heat exchanger according to any one of claims 1 to 4, wherein the sacrificial anode material further contains Mg: 2.5% or less. The sacrificial anode material further contains one or more of Cu: 0.2% or less, Cr: 0.3% or less, Zr: 0.3% or less, and B: 0.1% or less. The aluminum alloy clad material for a heat exchanger according to any one of claims 1 to 5. The aluminum alloy clad material for a heat exchanger according to claim 1, wherein the brazing material is an Al—Si based alloy brazing material containing Sr: 0.005 to 0.1%.

Images