JP4352454B2 - Method for producing brazing sheet for heat exchanger excellent in strength and wax erosion resistance - Google Patents

Description

  The present invention relates to a method for producing a brazing sheet for a heat exchanger excellent in strength and wax erosion resistance used for a tube material, a header tank material, a side support material, etc. of a heat exchanger, a brazing sheet produced by this method, and this The present invention relates to a heat exchanger in which a brazing sheet is brazed.

In general, a heat exchanger is composed of a header tank, a number of tubes made of an aluminum alloy provided between the header tanks in parallel with each other, a side support, and the like. It consists of corrugated fins brazed in between. The corrugated fin material is formed by processing a brazing sheet into a corrugated shape and brazing the corrugated sheet processed into the corrugated shape onto a tube.
The tube, the header tank, the side support, etc. are made of a brazing sheet. As an example of the brazing sheet, one or both surfaces of a core material made of an Al—Mn—Cu alloy are made of an Al—Mn alloy having a sacrificial anode effect. An intermediate material is coated, and further, an Al—Si brazing material (specified in JIS 4343, 4045, for example, an Al-7 to 11% by mass Si alloy) or an Al—Si—Mg based brazing material (JIS 4004, 4N04, 4104) is coated on both sides. For example, a brazing sheet clad with a brazing filler metal layer made of Al-9-13 mass% Si-0.2-2 mass% Mg alloy is known. In this brazing sheet, the matrix of the core material has a recrystallized structure, and the matrix of the intermediate material having a sacrificial anode effect has a processed structure (see Patent Document 1). The fins are brazed by assembling a brazing material layer made of a brazing sheet in contact with the fin material, and placing it in a heating furnace in a vacuum or an inert gas atmosphere and heating it to a temperature of around 600 ° C. The fins are joined to the tube to produce a heat exchanger.
JP-A-10-298686

  In recent years, automobiles are strongly demanded for comfort and fuel efficiency, and the demand for compactness and high performance of heat exchangers is increasing. Further, from the viewpoint of weight reduction, those members are required to be thin, and, for example, the tube material is shifting from a conventional plate thickness of about 0.3 to 0.4 mm to 0.2 mm or less. Even when the material is thinned as described above, in order to achieve a level equal to or higher than the durability of the conventional heat exchanger, a very high strength is required as compared with the conventional material.

Therefore, the present inventors have studied from the above viewpoint to obtain a brazing sheet with even higher strength. as a result,
(B) In mass% (hereinafter,% represents mass%), Mn: 0.1 to 2.5%, Zr: 0.05 to 0.3%, Si: 0.1 One or two of 1.2%, Mg: 0.1-2.0%, Ni: 0.05-1.2% are contained, and if necessary, Cu: 0.05-1 An aluminum alloy core material having a composition containing 0.0% and the remainder comprising Al and inevitable impurities, and an aluminum alloy core having a composition comprising Fe: 0.3 to 2.0% and the remainder comprising Al and inevitable impurities A brazing material, a brazing material, and a sacrificial material are prepared, and a laminated material in which these are laminated in the order of sacrificial material-aluminum alloy core material-aluminum alloy intermediate material-brazing material is prepared. After soaking at a temperature, this is hot-rolled, and then subjected to at least one intermediate annealing. Sacrificial material layer-aluminum alloy core material layer-aluminum alloy when cold rolling is performed at a low rolling rate of more than 5 to less than 15% (preferably more than 5 to 10%) from the intermediate annealing to the final sheet thickness A brazing sheet laminated in the order of the intermediate material layer-the brazing material layer is formed, and the brazing sheet is processed into a tube, a header tank, a side support, and brazed together with the fin material to produce a heat exchanger.
The sacrificial material layer and the aluminum alloy core material layer having a rolled structure containing Mn: 0.1 to 2.5% and Zr: 0.05 to 0.3% have characteristics that are difficult to recrystallize, so rolling during brazing. 50% or more of crystal grains having a crystal orientation difference of less than 20 ° and a crystal grain diameter of less than 20 μm exist with respect to adjacent crystal grains on the way from the structure to the recrystallized structure. Change to an unrecrystallized structure
On the other hand, an aluminum alloy intermediate material layer having a rolled structure containing Fe: 0.3 to 2.0% has a characteristic of being easily recrystallized, so that the difference in crystal orientation with respect to adjacent grains from the rolled structure during brazing. Is changed to a recrystallized structure in which 50% or more of crystal grains each having a crystal grain size of 20 μm or more are present at 20 ° or more,
The sacrificial material layer and the aluminum alloy core material layer having an unrecrystallized structure are remarkably superior in strength, whereas the aluminum alloy intermediate material layer has a recrystallized structure, so that the erosion route of the molten brazing material is reduced. There is an effect of preventing erosion by the brazing material, and thus, a heat exchanger composed of a brazing sheet having excellent strength and resistance to brazing erosion can be obtained.
(B) In this case, if a brazing material layer is further formed on the surface of the sacrificial material layer, the sacrificial material layer having an unrecrystallized structure is eroded and weakens the action of the sacrificial material. It was done.

This invention was made based on the above research results,
(1) Mn: 0.1 to 2.5%, Zr: 0.05 to 0.3%, Si: 0.1 to 1.2%, Mg: 0.1 to 2.0 %, Ni: One or two of 0.05 to 1.2%, with the remainder comprising Al and inevitable impurities on one side of an aluminum alloy core material having an Al-Zn system or Al-Zn- An Mg alloy sacrificial material is stacked, and the other surface of the aluminum alloy core material contains Fe: 0.3 to 2.0%, and the balance is composed of Al and inevitable impurities. A brazing material was laminated in the order of sacrificial material-aluminum alloy core material-aluminum alloy intermediate material-brazing material so that the aluminum alloy intermediate material was sandwiched between the aluminum alloy core material and the brazing material. Soaking was performed at a temperature of 430 to 530 ° C. This is hot-rolled and then subjected to at least one intermediate annealing, followed by cold rolling at a low rolling ratio of less than 5 to less than 15% from the last intermediate annealing to the final sheet thickness. A method for producing a brazing sheet for heat exchangers with excellent erosion,
(2) Mn: 0.1 to 2.5%, Zr: 0.05 to 0.3%, Si: 0.1 to 1.2%, Mg: 0.1 to 2.0 %, Ni: 0.05 to 1.2% of one or two of them, and Cu: 0.05 to 1.0%, with the balance being Al and an unavoidable impurity. Al—Zn-based or Al—Zn—Mg-based sacrificial material is superposed on one surface of the alloy core material, Fe: 0.3 to 2.0% is contained on the other surface of the aluminum alloy core material, and the rest is Al. In addition, an aluminum alloy intermediate material and an Al-Si brazing material having a composition comprising inevitable impurities are sacrificed so that the aluminum alloy intermediate material is sandwiched between the aluminum alloy core material and the brazing material-aluminum alloy core material-aluminum alloy intermediate material-brazing Create a laminated material in the order of the materials, and use this laminated material. After soaking at a temperature of 30 to 530 ° C., this is hot-rolled and then subjected to at least one intermediate annealing, and the rolling reduction from the last intermediate annealing to the final sheet thickness exceeds 5 to less than 15%. It has the characteristics in the manufacturing method of the brazing sheet | seat for heat exchangers which was excellent in the intensity | strength cold-rolled by the low rolling rate, and the brazing-proof corrosion resistance.

Since the Zr component in the aluminum alloy has a function of delaying recrystallization during the brazing heat treatment, it is not preferable that the aluminum alloy intermediate material contains Zr. Therefore, even if Zr is included as an inevitable impurity, it is possible. The smaller the content, the better. The content is preferably less than 0.03%. Therefore, the present invention
(3) Mn: 0.1-2.5%, Zr: 0.05-0.3%, Si: 0.1-1.2%, Mg: 0.1-2. 0%, Ni: One or two of 0.05 to 1.2%, further containing Cu: 0.05 to 1.0% as necessary, the remainder being Al and inevitable impurities Al-Zn-based or Al-Zn-Mg-based sacrificial material is superposed on one surface of an aluminum alloy core material having a composition comprising Fe: 0.3-2.0% on the other surface of the aluminum alloy core material And the remainder of the aluminum alloy intermediate material and the Al-Si brazing material composed of Al and inevitable impurities, the sacrificial material-aluminum alloy core material-aluminum so that the aluminum alloy intermediate material is sandwiched between the aluminum alloy core material and the brazing material. An alloy intermediate material-brazing material was laminated in this order, The laminated material is subjected to a soaking treatment at a temperature of 430 to 530 ° C., then hot-rolled, and then subjected to at least one intermediate annealing, and the rolling reduction from the last intermediate annealing to the final sheet thickness exceeds 5 A method for producing a brazing sheet for heat exchangers, which is excellent in strength and braze resistance against cold rolling at a low rolling rate of less than -15%, the content of Zr contained as an inevitable impurity in the aluminum alloy intermediate material It is characterized by a method for producing a brazing sheet for heat exchangers, which is made of an aluminum alloy having a composition regulated to less than 0.03% and has excellent strength and brazing corrosion resistance.

The heat exchangers produced using the brazing sheet for heat exchangers excellent in strength and wax erosion resistance produced by the production method according to the above (1), (2) or (3), An Al-Zn-based or Al-Zn-Mg-based sacrificial material layer having an unrecrystallized structure in which the difference in crystal orientation is less than 20 ° and each crystal grain size is less than 20 µm and there are 50% or more of crystal grains An aluminum alloy core layer composed of an unrecrystallized structure in which the difference in crystal orientation with respect to adjacent crystal grains is less than 20 ° and the crystal grain size of each crystal grain is less than 20 μm is 50% or more; An aluminum alloy intermediate material layer composed of a recrystallized structure in which a difference in crystal orientation with respect to the crystal grains is 20 ° or more and a crystal grain size of each crystal grain size is 20 μm or more is 50% or more, and an Al—Si system B Consists of a wood layer, and the sacrificial material layer - aluminum alloy core material layer - aluminum alloy intermediate material layer - formed by laminating in sequence consisting of the brazing material layer tube, header tanks, and a side support.
Therefore, the present invention
(4) A brazing sheet for a heat exchanger excellent in strength and wax erosion resistance produced by the production method according to (1), (2) or (3),
(5) A heat exchanger in which the brazing sheet according to (4) is brazed, wherein the brazing sheet constituting the heat exchanger has a difference in crystal orientation between adjacent crystal grains of less than 20 °. And an Al-Zn-based or Al-Zn-Mg-based sacrificial material layer composed of an unrecrystallized structure in which 50% or more of each crystal grain size is less than 20 µm, and each crystal with respect to adjacent crystal grains An aluminum alloy core material layer having an unrecrystallized structure in which a difference in orientation is less than 20 ° and each crystal grain size is less than 20 μm is present in an amount of 50% or more, and the crystal orientation of each crystal orientation with respect to adjacent crystal grains An aluminum alloy intermediate material layer composed of a recrystallized structure in which the difference is 20 ° or more and each crystal grain size is 20 μm or more and 50% or more exists, and an Al—Si brazing material layer, The sacrificial material layer - aluminum alloy core material layer - aluminum alloy intermediate material layer - heat exchanger formed by laminating in sequence consisting of the brazing material layer, and it has the characteristics to.

The structure of the brazing sheet excellent in strength and wax erosion resistance brazed to the heat exchanger of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional explanatory view of a heat exchanger in which fins are brazed to a brazing sheet having excellent strength and brazing erosion resistance according to the present invention. In FIG. 1, 1 is a brazing sheet excellent in strength and brazing corrosion resistance of the present invention, 2 is a brazed portion, 3 is a fin, and this brazing sheet 1 is composed of a sacrificial material layer 6-aluminum alloy core material layer 4 The aluminum alloy intermediate material layer 5 and the brazing material layer 7 are laminated and clad in this order, and the brazing portion 2 is formed by brazing the fins 3 to the brazing material layer 7 of the brazing sheet 1. The fins 3 are joined to a tube made of the brazing sheet 1 or the like.

The sacrificial material layer 6 and the aluminum alloy core material layer 4 in the brazing sheet 1 have 50% or more of crystal grains having a difference in crystal orientation of less than 20 ° with respect to adjacent crystal grains and a crystal grain size of less than 20 μm. It consists of an existing organization. Since the sacrificial material layer 6 and the aluminum alloy core material layer 4 have an extremely fine structure that is not sufficiently changed from the rolled structure to the recrystallized structure, the material strength is improved by the influence of dislocation growth, pinning, and the like. . However, on the other hand, this non-recrystallized structure has a low resistance to brazing metal erosion. This is because the brazing erosion caused by the molten brazing material during brazing becomes the erosion route of the molten brazing grain boundary, and there are a large number of grain boundaries (i.e. fine crystal grains). There are a number of erosion pathways, and wax erosion is likely to occur. In particular, the non-recrystallized structure has finer crystal grains than the recrystallized structure, so that significant braze erosion occurs during brazing, causing the clad fin to buckle and the like.

On the other hand, in the aluminum alloy intermediate material layer 5 in the brazing sheet 1, the difference in crystal orientation between adjacent crystal grains is 20 ° or more, and 50% or more of crystal grains each having a crystal grain size of 20 μm or more exist. This recrystallized structure has a large crystallized grain size of 20 μm or more, so that there are few crystal grain boundaries. Therefore, even if it is in contact with the brazing material, the molten brazing material is eroded. Excellent resistance to Therefore, the aluminum alloy intermediate material layer 5 functions as a barrier layer against the brazing corrosion of the aluminum alloy core material layer 4 which is inferior in the brazing corrosion resistance, and is a heat exchange in which a brazing sheet excellent in strength and brazing corrosion resistance is brazed. A vessel is obtained.
Furthermore, since the sacrificial material layer 6 is clad in the brazing sheet 1 provided in the heat exchanger of the present invention, the corrosion resistance of the entire heat exchanger can be improved.

  It is possible to obtain a heat exchanger that is brazed with a brazing sheet that is superior in strength and excellent in resistance to wax erosion, thereby further reducing the thickness of the brazing sheet and further reducing the life of the entire heat exchanger. It can be further improved and brings about an industrially useful effect.

Next, the reason why the component composition of each layer constituting the brazing sheet having further excellent strength and excellent corrosion resistance of the present invention is limited as described above will be described.
A. Component composition Mn of aluminum alloy core material layer:
Mn has the effect of improving the strength of the alloy and has a relatively high solid solubility in the Al alloy, so it has the effect of hardly promoting recrystallization during brazing heat treatment, but its content is 0.1% If the content is less than 2.5%, the desired effect cannot be obtained, which is not preferable. On the other hand, if Mn is contained in an amount of more than 2.5%, a crystallized product at the time of casting becomes coarse and workability is lowered. Therefore, Mn contained in the core material layer is set to 0.1 to 2.5%. A more preferable range of the Mn content is 1.0 to 1.7%.

Zr:
Zr has the effect of delaying recrystallization during brazing heat treatment. The reason why the amount of Zr added is limited to 0.05 to 0.3% is that the effect is small if it is less than 0.05%, and if it exceeds 0.3%, the crystallized product at the time of casting becomes coarse and workability is reduced. This is because of a decrease. A more preferable range of the Zr content is 0.10 to 0.15%.

Si, Mg, Ni:
These components all have the effect of forming fine precipitates and improving the strength of the alloy, but Si: 0.1 to 1.2%, Mg: 0.1 to 2.0%, Ni: 0 0.05 to 1.2% is limited because Si: less than 0.1%, Mg: less than 0.1%, Ni: less than 0.05%, a desired effect cannot be obtained, If Si exceeds 1.2%, the core material layer may melt at the time of brazing due to a decrease in melting point. If Mg exceeds 2.0%, the self-corrosion resistance of the brazing sheet decreases. For this reason, it is not preferable, and if Ni exceeds 1.2%, the self-corrosion resistance is lowered, which is not preferable. A more preferable range of the Si content in the core layer is 0.5 to 1.0%, a more preferable range of the Mg content is 0.10 to 0.50%, and a more preferable range of the Ni content is 0.3 to 1.0%.

Cu:
Cu has the effect of improving the strength of the alloy and is added as necessary. However, the addition amount is limited to 0.05 to 1.0%, and if it is less than 0.05%, the desired effect is obtained. On the other hand, adding over 1.0% is not preferable because the corrosion resistance of the brazing sheet is lowered and cracks are easily generated during casting. A more preferable range of the Cu content is 0.30 to 0.70%.

B. Component composition of aluminum alloy intermediate layer Fe:
Fe is easy to form coarse intermetallic compounds, and these coarse crystallization products serve as nuclei for recrystallization. Therefore, Fe has an effect of promoting recrystallization during brazing heat treatment. If it is less than 3, the desired effect cannot be obtained. On the other hand, if it exceeds 2.0%, the self-corrosion resistance of the tube material decreases, which is not preferable. Therefore, the content of Fe is set to 0.3 to 2.0%. A more preferable range of the Fe content is 0.5 to 1.5%.

C. Component composition of brazing material layer The brazing material layer may be an ordinary aluminum alloy brazing material, such as an Al-Si brazing material (for example, Al-7 to 11% by mass Si alloy defined in JIS 4343, 4045) or Al-Si-. Mg-based brazing material (specified in JIS 4004, 4N04, 4104, for example, Al-9 to 13 mass% Si-0.2 to 2 mass% Mg alloy) can be used, and is not particularly limited. .

D. Component composition of the sacrificial material layer The sacrificial material layer is defined by JIS7072 such as an ordinary Al—Zn alloy (for example, an aluminum alloy containing 0.8% to 1.3% of Zn and the remainder including Al and inevitable impurities). Aluminum alloy) or Al—Zn—Mg based alloy (for example, Zn: 0.5 to 3.0%, Mg: 0.20 to 3.0%, the balance being Al and inevitable impurities) An alloy defined by JIS7N82) can be used.

E. Final cold reduction rate The reason why the reduction rate from the last intermediate annealing to the final sheet thickness is a low pressure reduction rate of more than 5 to less than 15% is that if the reduction rate is 5% or less, the sacrificial material and the aluminum alloy core in the brazing sheet Since both the material and the intermediate material are not recrystallized by brazing and become an unrecrystallized structure, it is not preferable because the role of the intermediate material as a brazing corrosion prevention layer cannot be expected. On the other hand, the reduction ratio is 15% or more. In this case, the sacrificial material, the aluminum alloy core material, and the intermediate material all have a recrystallized structure by brazing, and therefore the role of improving the strength of the core material cannot be expected.

Next, the manufacturing method of the brazing sheet excellent in strength and wax erosion resistance of the present invention will be described.
First, Mn: 0.1 to 2.5%, Zr: 0.05 to 0.3%, Si: 0.1 to 1.2%, Mg: 0.1 to 2.0% Ni: 0.05 to 1.2% of 1 type or 2 types are contained, and Cu: 0.05 to 1.0% is further contained as required, and the remainder consists of Al and inevitable impurities. An aluminum alloy core material plate having a composition, Fe: 0.3 to 2.0% of an aluminum alloy intermediate material plate having a composition comprising Al and inevitable impurities, a sacrificial material plate, and a brazing material plate prepare.
A sacrificial material plate, an aluminum alloy core material plate, an aluminum alloy intermediate material plate, and a brazing material are laminated in this order to produce a laminated material. The laminated material is subjected to a soaking treatment at a temperature of 430 to 530 ° C., and then heated. The sacrificial material layer-aluminum alloy is subjected to cold rolling at a low rolling ratio of less than 5 to less than 15% by performing at least one intermediate annealing and then rolling at a reduction ratio from the last intermediate annealing to the final sheet thickness. A brazing sheet having a rolled structure is produced in any of the layers clad in the order of the core material layer-aluminum alloy intermediate material layer-brazing material layer.
The brazing sheet produced in this way is formed into a tube, header tank, side support, etc., for example, when a fin material is provided between the tubes and placed in a brazing heating furnace, and a normal brazing addition heat treatment is performed The sacrificial material layer and the aluminum alloy core layer of the brazing sheet are not completely recrystallized and become a non-recrystallized structure with excellent strength, while maintaining high strength, while the aluminum alloy intermediate material layer is completely recrystallized. In addition, it has a property excellent in resistance to wax erosion (suppression of wax erosion to the core material layer).

All have dimensions of 20 mm in length, 52 mm in width, 125 mm in length, Zn: 2.0% by mass, Zr: 0.15% by mass, and the balance is composed of Al and inevitable impurities. Aluminum alloy ingot of the material, aluminum alloy ingot of the aluminum alloy core material layer having the chemical composition shown in Tables 1-2, aluminum alloy ingot of the aluminum alloy intermediate material layer, and Si: 7.5% by mass Then, the aluminum alloy ingot of a brazing material having the balance consisting of Al and inevitable impurities was chamfered by 1/4 inch on each side, and then homogenized under conditions of temperature: 530 ° C. and holding for 4 hours.

The aluminum alloy ingot of the sacrificial material, the aluminum alloy core material layer, the aluminum alloy ingot of the aluminum alloy intermediate material layer, and the aluminum alloy ingot of the brazing material, which have been subjected to the homogenization treatment, are subjected to temperature: 480. After uniform heat treatment under the condition of holding at 1 ° C. for 1 hour, the aluminum alloy ingot of the sacrificial material—the aluminum alloy ingot of the aluminum alloy core layer—the aluminum alloy ingot of the aluminum alloy intermediate material layer—the aluminum alloy cast of the brazing material layer A laminated material was produced by superimposing the lumps in order, and the laminated material was hot-rolled to form a clad material having a thickness of about 6 mm. This clad material is further rolled to a thickness of about 1.3 mm by cold rolling, and then subjected to salt bath annealing at 500 ° C. as the first intermediate annealing, and further cold rolled to obtain a thickness of 0.212 to A clad rolled material within a range of 0.232 mm is prepared, and the obtained clad rolled material is subjected to batch annealing under the condition of holding the second intermediate annealing at a temperature of 360 ° C. for 3 hours, and further shown in Tables 1 and 2 By final rolling at the rolling reduction of the conditions, the clad rate is 10% for the brazing material layer, 10% for the aluminum alloy intermediate material layer, 65% for the aluminum alloy core material layer, and 15% for the sacrificial material layer. : 0.20 mm rolled brazing sheet materials A to e were produced.

Further, the composition of Mn: 1.2%, Cu: 0.4%, Si: 0.2%, Fe: 0.3% shown in the above-mentioned Patent Document 1, with the balance being Al and inevitable impurities And a composition comprising Si: 0.2%, Fe: 0.3%, Mn: 0.2% on one side of the core layer having a recrystallized structure, the balance being Al and inevitable impurities. A brazing material layer-core material layer-intermediate layer-brazing material layer formed by laminating an intermediate material layer having a processed structure and forming a brazing material layer defined in JIS 4104 outside the core material layer and the intermediate layer. A rolled brazing sheet material f having a laminated structure was prepared.

Examples 1 to 22, Comparative Examples 1 to 9 and Conventional Example The brazing material layers of the rolled brazing sheet materials A to f having the configurations shown in Tables 1 and 2 were fixed so as to contact the fin material, and the nitrogen atmosphere was maintained. A heat exchanger having a brazing sheet was prepared by charging in a heating furnace and holding at a temperature of 600 ° C. for 3 minutes to produce a heat exchanger having a brazing sheet (the brazing sheet material after brazing the rolled brazing sheet material to the fins) This is the same as the brazing sheet. With respect to this brazing sheet, the crystal grain orientation and grain size in one view of 1.6 mm × 1.6 mm at any point in the cross section of the sacrificial material layer, the aluminum alloy core material layer, and the aluminum alloy intermediate material layer are expressed by SEM-EBSP ( EBSP: Electron Back-Scatter Diffraction Pattern) Based on the measurement results, there are crystal grains having a difference in crystal orientation of adjacent crystal grains of less than 20 ° and a crystal grain diameter of less than 20 μm. A structure in which a structure having 50% or more is regarded as an unrecrystallized structure and a difference in crystal orientation between adjacent crystal grains is 20 ° or more and a crystal grain having a crystal grain size of 20 μm or more is present in 50% or more. The result was recognized as a recrystallized structure, and the results are shown in Tables 3 to 4 as the results obtained from Examples 1 to 22, Comparative Examples 1 to 9, and the conventional examples. Further, the following tests were conducted.

A tensile test piece was prepared from a brazing sheet brazed with a tensile test fin, and a tensile test was performed using this tensile test piece. The results are shown as results of Examples 1 to 22, Comparative Examples 1 to 9, and the conventional example. Shown in 3-4.

By observing the cross section of the aluminum alloy intermediate layer in contact with the brazing filler metal layer of the brazing sheet after brazing, the maximum brazing erosion depth from the surface was measured. As shown in Tables 3 to 4 as the results of Comparative Examples 1 to 9 and the conventional example, the brazing erosion resistance of the brazing sheet brazed to the heat exchanger was evaluated.

In Table 2, the values marked with * indicate that the values deviate from the conditions of the present invention.

  From the results shown in Tables 1 to 4, when the measurement results obtained in Examples 1 to 22 and the measurement results obtained in the conventional examples are compared, the rolled brazing sheet materials A to V obtained in Examples 1 to 22 are used. Is superior to the rolled brazing sheet material f prepared in the prior art in terms of strength after brazing and brazing corrosion resistance, so that the rolled brazing sheet materials A to V obtained by the production method of the present invention are brazed. It can be seen that the heat exchangers 1 to 22 of the present invention obtained by attaching are superior in strength to the heat exchanger obtained by brazing the rolled brazing sheet material f obtained by the conventional manufacturing method. . However, as can be seen from Comparative Examples 1 to 9, the rolled brazing sheet material We produced under conditions deviating from the present invention is difficult to manufacture, and even if it can be manufactured, the rolled brazing sheet material is waxed. It can be seen that the comparative heat exchangers 1 to 9 are not preferable because at least one of the strength and the erosion resistance is inferior.

It is a partial cross section for demonstrating the structure | tissue of the brazing sheet material of the joining part vicinity where the fin was brazed to the brazing sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brazing sheet 2 Brazing part 3 Fin 4 Aluminum alloy core material layer 5 Aluminum alloy intermediate material layer 6 Sacrificial material layer 7 Brazing material layer

Claims (5)

% By mass (hereinafter,% indicates% by mass), Mn: 0.1 to 2.5%, Zr: 0.05 to 0.3%, Si: 0.1 to 1.2 %, Mg: 0.1-2.0%, Ni: 0.05-1.2% of one or two kinds of aluminum alloy core material of the composition consisting of Al and inevitable impurities Al-Zn-based or Al-Zn-Mg-based sacrificial material is superposed on one surface, Fe: 0.3-2.0% is contained on the other surface of the aluminum alloy core material, and the remainder is made of Al and inevitable impurities. An aluminum alloy intermediate material and an Al-Si brazing material having the following composition are laminated in the order of sacrificial material-aluminum alloy core material-aluminum alloy intermediate material-brazing material so that the aluminum alloy intermediate material is sandwiched between the aluminum alloy core material and the brazing material. The laminated material was produced, and this laminated material was 430-5. After soaking at a temperature of 0 ° C., this is hot-rolled and then subjected to at least one intermediate annealing, and the rolling reduction from the last intermediate annealing to the final sheet thickness is less than 5 to less than 15%. A method for producing a brazing sheet for a heat exchanger excellent in strength and wax erosion resistance, characterized by cold rolling at a rolling rate. % By mass (hereinafter,% indicates% by mass), Mn: 0.1 to 2.5%, Zr: 0.05 to 0.3%, Si: 0.1 to 1.2 %, Mg: 0.1 to 2.0%, Ni: 0.05 to 1.2%, or 1 or 2 of Cu, and further Cu: 0.05 to 1.0%, An Al—Zn-based or Al—Zn—Mg-based sacrificial material is superposed on one surface of an aluminum alloy core material having a composition composed of Al and inevitable impurities, and Fe: 0.3 to Sacrificial material containing 2.0% of aluminum alloy intermediate material and Al-Si brazing material with the balance consisting of Al and inevitable impurities so that the aluminum alloy intermediate material is sandwiched between the aluminum alloy core material and the brazing material Aluminum alloy core material-Aluminum alloy intermediate material-Brazing material A laminated material is prepared, and the laminated material is soaked at a temperature of 430 to 530 ° C., then hot-rolled, and then subjected to at least one intermediate annealing, from the last intermediate annealing to the final plate thickness. A method for producing a brazing sheet for a heat exchanger excellent in strength and resistance to brazing erosion, characterized by cold rolling at a rolling ratio of less than 5 to less than 15%. The said aluminum alloy intermediate material consists of an aluminum alloy of the composition which controlled content of Zr contained as an unavoidable impurity to less than 0.03%, The intensity | strength and brazing-proof corrosion resistance of Claim 1 or 2 characterized by the above-mentioned. An excellent method for producing a brazing sheet for a heat exchanger. A brazing sheet for a heat exchanger excellent in strength and wax erosion resistance, characterized by being produced by the production method according to claim 1, 2 or 3. 5. A heat exchanger in which the brazing sheet according to claim 4 is brazed, wherein the brazed sheet after brazing constituting the heat exchanger has a difference in crystal orientation between adjacent crystal grains of less than 20 °. And an Al-Zn-based or Al-Zn-Mg-based sacrificial material layer having an unrecrystallized structure in which 50% or more of crystal grains each having a crystal grain size of less than 20 μm are present, and each adjacent crystal grain An aluminum alloy core material layer having an unrecrystallized structure in which a difference in crystal orientation is less than 20 ° and each crystal grain size is less than 20 μm is present in an amount of 50% or more, and each crystal with respect to adjacent crystal grains An aluminum alloy intermediate material layer composed of a recrystallized structure in which a difference in orientation is 20 ° or more and each crystal grain size is 20 μm or more is present in an amount of 50% or more, an Al—Si based brazing material layer, etc. It becomes, and the sacrificial material layer - aluminum alloy core material layer - aluminum alloy intermediate material layer - heat exchanger, characterized in that formed by laminating in sequence consisting of the brazing material layer.

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