JP2009161827A - Brazing sheet for tube material of heat exchanger, and method for producing heat exchanger using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brazing sheet for a tube material of a heat exchanger obtained by being clad with an Al-Si based brazing filler metal, and where Si in the solidified structural material in the brazing filler metal after brazing heating can be micronized. <P>SOLUTION: A core material is composed of an aluminum alloy comprising, by mass, 0.6 to 2.0% Mn, 0.6 to 1.3% Si, 0.2 to 1.0% Cu, 0.05 to 0.3% Zr and 0.05 to 0.3% Ti, and a sacrificial anode material is composed of an aluminum alloy comprising 1.0 to 6.0% Zn, 0.5 to 2.0% Mn and 0.2 to 1.3% Si. A brazing filler metal on the core material side is composed of an aluminum alloy comprising 6 to 15% Si, either or both of the core material and the brazing filler metal on the core material contain Sr, wherein the content of Sr in the core material is ≤0.6%, and the content of Sr in the brazing filler metal on the core material size is also ≤0.6%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a brazing sheet for a tube material of an aluminum alloy heat exchanger used for manufacturing a radiator, a heater core, an oil cooler, an intercooler, a condenser of an air conditioner, an evaporator, and the like, and a brazing flux using the brazing sheet. The present invention relates to a heat exchanger obtained by brazing a tube material and a fin material, and a method for manufacturing the same.

  Aluminum alloy heat exchangers are widely used as heat exchangers for automobile radiators, heater cores, oil coolers, intercoolers, car air conditioner evaporators, condensers, and the like. Aluminum alloy heat exchanger is an inert gas atmosphere brazing that uses a tube material made of Al-Mn alloy, Al-Mn-Cu alloy, etc., and fin material of aluminum alloy, and uses chloride flux or fluorine flux. Manufactured by a brazing method or a vacuum brazing method.

  As the brazing material for brazing the tube material and the fin material, an Al—Si based brazing material is generally used. The brazing material is disposed on the tube material side, or is disposed on one or both sides of the fin material. After the tube material and the fin material are assembled, the brazing material is heated by brazing, The brazing material is melted and the members are joined.

  Usually, a brazing material solidified after brazing heating has a eutectic structure of acicular Si and a eutectic α phase, and a primary crystal α phase in which Si is dissolved in aluminum. Since acicular Si and the eutectic α phase have different potentials, the potential eutectic eutectic α phase is preferentially corroded to cause early corrosion of the fillet (brazing portion). In addition, the solidified brazing material that remains thinly on the surface of the general part of the tube material after brazing heating is in a state where many crystal grain boundaries are dissolved, and most of the needle-like Si is in the crystal grain boundary where the melting is the largest. Crystallized along. Since there is a Si deficient layer at the boundary between the eutectic α phase and acicular Si, the potential deficient layer corrodes preferentially, and the thickness of the plate along the grain boundary of the core material Corrosion proceeds in the direction. Therefore, in the brazing sheet clad with the Al—Si brazing material, there is a problem that the acicular Si contributes to a reduction in life. In addition, since the strength differs between acicular Si and the eutectic α phase, the strength of the fillet joint varies, and the surface becomes rough, which becomes the starting point of fatigue failure. Therefore, the brazing sheet clad with the Al—Si brazing material has a problem that the needle-like Si contributes to a decrease in fatigue strength.

  As a brazing sheet excellent in corrosion resistance, for example, in Japanese Patent Application Laid-Open No. 2003-306735 (Patent Document 1), Mn: 0.5 to 2.0% in mass% (hereinafter,% represents mass%), Si: 0.1 to 1.0%, Cu: 0.1 to 1.0%, Fe: 0.1 to 1.0%, with the balance being an Al alloy having a composition consisting of Al and inevitable impurities And Zn: 2.6 to 10%, Si: 0.25 to 1.0%, Ni: 0.01 to 1.0%, Mn: 0.1 to 1.5% on one side of the core material , Ti: 0.01 to 0.25%, the remainder is clad with a sacrificial anode skin material composed of Al and inevitable impurities, and the other side of the core material is Al-Si-based or Al-Si- Aluminum alloy brazing for heat exchangers with excellent corrosion resistance, characterized by clad Zn-based brazing material Gushito have been disclosed.

  Moreover, as a brazing sheet | seat excellent in the erosion-proof characteristic, it is Al alloy containing Unexamined-Japanese-Patent No. 2000-303132 (patent document 2) Mn: 0.05-2.0% (wt%, and the following similarly). An Al alloy brazing sheet in which a brazing material formed of an Al alloy containing Si: 6.0 to 13.5% or Ge: 0.4 to 5.5% is laminated on both surfaces or one surface of the formed core material. In addition to Mn, the core material is further Ca: 0.1 to 5.0%, Li: 0.1 to 10.0%, Sr: 0.05 to 0.8%, Sc: 0.05 to 0.8%, Y: 0.05-1.0%, Ti: 0.17-1.0%, Zr: 0.3-1.0%, V: 0.2-1.0%, Nb : 0.05 to 1.0%, Co: 0.1 to 0.5%, Ni: 0.05 to 0.5%, Ba: 0.05 to 0 Disclosed is an Al alloy brazing sheet excellent in erosion resistance formed of an Al alloy containing one of 8%, Be: 0.05 to 0.8%, and Ta: 0.05 to 1.0%. Has been.

  Moreover, as a brazing sheet which improved the fluidity | liquidity of the brazing material, Unexamined-Japanese-Patent No. 51-46548 (patent document 3) has Si: 6.8 to 10.5%, Mg: 10-30, for example. %, Fe: 0.2-1.2%, Mn: 0.2-0.5%, Al and impurities: the rest, aluminum alloy is used as a brazing material, Si: 0.2-0.6%, Mg: 0.3 to 0.65%, Fe: 0.2 to 0.6%, Mn: 0.3 to 0.8, Cr: 0.6% or less, Ti: 0.1% or less, Al and An aluminum alloy clad composite material for brazing is disclosed, characterized in that an aluminum alloy consisting of impurities: remaining is used as a core material.

JP 2003-306735 A (Claims) JP 2000-303132 A (Claims) JP 51-46548 A (Claims)

  However, Patent Documents 1 to 3 cannot solve the above problem.

  In recent years, brazing sheet materials in which a flux precoat layer made of flux is previously formed on the surface of a brazing material have been used. The brazing sheet on which such a flux precoat layer is formed similarly has the above problems.

When a brazing sheet having a flux precoat layer formed on the surface of the brazing material is processed to produce a tube material, the tube material and the fin material are assembled, brazed, heated, and brazed, the flux precoat The application amount of the fluoride flux with respect to the area where the layer is formed is generally about 1 to 15 g / m ² .

  Regarding the above problem, if the brazing material solidified after the brazing heating can be made to have fine crystal grains without causing the Si to become needle-like, that is, the solidification of the brazing material after the brazing heating. If the Si in the structure can be refined, a brazing sheet for a tube material of a heat exchanger having excellent corrosion resistance after brazing and less variation in strength can be obtained. Accordingly, an object of the present invention is a brazing sheet clad with an Al—Si brazing material, and is a tube material for a heat exchanger that can refine Si in the solidified structure of the brazing material after brazing and heating. It is to provide a brazing sheet for use. Also, an object of the present invention is a method of manufacturing a heat exchanger for obtaining a heat exchanger by brazing a tube material made of a brazing sheet clad with an Al-Si brazing material, the brazing after brazing heating An object of the present invention is to provide a method of manufacturing a heat exchanger in which Si in a solidified structure of a material is refined.

  As a result of intensive studies to solve the above-described problems in the prior art, the inventors have specified the additive elements and the content of the core material and brazing material constituting the brazing sheet, the core material and The inventors have found that the above problem can be solved by setting the relationship between the Sr contained in the brazing filler metal and the flux coating amount within a specific range, and have completed the present invention.

That is, the present invention (1) is a brazing for a tube material of a heat exchanger in which a core material brazing material is clad on one surface of a core material, and a sacrificial anode material is clad on the other surface of the core material. A sheet,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6% by mass or less,
A brazing sheet for a tube material of a heat exchanger is provided.

Further, the present invention (2) is a brazing for tube material of a heat exchanger in which a core material brazing material is clad on one surface of the core material, and a sacrificial anode material is clad on the other surface of the core material. A sheet,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
A flux precoat layer made of fluoride flux is formed on the surface of the core side brazing material,
A brazing sheet for a tube material of a heat exchanger is provided.

Further, in the present invention (3), the Sr content Cs (mass%) in the core material, the Sr content Rx (mass%) in the core material brazing material, and the thickness Dx of the core material brazing material (Μm) and the application amount Fx (g / m ² ) of the fluoride flux of the flux precoat layer is expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The present invention provides a brazing sheet for a tube material of a heat exchanger according to the present invention (2).

Moreover, this invention (4) apply | coats a fluoride flux on the surface of the brazing material side brazing material of the tube material which consists of a brazing sheet for tube materials of the heat exchanger of the said this invention (1), and this tube material and Assembling and heating the fin material, and brazing the tube material and the fin material;
Sr content Cs (mass%) in the core material of the tube material before brazing, Sr content Rx (mass%) in the brazing material side brazing material of the tube material before brazing, The thickness Dx (μm) of the core material brazing material of the tube material and the coating amount Fx (g / m ² ) of the fluoride flux are expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Meeting,
The manufacturing method of the heat exchanger characterized by these is provided.

  Moreover, this invention (5) assembles and heats the tube material and fin material which consist of the brazing sheet for tube materials of the heat exchanger of the said invention (2) or (3), this tube material and this fin material are assembled. It is intended to provide a method of manufacturing a heat exchanger characterized by having a brazing process for brazing.

In the present invention (6), the core material is brazing material side brazing material, sacrificial anode material and sacrificial anode material side brazing material, the core material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode. A brazing sheet for a tube material of a heat exchanger clad in the order of the brazing material on the material side,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The sacrificial anode material side brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr,
Sr content in the sacrificial anode material is 0.6 mass% or less,
Sr content in the sacrificial anode material side brazing material is 0.6 mass% or less,
A brazing sheet for a tube material of a heat exchanger is provided.

In the present invention (7), the core material side brazing material, the sacrificial anode material, and the sacrificial anode material side brazing material are the core material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode. A brazing sheet for a tube material of a heat exchanger clad in the order of the brazing material on the material side,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
A first flux precoat layer made of fluoride flack is formed on the surface of the brazing material side brazing material,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The sacrificial anode material side brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr,
Sr content in the sacrificial anode material is 0.6 mass% or less,
Sr content in the sacrificial anode material side brazing material is 0.6 mass% or less,
A second flux precoat layer made of fluoride flux is formed on the surface of the sacrificial anode material side brazing material;
A brazing sheet for a tube material of a heat exchanger is provided.

Further, in the present invention (8), the Sr content Cs (mass%) in the core material, the Sr content Rx (mass%) in the core material brazing material, and the thickness Dx of the core material brazing material (Μm) and the application amount Fx (g / m ² ) of the fluoride flux of the first flux precoat layer is represented by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The filling,
And Sr content Gs (mass%) in the sacrificial anode material, Sr content Ry (mass%) in the sacrificial anode material side brazing material, thickness Dy (μm) of the sacrificial anode material side brazing material And the application amount Fy (g / m ² ) of the fluoride flux of the second flux precoat layer is represented by the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Meeting,
The present invention provides a brazing sheet for a tube material of a heat exchanger according to the present invention (7).

Moreover, this invention (9) is a fluoride on the surface of the brazing material side brazing material and the sacrificial anode material side brazing material of the tube material comprising the brazing sheet for the tube material of the heat exchanger of the present invention (6). Applying a flux, assembling the tube material and the fin material, heating, and brazing the tube material and the fin material;
Sr content Cs (mass%) in the core material of the tube material before brazing, Sr content Rx (mass%) in the brazing material side brazing material of the tube material before brazing, The thickness Dx (μm) of the core material side brazing material of the tube material and the application amount Fx (g / m ² ) of the fluoride flux applied to the surface of the core material side brazing material of the tube material are expressed by the following formulas: (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The filling,
And Sr content Gs (mass%) in the sacrificial anode material of the tube material before brazing, Sr content Ry (mass%) in the brazing material side brazing material of the tube material before brazing, brazing The thickness Dy (μm) of the sacrificial anode material side brazing material of the tube material before application, and the application amount Fy (g / m ^{2) of the} fluoride flux applied to the surface of the sacrificial anode material side brazing material of the tube material. ) Is the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Meeting,
The manufacturing method of the heat exchanger characterized by these is provided.

  Moreover, this invention (10) assembled | attached and heated the tube material and fin material which consist of the brazing sheet for tube materials of the heat exchanger of the said this invention (7) or (8), this tube material and this fin material are used. It is intended to provide a method of manufacturing a heat exchanger characterized by having a brazing process for brazing.

  According to the present invention, a brazing sheet clad with an Al-Si brazing material, which is used for a tube material of a heat exchanger capable of refining Si in a solidified structure material of a brazing material after brazing and heating. A brazing sheet can be provided. According to the present invention, there is also provided a heat exchanger manufacturing method for brazing a tube material made of a brazing sheet clad with an Al-Si brazing material, wherein the brazing material in the solidified structure of the brazing material after brazing heating is used. A method of manufacturing a heat exchanger having a fine Si content can be provided. Therefore, according to the present invention, it is possible to obtain a brazing sheet for a tube material of a heat exchanger that is excellent in corrosion resistance after brazing and has little variation in strength, and a heat exchanger that is excellent in corrosion resistance and has little variation in strength.

The brazing sheet for a tube material of the heat exchanger according to the first embodiment of the present invention (hereinafter also referred to as the brazing sheet (1) of the present invention) has a core material brazing material clad on one surface of the core material. And a brazing sheet for a tube material of a heat exchanger in which a sacrificial anode material is clad on the other surface of the core material,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6% by mass or less,
It is a brazing sheet for tube materials of a heat exchanger.

  The brazing sheet (1) of the present invention is used for a tube material of a heat exchanger in which a core material brazing material is clad on one surface of a core material and a sacrificial anode material is clad on the other surface of the core material. Since it is a brazing sheet, it is a three-layer material having the core material brazing material, the core material, and the sacrificial anode material in this order.

  The core material according to the brazing sheet (1) of the present invention contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, and 0.2 to 1 of Cu. It is an aluminum alloy containing 0.0 mass%, Zr 0.05-0.3 mass%, and Ti 0.05-0.3 mass%.

  The Mn content in the core material is preferably 1.0 to 1.7% by mass. Mn in the core material is an element added to ensure strength, and functions as an element that improves high temperature buckling resistance. If the content of Mn in the core material is less than the above range, the effect of adding the Mn element is small, and if it exceeds the above range, coarse crystallized products are generated at the time of casting and rolling workability is impaired. Therefore, it becomes difficult to manufacture the plate material.

  The Si content in the core material is preferably 0.8 to 1.0% by mass. Si in the core material functions as an element that improves the strength. If the Si content in the core material is less than the above range, the effect of improving the strength by adding the Si element is small, and if it exceeds the above range, the corrosion resistance is lowered and the melting point of the core material is lowered. Local melting is likely to occur during brazing.

  The content of Cu in the core material is preferably 0.3 to 0.7% by mass. Cu in the core material functions as an element that improves the strength. When the content of Cu in the core material is less than the above range, the effect of improving the strength due to the addition of the Cu element is small, and when it exceeds the above range, it diffuses into the sacrificial anode material layer during brazing and is sacrificed. The potential of the material layer is raised, the corrosion resistance is lowered, and an Al—Si—Cu ternary composition is formed with Si to lower the melting point of the core material.

  The Zr content in the core material is preferably 0.1 to 0.2% by mass. Zr in the core material functions as an element that coarsens the crystal grain size of the core material and suppresses penetration of the molten solder. If the content of Zr in the core material is less than the above range, the effect of adding the Zr element is small, and even if added beyond the above range, the effect is saturated. Need not be added.

  The content of Ti in the core material is preferably 0.1 to 0.2% by mass. When Ti in the core material is added to the core material, it is divided into a high-concentration region and a low region in the plate pressure direction of the core material, and these regions exist in a layered manner in which the regions are alternately distributed. Since the low concentration region corrodes preferentially compared to the high region, Ti in the core material has an effect of layering the corrosion form, thereby preventing the progress of corrosion in the thickness direction of the material. It functions as an element that improves pitting corrosion resistance. If the content of Ti in the core material is less than the above range, the effect of adding the Ti element is small, and if it exceeds the above range, casting becomes difficult, workability deteriorates, and a sound material can be produced. It becomes difficult.

  The sacrificial anode according to the brazing sheet (1) of the present invention contains 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1 Si. .3% by mass aluminum alloy.

  The content of Zn in the sacrificial anode material is preferably 2 to 5% by mass. Zn in the sacrificial anode material functions as an element that enhances the sacrificial anode effect. If the Zn content in the sacrificial anode material is less than the above range, the effect of adding the Zn element is small, and if it exceeds the above range, the consumption rate of the sacrificial anode material is increased and the life is shortened.

  The content of Mn in the sacrificial anode material is preferably 1.0 to 1.7% by mass. Mn in the core material is an element added to ensure strength, and functions as an element that improves high temperature buckling resistance. If the content of Mn in the sacrificial anode material is less than the above range, the effect of adding the Mn element is small, and if it exceeds the above range, coarse crystallized products are generated at the time of casting and rolling workability is reduced. This makes it difficult to manufacture the plate material.

  The content of Si in the sacrificial anode material is preferably 0.3 to 1.0% by mass. Si in the sacrificial anode material functions as an element for improving the strength of the sacrificial anode material layer. If the content of Si in the sacrificial anode material is less than the above range, the effect of improving the strength due to the addition of the Si element is small, and if it exceeds the above range, the corrosion resistance is lowered and the melting point of the sacrificial anode material is reduced. Lowering and local melting are likely to occur during brazing.

  The core material side brazing material according to the brazing sheet (1) of the present invention is an aluminum alloy containing 6 to 15% by mass of Si. The Si content in the core side brazing material is preferably 7 to 12% by mass. Si in the core brazing filler metal is an element added to lower the melting point of the brazing filler metal and functions as an element that improves the flowability of the molten brazing filler metal. If the content of Si in the brazing filler metal side brazing material is less than the above range, the addition effect of the Si element is small, and if it exceeds the above range, the melting point increases rapidly, Workability is reduced.

  In the brazing sheet (1) of the present invention, either or both of the core material and the core material side brazing material contain Sr. That is, when only the core material contains Sr, when only the core material side brazing material contains Sr, both the core material and the core material side brazing material may contain Sr. And Sr content in this core material is 0.6 mass% or less, and Sr content in this core side brazing material is 0.6 mass% or less. Sr in the core material diffuses from the core material into the brazing material at the time of melting of the brazing material, and Si in the solidified structure of the brazing material after brazing can be refined. That is, Sr in the core material is an element added to refine Si in the solidified structure of the brazing material after brazing, and the brazing material after brazing is contained by the core material containing Sr. Since Si in the solidified structure of the material can be refined, the corrosion resistance of the heat exchanger can be improved and the variation in strength can be reduced. Further, Sr in the brazing material side brazing material refines the solidified particles of Si in the brazing material at the time of casting solidification, that is, refines the Si particles of the brazing material before brazing and brazes after brazing. Si in the solidified structure of the material can be refined. That is, Sr in the brazing material side brazing material is added to refine the solidified particles of Si in the brazing material before brazing and to refine Si in the solidified structure of the brazing material after brazing. It is an element, and when the core brazing filler metal contains Sr, the productivity after rolling can be improved, the corrosion resistance of the heat exchanger can be improved, and the variation in strength can be reduced. On the other hand, if the Sr content in the core material or the Sr content in the core-side brazing material exceeds 0.6% by mass, a huge crystallized product is generated at the time of casting, resulting in rolling cracks. . Therefore, in the brazing sheet (1) of the present invention, when only the core material contains Sr, the content of Sr in the core material is 0.6% by mass or less, and the core material side brazing material When only Sr contains Sr, the content of Sr in the brazing material is 0.6% by mass or less, and when both the core material and the brazing material side brazing material contain Sr, the core The Sr content in the material is 0.6% by mass or less, and the Sr content in the core side brazing material is 0.6% by mass or less.

  Furthermore, in the brazing sheet (1) of the present invention, the core material contains 0.005 to 0.6% by mass of Sr and the core material side brazing material is 0 in that the effect of adding Sr is easy to obtain. 0.005 to 0.6% by mass of Sr is preferable, the core material contains 0.005 to 0.4% by mass of Sr, and the core side brazing material is 0.005 to 0.4%. It is particularly preferable to contain Sr by mass%. That is, in the brazing sheet (1) of the present invention, both the core material and the brazing material side brazing material contain Sr in the above range, so that the Si in the solidified structure of the brazing material after brazing can be finely divided. The effect of making it higher becomes higher.

  The brazing material side brazing material contains Mn, so that Si in the solidified structure of the brazing material before brazing is refined to improve the flowability of the brazing and in the solidified structure of the brazing material after brazing. Si can be refined. That is, Mn in the brazing material side brazing material is an element added to improve the fluidity of the brazing and to refine Si in the solidified structure of the brazing material after brazing. Moreover, when there is too much Mn content in this core side brazing material, a huge crystallized substance will produce | generate at the time of casting, and a rolling crack will be produced. Therefore, it is preferable that the brazing filler metal side brazing material contains 0.05 to 1.4% by mass of Mn from the viewpoint of obtaining the above Mn addition effect.

  In addition, since an aluminum ingot having an Fe content of 0.1% by mass or less is expensive, the core material, the brazing material side brazing material, and the sacrificial anode material are usually ground with an Fe content of 0.4% by mass or less. Gold is used. And a core material, a core material side brazing material, or a sacrificial anode material contains a 0.4 mass% or less Fe, and intensity | strength improves a little. On the other hand, when the Fe content of the core material, the core material side brazing material or the sacrificial anode material exceeds 0.4% by mass, the self-corrosion resistance is lowered. Therefore, usually, a bare metal having an Fe content of 0.1 to 0.4% by mass is used.

  Further, the core material, the core material side brazing material, and the sacrificial anode material may contain the following additive elements in addition to the above additive elements.

  In order to improve the strength of the brazing sheet, the core material is 1.0% by mass or less of Fe, 1.0% by mass or less of Mg, 0.3% by mass or less of V, and 0.3% by mass or less of Mo. Or 0.3 mass% or less of Ni can be contained. Further, the core material has a low potential without substantially reducing the thermal conductivity of the brazing sheet, and in order to ensure the sacrificial anode effect, 3.0% by mass or less of Zn, 0.3% by mass or less of In, 0.3 mass% or less Sn or 0.3 mass% or less Ga can be contained. Further, the core material can contain 0.3% by mass or less of Cr in order to increase the crystal grain size after brazing. Moreover, this core material can contain 0.1 mass% or less Pb, 0.1 mass% or less Li, 0.1 mass% or less Ca, or 0.1 mass% or less Na. Moreover, this core material can contain 0.4 mass% or less B for oxidation prevention.

  The brazing filler metal side brazing material is 0.3 mass% or less of Cr, 0.3 mass% or less of Cu, 0.1 mass% or less of Pb, 0.1 mass% or less of Li, or 0.1 mass%. The following Ca can be contained. Further, the brazing filler metal side brazing material may contain 0.3% by mass or less of Ti or 0.1% by mass or less of B in order to refine the cast structure. Moreover, in order to ensure the sacrificial anode effect, the core material brazing filler metal is 3.0% by mass or less of Zn, 0.1% by mass or less of In, 0.1% by mass or less of Sn, or 0.1% It can contain Ga or less by mass%. Further, the brazing filler metal side brazing material can contain 0.1% by mass or less of Be in order to suppress the growth of the surface oxide film. Further, the brazing material side brazing material can contain 0.1% by mass or less of Bi in order to improve the fluidity of the brazing material.

  The sacrificial anode material has a lower potential without substantially reducing the thermal conductivity of the brazing sheet, and in order to ensure the sacrificial anode effect, 0.3% by mass or less of In, 0.3% by mass or less of Sn, Or 0.3 mass% or less Ga can be contained. Further, the sacrificial anode material is made of 1.0 mass% or less of Cu, 1.0 mass% or less of Fe, 1.0 mass% or less of Mg, 0.3 mass% or less of V, It can contain 0.3 mass% or less of Mo or 0.3 mass% or less of Ni. The sacrificial anode layer can contain 0.3 mass% or less of Zr or 0.3 mass% or less of Cr in order to coarsen the crystal grain size after brazing. Further, the sacrificial anode layer can contain 0.1% by mass or less of Pb, 0.1% by mass or less of Li, 0.1% by mass or less of Ca, or 0.1% by mass or less of Na. . The sacrificial anode layer can contain 0.3% by mass or less of Ti for refinement of the cast structure. In addition, the sacrificial anode layer can contain 0.1% by mass or less of B for preventing oxidation. In addition, the sacrificial anode layer may contain 0.6% by mass or less of Sr in order to refine Si in the solidified structure of the brazing material that flows and joins the sacrificial anode layer.

  The core material, the core material-side brazing material, and the sacrificial anode material are all aluminum alloys composed of the above additive elements, inevitable impurities, and aluminum.

  The brazing sheet (1) of the present invention is obtained by cladding the core material brazing material on one surface of the core material and cladding the sacrificial anode material on the other surface of the core material. As a method of cladding the core material side brazing material and the sacrificial anode material on the core material, the core material, the core material side brazing material, or a core material having the same composition as each element in the sacrificial anode material Cast alloy ingot for alloy, alloy ingot for brazing filler metal and sacrificial anode material, then homogenize the alloy ingot for core according to a conventional method, The alloy ingot for the core material side brazing material and the alloy ingot for the sacrificial anode material are hot-rolled, and then the alloy ingot for the core material and the core material side brazing after homogenization treatment are performed. Combine the hot rolled product of the alloy ingot for the material and the hot rolled product of the alloy ingot for the sacrificial anode material, and perform hot rolling → annealing → cold rolling in this order, or hot rolling → cold A method of performing rolling → annealing in order and then performing finish cold rolling can be mentioned.

  The thickness of the brazing sheet (1) of the present invention is not particularly limited, but is usually 0.2 to 0.3 mm.

The brazing sheet for a tube material of the heat exchanger according to the second aspect of the present invention (hereinafter also referred to as the brazing sheet (2) of the present invention) is the brazing material side brazing material of the brazing sheet (1) of the present invention. A flux precoat layer made of fluoride flux is formed on the surface.
That is, the brazing sheet (2) of the present invention is a heat exchanger tube in which a core material brazing material is clad on one surface of the core material, and a sacrificial anode material is clad on the other surface of the core material. A brazing sheet for wood,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
On the surface of the brazing material side brazing material, a flux precoat layer made of fluoride flack is formed,
It is a brazing sheet for tube materials of a heat exchanger.

  That is, the brazing sheet (2) of the present invention is a brazing sheet in which the brazing sheet (1) of the present invention further has the flux precoat layer. Therefore, in the brazing sheet (2) of the present invention, the brazing sheet on which the flux precoat layer is formed is the same as the brazing sheet (1) of the present invention.

The flux precoat layer according to the brazing sheet (2) of the present invention is formed by the fluoride flux. The fluoride flux is a fluoride flux and is not particularly limited as long as it is a flux that is normally used for brazing the tube material and the fin material with the flux in the manufacture of an aluminum alloy heat exchanger. For example, KAlF ₄ , K ₃ AlF ₆ , K ₂ AlF ₅ , K ₂ AlF ₅ .H ₂ O, KZnF ₃ , K ₂ SiF ₆ may be mentioned. These may be used alone or in combination of two or more.

  As a method of forming the flux precoat layer on the surface of the core side brazing material, for example, the fluoride flux is mixed with a binder such as an acrylic resin and dissolved or dispersed in a solvent, and a roll coat method or a spray method. Alternatively, the flux precoat layer is formed on the surface of the brazing material side brazing material by applying it to the surface of the brazing material side brazing material of the brazing sheet (1) according to the present invention and drying it. Is mentioned.

In the brazing sheet (2) of the present invention, the Sr content Cs (mass%) in the core material, the Sr content Rx (mass%) in the core material brazing material, and the thickness of the core material brazing material Dx (μm) and the application amount Fx (g / m ² ) of the fluoride flux forming the flux precoat layer are expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Preferably, the following formula (1a):
Cs + 0.025 × Rx × Dx ≧ 0.002 × Fx + 0.005 (1a)
And particularly preferably, the following formula (1b):
Cs + 0.025 × Rx × Dx ≧ 0.005 × Fx + 0.005 (1b)
By satisfying the above, Si in the solidified structure of the brazing material after brazing can be refined.

In the above formulas (1), (1a) and (1b), Fx represents the application amount (g / m ² ) of the fluoride flux forming the flux precoat layer, and the core material side brazing This is a value obtained by dividing the total mass (g) of the fluoride flux itself forming a layer on the surface of the material by the area (m ² ) on which the fluoride flux is applied. In the brazing sheet (2) of the present invention, Si in the solidified structure of the brazing material after brazing can be refined by satisfying the above formula (1), (1a) or (1b). The corrosion resistance of the exchanger can be improved and the variation in strength can be reduced.

  The brazing sheets (1) and (2) of the present invention are processed into the shape of a tube material and used as a tube material for a heat exchanger. For example, a brazing tube is manufactured by processing the brazing sheet (1) or (2) of the present invention into a flat tubular shape and brazing and joining with a brazing material to form a refrigerant flow path.

When the heat exchanger is manufactured by assembling the tube material and the fin material and brazing, the flux may be applied to the tube material side. The manufacturing method of the heat exchanger of the first aspect of the present invention (hereinafter also referred to as the manufacturing method (1) of the heat exchanger of the present invention) is a tube material (1) comprising the brazing sheet (1) of the present invention. The brazing step of brazing the tube material (1) and the fin material by applying fluoride flux to the surface of the brazing material side brazing material) and assembling and heating the tube material (1) and the fin material. Have
Sr content Cs (mass%) in the core material of the tube material (1) before brazing, Sr content Rx (mass%) in the core material side brazing material of the tube material (1) before brazing. The thickness Dx (μm) of the core material side brazing material of the tube material (1) before brazing and the application amount Fx (g / m ² ) of the fluoride flux are expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Meet,
It is a manufacturing method of a heat exchanger.

  The manufacturing method (1) of the heat exchanger of this invention has this brazing process (1). In the brazing step (1), the fluoride flux is applied to the tube material (1) obtained by processing the brazing sheet (1) of the present invention into the shape of a tube material of a predetermined heat exchanger. Next, the tube material (1) to which the fluoride flux is applied and the fin material are assembled, heated, and the tube material (1) and the fin material are brazed.

In the brazing step (1) according to the manufacturing method of the heat exchanger (1) of the present invention, the Sr content Cs (mass%) in the core material of the tube material (1) before brazing, before brazing Sr content Rx (mass%) in the core material side brazing material of the tube material (1) and the thickness Dx (μm) of the core material side brazing material of the tube material (1) before brazing, The application amount Fx (g / m ² ) of the fluoride flux applied to the surface of the core material brazing material of the tube material (1) is the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Preferably, the following formula (1a):
Cs + 0.025 × Rx × Dx ≧ 0.002 × Fx + 0.005 (1a)
And particularly preferably, the following formula (1b):
Cs + 0.025 × Rx × Dx ≧ 0.005 × Fx + 0.005 (1b)
By satisfying the above, Si in the solidified structure of the brazing material after brazing can be refined, so that the corrosion resistance of the heat exchanger can be improved and the variation in strength can be reduced.

In the above formulas (1), (1a) and (1b), Fx represents the coating amount (g / m ² ) of the fluoride flux, and the core material of the tube material (1) before brazing. This is a value obtained by dividing the total mass (g) of the fluoride flux applied to the surface of the side brazing material by the area (m ² ) to which the fluoride flux is applied. The fluoride flux is dissolved or dispersed in a solvent. In the above (1), (1a) and (1b), the amount of the fluoride flux applied depends on the solvent in the coating film after coating. It refers to the mass of the fluoride flux itself that is dissolved or dispersed.

  The tube material (1) according to the method for producing the heat exchanger (1) of the present invention is the brazing sheet (1) of the present invention, and the brazing sheet (1) of the present invention is the tube material in the heat exchanger. It is processed into the shape.

  In the brazing step (1), first, the fluoride flux is applied to the surface of the core material brazing material of the tube material (1).

  The fluoride flux according to the brazing step (1) is the same as the fluoride flux according to the brazing sheet (2) of the present invention.

  In the brazing step (1), the tube material (1) coated with the fluoride flux and the fin material are then assembled.

  The fin material according to the manufacturing method of the heat exchanger (1) of the present invention is not particularly limited as long as it is usually used for manufacturing an aluminum alloy heat exchanger, and the brazing material is clad. Even the fin material may be a fin material in which the brazing material is not clad.

  In the brazing step (1), after assembling the tube material (1) to which the fluoride flux is applied and the fin material, other members necessary for the heat exchanger, such as a header, are further added. Combine and then heat.

  As brazing conditions for brazing in the brazing step (1), a brazing temperature is 590 to 610 ° C., preferably 595 to 600 ° C., and a brazing time is 10 minutes to 60 minutes, preferably 15 The brazing atmosphere is preferably an atmosphere having an oxygen concentration of 100 ppm or lower and a dew point of −40 ° C. or lower by replacing air with nitrogen.

  And by performing this brazing process (1), this tube material (1) and this fin material are brazed, and these joined bodies are obtained.

  The manufacturing method of the heat exchanger according to the second aspect of the present invention (hereinafter also referred to as the manufacturing method (2) of the heat exchanger of the present invention) is a tube material (2) comprising the brazing sheet (2) of the present invention. And the fin material are assembled and heated to braze the tube material (2) and the fin material.

  The tube material (2) according to the production method (2) of the heat exchanger of the present invention is the brazing sheet (2) of the present invention, and the brazing sheet (2) of the present invention is the tube material in the heat exchanger. It is processed into the shape.

  In the brazing step (2), the tube material (2) and the fin material are assembled.

  The fin material according to the heat exchanger (2) of the present invention is the same as the fin material according to the heat exchanger (1) of the present invention.

  In the brazing step (2), after the tube material (2) and the fin material are assembled, other members necessary for the heat exchanger, such as a header, are further combined, and then heated.

  As brazing conditions for brazing in the brazing step (2), the brazing temperature is 590 to 610 ° C., preferably 595 to 600 ° C., and the brazing time is 10 minutes to 60 minutes, preferably 15 The brazing atmosphere is preferably an atmosphere having an oxygen concentration of 100 ppm or lower and a dew point of −40 ° C. or lower by replacing air with nitrogen.

  And by performing this brazing process (2), this tube material (2) and this fin material are brazed, and these joined bodies are obtained.

  In the manufacturing method (2) of the heat exchanger of the present invention, the fluoride flux satisfying the formula (1), (1a) or (1b) on the surface of the core material side brazing material of the tube material (2). Since the flux precoat layer is formed, Si in the solidified structure of the brazing material after brazing can be refined, the corrosion resistance of the heat exchanger can be improved, and variation in strength can be reduced.

The brazing sheet for a tube material of the heat exchanger according to the third aspect of the present invention (hereinafter also referred to as the brazing sheet (3) of the present invention) includes a core material brazing material, a sacrificial anode material and a sacrificial anode material. A brazing sheet for a tube material of a heat exchanger clad in the order of the brazing material side brazing material, the brazing material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode material side brazing material,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The sacrificial anode material side brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr,
Sr content in the sacrificial anode material is 0.6 mass% or less,
Sr content in the sacrificial anode material side brazing material is 0.6 mass% or less,
It is a brazing sheet for tube materials of a heat exchanger.

  The brazing sheet (3) of the present invention comprises a core material brazing material, a sacrificial anode material, and a sacrificial anode material side brazing material, the core material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode material. Since the brazing sheet for tube material of the heat exchanger is clad in order of the anode material side brazing material, it has the core material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode material side brazing material in order. It is a four-layer material.

  The core material according to the brazing sheet (3) of the present invention contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, and 0.2 to 1 of Cu. It is an aluminum alloy containing 0.0 mass%, Zr 0.05-0.3 mass%, and Ti 0.05-0.3 mass%.

  The Mn content in the core material is preferably 1.0 to 1.7% by mass. Mn in the core material is an element added to ensure strength, and functions as an element that improves high temperature buckling resistance. If the content of Mn in the core material is less than the above range, the effect of adding the Mn element is small, and if it exceeds the above range, coarse crystallized products are generated at the time of casting and rolling workability is impaired. Therefore, it becomes difficult to manufacture the plate material.

  The Si content in the core material is preferably 0.8 to 1.0% by mass. Si in the core material functions as an element that improves the strength. If the Si content in the core material is less than the above range, the effect of improving the strength by adding the Si element is small, and if it exceeds the above range, the corrosion resistance is lowered and the melting point of the core material is lowered. Local melting is likely to occur during brazing.

  The content of Cu in the core material is preferably 0.3 to 0.7% by mass. Cu in the core material functions as an element that improves the strength. When the content of Cu in the core material is less than the above range, the effect of improving the strength due to the addition of the Cu element is small, and when it exceeds the above range, it diffuses into the sacrificial anode material layer during brazing and is sacrificed. The potential of the material layer is raised, the corrosion resistance is lowered, and an Al—Si—Cu ternary composition is formed with Si, so that the melting point of the core material is lowered.

  The Zr content in the core material is preferably 0.1 to 0.2% by mass. Zr in the core material functions as an element that coarsens the crystal grain size of the core material and suppresses penetration of the molten solder. If the content of Zr in the core material is less than the above range, the effect of adding the Zr element is small, and even if added beyond the above range, the effect is saturated. Need not be added.

  The content of Ti in the core material is preferably 0.1 to 0.2% by mass. When Ti in the core material is added to the core material, it is divided into a high-concentration region and a low region in the plate pressure direction of the core material, and these regions exist in a layered manner in which the regions are alternately distributed. Since the low concentration region corrodes preferentially compared to the high region, Ti in the core material has an effect of layering the corrosion form, thereby preventing the progress of the corrosion in the thickness direction of the plate and preventing the resistance of the material. It functions as an element that improves pitting corrosion. If the content of Ti in the core material is less than the above range, the effect of adding the Ti element is small, and if it exceeds the above range, casting becomes difficult, workability deteriorates, and a sound material can be produced. It becomes difficult.

  The core material side brazing material according to the brazing sheet (3) of the present invention is an aluminum alloy containing 6 to 15% by mass of Si. The Si content in the core side brazing material is preferably 7 to 12% by mass. Si in the core brazing filler metal is an element added to lower the melting point of the brazing filler metal and functions as an element that improves the flowability of the molten brazing filler metal. If the content of Si in the brazing filler metal side brazing material is less than the above range, the addition effect of the Si element is small, and if it exceeds the above range, the melting point increases rapidly, Workability is reduced.

  In the brazing sheet (3) of the present invention, either or both of the core material and the core material side brazing material contain Sr. That is, when only the core material contains Sr, when only the core material side brazing material contains Sr, both the core material and the core material side brazing material may contain Sr. And Sr content in this core material is 0.6 mass% or less, and Sr content in this core side brazing material is 0.6 mass% or less. Sr in the core material diffuses from the core material into the brazing material at the time of melting of the brazing material, and Si in the solidified structure of the brazing material after brazing can be refined. That is, Sr in the core material is an element added to refine Si in the solidified structure of the brazing material after brazing, and the brazing material after brazing is contained by the core material containing Sr. Since Si in the solidified structure of the material can be refined, the corrosion resistance of the heat exchanger can be improved and the variation in strength can be reduced. Further, Sr in the brazing material side brazing material refines the solidified particles of Si in the brazing material at the time of casting solidification, that is, refines the Si particles of the brazing material before brazing and brazes after brazing. Si in the solidified structure of the material can be refined. That is, Sr in the brazing material side brazing material is added to refine the solidified particles of Si in the brazing material before brazing and to refine Si in the solidified structure of the brazing material after brazing. It is an element, and when the core brazing filler metal contains Sr, the productivity after rolling can be improved, the corrosion resistance of the heat exchanger can be improved, and the variation in strength can be reduced. On the other hand, if the Sr content in the core material or the Sr content in the core-side brazing material exceeds 0.6% by mass, a huge crystallized product is generated at the time of casting, resulting in rolling cracks. . Therefore, in the brazing sheet (3) of the present invention, when only the core material contains Sr, the content of Sr in the core material is 0.6% by mass or less, and the core material side brazing material When only Sr contains Sr, the content of Sr in the brazing material is 0.6% by mass or less, and when both the core material and the brazing material side brazing material contain Sr, the core The Sr content in the material is 0.6% by mass or less, and the Sr content in the core side brazing material is 0.6% by mass or less.

  Furthermore, in the brazing sheet (3) of the present invention, the core material contains 0.005 to 0.6% by mass of Sr and the core material side brazing material is 0 in that the effect of adding Sr is easily obtained. 0.005 to 0.6% by mass of Sr is preferable, the core material contains 0.005 to 0.4% by mass of Sr, and the core side brazing material is 0.005 to 0.4%. It is particularly preferable to contain Sr by mass%. That is, in the brazing sheet (3) of the present invention, both the core material and the brazing material side brazing material contain Sr in the above range, so that the Si in the solidified structure of the brazing material after brazing can be finely divided. The effect of making it higher becomes higher.

  The brazing material side brazing material contains Mn, so that Si in the solidified structure of the brazing material before brazing is refined to improve the flowability of the brazing and in the solidified structure of the brazing material after brazing. Si can be refined. That is, Mn in the brazing material side brazing material is an element added to improve the fluidity of the brazing and to refine Si in the solidified structure of the brazing material after brazing. Moreover, when there is too much Mn content in this brazing material, a huge crystallization thing will produce | generate at the time of casting, and a rolling crack will be produced. Therefore, it is preferable that the brazing material contains 0.05 to 1.4% by mass of Mn from the viewpoint of obtaining the above Mn addition effect.

  The sacrificial anode material according to the brazing sheet (3) of the present invention contains 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to Si. It is an aluminum alloy containing 1.3% by mass.

  The content of Zn in the sacrificial anode material is preferably 2 to 5% by mass. Zn in the sacrificial anode material functions as an element that enhances the sacrificial anode effect. If the Zn content in the sacrificial anode material is less than the above range, the effect of adding the Zn element is small, and if it exceeds the above range, the consumption rate of the sacrificial anode material is increased and the life is shortened.

  The content of Mn in the sacrificial anode material is preferably 1.0 to 1.7% by mass. Mn in the core material is an element added to ensure strength, and functions as an element that improves high temperature buckling resistance. If the content of Mn in the sacrificial anode material is less than the above range, the effect of adding the Mn element is small, and if it exceeds the above range, coarse crystallized products are generated at the time of casting and rolling workability is reduced. This makes it difficult to manufacture the plate material.

  The content of Si in the sacrificial anode material is preferably 0.3 to 1.0% by mass. Si in the sacrificial anode material functions as an element for improving the strength of the sacrificial anode material layer. If the content of Si in the sacrificial anode material is less than the above range, the effect of improving the strength due to the addition of the Si element is small, and if it exceeds the above range, the corrosion resistance is lowered and the melting point of the sacrificial anode material is reduced. Lowering and local melting are likely to occur during brazing.

  The sacrificial anode material side brazing material according to the brazing sheet (3) of the present invention is an aluminum alloy containing 6 to 15% by mass of Si. The content of Si in the sacrificial anode material side brazing material is preferably 7 to 12% by mass. Si in the sacrificial anode material side brazing filler metal is an element added to lower the melting point of the brazing filler metal, and functions as an element that improves the flowability of the molten brazing filler metal. When the content of Si in the sacrificial anode material side brazing material is less than the above range, the effect of adding the Si element is small. When the content exceeds the above range, the melting point rapidly increases, and the brazing sheet is produced. The workability of is reduced.

  In the brazing sheet (3) of the present invention, either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr. That is, when only the sacrificial anode material contains Sr, when only the sacrificial anode material side brazing material contains Sr, both the sacrificial anode material and the sacrificial anode material side brazing material may contain Sr. is there. And Sr content in this sacrificial anode material is 0.6 mass% or less, and Sr content in this sacrificial anode material side brazing material is 0.6 mass% or less. Sr in the sacrificial anode material diffuses from the sacrificial anode material into the brazing material when the braze is melted, and can refine Si in the solidified structure of the brazing material after brazing. That is, Sr in the sacrificial anode material is an element added to refine Si in the solidified structure of the brazing material after brazing, and the sacrificial anode material contains Sr, so that after brazing Since the Si in the solidified structure of the brazing filler metal can be refined, the corrosion resistance of the heat exchanger can be improved and the variation in strength can be reduced. In addition, the Sr in the sacrificial anode material brazing material refines the solidified particles of Si in the brazing material during casting solidification, that is, refines the Si particles of the brazing material before brazing, and after brazing. Si in the solidified structure of the brazing material can be refined. That is, Sr in the sacrificial anode material side brazing material is added to refine the solidified particles of Si in the brazing material before brazing and to refine Si in the solidified structure of the brazing material after brazing. When the sacrificial anode material side brazing material contains Sr, the productivity after rolling can be improved, the corrosion resistance of the heat exchanger can be improved, and the variation in strength can be reduced. On the other hand, if the Sr content in the sacrificial anode material or the Sr content in the sacrificial anode material side brazing material exceeds 0.6% by mass, a giant crystallized product is formed during casting, and rolling cracks occur. Produce. Therefore, in the brazing sheet (3) of the present invention, when only the sacrificial anode material contains Sr, the content of Sr in the sacrificial anode material is 0.6% by mass or less, and the sacrificial anode material When only the side brazing material contains Sr, the content of Sr in the sacrificial anode side brazing material is 0.6% by mass or less, and both the sacrificial anode material and the sacrificial anode material side brazing material are When Sr is contained, the content of Sr in the sacrificial anode material is 0.6% by mass or less, and the content of Sr in the sacrificial anode material side brazing material is 0.6% by mass or less.

  Furthermore, in the brazing sheet (3) of the present invention, the sacrificial anode material contains 0.005 to 0.6% by mass of Sr and the sacrificial anode material side brazing material in that the effect of adding Sr is easy to obtain. Preferably, the sacrificial anode material contains 0.005 to 0.4 mass% Sr and the sacrificial anode material side brazing material is 0.005. It is particularly preferred to contain ˜0.4 mass% Sr. That is, in the brazing sheet (3) of the present invention, since both the sacrificial anode material and the sacrificial anode material side brazing material contain Sr in the above range, Si in the solidified structure of the brazing material after brazing. The effect of miniaturizing is increased.

  The sacrificial anode material side brazing material contains Mn, so that Si in the solidified structure of the brazing material before brazing is refined to improve the fluidity of the brazing material and the solidified structure of the brazing material after brazing. The inside Si can be made finer. That is, Mn in the sacrificial anode material side brazing material is an element added to improve the fluidity of the brazing and to refine Si in the solidified structure of the brazing material after brazing. Moreover, when there is too much Mn content in this sacrificial anode material side brazing material, a huge crystallization thing will produce | generate at the time of casting, and a rolling crack will be produced. Therefore, it is preferable that the sacrificial anode material side brazing material contains 0.05 to 1.4% by mass of Mn from the viewpoint of obtaining the above Mn addition effect.

  In addition, since an aluminum ingot having an Fe content of 0.1% by mass or less is expensive, the core material, the core material side brazing material, the sacrificial anode material, and the sacrificial anode material side brazing material usually have an Fe content. 0.4% by mass or less bullion is used. And a core material, a core material side brazing material, a sacrificial anode material, or a sacrificial anode material side brazing material contains 0.4 mass% or less of Fe, so that the strength is slightly improved. On the other hand, when the Fe content of the core material, the core material side brazing material, the sacrificial anode material or the sacrificial anode material side brazing material exceeds 0.4% by mass, the self-corrosion resistance is lowered. Therefore, usually, a bare metal having an Fe content of 0.1 to 0.4% by mass is used.

  Further, the core material, the core material side brazing material, the sacrificial anode material and the sacrificial anode material side brazing material may contain the following additional elements in addition to the above additive elements.

  In order to improve the strength of the brazing sheet, the core material is 1.0% by mass or less of Fe, 1.0% by mass or less of Mg, 0.3% by mass or less of V, and 0.3% by mass or less of Mo. Or 0.3 mass% or less of Ni can be contained. Further, the core material has a low potential without substantially reducing the thermal conductivity of the brazing sheet, and in order to ensure the sacrificial anode effect, 3.0% by mass or less of Zn, 0.3% by mass or less of In, 0.3 mass% or less Sn or 0.3 mass% or less Ga can be contained. Further, the core material can contain 0.3% by mass or less of Cr in order to increase the crystal grain size after brazing. Moreover, this core material can contain 0.1 mass% or less Pb, 0.1 mass% or less Li, 0.1 mass% or less Ca, or 0.1 mass% or less Na. Moreover, this core material can contain 0.4 mass% or less B for oxidation prevention.

  The brazing material side brazing material and the sacrificial anode material side brazing material are 0.3 mass% or less of Cr, 0.3 mass% or less of Cu, 0.1 mass% or less of Pb, and 0.1 mass% or less of Cr. Li or 0.1 mass% or less of Ca can be contained. Further, the brazing material side brazing material and the sacrificial anode material side brazing material may contain 0.3 mass% or less of Ti or 0.1 mass% or less of B in order to refine the cast structure. it can. Further, the brazing material side brazing material and the sacrificial anode material side brazing material are composed of 3.0% by mass or less of Zn, 0.1% by mass or less of In, 0.1% by mass in order to ensure the sacrificial anode effect. The following Sn or 0.1 mass% or less Ga can be contained. Further, the brazing material side brazing material and the sacrificial anode material side brazing material can contain 0.1 mass% or less of Be in order to suppress the growth of the surface oxide film. Further, the brazing material side brazing material and the sacrificial anode material side brazing material can contain 0.1% by mass or less of Bi in order to improve the fluidity of the brazing material.

  The sacrificial anode material has a lower potential without substantially reducing the thermal conductivity of the brazing sheet, and in order to ensure the sacrificial anode effect, 0.3% by mass or less of In, 0.3% by mass or less of Sn, Or 0.3 mass% or less Ga can be contained. Further, the sacrificial anode material is made of 1.0 mass% or less of Cu, 1.0 mass% or less of Fe, 1.0 mass% or less of Mg, 0.3 mass% or less of V, It can contain 0.3 mass% or less of Mo or 0.3 mass% or less of Ni. In addition, the sacrificial anode material can contain 0.3% by mass or less of Zr or 0.3% by mass or less of Cr in order to coarsen the crystal grain size after brazing. The sacrificial anode material may contain 0.1% by mass or less of Pb, 0.1% by mass or less of Li, 0.1% by mass or less of Ca, or 0.1% by mass or less of Na. . The sacrificial anode material can contain 0.3% by mass or less of Ti in order to refine the cast structure. In addition, the sacrificial anode material can contain 0.1% by mass or less of B for preventing oxidation. Further, the sacrificial anode material can contain 0.6% by mass or less of Sr in order to refine Si in the solidified structure of the brazing material at the portion that flows and joins to the sacrificial anode material.

  The core material, the core material-side brazing material, the sacrificial anode material, and the sacrificial anode material-side brazing material are all aluminum alloys composed of the above additive elements, unavoidable impurities, and aluminum.

  The brazing sheet (3) of the present invention comprises the core material-side brazing material, the sacrificial anode material and the sacrificial anode material-side brazing material, the core material-side brazing material, the core material, and the sacrificial anode. It is obtained by cladding in the order of the material and the sacrificial anode material side brazing material. The core material, the core material side brazing material, the sacrificial anode material, and the sacrificial anode material side brazing material may be clad with the core material, the core material side brazing material, the sacrificial anode material, or the sacrificial anode material. Alloy ingot for core material having the same composition as that of each element in anode material side brazing material, alloy ingot for core material side brazing material, alloy ingot for sacrificial anode material, and sacrificial anode material side brazing material Then, the alloy ingot for the core material is homogenized according to a conventional method, and the alloy ingot for the core side brazing material and the alloy cast for the sacrificial anode material are cast. The alloy ingot for the ingot and the sacrificial anode material side brazing material is hot-rolled, and then the alloy ingot for the core material and the alloy ingot for the brazing material side brazing material after the homogenization treatment The hot rolled product, the hot rolled product of the alloy ingot of the sacrificial anode material, and the hot rolled product of the alloy ingot for the sacrificial anode material side brazing material are combined and hot rolled → annealed. Perform cold rolling sequentially, or hot rolling → cold rolling → annealing sequentially performed, then, a method for the finish cold rolling.

  The thickness of the brazing sheet (3) of the present invention is not particularly limited, but is usually 0.2 to 0.3 mm.

The brazing sheet for a tube material of the heat exchanger of the fourth aspect of the present invention (hereinafter also referred to as the brazing sheet (4) of the present invention) is the brazing material side brazing material of the brazing sheet (3) of the present invention. A first flux precoat layer made of fluoride flux is formed on the surface, and a second flux precoat layer made of fluoride flux is formed on the surface of the sacrificial anode material side brazing material.
That is, in the brazing sheet (3) of the present invention, the core material is brazing material side brazing material, sacrificial anode material and sacrificial anode material side brazing material, the core material side brazing material, the core material, the sacrificial anode material, A brazing sheet for a tube material of a heat exchanger clad in the order of the sacrificial anode material side brazing material,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
A first flux precoat layer made of fluoride flack is formed on the surface of the brazing material side brazing material,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The sacrificial anode material side brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr,
Sr content in the sacrificial anode material is 0.6 mass% or less,
Sr content in the sacrificial anode material side brazing material is 0.6 mass% or less,
On the surface of the sacrificial anode material side brazing material, a second flux precoat layer made of fluoride flux is formed,
It is a brazing sheet for tube materials of a heat exchanger.

  That is, the brazing sheet (4) of the present invention is a brazing sheet in which the brazing sheet (3) of the present invention further has the first flux precoat layer and the second flux precoat layer. Therefore, in the brazing sheet (4) of the present invention, the brazing sheet on which the flux precoat layer is formed is the same as the brazing sheet (3) of the present invention.

The first flux precoat layer and the second flux precoat layer according to the brazing sheet (4) of the present invention are formed by the fluoride flux. The fluoride flux is a fluoride flux and is not particularly limited as long as it is a flux that is normally used for brazing the tube material and the fin material with the flux in the manufacture of an aluminum alloy heat exchanger. For example, KAlF ₄ , K ₃ AlF ₆ , K ₂ AlF ₅ , K ₂ AlF ₅ .H ₂ O, KZnF ₃ , K ₂ SiF ₆ may be mentioned. These may be used alone or in combination of two or more.

  As a method of forming the first flux precoat layer on the surface of the core side brazing material, for example, the fluoride flux is mixed with a binder such as an acrylic resin and dissolved or dispersed in a solvent, The first flux precoat layer is applied to the surface of the brazing material side brazing material by spraying or dipping onto the surface of the brazing material side brazing material of the present invention and drying. The method of forming is mentioned. The method of forming the second flux precoat layer on the surface of the sacrificial anode material side brazing material is the same.

In the brazing sheet (4) of the present invention, the Sr content Cs (mass%) in the core material, the Sr content Rx (mass%) in the core material brazing material, and the thickness of the core material brazing material Dx (μm) and the application amount Fx (g / m ² ) of the fluoride flux forming the first flux precoat layer are expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Preferably, the following formula (1a):
Cs + 0.025 × Rx × Dx ≧ 0.002 × Fx + 0.005 (1a)
And particularly preferably, the following formula (1b):
Cs + 0.025 × Rx × Dx ≧ 0.005 × Fx + 0.005 (1b)
The filling,
Further, the Sr content Gs (mass%) in the sacrificial anode material, the Sr content Ry (mass%) in the sacrificial anode material side brazing material, and the thickness Dy (μm) of the sacrificial anode material side brazing material And the application amount Fy (g / m ² ) of the fluoride flux forming the second flux precoat layer is the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Preferably, the following formula (2a):
Gs + 0.025 × Ry × Dy ≧ 0.002 × Fy + 0.005 (2a)
And particularly preferably, the following formula (2b):
Gs + 0.025 × Ry × Dy ≧ 0.005 × Fy + 0.005 (2b)
By satisfying the above, Si in the solidified structure of the brazing material after brazing can be refined.

In the above formulas (1), (1a) and (1b), Fx represents the coating amount (g / m ² ) of the fluoride flux forming the first flux precoat layer, and the core material This is a value obtained by dividing the total mass (g) of the fluoride flux itself forming a layer on the surface of the side brazing material by the area (m ² ) on which the fluoride flux is applied. In the above formulas (2), (2a) and (2b), Fy represents the application amount (g / m ² ) of the fluoride flux forming the second flux precoat layer, and the sacrificial anode This is a value obtained by dividing the total mass (g) of the fluoride flux itself layered on the surface of the brazing filler metal by the area (m ² ) on which the fluoride flux is applied. In the brazing sheet (4) of the present invention, by satisfying the above formula (1), (1a) or (1b) and satisfying the above formula (2), (2a) or (2b), Since Si in the solidified structure of the brazing material can be refined, the corrosion resistance of the heat exchanger can be improved and the variation in strength can be reduced.

  The brazing sheets (3) and (4) of the present invention are processed into the shape of a tube material and used as a tube material for a heat exchanger. For example, the brazing sheet (3) or (4) of the present invention is formed into a semi-elliptical tubular shape, leaving an end for brazing. Then, using the two processed brazing sheets, the brazing material side brazing members at the end portions are opposed to each other and brazed to manufacture a brazing tube.

The manufacturing method of the heat exchanger of the third aspect of the present invention (hereinafter also referred to as the manufacturing method (3) of the heat exchanger of the present invention) is a tube material (3) comprising the brazing sheet (3) of the present invention. ) Fluoride flux is applied to the surface of the brazing material side brazing material and the surface of the sacrificial anode material side brazing material, the tube material (3) and the fin material are assembled and heated, and the tube material and the fin material are heated. A brazing process for brazing,
Sr content Cs (mass%) in the core material of the tube material before brazing, Sr content Rx (mass%) in the brazing material side brazing material of the tube material before brazing, The thickness Dx (μm) of the core material side brazing material of the tube material and the application amount Fx (g / m ² ) of the fluoride flux applied to the surface of the core material side brazing material of the tube material are expressed by the following formulas: (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The filling,
Further, the Sr content Gs (mass%) in the sacrificial anode material, the Sr content Ry (mass%) in the sacrificial anode material side brazing material, and the thickness Dy (μm) of the sacrificial anode material side brazing material And the application amount Fy (g / m ² ) of the fluoride flux applied to the surface of the sacrificial anode material side brazing material of the tube material is represented by the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Preferably, the following formula (2a):
Gs + 0.025 × Ry × Dy ≧ 0.002 × Fy + 0.005 (2a)
And particularly preferably, the following formula (2b):
Gs + 0.025 × Ry × Dy ≧ 0.005 × Fy + 0.005 (2b)
It is the manufacturing method of the heat exchanger which satisfy | fills.

  The manufacturing method (3) of the heat exchanger of this invention has this brazing process (3). In the brazing step (3), the fluoride flux is applied to the tube material (3) obtained by processing the brazing sheet (3) of the present invention into the shape of the tube material of a predetermined heat exchanger. Next, the tube material (3) coated with the fluoride flux and the fin material are assembled, heated, and the tube material (3) and the fin material are brazed.

In the brazing step (3) according to the manufacturing method (3) of the heat exchanger of the present invention, the Sr content Cs (mass%) in the core material of the tube material (3) before brazing, before brazing Sr content Rx (mass%) in the brazing material side brazing material of the tube material (3) and the thickness Dx (μm) of the brazing material side brazing material of the tube material (3) before brazing, The application amount Fx (g / m ² ) of the fluoride flux applied to the surface of the core material side brazing material of the tube material (3) before brazing is expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Preferably, the following formula (1a):
Cs + 0.025 × Rx × Dx ≧ 0.002 × Fx + 0.005 (1a)
And particularly preferably, the following formula (1b):
Cs + 0.025 × Rx × Dx ≧ 0.005 × Fx + 0.005 (1b)
The filling,
Further, the Sr content Gs (mass%) in the sacrificial anode material, the Sr content Ry (mass%) in the sacrificial anode material side brazing material, and the thickness Dy (μm) of the sacrificial anode material side brazing material And the application amount Fy (g / m ² ) of the fluoride flux applied to the surface of the sacrificial anode material side brazing material of the tube material before brazing is expressed by the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Preferably, the following formula (2a):
Gs + 0.025 × Ry × Dy ≧ 0.002 × Fy + 0.005 (2a)
And particularly preferably, the following formula (2b):
Gs + 0.025 × Ry × Dy ≧ 0.005 × Fy + 0.005 (2b)
By satisfying the above, Si in the solidified structure of the brazing material after brazing can be refined, so that the corrosion resistance of the heat exchanger can be improved and the variation in strength can be reduced.

In the above formulas (1), (1a) and (1b), Fx represents the coating amount (g / m ² ) of the fluoride flux, and the core material of the tube material (1) before brazing. This is a value obtained by dividing the total mass (g) of the fluoride flux applied to the surface of the side brazing material by the area (m ² ) to which the fluoride flux is applied. In the above formulas (2), (2a) and (2b), Fy represents the coating amount (g / m ² ) of the fluoride flux, and the brazing material side brazing material of the tube material before brazing. This is a value obtained by dividing the total mass (g) of the fluoride flux applied to the surface of the film by the area (m ² ) to which the fluoride flux is applied. The fluoride flux is dissolved or dispersed in a solvent. In the above (1), (1a) and (1b) and the above (2), (2a) and (2b), the fluoride flux is applied. The amount refers to the mass of the fluoride flux itself dissolved or dispersed in the solvent in the coated film after application.

  The tube material (3) according to the production method (3) of the heat exchanger of the present invention is the brazing sheet (3) of the present invention, and the brazing sheet (3) of the present invention is the tube material in the heat exchanger. It is processed into the shape.

  In the brazing step (3), first, the fluoride flux is applied to the surface of the core material brazing material of the tube material (3).

  The fluoride flux according to the brazing step (3) is the same as the fluoride flux according to the brazing sheet (3) of the present invention.

  In the brazing step (3), the tube material (3) coated with the fluoride flux and the fin material are then assembled.

  The fin material according to the heat exchanger manufacturing method (3) of the present invention is not particularly limited as long as it is usually used for manufacturing an aluminum alloy heat exchanger, and the brazing material is clad. Even the fin material may be a fin material in which the brazing material is not clad.

  In the brazing step (3), after assembling the tube material (3) coated with the fluoride flux and the fin material, other members necessary for the heat exchanger, such as a header, are further added. Combine and then heat.

  As brazing conditions for brazing in the brazing step (3), the brazing temperature is 590 to 610 ° C., preferably 595 to 600 ° C., and the brazing time is 10 minutes to 60 minutes, preferably 15 The brazing atmosphere is preferably an atmosphere having an oxygen concentration of 100 ppm or lower and a dew point of −40 ° C. or lower by replacing air with nitrogen.

  And by performing this brazing process (3), this tube material (3) and this fin material are brazed, and these joined bodies are obtained.

  The manufacturing method of the heat exchanger of the fourth aspect of the present invention (hereinafter also referred to as the manufacturing method (4) of the heat exchanger of the present invention) is a tube material (4) comprising the brazing sheet (4) of the present invention. And a fin material are assembled and heated, and the tube material (4) and the fin material are brazed, and a method of manufacturing a heat exchanger.

  The tube material (4) according to the production method (4) of the heat exchanger of the present invention is the brazing sheet (4) of the present invention, and the brazing sheet (4) of the present invention is the tube material in the heat exchanger. It is processed into the shape.

  In the brazing step (4), the tube material (4) and the fin material are assembled.

  The fin material according to the manufacturing method (4) of the heat exchanger of the present invention is the same as the fin material according to the heat exchanger (3) of the present invention.

  In the brazing step (4), after the tube material (4) and the fin material are assembled, other members necessary for the heat exchanger, such as a header, are further combined and then heated.

  As brazing conditions for brazing in the brazing step (4), a brazing temperature is 590 to 610 ° C., preferably 595 to 600 ° C., and a brazing time is 10 minutes to 60 minutes, preferably 15 The brazing atmosphere is preferably an atmosphere having an oxygen concentration of 100 ppm or lower and a dew point of −40 ° C. or lower by replacing air with nitrogen.

  And by performing this brazing process (4), this tube material (4) and this fin material are brazed, and these joined bodies are obtained.

  In the manufacturing method (4) of the heat exchanger of the present invention, the surface of the brazing material of the tube material (4) satisfies the formula (1), (1a) or (1b), and the formula (2). Since the flux precoat layer of the fluoride flux satisfying (2a) or (2b) is formed, Si in the solidified structure of the brazing material after brazing can be refined, and the corrosion resistance of the heat exchanger is improved. Variation in strength can be reduced.

  As a result of intensive studies, the present inventors have found that (i) the effect of refining Si in the solidified structure of the brazing material after brazing with Sr added to the core material or brazing material is a reaction between Sr and fluoride flux. It was found that if the amount of fluoride flux applied is too large relative to Sr, the Si refinement effect by Sr is reduced. In addition, (ii) Sr in the brazing material reacts easily with the fluoride flux after the brazing melt, and (iii) Sr in the core material diffuses toward the surface when the brazing melts. And Sr in the core material is also effective for the effect of refining Si in the solidified structure of the brazing material, and (iv) Sr in the core material is Since the material does not melt, it has been found that the reaction with the fluoride flux is limited to Sr diffused on the surface of the core material. Based on these findings, further investigations were made, and Sr content (Cs) in the core material before brazing, Sr content (Rx) in the core side brazing material before brazing, brazing By setting the relationship between the thickness (Dx) of the brazing filler metal side brazing material before application and the application amount (Fx) of the fluoride flux to the range shown in the above formula (1), (1a) or (1b) It has been found that the effect of refining Si in the solidified structure of the brazing material after brazing can be obtained, the corrosion resistance of the heat exchanger can be improved, and the variation in strength can be reduced.

  In addition, the present inventors have found that the relationship between the sacrificial anode material, the sacrificial anode material side brazing material, and the fluoride flux is the relationship between the core material, the core material side brazing material, and the fluoride flux. I also found that it would be the same.

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

(Examples and Comparative Examples)
(Manufacture of brazing sheet material for heat exchangers)
Cast aluminum alloy ingot for core material, aluminum alloy ingot for core material side brazing material, aluminum alloy ingot for sacrificial anode and aluminum alloy ingot for sacrificial anode side brazing material by continuous casting. And homogenized according to a conventional method. The aluminum alloy ingot for brazing material side brazing material, the aluminum alloy ingot for sacrificial anode and the aluminum alloy ingot for brazing material side brazing material were further hot-rolled. Next, the aluminum alloy ingot for the core material, the aluminum alloy ingot for the core material side brazing material, the aluminum alloy ingot for the sacrificial anode and the aluminum alloy ingot for the sacrificial anode material side brazing material are shown in Tables 4 and 7. In the combination shown, after superposing, hot clad rolling and then cold rolling were performed, and after final annealing, a brazing sheet (H14 material tempered) having a thickness of 0.20 mm was produced.
Next, after applying a coating amount of fluoride flux (Noroclock flux) shown in Tables 4 and 7 to the brazing material side of the brazing sheet, it was heated to 600 ° C. (attainment temperature) in a nitrogen gas atmosphere to be brazed. Heating was performed.

<Evaluation of solidification structure of brazing material after brazing heating>
The cross section of the brazing material after the brazing heating is observed with an optical microscope, and the solidified structure of the brazing material corresponds to which level of the three-stage photographs with different Si sizes shown in FIGS. It was judged. In FIG. 1, Si in the solidified structure of the brazing material is finely granular. In FIG. 2, Si in the solidified structure of the brazing material is granular although the particle size is larger than that in FIG. In FIG. 3, Si in the solidified structure of the brazing material is acicular. Then, the solidified structure level of the brazing material in FIG. 1 is good (良), the solidified structure level of the brazing material in FIG. 2 is acceptable (◯), and the solidified structure level of the brazing material in FIG. X).

<Sag test (high temperature buckling resistance)>
In accordance with LWS T8801 of the Light Metal Welding Structure Association standard, high temperature buckling was evaluated by sag characteristics. In the test, after brazing and heating the test piece protruding 22 mm wide and 60 mm long, the high temperature buckling resistance is good (○) when the drooping length is within 20 mm, and the high temperature resistance when exceeding 20 mm. The buckling property was determined to be poor (x).

<Flux fluidity test>
The fluidity of the braze was evaluated in accordance with LWS T8801 of the Light Metal Welding Structure Association standard. In the test, 25 mm × 60 mm JIS3003 was used for the vertical plate, and the brazing sheet shown in Table 4 and Table 7 of 25 mm × 60 mm was used for the horizontal plate, and an inverted T-shaped test piece was prepared and brazed and heated. The material before brazing is embedded in the resin, the cross-sectional microstructure is observed, the area of the brazing material before brazing is measured, and the material after brazing with another sample is similarly embedded in the resin, Observe and measure the area of the fillet after brazing. When the ratio of the wax flowing was 10% or more, the flowability of the wax was good (◯), and when it was less than 10%, the flowability of the wax was poor (x).

<Sacrificial anode material surface side corrosion resistance test>
The sacrificial anode material surface side resistance characteristics were evaluated based on the ASTM SWAAT test. Only the flat sacrificial anode material was left as the evaluation surface, and the other portions were masked and inserted into the SWAAT testing machine. On the SWAAT 40 day, those that did not penetrate were rated as good (◯), and those that penetrated were marked as (x).

１）芯材側ろう材の表面に塗布したフラックス塗布量
２）犠牲陽極材側ろう材の表面に塗布したフラックス塗布量
３）表中「−−」は、犠牲陽極材側ろう材がクラッドされていないことを示す。

1) The amount of flux applied to the surface of the brazing material side brazing material 2) The amount of flux applied to the surface of the sacrificial anode material side brazing material 3) In the table, “-” indicates that the sacrificial anode material side brazing material is clad. Indicates not.

１）芯材側ろう材の表面に塗布したフラックス塗布量
２）犠牲陽極材側ろう材の表面に塗布したフラックス塗布量
３）表中「−−」は、犠牲陽極材側ろう材がクラッドされていないことを示す。

1) The amount of flux applied to the surface of the brazing material side brazing material 2) The amount of flux applied to the surface of the sacrificial anode material side brazing material 3) In the table, “-” indicates that the sacrificial anode material side brazing material is clad. Indicates not.

In Comparative Examples 73 and 75, the wax was too little to flow.
In Comparative Examples 74 and 76, too much wax was dissolved in the fins.

Example when brazing material has a good solidification level (◎) Example when brazing material solidification structure level is acceptable (○) Example when the brazing filler metal solidification level is not possible (x)

Claims (22)

A brazing sheet for a tube material of a heat exchanger in which a core material brazing material is clad on one surface of a core material, and a sacrificial anode material is clad on the other surface of the core material,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6% by mass or less,
A brazing sheet for tube material of a heat exchanger characterized by Sr content in the core material is 0.005 to 0.6 mass%,
Sr content in the brazing material side brazing material is 0.005 to 0.6 mass%,
The brazing sheet for a tube material of a heat exchanger according to claim 1.   The brazing sheet for a tube material of a heat exchanger according to any one of claims 1 and 2, wherein the brazing material side brazing material further contains 0.05 to 1.4 mass% of Mn.   The sacrificial anode material further contains one or two of 0.05 to 0.3% by mass of Ti and 0.05 to 0.3% by mass of Zr. The brazing sheet for tube materials of the heat exchanger of any one of -3. A brazing sheet for a tube material of a heat exchanger in which a core material brazing material is clad on one surface of a core material, and a sacrificial anode material is clad on the other surface of the core material,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
A flux precoat layer made of fluoride flux is formed on the surface of the core side brazing material,
A brazing sheet for tube material of a heat exchanger characterized by Sr content Cs (mass%) in the core material, Sr content Rx (mass%) in the core material brazing material, thickness Dx (μm) of the core material brazing material, and the flux precoat layer The application amount Fx (g / m ² ) of the fluoride flux of the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The brazing sheet for a tube material of a heat exchanger according to claim 5, wherein: Sr content in the core material is 0.005 to 0.6 mass%,
Sr content in the brazing material side brazing material is 0.005 to 0.6 mass%,
The brazing sheet for a tube material of a heat exchanger according to any one of claims 5 and 6.   The brazing sheet for a tube material of a heat exchanger according to any one of claims 5 to 7, wherein the core side brazing material further contains 0.05 to 1.4 mass% of Mn.   6. The sacrificial anode material further contains one or two of 0.05 to 0.3% by mass of Ti and 0.05 to 0.3% by mass of Zr. The brazing sheet for tube materials of the heat exchanger of any one of -8. Applying fluoride flux to the surface of the core material brazing material of the tube material comprising the brazing sheet for the tube material of the heat exchanger according to any one of claims 1 to 4, and assembling the tube material and the fin material, Heating and brazing the tube material and the fin material;
Sr content Cs (mass%) in the core material of the tube material before brazing, Sr content Rx (mass%) in the brazing material side brazing material of the tube material before brazing, The thickness Dx (μm) of the core material brazing material of the tube material and the coating amount Fx (g / m ² ) of the fluoride flux are expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
Meeting,
The manufacturing method of the heat exchanger characterized by these.   It has a brazing process of assembling and heating a tube material and a fin material which consist of a brazing sheet for a tube material of a heat exchanger according to any one of claims 5 to 9, and brazing the tube material and the fin material. The manufacturing method of the heat exchanger characterized by these. The core material brazing material, the sacrificial anode material, and the sacrificial anode material side brazing material were clad in the order of the core material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode material side brazing material. A brazing sheet for a tube material of a heat exchanger,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The sacrificial anode material side brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr,
Sr content in the sacrificial anode material is 0.6 mass% or less,
Sr content in the sacrificial anode material side brazing material is 0.6 mass% or less,
A brazing sheet for tube material of a heat exchanger characterized by Sr content in the core material is 0.005 to 0.6 mass%,
Sr content in the core side brazing material is 0.005 to 0.6 mass%,
Sr content in the sacrificial anode material is 0.005 to 0.6 mass%,
Sr content in the sacrificial anode material side brazing material is 0.005 to 0.6 mass%,
The brazing sheet for a tube material of a heat exchanger according to claim 12. The core side brazing material further contains 0.05 to 1.4% by mass of Mn,
The sacrificial anode material side brazing material further contains 0.05 to 1.4% by mass of Mn,
The brazing sheet for a tube material of a heat exchanger according to any one of claims 12 and 13.   The sacrificial anode material further contains one or two of 0.05 to 0.3% by mass of Ti and 0.05 to 0.3% by mass of Zr. The brazing sheet for tube materials of the heat exchanger of any one of -14. The core material brazing material, the sacrificial anode material, and the sacrificial anode material side brazing material were clad in the order of the core material side brazing material, the core material, the sacrificial anode material, and the sacrificial anode material side brazing material. A brazing sheet for a tube material of a heat exchanger,
The core material contains 0.6 to 2.0 mass% of Mn, 0.6 to 1.3 mass% of Si, 0.2 to 1.0 mass% of Cu, and 0 Zr. 0.05 to 0.3 mass% aluminum alloy containing 0.05 to 0.3 mass% Ti,
The core material brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either one or both of the core material and the core material side brazing material contains Sr,
Sr content in the core material is 0.6% by mass or less,
Sr content in the brazing material side brazing material is 0.6 mass% or less,
A first flux precoat layer made of fluoride flack is formed on the surface of the brazing material side brazing material,
The sacrificial anode material is an aluminum alloy containing 1.0 to 6.0% by mass of Zn, 0.5 to 2.0% by mass of Mn, and 0.2 to 1.3% by mass of Si. Yes,
The sacrificial anode material side brazing material is an aluminum alloy containing 6 to 15% by mass of Si,
Either or both of the sacrificial anode material and the sacrificial anode material side brazing material contain Sr,
Sr content in the sacrificial anode material is 0.6 mass% or less,
Sr content in the sacrificial anode material side brazing material is 0.6 mass% or less,
A second flux precoat layer made of fluoride flux is formed on the surface of the sacrificial anode material side brazing material;
A brazing sheet for tube material of a heat exchanger characterized by Sr content Cs (mass%) in the core material, Sr content Rx (mass%) in the core material brazing material, thickness Dx (μm) of the core material brazing material, and the first flux The application amount Fx (g / m ² ) of the fluoride flux of the precoat layer is expressed by the following formula (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The filling,
And Sr content Gs (mass%) in the sacrificial anode material, Sr content Ry (mass%) in the sacrificial anode material side brazing material, thickness Dy (μm) of the sacrificial anode material side brazing material And the application amount Fy (g / m ² ) of the fluoride flux of the second flux precoat layer is represented by the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Meeting,
The brazing sheet for a tube material of a heat exchanger according to claim 17. Sr content in the core material is 0.005 to 0.6 mass%,
Sr content in the core side brazing material is 0.005 to 0.6 mass%,
Sr content in the sacrificial anode material is 0.005 to 0.6 mass%,
Sr content in the sacrificial anode material side brazing material is 0.005 to 0.6 mass%,
The brazing sheet for a tube material of a heat exchanger according to any one of claims 16 and 17. The core side brazing material further contains 0.05 to 1.4% by mass of Mn,
The sacrificial anode material side brazing material further contains 0.05 to 1.4% by mass of Mn,
The brazing sheet for a tube material of a heat exchanger according to any one of claims 16 to 18.   The sacrificial anode material further contains one or two of 0.05 to 0.3% by mass of Ti and 0.05 to 0.3% by mass of Zr. The brazing sheet for tube materials of the heat exchanger of any one of -19. Applying a fluoride flux to the surface of the brazing material side brazing material and the surface of the sacrificial anode material side brazing material of the tube material comprising the brazing sheet for a tube material of the heat exchanger according to any one of claims 12 to 15, Assembling and heating the tube material and the fin material, and brazing the tube material and the fin material;
Sr content Cs (mass%) in the core material of the tube material before brazing, Sr content Rx (mass%) in the brazing material side brazing material of the tube material before brazing, The thickness Dx (μm) of the core material side brazing material of the tube material and the application amount Fx (g / m ² ) of the fluoride flux applied to the surface of the core material side brazing material of the tube material are expressed by the following formulas: (1):
Cs + 0.025 × Rx × Dx ≧ 0.001 × Fx + 0.005 (1)
The filling,
And Sr content Gs (mass%) in the sacrificial anode material of the tube material before brazing, Sr content Ry (mass%) in the brazing material side brazing material of the tube material before brazing, brazing The thickness Dy (μm) of the sacrificial anode material side brazing material of the tube material before application, and the application amount Fy (g / m ^{2) of the} fluoride flux applied to the surface of the sacrificial anode material side brazing material of the tube material. ) Is the following formula (2):
Gs + 0.025 × Ry × Dy ≧ 0.001 × Fy + 0.005 (2)
Meeting,
The manufacturing method of the heat exchanger characterized by these.   A brazing step of assembling and heating the tube material and the fin material comprising the brazing sheet for a tube material of the heat exchanger according to any one of claims 16 to 20, and brazing the tube material and the fin material. The manufacturing method of the heat exchanger characterized by these.

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