WO2017007019A1

WO2017007019A1 - Aluminum alloy cladding material, manufacturing method therefor, and heat exchanger using said aluminum alloy cladding material

Info

Publication number: WO2017007019A1
Application number: PCT/JP2016/070277
Authority: WO
Inventors: 太一浅野; 真樹原田; 手島　聖英; 安藤　誠; 渉成田; 尚希山下
Original assignee: 株式会社Uacj
Priority date: 2015-07-08
Filing date: 2016-07-08
Publication date: 2017-01-12

Abstract

Provided is an aluminum alloy cladding material having an aluminum alloy core material and a first filler metal cladded to one surface or both surfaces of the core material, wherein the core material and the first filler metal are made from an aluminum alloy having a predetermined composition, the existence density of Al-Mn intermetallic compounds having a circle-equivalent diameter of at least 0.1 μm in the first filler metal before brazing heating is at least 1.0×10⁵ compounds/mm², and the existence density of Al-Mn intermetallic compounds having a circle-equivalent diameter of at least 2 μm in the first filler metal after brazing heating is at least 300 compounds/mm². Further provided are a manufacturing method for the aluminum alloy cladding material, and a heat exchanger using the aluminum alloy cladding material.

Description

Aluminum alloy clad material, method for producing the same, and heat exchanger using the aluminum alloy clad material

The present invention relates to a highly corrosion-resistant aluminum alloy clad material suitably used as a refrigerant or high-temperature compressed air passage component in a heat exchanger such as a radiator, and a method for producing the same. Furthermore, the present invention relates to a heat exchanger for an automobile or the like provided with a flow path forming component using the highly corrosion-resistant aluminum alloy clad material.

Aluminum alloy is lightweight and has high thermal conductivity, and high corrosion resistance can be realized by appropriate treatment, so it is used for heat exchangers for automobiles, such as radiators, condensers, evaporators, heaters, intercoolers, oil coolers, etc. It has been. As a tube material for an automotive heat exchanger, an Al—Mn alloy such as 3003 alloy is used as a core material, and an Al—Si alloy brazing material or an Al—Zn alloy sacrificial anode material is provided on one side of the tube material. A two-layer clad material clad with an Al—Si alloy brazing material on the other surface is used. The heat exchanger is usually joined by combining such a clad material and a corrugated fin material and brazing at a high temperature of about 600 ° C.

For example, in an oil cooler, it is common to adopt a water cooling type in which engine oil and cooling water are subjected to heat exchange to cool the engine oil. In recent years, intercoolers of a type that employs a water-cooling type have been seen. For this cooling water, LLC to which a rust inhibitor is added is originally used, but tap water or well water may be used in developing countries. Since tap water and well water may contain chloride ions, the aluminum oxide film may be destroyed to cause pitting corrosion, which may cause corrosion penetration in the cooling water flow path.

As a countermeasure, it is common to provide a sacrificial anticorrosive effect by cladding a sacrificial anode material made of an Al—Zn alloy, and to prevent corrosion penetration due to pitting corrosion by spreading the progress of corrosion laterally. However, since chloride ions contained in tap water and well water are usually at a low concentration of about 1200 ppm or less, pitting corrosion is likely to occur when the cooling water is at a low temperature near room temperature, and an aluminum oxide film is formed at a high temperature. Since pitting corrosion is difficult to occur, corrosion products such as aluminum hydroxide are formed between pitting corrosion outside and pitting corrosion occurring at room temperature, and the inside of the pitting corrosion is blocked. This facilitates local alkalinization inside the pitting corrosion. When the inside of the closed pitting corrosion becomes strong alkalinity, the corrosion rate is large and the sacrificial anode effect does not function sufficiently, so that deep corrosion penetration that does not spread laterally occurs.

As a means for forming a cooling water flow path in the heat exchanger, as shown in FIG. 1, a method of laminating a plate 1 that forms a cooling water flow path through a corrugated fin 2 by forming a clad material. There is. This method has an advantage that the degree of freedom in design is high because the size of the heat exchanger can be changed simply by changing the number of stacks. However, in order to join the plates together, it is necessary to supply the brazing from the plate material itself during brazing.

In consideration of the above, when a laminated type is applied to a water-cooled heat exchanger, the brazing is supplied to the inner surface of the flow path of the material used for the flow path forming component at the time of brazing, and the holes It is necessary to clad a layer having a plurality of functions such as having a sacrificial anticorrosion function against corrosion and preventing the occurrence of corrosion due to local strong alkalinization.

Patent Documents

1 and 2 describe a technique for supplying brazing at the time of brazing and imparting a sacrificial anticorrosion function to pitting corrosion. In these patent documents, by adding Zn and low-concentration Si to the cladding layer, a liquid phase brazing is formed at the time of brazing to enable bonding, and a part of the cladding layer is made of a solid phase. There has been proposed a method of leaving it as it is and having a high sacrificial anticorrosive function. In this technique, the solidified structure generated after brazing due to melting of the clad layer becomes a primary phase and a eutectic phase. And, due to the fact that the potential of the eutectic is lower than that of the primary crystal, preferential corrosion of the eutectic portion occurs, and the primary crystal portion that should act as a sacrificial anode material is dropped early, resulting in a decrease in corrosion resistance. The problem and its solution are also disclosed. However, these patent documents do not recognize the problem of occurrence of corrosion due to local strong alkalinization, and do not describe any means for preventing it.

JP 2010-255013 A International Publication No. 2011/034102

As described above, when an aluminum alloy clad material is used, for example, as a material for a flow path forming part of a heat exchanger, brazing is supplied at the time of brazing addition heat, and after sacrificial heating, it has a sacrificial anticorrosion function and is also localized It has been difficult to provide an aluminum alloy clad material that prevents corrosion due to alkalinization by conventional techniques.

The present invention has been completed to solve such problems, and in an aluminum alloy clad material, brazing is supplied at the time of brazing addition heat, and after sacrificial heating, it has a sacrificial anticorrosion function, and is also localized. An object of the present invention is to provide a highly corrosion-resistant aluminum alloy clad material that prevents corrosion due to alkalinization, and a flow path forming part for a heat exchanger such as an automobile using the same.

As a result of intensive research on the above problems, the present inventors prepared a core material, a brazing material (first and second), and a sacrificial anode material each having a specific alloy composition and metal structure, and one or both of the core materials. The above-mentioned problem is solved by a clad material in which a first brazing material is clad on one surface and a clad material in which a first brazing material is clad on one surface of a core material and a sacrificial anode material or a second brazing material is clad on the other surface. As a result, the present invention has been completed.

According to a first aspect of the present invention, in the aluminum alloy clad material comprising an aluminum alloy core material and a first brazing material clad on one or both surfaces of the core material, the core material comprises Si: 0.05 to 1 .50 mass%, Fe: 0.05 to 2.00 mass%, Mn: 0.5 to 2.0 mass%, the balance being made of an aluminum alloy composed of Al and inevitable impurities, wherein the first brazing material is Si : 2.5 to 7.0 mass%, Fe: 0.05 to 1.20 mass%, Zn: 0.5 to 8.0 mass%, Mn: 0.3 to 2.0 mass%, balance Al and inevitable The presence density of the Al—Mn intermetallic compound having an equivalent circle diameter of 0.1 μm or more in the first brazing filler metal is 1.0 ×. 10 ⁵ pieces / mm ² or more, and the presence density of Al—Mn intermetallic compounds having an equivalent circle diameter of 2 μm or more in the first brazing material after the brazing heat is 300 pieces / mm ² or more. It was set as the characteristic aluminum alloy clad material.

According to a second aspect of the present invention, in the first aspect, the first brazing material is Cu: 0.05 to 0.60 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass. %, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass%, and an aluminum alloy further containing one or more selected from Cr.

According to a third aspect of the present invention, in the first or second aspect, the first brazing material is one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. It was made of an aluminum alloy further containing seeds.

According to a fourth aspect of the present invention, the core material according to any one of the first to third aspects includes Mg: 0.05 to 0.50 mass%, Cu: 0.05 to 1.50 mass%, and Ti: 0.05. One or more selected from ˜0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass% The aluminum alloy contained was used.

The present invention provides the method for producing an aluminum alloy clad material according to any one of claims 1 to 4, wherein the aluminum alloy for the core material and the first brazing material are respectively casted. A hot rolling process in which the ingot of the cast first brazing material is hot-rolled to a predetermined thickness, and one or both surfaces of the core material ingot are clad with the first brazing material having a predetermined thickness by hot rolling. A clad process for forming a clad material, a hot clad roll process for hot rolling the clad material, a cold roll process for cold rolling the clad material that has been hot clad rolled, One or more annealing steps for annealing the clad material in one or both after the rolling step, and the hot rolling step of the first brazing material includes a heating step, a holding step, and a hot rolling step, and heating In stage 4, The temperature rising rate until reaching 0 ° C. is 30 ° C./h or more, the temperature rising rate from reaching 400 ° C. to reaching the holding temperature in the holding stage is 60 ° C./h or less, and the holding temperature in the holding stage is 450.degree. C. or higher and 560.degree. C. or lower, the holding time is 1 hour or longer, and the time during which the temperature of the first brazing material is 400.degree. C. or higher is 5 minutes or longer during the hot rolling stage. A method for producing a clad material was adopted.

The present invention provides, in claim 6, an aluminum alloy clad comprising an aluminum alloy core material, a first brazing material clad on one surface of the core material, and a second brazing material clad on the other surface of the core material. In the material, the core material contains Si: 0.05 to 1.50 mass%, Fe: 0.05 to 2.00 mass%, Mn: 0.5 to 2.0 mass%, and the remainder from Al and inevitable impurities The first brazing filler metal is made of an aluminum alloy having the following composition: Si: 2.5 to 7.0 mass%, Fe: 0.05 to 1.20 mass%, Zn: 0.5 to 8.0 mass%, Mn: 0.00. Containing 3 to 2.0 mass%, the balance being made of an aluminum alloy consisting of Al and inevitable impurities, the second brazing filler metal is Si: 2.5 to 13.0 mass%, Fe: 0.05 to 1.20 m An abundance density of an Al—Mn intermetallic compound having an equivalent circle diameter of 0.1 μm or more in the first brazing filler metal, which is made of an aluminum alloy containing ss%, the balance being Al and inevitable impurities, and before the brazing heat Is 1.0 × 10 ⁵ pieces / mm ² or more, and the presence density of Al—Mn intermetallic compounds having a circle-equivalent diameter of 2 μm or more in the first brazing material after the brazing heat is 300 pieces / mm ^2. It was set as the aluminum alloy clad material characterized by the above.

According to a seventh aspect of the present invention, in the sixth aspect, the first brazing material is Cu: 0.05 to 0.60 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass. %, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass%, and an aluminum alloy further containing one or more selected from Cr.

According to the present invention, in claim 8, in claim 6 or 7, the first brazing material is one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. It was made of an aluminum alloy further containing seeds.

In the ninth aspect of the present invention, the core material according to any one of the sixth to eighth aspects includes: Mg: 0.05 to 0.50 mass%, Cu: 0.05 to 1.50 mass%, Ti: 0.05. One or more selected from ˜0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass% The aluminum alloy contained was used.

According to a tenth aspect of the present invention, there is provided the method according to any one of the sixth to ninth aspects, wherein the second brazing material is Mn: 0.05 to 2.00 mass%, Cu: 0.05 to 1.50 mass%, Ti: One or two selected from 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass% The aluminum alloy further contains the above.

In the eleventh aspect of the present invention, in the eleventh aspect, the second brazing material is selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. It was made of an aluminum alloy further containing one or two kinds.

The present invention provides the method for producing an aluminum alloy clad material according to any one of claims 6 to 11, wherein the aluminum alloy for the core material, the first brazing material, and the second brazing material is defined in claim 12. , A hot rolling process in which the cast ingots of the first brazing material and the second brazing material are each hot-rolled to a predetermined thickness, and one surface of the core material ingot is predetermined by hot rolling. A clad process in which the first brazing material having a thickness is clad with a second brazing material having a predetermined thickness by hot rolling on the other surface, and a hot clad rolling process in which the clad material is hot-rolled A cold rolling step of cold rolling the clad material that has been hot-clad rolled, and one or more annealing steps of annealing the clad material in one or both of the middle of the cold rolling step and after the cold rolling step; Including The hot rolling process of the first brazing filler metal includes a heating stage, a holding stage, and a hot rolling stage, and in the heating stage, the rate of temperature rise until reaching 400 ° C. is 30 ° C./h or more, reaching 400 ° C. The heating rate from the time until reaching the holding temperature in the holding stage is 60 ° C./h or less, the holding temperature in the holding stage is 450 ° C. or more and 560 ° C. or less, the holding time is 1 hour or more, and the hot rolling stage The method for producing an aluminum alloy clad material characterized in that the time during which the temperature of the first brazing material is 400 ° C. or higher is 5 minutes or longer.

According to a thirteenth aspect of the present invention, an aluminum alloy clad material comprising: an aluminum alloy core material; a first brazing material clad on one surface of the core material; and a sacrificial anode material clad on the other surface of the core material. The core material contains Si: 0.05 to 1.50 mass%, Fe: 0.05 to 2.00 mass%, Mn: 0.5 to 2.0 mass%, and the balance is Al and inevitable impurities. It is made of an aluminum alloy, and the first brazing material is Si: 2.5-7.0 mass%, Fe: 0.05-1.20 mass%, Zn: 0.5-8.0 mass%, Mn: 0.3 The sacrificial anode material contains Zn: 0.5 to 8.0 mass%, Si: 0.05 to 1.50 m. ss%, Fe: 0.05 to 2.00 mass%, consisting of an aluminum alloy composed of the balance Al and inevitable impurities, and having an equivalent circle diameter of 0.1 μm or more in the first brazing material before the heat of brazing The Al—Mn-based metal having an abundance density of Al—Mn-based intermetallic compound of 1.0 × 10 ⁵ pieces / mm ² or more and having an equivalent circle diameter of 2 μm or more in the first brazing material after the heat of brazing addition An aluminum alloy clad material characterized in that the density of intermetallic compounds is 300 / mm ² or more.

According to a fourteenth aspect of the present invention, in the fourteenth aspect, the first brazing material is Cu: 0.05 to 0.60 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass. %, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass%, and an aluminum alloy further containing one or more selected from Cr.

According to a fifteenth aspect of the present invention, in the fifteenth or fourteenth aspect, the first brazing material is one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. It was made of an aluminum alloy further containing seeds.

According to a sixteenth aspect of the present invention, in the sixteenth aspect, the core material is Mg: 0.05 to 0.50 mass%, Cu: 0.05 to 1.50 mass%, Ti: 0.05. One or more selected from ˜0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass% The aluminum alloy contained was used.

In the seventeenth aspect of the present invention, the sacrificial anode material according to any one of the thirteenth to sixteenth aspects includes Ni: 0.05 to 2.00 mass%, Mn: 0.05 to 2.00 mass%, and Mg: 0. .05 to 3.00 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass The aluminum alloy further contains one or more selected from%.

The present invention according to claim 18, wherein the aluminum alloy for the core material, the first brazing material, and the sacrificial anode material are respectively casted, and the ingots of the cast first brazing material and sacrificial anode material are each set to a predetermined thickness. A hot rolling step for hot rolling, a first brazing material having a predetermined thickness by hot rolling on one surface of the core ingot, and a sacrificial anode material having a predetermined thickness by hot rolling on the other surface, respectively. A clad process for clad and clad material; a hot clad roll process for hot rolling the clad material; a cold roll process for cold rolling the clad material that has been hot clad rolled; One or more annealing steps for annealing the clad material in one or both after the cold rolling step, and the hot rolling step of the first brazing material includes a heating step, a holding step, and a hot rolling step. In the heating stage The rate of temperature rise until reaching 400 ° C. is 30 ° C./h or more, and the rate of temperature rise from reaching 400 ° C. to reaching the holding temperature in the holding stage is 60 ° C./h or less. The temperature is 450 ° C. or more and 560 ° C. or less, the holding time is 1 hour or more, and in the hot rolling step, the time that the temperature of the first brazing material is 400 ° C. or more is 5 minutes or more. The method for producing an aluminum alloy clad material according to any one of 17, wherein the aluminum alloy clad material is produced by a characteristic method.

The present invention provides a heat exchanger according to claim 19, wherein the aluminum alloy clad material according to any one of claims 1 to 4 is used for at least a flow path forming component, wherein at least one of the first brazing material surfaces The heat exchanger was characterized by being exposed to a solution having a chloride ion concentration of 1200 ppm or less.

The present invention provides a heat exchanger according to claim 20, wherein the aluminum alloy clad material according to any one of claims 6 to 11 and 13 to 17 is used for at least a flow path forming component, wherein the first brazing material The heat exchanger is characterized in that the surface is exposed to a solution having a chloride ion concentration of 1200 ppm or less.

According to the present invention, an aluminum alloy clad material that supplies brazing at the time of brazing addition heat, has a sacrificial anticorrosion function after brazing heat addition, and prevents corrosion due to local alkalinization, and an automobile using the same For example, a heat exchanger flow path forming component is provided. This clad material is excellent in brazing properties such as erosion resistance, and is suitably used as a flow path forming component material for heat exchangers for automobiles and the like from the viewpoint of light weight and good thermal conductivity.

It is a perspective view which shows the heat exchanger which laminated | stacked the plate used as the flow path of the cooling water which shape | molded the clad material through the corrugated fin.

The preferred embodiments of the highly corrosion-resistant aluminum alloy clad material and the method for producing the same according to the present invention will be described in detail.

1. Layers constituting the aluminum alloy clad material The aluminum alloy clad material of the present invention has brazing properties by appropriately controlling the alloy composition and metal structure of the first brazing material that has both brazing and sacrificial corrosion resistance. In addition, it has excellent corrosion resistance. The first brazing material may be clad on one surface of the core material to form a two-layer clad material, or may be clad on both surfaces of the core material to form a three-layer clad material.
Further, in the above-mentioned two-layer clad material, a three-layer clad material in which a second brazing material, which is a normal Al—Si alloy brazing material, is clad on the other surface of the core material not clad with the first brazing material may be used. Alternatively, a three-layer clad material clad with an Al—Zn alloy sacrificial anode material may be used.
In the following, the components of these first brazing material, core material, second brazing material and sacrificial anode material will be described.

2. The first brazing material includes: Si: 2.5 to 7.0 mass% (hereinafter simply referred to as “%”), Fe: 0.05 to 1.20%, Zn: 0.5 to 8 An aluminum alloy containing 0.0%, Mn: 0.3 to 2.0% as an essential element, and the balance being Al and inevitable impurities is used.

The first brazing filler metal is Cu: 0.05-0.60%, Ti: 0.05-0.30%, Zr: 0.05-0.30%, Cr: 0.05-0.30. % And V: One or more selected from 0.05 to 0.30% may be further contained as the first selective additive element. Furthermore, the first brazing material contains one or two selected from Na: 0.001 to 0.050% and Sr: 0.001 to 0.050% as a second selective additive element. Also good. In addition to the essential elements and the first and second selective additive elements, unavoidable impurities may be contained in amounts of 0.05% or less, respectively, and 0.15% in total. Below, each component is demonstrated.

Si:
By adding Si, the melting point of the brazing material is lowered to form a liquid phase, thereby enabling brazing. For example, a general alloy for brazing filler metals allows an upper limit of up to about 11% if it is a 4045 alloy, but by keeping this low, a certain proportion remains in the solid phase at the time of brazing, and excellent sacrificial corrosion protection Functions can be added. The Si content is 2.5 to 7.0%. If it is less than 2.5%, the resulting liquid phase is small and it becomes difficult to obtain a brazing function. On the other hand, if it exceeds 7.0%, for example, the amount of Si diffused into the counterpart material such as fins becomes excessive, and the counterpart material will melt. A preferable content of Si is 3.5 to 6.0%.

Fe:
Fe easily forms intermetallic compounds of Al-Fe, Al-Fe-Si, Al-Fe-Mn, and Al-Fe-Mn-Si, reducing the amount of Si effective for brazing. Causing a reduction in brazability. The Fe content is 0.05 to 1.20%. If it is less than 0.05%, high-purity aluminum ingots must be used, resulting in high costs. On the other hand, if it exceeds 1.20%, the amount of Si effective for brazing is reduced and brazing becomes insufficient. A preferable content of Fe is 0.1 to 0.5%.

Zn:
Zn can lower the pitting corrosion potential, and can improve the corrosion resistance due to the sacrificial anticorrosion effect by forming a potential difference with the core material. The Zn content is 0.5 to 8.0%. If it is less than 0.5%, the effect of improving the corrosion resistance due to the sacrificial anticorrosive effect cannot be sufficiently obtained. On the other hand, if it exceeds 8.0%, the corrosion rate increases, the sacrificial anticorrosion layer disappears early, and the corrosion resistance decreases. A preferable content of Zn is 1.0 to 6.0%.

Mn:
Mn forms Al—Mn, Al—Fe—Mn, and Al—Fe—Mn—Si intermetallic compounds (hereinafter, simply referred to as “Al—Mn intermetallic compounds”). By activating the cathode reaction, the corrosion potential can be made noble and pitting corrosion can be easily generated. As already described, if the corrosion form is pitting corrosion, corrosion due to local alkalinization does not occur. That is, Mn has the effect of preventing local alkalization and improving corrosion resistance. The Mn content is 0.3 to 2.0%. If it is less than 0.3%, the above effect cannot be obtained sufficiently. On the other hand, if it exceeds 2.0%, a giant intermetallic compound is likely to be formed during casting, and the plastic workability is lowered. The Mn content is preferably 0.4 to 1.8%.

Cu:
Since Cu improves strength by solid solution strengthening, Cu may be contained. The Cu content is 0.05 to 0.60%. If it is less than 0.05%, the above effect is insufficient, and if it exceeds 0.60%, the pitting potential becomes noble, and the sacrificial anticorrosive effect by Zn is lost. The Cu content is preferably 0.10 to 0.50%.

Ti:
Ti may be contained because it improves strength and improves corrosion resistance by solid solution strengthening. The Ti content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Ti content is preferably 0.10 to 0.20%.

Zr:
Zr may be contained because it has the effect of improving the strength by solid solution strengthening and precipitating Al—Zr-based intermetallic compounds to coarsen the crystal grains after the heat of brazing addition. The Zr content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Zr content is preferably 0.10 to 0.20%.

Cr:
Cr may be contained because it has the effect of improving strength by solid solution strengthening and precipitating Al—Cr-based intermetallic compounds to coarsen crystal grains after brazing addition heat. The Cr content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Cr content is preferably 0.10 to 0.20%.

V:
V may be contained because it improves the strength by solid solution strengthening and also improves the corrosion resistance. The V content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The V content is preferably 0.10 to 0.20%.

Na, Sr:
Na and Sr exhibit the effect of refining the Si particles in the first brazing material. The contents of Na and Sr are 0.001 to 0.050%, respectively. If the respective contents are less than 0.001%, the above effects cannot be obtained sufficiently. On the other hand, when each content exceeds 0.050%, an oxide film becomes thick and brazeability is reduced. Each preferable content is 0.003 to 0.020%.

These Cu, Ti, Zr, Cr, V, Na, and Sr may be added to the first brazing material if necessary.

3. Core material The core material contains Si: 0.05 to 1.50%, Fe: 0.05 to 2.00%, Mn: 0.5 to 2.0% as essential elements, the balance Al and inevitable impurities An aluminum alloy is used.

The core material is Mg: 0.05 to 0.50%, Cu: 0.05 to 1.50%, Ti: 0.05 to 0.30%, Zr: 0.05 to 0.30%, Cr One or more selected from: 0.05 to 0.30% and V: 0.05 to 0.30% may be further contained as a selective additive element.

Furthermore, in addition to the above essential elements and selective additive elements, unavoidable impurities may be contained in amounts of 0.05% or less, respectively, and 0.15% in total.

As the aluminum alloy used for the core material of the present invention, a JIS 3000 series alloy, for example, an Al—Mn series alloy such as JIS 3003 alloy is preferably used. Below, each component is demonstrated in detail.

Si:
Si forms an Al-Fe-Mn-Si intermetallic compound together with Fe and Mn and improves strength by dispersion strengthening, or improves strength by solid solution strengthening by solid solution in an aluminum matrix. . The Si content is 0.05 to 1.50%. If it is less than 0.05%, high-purity aluminum ingots must be used, resulting in high costs. If it exceeds 1.50%, the melting point of the core material is lowered and the possibility of melting is increased. A preferable content of Si is 0.10 to 1.20%.

Fe:
Fe forms an Al—Fe—Mn—Si intermetallic compound together with Si and Mn, and improves the strength by dispersion strengthening. The amount of Fe added is 0.05 to 2.00%. If the content is less than 0.05%, high-purity aluminum ingots must be used, resulting in high costs. On the other hand, if it exceeds 2.00%, a giant intermetallic compound is easily formed during casting, and the plastic workability is lowered. A preferable content of Fe is 0.10 to 1.50%.

Mn:
Mn forms an Al—Mn—Si intermetallic compound together with Si, and an Al—Mn—Fe—Si intermetallic compound together with Si and Fe to improve strength by dispersion strengthening, or an aluminum matrix. Strengthened by solid solution in the phase and solid solution strengthening. The Mn content is 0.5 to 2.0%. If the content is less than 0.5%, the above effect is insufficient. If the content exceeds 2.0%, a giant intermetallic compound is easily formed during casting, and the plastic workability is lowered. A preferable content of Mn is 0.8 to 1.8%.

Mg:
Mg may be contained because the strength is improved by precipitation of Mg ₂ Si. The Mg content is 0.05 to 0.50%. If it is less than 0.05%, the above effect is insufficient, and if it exceeds 0.50%, brazing becomes difficult. The Mg content is preferably 0.10 to 0.40%.

Cu:
Since Cu improves strength by solid solution strengthening, Cu may be contained. The Cu content is 0.05 to 1.50%. If it is less than 0.05%, the above effect is insufficient, and if it exceeds 1.50%, there is a high risk of cracking of the aluminum alloy during casting. The Cu content is preferably 0.30 to 1.00%.

Ti:
Ti may be contained because it improves the strength by solid solution strengthening. The Ti content is 0.05 to 0.30%. If it is less than 0.05%, the above effect is insufficient. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Ti content is preferably 0.10 to 0.20%.

These Mg, Cu, Ti, Zr, Cr, and V may be added to the core material if necessary.

4). Sacrificial anode material The sacrificial anode material contains Zn: 0.5 to 8.0%, Si: 0.05 to 1.50%, Fe: 0.05 to 2.00% as essential elements, and the balance Al In addition, an aluminum alloy made of inevitable impurities is used.

Sacrificial anode materials are Ni: 0.05 to 2.00%, Mn: 0.05 to 2.00%, Mg: 0.05 to 3.00%, Ti: 0.05 to 0.30% One or more selected from Zr: 0.05 to 0.30%, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass% are further added as selective additive elements. You may contain. Furthermore, in addition to the above essential elements and selective additive elements, 0.05% or less each of unavoidable impurities may be contained in total, and 0.15% in total. Below, each component is demonstrated.

Si:
Si forms an Al—Fe—Si based intermetallic compound with Fe, and when it contains Mn at the same time, forms an Al—Fe—Mn—Si based intermetallic compound with Fe and Mn, The strength is improved by dispersion strengthening, or the solid strength is improved by solid solution strengthening in the aluminum matrix. Moreover, since Si makes the potential of the sacrificial anode layer noble, the sacrificial anticorrosive effect is hindered and the corrosion resistance is lowered. The Si content is 0.05 to 1.50%. If the content is less than 0.05%, high-purity aluminum ingots must be used, resulting in high costs. On the other hand, when it exceeds 1.50%, the pitting corrosion potential of the sacrificial anode material becomes noble and the sacrificial anticorrosive effect is lost, and the corrosion resistance is lowered. A preferable content of Si is 0.10 to 1.20%.

Fe:
Fe forms an Al—Fe—Si intermetallic compound together with Si, and if it contains Mn simultaneously, forms an Al—Fe—Mn—Si intermetallic compound together with Si and Mn, Strength is improved by dispersion strengthening. The amount of Fe added is 0.05 to 2.00%. If the content is less than 0.05%, high-purity aluminum ingots must be used, resulting in high costs. On the other hand, if it exceeds 2.00%, a giant intermetallic compound is easily formed during casting, and the plastic workability is lowered. A preferable content of Fe is 0.10 to 1.50%.

Ni:
Ni forms an Al-Ni-based or Al-Fe-Ni-based intermetallic compound together with Fe. Since these intermetallic compounds have a higher corrosion potential than aluminum matrix and are noble, they act as corrosion cathode sites. Therefore, when these intermetallic compounds are dispersed in the sacrificial anode material, the starting point of corrosion is dispersed. As a result, corrosion in the depth direction is difficult to proceed, and the corrosion resistance is improved. The Ni content is 0.05 to 2.00%. If the content is less than 0.05%, the above effect cannot be obtained sufficiently. On the other hand, if it exceeds 2.00%, a giant intermetallic compound is easily formed during casting, and the plastic workability is lowered. The Ni content is preferably 0.10 to 1.50%.

Mn:
Mn may be contained because it improves strength and corrosion resistance. The Mn content is 0.05 to 2.00%. If it exceeds 2.00%, a huge intermetallic compound is likely to be formed during casting, and the plastic workability is lowered. On the other hand, if it is less than 0.05%, the effect cannot be sufficiently obtained. The Mn content is preferably 0.05 to 1.80%.

Mg:
Since Mg improves the strength of the sacrificial anode material by precipitation of Mg ₂ Si, it may be contained. In addition to improving the strength of the sacrificial anode material itself, brazing causes Mg to diffuse from the sacrificial anode material to the core material, thereby improving the strength of the core material. For these reasons, Mg may be included. The Mg content is 0.05 to 3.00%. If it is less than 0.05%, the above effect cannot be obtained sufficiently. On the other hand, if it exceeds 3.00%, it becomes difficult to press the sacrificial anode material and the core material in the hot clad rolling process. A preferable content of Mg is 0.10 to 2.00%. In addition, since Mg deteriorates the flux in Nocolok brazing and inhibits brazeability, when the sacrificial anode material contains 0.50% or more Mg, Nocolok brazing cannot be used for joining the tube materials. . In this case, it is necessary to use means such as welding for joining the tube materials, for example.

Ti:
Ti may be contained because it improves strength and improves corrosion resistance by solid solution strengthening. The Ti content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Ti content is preferably 0.05 to 0.20%.

V:
V may be contained because it improves the strength by solid solution strengthening and also improves the corrosion resistance. The V content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The V content is preferably 0.05 to 0.20%.

These Ni, Mn, Mg, Ti, Zr, Cr, and V may be added to the sacrificial anode material as required, if necessary.

5). Second brazing material The second brazing material contains Si: 2.5 to 13.0%, Fe: 0.05 to 1.20% as essential elements, the balance being Al and unavoidable impurities Is used.

The second brazing filler metal is Mn: 0.05 to 2.00%, Cu: 0.05 to 1.50%, Ti: 0.05 to 0.30%, Zr: 0.05 to 0.30. %, Cr: 0.05 to 0.30% and V: 0.05 to 0.30% may be further included as a first selective additive element. Further, the second brazing material contains one or two selected from Na: 0.001 to 0.050% and Sr: 0.001 to 0.050% as a second selective additive element. Also good. In addition to the essential elements and the first and second selective additive elements, unavoidable impurities may be contained in amounts of 0.05% or less, respectively, and 0.15% in total. Below, each component is demonstrated.

Si:
By adding Si, the melting point of the second brazing material is lowered to form a liquid phase, thereby enabling brazing. The Si content is 2.5 to 13.0%. If it is less than 2.5%, the resulting liquid phase is small and it becomes difficult to obtain a brazing function. On the other hand, if it exceeds 13.0%, for example, when this second brazing material is used as a tube material, the amount of Si diffusing into the mating material such as fins becomes excessive, and the mating material will melt. A preferable content of Si is 3.5 to 12.0%.

Fe:
Fe easily forms an Al-Fe-based or Al-Fe-Si-based intermetallic compound, and when it contains Mn at the same time, Al-Fe-Mn-based or Al-Fe-Mn-Si-based Since it is easy to form an intermetallic compound, the amount of Si that is effective for brazing is reduced and brazing properties are reduced. The Fe content is 0.05 to 1.20%. If it is less than 0.05%, high-purity aluminum ingots must be used, resulting in high costs. On the other hand, if it exceeds 1.20%, the amount of Si effective for brazing is reduced and brazing becomes insufficient. A preferable content of Fe is 0.10 to 0.50%.

Mn:
Mn may be contained because it improves the strength and corrosion resistance of the brazing material. The Mn content is 0.05 to 2.00%. If it exceeds 2.00%, a huge intermetallic compound is likely to be formed during casting, and the plastic workability is lowered. On the other hand, if it is less than 0.05%, the effect cannot be sufficiently obtained. The Mn content is preferably 0.05 to 1.80%.

Cu:
Cu may be included because it improves the strength of the second brazing filler metal by solid solution strengthening. The Cu content is 0.05 to 1.50%. If it is less than 0.05%, the above effect is insufficient, and if it exceeds 1.50%, there is a high risk of cracking of the aluminum alloy during casting. The Cu content is preferably 0.30 to 1.00%.

Ti:
Ti may be contained because it improves the strength of the second brazing filler metal by solid solution strengthening and also improves the corrosion resistance. The Ti content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Ti content is preferably 0.10 to 0.20%.

Zr:
Zr may be contained because it has the effect of improving the strength of the second brazing filler metal by solid solution strengthening and precipitating Al—Zr-based intermetallic compounds to coarsen the crystal grains after brazing addition heat. . The Zr content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Zr content is preferably 0.10 to 0.20%.

Cr:
Cr may be contained because it has the effect of improving the strength of the second brazing filler metal by solid solution strengthening and precipitating Al—Cr intermetallic compounds to coarsen the crystal grains after brazing addition heat. . The Cr content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The Cr content is preferably 0.10 to 0.20%.

V:
V may be contained because it improves the strength of the second brazing filler metal by solid solution strengthening and also improves the corrosion resistance. The V content is 0.05 to 0.30%. If it is less than 0.05%, the above effect cannot be obtained. If it exceeds 0.30%, it becomes easy to form a giant intermetallic compound, and the plastic workability is lowered. The V content is preferably 0.10 to 0.20%.

Na, Sr:
Na and Sr exhibit the effect of refining the Si particles in the second brazing material. The contents of Na and Sr are 0.001 to 0.050%, respectively. If the respective contents are less than 0.001%, the above effects cannot be obtained sufficiently. On the other hand, when each content exceeds 0.050%, an oxide film becomes thick and brazeability is reduced. Each preferable content is 0.003 to 0.020%.
These Mn, Cu, Ti, Zr, Cr, V, Na, and Sr may be added in the second brazing material as required.

6). Structure of the first brazing material The aluminum alloy clad material according to the present invention has a density of Al-Mn intermetallic compounds having a circle equivalent diameter of 0.1 μm or more before the brazing heat of the first brazing material is 1.0. The existence density of the Al—Mn intermetallic compound having a circle equivalent diameter of 2 μm or more after the heat of brazing addition of the first brazing material is limited to 300 pieces / mm ² or more to × 10 ⁵ pieces / mm ² or more. These limitations are intended to improve the corrosion resistance of the surface on the first brazing material side after the brazing heat. The existence density here refers to the number density per unit area when an arbitrary cross section in the first brazing filler metal layer is observed. The reason for this limitation will be described below.

A part of the first brazing material is melted at the time of brazing so that the brazing is supplied and joining is possible, and the first brazing material itself is preferentially corroded to cause the corrosion to progress into a plane, thereby forming a tube. The core material is clad for the purpose of exerting a sacrificial anti-corrosion function for preventing perforation corrosion. However, as already described, when the corrosion form is not pitting corrosion, local alkalinization occurs, and the sacrificial anticorrosive function is not exhibited, and corrosion penetration occurs early. As a result of diligent research, the present inventors have investigated the cathode during corrosion by dispersing an Al—Mn intermetallic compound in an appropriate size (equivalent circle diameter) and density in the first brazing material after brazing. It was found that the reaction was activated to facilitate pitting corrosion and corrosion penetration due to local alkalinization could be prevented.

After brazing, an Al—Mn-based intermetallic compound having a circle-equivalent diameter of 2 μm or more has an effect of activating the cathode reaction, and those less than 2 μm have an insufficient effect. Therefore, in the present invention, Al—Mn intermetallic compounds having an equivalent circle diameter of less than 2 μm after brazing are excluded. Further, if the existence density of Al—Mn intermetallic compounds having an equivalent circle diameter of 2 μm or more after brazing is 300 pieces / mm ² or more, there is a sufficient cathode reaction activation effect, 300 pieces If it is less than / mm ^2, the effect is insufficient. The equivalent circle diameter of the Al—Mn intermetallic compound after brazing is preferably 3 μm or more, and its density is preferably 1000 / mm ² or more. From the viewpoint of corrosion resistance, the upper limit of the equivalent circle diameter of the Al—Mn intermetallic compound after brazing is not limited. However, if a compound exceeding 200 μm is present, composition workability is reduced and rolling is in progress. There is a risk of breaking. Therefore, the upper limit of the equivalent circle diameter is preferably 200 μm. From the viewpoint of corrosion resistance, the upper limit of the density of Al—Mn intermetallic compounds is not limited, but exceeds 5.0 × 10 ⁵ pieces / mm ² from the alloy composition and production method of the present invention. It is difficult to exist. Therefore, the upper limit of the existence density is 5.0 × 10 ⁵ pieces / mm ² .

To obtain the equivalent circle diameter and density distribution of the Al—Mn intermetallic compound as described above after brazing, the equivalent circle diameter and density distribution of the Al—Mn intermetallic compound before brazing are controlled. There is a need to. Al-Mn intermetallic compounds with an equivalent circle diameter of 0.1 μm or more before brazing do not dissolve in the matrix during brazing, and form an Al—Mn compound with an equivalent circle diameter of 2 μm or more after brazing. Can do. An Al—Mn intermetallic compound having an equivalent circle diameter of less than 0.1 μm before brazing is dissolved in the matrix at the time of brazing, or its size is reduced, and after the brazing, an equivalent circle diameter of 2 μm or more. An Al—Mn intermetallic compound cannot be formed. Therefore, in the present invention, Al—Mn intermetallic compounds having an equivalent circle diameter of less than 0.1 μm before brazing are excluded.

Here, the equivalent circle diameter of the Al—Mn intermetallic compound existing before brazing is preferably 0.2 μm or more. In addition, if the density of Al—Mn intermetallic compounds having an equivalent circle diameter of 0.1 μm or more before brazing is 1 × 10 ⁵ pieces / mm ² or more, Al—Mn with an equivalent circle diameter of 2 μm or more after brazing is used. The density of Mn-based intermetallic compounds can be 300 / mm ² or more. When the density of Al-Mn intermetallic compounds having an equivalent circle diameter of 0.1 μm or more before brazing is less than 1.0 × 10 ⁵ pieces / mm ² , Al— The density of Mn-based intermetallic compounds cannot be 300 / mm ² or more. The density of Al—Mn compounds having an equivalent circle diameter of 0.1 μm or more before brazing is preferably 3.0 × 10 ⁵ pieces / mm ² or more. From the viewpoint of corrosion resistance, the upper limit of the equivalent circle diameter of the Al—Mn intermetallic compound before brazing is not limited. However, if a compound exceeding 200 μm is present, the composition workability deteriorates and rolling There is a risk of breaking inside. Therefore, the upper limit of the equivalent circle diameter is preferably 200 μm. In addition, from the viewpoint of corrosion resistance, the upper limit of the density of Al—Mn compound is not limited, but it exists in excess of 5.0 × 10 ⁷ / mm ² from the alloy composition and production method of the present invention. It is difficult to make it. Therefore, the upper limit of the existence density is 5.0 × 10 ⁷ pieces / mm ² .

7). 7. Production method of aluminum alloy clad material 7-1. Each manufacturing process The manufacturing method of the aluminum alloy clad material according to the present invention includes a step of casting an aluminum alloy for the core material and the first brazing material, and hot casting the ingot of the cast first brazing material to a predetermined thickness. A rolling step, a cladding step of cladding a first brazing material having a predetermined thickness by hot rolling on one or both surfaces of the core ingot, and a hot cladding rolling step of hot rolling the cladding material A cold rolling process for cold rolling the clad material that has been hot clad rolled, and one or more annealing processes for annealing the clad material in one or both of the cold rolling process and after the cold rolling process. Including. When the first brazing material is clad only on one surface of the core material, the second brazing material or the sacrificial anode material hot-rolled to a predetermined thickness is clad on the other surface of the core material.

The aluminum alloy clad material of the present invention realizes excellent corrosion resistance by controlling the structure of the first brazing material. As a result of intensive studies, the present inventors have found that the greatest influence on the structure control during the manufacturing process is the hot rolling process of the cast first brazing filler metal. Below, the control method of the hot rolling process of this 1st brazing material is demonstrated.

7-2. Hot-rolling process of first brazing material In the method for producing an aluminum alloy clad material according to the present invention, after casting the first brazing material, the first brazing material is cast to a predetermined thickness in order to obtain a desired cladding rate. It is characterized by a hot rolling process in which the ingot is hot rolled. The hot rolling process includes a heating stage for heating the ingot, a holding stage following the heating stage, and a hot rolling stage for rolling the heated and held ingot. In the heating stage, the rate of temperature rise until reaching 400 ° C. is defined as 30 ° C./h or more, and the rate of temperature rise from reaching 400 ° C. to reaching the holding temperature in the holding stage is defined as 60 ° C./h or less. . In the holding stage, the holding temperature is set to 450 ° C. or more and 560 ° C. or less, and the holding time is set to 1 hour or more. Furthermore, in the hot rolling stage, the time during which the temperature of the rolled material is 400 ° C. or higher is defined as 5 minutes or longer. Thus, by defining the conditions for the hot rolling process of the first brazing material, the aluminum alloy clad material according to the present invention can be obtained between the Al—Mn-based metals defined in the present invention before and after brazing. The distribution of the compound can be obtained, and excellent corrosion resistance can be exhibited after brazing. The reason for this will be described below.

In the casting process of the first brazing filler metal, a large amount of Mn is dissolved in the ingot matrix. In this way, a large amount of Mn dissolved in the matrix is precipitated in a large amount as an Al-Mn intermetallic compound in the heating stage before the rolling stage in the hot rolling process, and these are aluminum alloy cladding before brazing. The structure of the first brazing filler metal is almost determined. As described above, in order to leave the Al—Mn intermetallic compound in a size effective for corrosion resistance after brazing, the equivalent circle diameter of the Al—Mn intermetallic compound before brazing is 0.1 μm or more. It needs to be. Here, in the heating stage before the rolling stage in the hot rolling process, a relatively small Al—Mn intermetallic compound precipitate is formed until the ingot of the first brazing material reaches 400 ° C., and 400 A relatively large Al—Mn-based intermetallic compound precipitate is formed after the temperature reaches ℃.

In the heating stage prior to the rolling stage in the hot rolling process, when the rate of temperature increase until reaching 400 ° C. is less than 30 ° C./h, a relatively small amount of Al—Mn intermetallic compound is generated as a precipitate. As a result, the target Al—Mn intermetallic compound precipitate distribution cannot be obtained. Further, when the rate of temperature increase from reaching 400 ° C. to reaching the holding temperature in the holding stage exceeds 60 ° C./h, the formation of relatively large Al—Mn intermetallic compound precipitates is small, which is the target. The precipitate distribution of the Al—Mn intermetallic compound cannot be obtained. Furthermore, when the holding temperature in the holding stage is lower than 450 ° C., the formation of a relatively large Al—Mn intermetallic compound precipitate is small, and the desired Al—Mn intermetallic compound precipitate distribution is obtained. I can't. In addition, when the holding time is less than 1 hour, a relatively large Al—Mn-based intermetallic compound precipitate is generated, and the target Al—Mn-based intermetallic compound precipitate distribution cannot be obtained.

The heating rate until reaching 400 ° C. is preferably 40 ° C./h or more, and the heating rate from reaching 400 ° C. to reaching the holding temperature in the holding stage is preferably 50 ° C./h or less. . Further, the holding temperature in the holding stage is preferably 460 ° C. or more, and the holding time is preferably 2 hours or more.

From the viewpoint of corrosion resistance, the upper limit of the heating rate until reaching 400 ° C. is not particularly limited, but exceeding 100 ° C./h is difficult in terms of the heat capacity of the ingot. Therefore, in this invention, the upper limit of this temperature increase rate shall be 100 degrees C / h. From the viewpoint of corrosion resistance, the lower limit of the rate of temperature rise from the time when reaching 400 ° C. to the time when the holding temperature in the holding stage is reached is not particularly limited. It takes a long time and the economic efficiency is significantly impaired. Therefore, in the present invention, the lower limit of the temperature increase rate is set to 20 ° C./h. When the holding temperature in the holding stage exceeds 560 ° C., the first brazing material is melted, and the clad material may not be manufactured. Therefore, the upper limit of the holding temperature is 560 ° C. In addition, from the viewpoint of corrosion resistance, the upper limit of the holding time is not particularly limited, but if it exceeds 20 hours, the economy is significantly impaired. Therefore, the upper limit of the holding time is preferably 20 hours.

In addition, the time required for the hot rolling stage is shorter than that of the heating stage and the holding stage, which are the previous stages, but during the hot rolling stage, precipitation of intermetallic compounds is promoted by the introduced strain. Therefore, in this hot rolling stage, a relatively large Al—Mn intermetallic compound precipitate is formed even if the rolling time is short. When the temperature of the first brazing filler metal is 400 ° C. or higher during the hot rolling stage is less than 5 minutes, the formation of relatively large Al—Mn intermetallic compound precipitates is small, and the target A distribution of precipitates of the Al—Mn intermetallic compound cannot be obtained.

Also, during the hot rolling stage, the time during which the temperature of the first brazing material is 400 ° C. or higher is preferably 7 minutes or longer. From the viewpoint of corrosion resistance, the upper limit of this time is not particularly limited, but it is difficult to maintain 400 ° C. or more over 30 minutes from the viewpoint of the heat capacity of the ingot. Therefore, in the present invention, the upper limit of this time is 30 minutes. In the hot rolling stage, in the temperature range where the temperature of the first brazing material is less than 400 ° C., precipitation hardly occurs, and it is not necessary to control the time required during that time.

The process that greatly affects the corrosion resistance is as described above. Below, the preferable manufacturing conditions in processes other than the hot rolling process of a 1st brazing material are demonstrated.

7-3. Casting process, hot rolling process The conditions in the casting process of the first brazing material, core material, second brazing material and sacrificial anode material are not particularly limited, but a water-cooled semi-continuous casting method is usually used. The hot rolling process in which the second brazing material and the sacrificial anode material are each hot-rolled to a predetermined thickness includes a heating and holding stage and a hot rolling stage. The heating conditions in the heating and holding stage are usually 400 to 560. The reaction is preferably carried out at a temperature of 0.5 to 10 hours, more preferably at a temperature of 420 to 540 ° C. for 0.5 to 8 hours. If it is less than 400 ° C., cracking or the like may occur during rolling because of poor plastic workability. On the other hand, when the temperature is higher than 560 ° C., the ingot may be melted during heating. In addition, if the time is less than 0.5 hours, the temperature of the ingot may not be uniform, and if it exceeds 10 hours, the economy is significantly impaired.

7-4. Homogenization process The ingot obtained by casting the core material may be subjected to a homogenization process before the hot clad rolling process. The homogenization treatment step is usually preferably performed at 450 to 620 ° C. for 1 to 24 hours, more preferably at 480 to 620 ° C. for 1 to 20 hours. If the temperature is less than 450 ° C. or the time is less than 1 hour, the homogenization effect may not be sufficient, and if it exceeds 620 ° C., the core material ingot may be melted. Further, if the time exceeds 24 hours, the economic efficiency is remarkably impaired.

7-5. Hot clad rolling process In the hot clad rolling process, the clad material is heated in the heating stage before the clad rolling stage. The heating temperature is usually preferably 400 to 560 ° C. for 0.5 to 10 hours, more preferably 420 to 540 ° C. for 0.5 to 8 hours. If the temperature is less than 400 ° C., the plastic workability is poor, and cracking may occur during clad rolling. When it exceeds 560 ° C., the ingot may be melted during heating. If the time is less than 0.5 hours, the temperature of the clad material may not be uniform, and if it exceeds 10 hours, the economic efficiency is remarkably impaired. The hot clad rolling process may be divided into a rough rolling process with a rolling reduction of 70 to 95% and a finish rolling process with a subsequent rolling reduction of 70 to 95%.

7-6. Cold rolling process, annealing process An annealing process is performed once or more in the middle of the cold rolling process and one or both after the cold rolling process for the purpose of improving formability. Specifically, (1) one or more intermediate annealings are performed during the cold rolling process, (2) the final annealing process is performed once after the cold rolling process, or (3) (1 ) And (2) are implemented. In this annealing step, the clad material is preferably held at 200 to 560 ° C. for 1 to 10 hours. When the temperature is less than 200 ° C. and the holding time is less than 1 hour, the above effect may not be sufficient. If the temperature exceeds 560 ° C., the clad material may be melted during heating, and if the holding time exceeds 10 hours, the economical efficiency is remarkably impaired. More preferable annealing conditions are a temperature of 230 to 500 ° C. and a holding time of 1 to 8 hours. In addition, although the upper limit of the frequency | count of an annealing process is not specifically limited, In order to avoid the cost increase by the increase in the number of processes, it is preferable to set it as 3 times.

8). Clad rate and plate thickness In the aluminum alloy clad material according to the present invention, the clad rate (one side) of the first brazing material, the second brazing material and the sacrificial anode material is preferably 3 to 25%. If each of these cladding ratios is less than 3%, the material to be clad is too thin, so that it may not be possible to cover the entire core material during hot clad rolling. If each of these cladding ratios exceeds 25%, warpage may occur during hot cladding rolling, and the cladding material may not be manufactured. Each of these cladding rates is more preferably 5 to 20%.

The thickness of the aluminum alloy clad material according to the present invention is not particularly limited. For example, when used as a flow path forming part of a heat exchanger described later, a thickness of 0.15 to 0.6 mm is usually used. It is done. It is also possible to use it for a header plate or the like with a plate thickness of about 0.6 to 3 mm.

9. Heat Exchanger The aluminum alloy clad material according to the present invention is suitably used as a heat exchanger member such as a flow path forming component, a header plate, and a fin material, particularly as a flow path forming component. For example, the aluminum alloy clad material is bent, and the overlapping portions at both ends thereof are brazed and joined to produce a flow path forming component for flowing a medium such as cooling water. The heat exchanger according to the present invention has a structure in which, for example, the above-mentioned flow path forming component is combined with a fin material and a header plate, and these are brazed at once.

¡The heat exchanger is assembled by disposing fin materials on the outer surface of the flow path forming component with both end portions attached to the header plate. Next, the overlapping portions on both ends of the flow path forming component, the fin material and the outer surface of the flow path forming component, and both ends of the flow path forming component and the header plate are simultaneously joined by one brazing heating. As the brazing method, a flux-free brazing method, a nocolok brazing method, or a vacuum brazing method is used, but the nocolock brazing method is preferable. The brazing is usually performed by heating at a temperature of 590 to 610 ° C. for 2 to 10 minutes, preferably at a temperature of 590 to 610 ° C. for 2 to 6 minutes. The brazed one is usually cooled at a cooling rate of 20 to 500 ° C./min.

10. Corrosive Environment The aluminum alloy clad material according to the present invention is used as at least a flow path forming component of a heat exchanger. In the following, a description will be given of a corrosive environment in which the superiority in terms of corrosion resistance can be exhibited when used as a flow path forming component of a heat exchanger.

As already mentioned, when tap water or well water is used as the cooling water flowing into the heat exchanger, chloride ions contained in it are usually at a low concentration of 1200 ppm or less. Therefore, when the temperature becomes high, the corrosion form becomes different from the pitting corrosion, and the sacrificial anticorrosive action is hardly exhibited. As a result, local corrosion may occur due to generation of aluminum oxide, aluminum hydroxide, or the like in the corroded portion, and severe corrosion may occur. The aluminum alloy clad material according to the present invention has been developed as a technical problem to suppress such a phenomenon, and has achieved this. That is, when the corrosive environment has a chloride ion concentration of 1200 ppm or less, local alkalinization easily occurs. In such a case, the superiority of the present invention is exhibited. When the corrosive environment exceeds 1200 ppm in terms of chloride ion concentration, the corrosion form remains pitting even at high temperatures, and sacrificial corrosion protection continues to act. As a result, local alkalinization hardly occurs, and the superiority of the present invention is not sufficiently exhibited. In addition, when the chloride ion concentration is less than 5 ppm, corrosion holes are not generated in the first place, so the advantage of the present invention is not particularly exhibited. The aluminum alloy clad material according to the present invention can exhibit superiority in corrosion resistance in an environment where chloride ions are 1200 ppm or less, but as a corrosive environment in which the superiority of the present invention is exhibited, the chloride ion concentration is 5 -1000 ppm is preferable, and 10-800 ppm is more preferable. As described above, in the heat exchanger according to the present invention, the aluminum alloy clad material according to the present invention is used at least for the flow path forming component. When the first brazing material is used on both surfaces of the core material, at least one surface of the first brazing material surface is used in a state where it is exposed to a solution having a chloride ion concentration of 1200 ppm or less. When the first brazing material is used on one surface of the core material, the surface of the first brazing material is used in a state where it is exposed to a solution having a chloride ion concentration of 1200 ppm or less.

Next, the present invention will be described in more detail based on examples of the present invention and comparative examples, but the present invention is not limited to these.

The first brazing alloy having the alloy composition shown in Table 1, the core alloy having the alloy composition shown in Table 2, the second brazing alloy having the alloy composition shown in Table 3, and the sacrificial anode material having the alloy composition shown in Table 4. Each alloy was cast by DC casting and each side was chamfered and finished. The thickness of the ingot after chamfering was 400 mm in all cases. For the first brazing filler metal, the second brazing filler metal, and the sacrificial anode material, calculate the clad ratio to be the desired thickness by the final thickness, and heat at 480 ° C. for 3 hours so as to obtain the required thickness at the time of matching. And then subjected to a hot rolling step to a predetermined thickness. Table 5 shows the conditions for the hot rolling process of the first brazing filler metal. The second brazing material and the sacrificial anode material were both hot-rolled under the conditions of E1 in Table 5.

Using these alloys, the first brazing material in Table 1 is combined with one side of the core alloy and nothing is combined with the other side of the core material, or the first brazing material in Table 1 or the first brazing material in Table 3 is used. Two brazing materials or sacrificial anode materials from Table 4 were combined. Tables 6 to 9 show combinations of the first brazing material, the core material, the second brazing material, and the sacrificial anode material in each sample. The cladding rates of the first brazing material, the second brazing material, and the sacrificial anode material were all 10% (one side). These laminated materials were subjected to a hot clad rolling process. That is, in the heating stage, the clad material was heated and held at 500 ° C. for 3 hours, and then the clad rolling stage was performed to produce a 2-layer or 3-layer clad material having a thickness of 3 mm. Then, after cold rolling in Table 5, (1) cold rolling → intermediate annealing → final cold rolling, (2) cold rolling → final annealing, (3) cold rolling → intermediate annealing A final clad material sample having a final thickness of 0.4 mm was prepared in any of the order of final cold rolling and final annealing. The conditions for intermediate annealing and final annealing were both 2 hours at 370 ° C., and the rolling ratio in final cold rolling after intermediate annealing was 30%. Table 5 shows the process combinations.

If no problems occur in the above manufacturing process and the roll can be rolled to a final thickness of 0.4 mm, the manufacturability is set to “◯”, and cracking occurs during casting or rolling to roll to a final thickness of 0.4 mm. If the clad material could not be manufactured due to melting during the heating stage or intermediate annealing process before the hot clad rolling process, or poor crimping during the hot clad rolling stage, It is shown in Tables 6 to 9 as “x”.

Tables 6 to 9 show the results obtained by subjecting the above clad material samples to the following evaluations. In addition, since the samples could not be manufactured for those with the productivity “x” in Tables 7 to 9, the following evaluation could not be performed.

(Evaluation of brazing)
A fin material having a thickness of 0.07 mm, a tempered H14, and an alloy component of 3003 alloy with 1.0% Zn added thereto was corrugated to obtain a heat exchanger fin material. This fin material is placed on the first brazing filler metal surface or the second brazing filler metal surface of the clad material sample, immersed in a 5% fluoride flux aqueous solution, and subjected to brazing addition heat at 600 ° C. for 3 minutes. A sample was prepared. When the fin joint rate of this mini-core sample is 95% or more and the clad material sample and the fin are not melted, the brazing property is passed (O), while (1) the fin joint rate is 95%. Less than (1) and (2), or (1) or (2) in the case where melting occurs in at least one of the clad material sample and the fin. (X).

(Measurement of tensile strength after brazing heat)
A clad material sample subjected to heat treatment at 600 ° C. for 3 minutes (corresponding to brazing additional heat) was subjected to a tensile test in accordance with JIS Z2241 under the conditions of a tensile speed of 10 mm / min and a gauge length of 50 mm. The tensile strength was read from the obtained stress-strain curve. As a result, the case where the tensile strength was 120 MPa or more was determined to be acceptable (O), and the case where the tensile strength was less than that was rejected (X).

(Measurement of density distribution of intermetallic compounds)
For the Al—Mn intermetallic compound before brazing equivalent heating, a thin film sample was cut out from the L-ST surface of the first brazing material portion of each cladding material sample by FIB, and this thin film sample was subjected to a scanning transmission electron microscope. (STEM) was investigated by mapping the Mn element distribution with an energy dispersive X-ray spectrometer (EDS). At this time, the film thickness of the observation part was measured using an electron spectroscope (EELS), and STEM observation was performed only at a position where the film thickness was 0.10 to 0.15 μm, and a visual field of 10 μm × 10 μm was obtained for each sample. The distribution of Al—Mn intermetallic compounds having a circle-equivalent diameter of 0.1 μm or more was determined by observing 5 fields of view and analyzing the mapping of Mn in each field of view.

For the Al—Mn intermetallic compound after brazing equivalent heating that has undergone heat treatment equivalent to brazing, the L-LT surface of the first brazing filler metal part is ground by polishing, and EPMA is used to determine the Mn element distribution. It was examined by performing mapping. By observing five fields of 500 μm × 500 μm for each sample and analyzing the mapping of Mn in each field, the distribution of Al—Mn intermetallic compounds having an equivalent circle diameter of 2 μm or more was obtained. Note that the brazing equivalent heating condition in the present invention is that the ultimate temperature is 600 ° C. and the holding time of 580 ° C. or more is 5 minutes.

(Evaluation of corrosion resistance by measuring corrosion depth)
The clad material sample was heated corresponding to the above brazing, then cut into 50 mm × 50 mm, and the opposite surface of the test surface was masked with resin. In each sample, the first brazing material surface was used as a test surface, and in the sample in which the sacrificial anode material was clad, the sacrificial anode material surface was also used as a test surface. The test using the second brazing filler metal surface as a test surface was not performed. The test solution when the test surface is the first brazing filler metal is a NaCl aqueous solution (pure water) having a chloride ion concentration of 3 ppm (solution A), 5 ppm (solution B), 1000 ppm (solution C), and 1200 ppm (solution D), respectively. Was used. Each test sample was immersed in these solutions, and a cycle immersion test was performed for 3 hours in 88 ° C high-temperature water for 8 hours and then at room temperature for 16 hours. (○) and the resulting product was rejected (×). When the test surface is a sacrificial anode material, it was subjected to the SWAAT test based on ASTM-G85, and the one that did not cause corrosion penetration in 1000 hours was accepted (○), and the one that caused corrosion penetration was rejected (×) It was.

In Examples 1 to 20 and 55 to 59 of the present invention, the conditions specified in the present invention were satisfied, and all of the manufacturability, brazing property, tensile strength after brazing, and corrosion resistance were acceptable.

In contrast, in Comparative Example 21, the brazing property was rejected because the Si component of the first brazing material was too small.

In Comparative Example 22, the brazing property was unacceptable because the Si component of the first brazing material was too much.

In Comparative Example 23, the brazing property was unacceptable because the Fe component of the first brazing material was too much.

In Comparative Example 24, since the Cu component of the first brazing material was too much, the corrosion resistance in the solutions A, B, and C was unacceptable.

In Comparative Example 25, since the Mn component of the first brazing material was too small, an appropriate Al—Mn intermetallic compound distribution could not be obtained after the brazing heat, and the corrosion resistance in the solutions A and B was unacceptable.

In Comparative Example 26, since the Mn component of the first brazing material was too much, cracking occurred during rolling, and the clad material could not be produced, resulting in an unacceptable productivity.

In Comparative Example 27, since the Ti, Zr, Cr, and V components of the first brazing material were too much, cracks were generated during rolling, and the clad material could not be produced, resulting in an unacceptable productivity.

In Comparative Example 28, the brazing property was unacceptable because the Na component of the first brazing material was too much.

In Comparative Example 29, the brazing property was unacceptable because the Sr component of the first brazing material was too much.

In Comparative Example 30, since the Zn component of the first brazing material was too small, the corrosion resistance in the solutions A, B, and C was unacceptable.

In Comparative Example 31, the corrosion resistance in the solutions A, B, and C was unacceptable because there was too much Zn component in the first brazing filler metal.

In Comparative Example 32, the brazing property was unacceptable because the Si component of the core material was too much.

In Comparative Example 33, since there was too much Mg component of the core material, the brazeability was unacceptable.

In Comparative Example 34, since there was too much Fe component in the core material, cracking occurred at the time of rolling, and the clad material could not be produced.

In Comparative Example 35, since there were too many Ti, Zr, Cr, and V components in the core material, cracks occurred during rolling, and the clad material could not be produced, resulting in an unacceptable manufacturability.

In Comparative Example 36, since there was too much Mn component in the core material, cracking occurred during rolling, and a brazing sheet could not be produced, resulting in an unacceptable productivity.

In Comparative Example 37, since there were too many Cu components in the core material, cracks occurred during casting, and a brazing sheet could not be produced, resulting in an unacceptable productivity.

In Comparative Example 38, there was too little Mn component in the core material, so the tensile strength after brazing was unacceptable.

In Comparative Example 39, the brazing property of the second brazing material was unacceptable because the Si component of the second brazing material was too small.

In Comparative Example 40, the brazing property of the second brazing material was unacceptable because the Si component of the second brazing material was excessive.

In Comparative Example 41, the brazing property of the second brazing material was unacceptable because the Fe component of the second brazing material was too much.

In Comparative Example 42, since there was too much Cu component in the second brazing material, cracking occurred at the time of casting, and the clad material could not be produced and the productivity was unacceptable.

In Comparative Example 43, since the Mn component of the second brazing material was too much, cracking occurred during rolling, and the clad material could not be produced, resulting in an unacceptable productivity.

In Comparative Example 44, since the Ti, Zr, Cr, and V components of the second brazing material were too much, cracking occurred during rolling, and the brazing sheet could not be produced, resulting in failure of productivity.

In Comparative Example 45, the brazing property of the second brazing material was unacceptable because the Na component of the second brazing material was too much.

In Comparative Example 46, the brazing property of the second brazing material was unacceptable because the Sr component of the second brazing material was too much.

In Comparative Example 47, the sacrificial anode material failed in the corrosion resistance because there was too much Si component in the sacrificial anode material.

In Comparative Example 48, since there were too many Fe components in the sacrificial anode material, cracking occurred at the time of rolling, and the clad material could not be produced, and the productivity was unacceptable.

In Comparative Example 49, there were too many Ti, Zr, Cr and V components in the sacrificial anode material, so that cracking occurred during rolling, and the clad material could not be produced, resulting in rejected productivity.

In Comparative Example 50, since the Zn component of the sacrificial anode material was too small, the corrosion resistance of the sacrificial anode material was unacceptable.

In Comparative Example 51, since the Zn component of the sacrificial anode material was too much, the corrosion resistance of the sacrificial anode material was unacceptable.

In Comparative Example 52, since the Ni component of the sacrificial anode material was too much, cracks occurred during rolling, and the clad material could not be produced, resulting in a failure in manufacturability.

In Comparative Example 53, since there were too many Mn components in the sacrificial anode material, cracking occurred during rolling, and the clad material could not be produced, resulting in a failure in productivity.

In Comparative Example 54, since the Mg component of the sacrificial anode material was too much, the core material and the sacrificial anode material were not pressure-bonded during the hot rolling of the clad, and the clad material could not be produced and the manufacturability was rejected.

In Comparative Example 60, since the rate of temperature increase until reaching 400 ° C. in the heating stage of the hot rolling process of the first brazing material was too slow, an appropriate Al—Mn compound distribution could not be obtained after the brazing addition heat, The corrosion resistance in solutions A and B was unacceptable.

In Comparative Example 61, since the temperature increase rate from reaching 400 ° C. in the heating stage of the hot rolling process of the first brazing filler metal to reaching the holding temperature in the holding stage was too high, an appropriate Al—Mn system after the brazing addition heat was used. The distribution of intermetallic compounds could not be obtained, and the corrosion resistance in solutions A and B was unacceptable.

In Comparative Example 62, since the holding temperature in the holding stage of the hot rolling process of the first brazing material was too low, an appropriate Al—Mn intermetallic compound distribution could not be obtained after the brazing addition heat, and in the solutions A and B Corrosion resistance was unacceptable.

In Comparative Example 63, since the holding time in the holding stage of the hot rolling process of the first brazing material was too short, an appropriate Al—Mn intermetallic compound distribution could not be obtained after the brazing addition heat, and in the solutions A and B Corrosion resistance was unacceptable.

In Comparative Example 64, since the time during which the temperature of the clad material was 400 ° C. or higher was too short during hot rolling of the first brazing material, an appropriate Al—Mn intermetallic compound distribution could not be obtained after the brazing addition heat. The corrosion resistance in solutions A and B was unacceptable.

In Comparative Example 65, since the heating temperature in the holding stage in the hot rolling process of the first brazing material was too high, the first brazing material was melted, and a brazing sheet could not be produced, resulting in a failure in productivity. there were.

The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope of the present invention. The above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

This application is based on Japanese Patent Application No. 2015-137331 filed on July 8, 2015 and Japanese Patent Application No. 2016-132727 filed on July 4, 2016. In this specification, the specifications, claims, and entire drawings of Japanese Patent Application No. 2015-137331 and Japanese Patent Application No. 2016-132727 are incorporated by reference.

The aluminum alloy clad material according to the present invention is excellent in corrosion resistance and excellent in brazing properties such as fin joint ratio and erosion resistance, and therefore is particularly suitably used as a flow path forming part of an automotive heat exchanger.

1 ... Plate 2 ... Corrugated fin

Claims

In an aluminum alloy clad material comprising an aluminum alloy core material and a first brazing material clad on one or both surfaces of the core material, the core material comprises Si: 0.05 to 1.50 mass%, Fe:. It is made of an aluminum alloy containing 05 to 2.00 mass%, Mn: 0.5 to 2.0 mass%, the balance being Al and inevitable impurities, and the first brazing material is Si: 2.5 to 7.0 mass. %, Fe: 0.05-1.20 mass%, Zn: 0.5-8.0 mass%, Mn: 0.3-2.0 mass%, and the balance is made of an aluminum alloy composed of Al and inevitable impurities. , the density of the Al-Mn intermetallic compound having a 0.1μm or more circle-equivalent diameter in the first brazing material before heating brazing 1.0 × 10 5 cells / mm 2 or more There, an aluminum alloy clad material, characterized in that the density of the Al-Mn intermetallic compound having a 2μm or more equivalent circle diameter at said first brazing material is 300 / mm 2 or more after heating the brazing.
The first brazing material is Cu: 0.05-0.60 mass%, Ti: 0.05-0.30 mass%, Zr: 0.05-0.30 mass%, Cr: 0.05-0.30 mass%. The aluminum alloy clad material according to claim 1, wherein the clad material is made of an aluminum alloy further containing one or more selected from V: 0.05 to 0.30 mass%.
The first brazing material is made of an aluminum alloy further containing one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. 2. The aluminum alloy clad material according to 2.
The core material is Mg: 0.05 to 0.50 mass%, Cu: 0.05 to 1.50 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: The aluminum alloy further comprising one or more selected from 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass%, according to any one of claims 1 to 3. Aluminum alloy clad material.
A method for producing an aluminum alloy clad material according to any one of claims 1 to 4, comprising the steps of casting the aluminum alloy for the core material and the first brazing material, respectively, A hot rolling process in which the ingot is hot-rolled to a predetermined thickness, and a cladding process in which one or both surfaces of the core ingot are clad with a first brazing material having a predetermined thickness by hot rolling to form a cladding material; One or both of a hot-clad rolling process for hot-rolling the clad material, a cold-rolling process for cold-rolling the clad material that has been hot-clad rolled, and one or both during the cold-rolling process and after the cold-rolling process At least one annealing step of annealing the clad material, and the hot rolling step of the first brazing material includes a heating step, a holding step, and a hot rolling step, and in the heating step, until reaching 400 ° C. Heating rate 30 ° C./h or more, the rate of temperature increase from reaching 400 ° C. to reaching the holding temperature in the holding stage is 60 ° C./h or less, the holding temperature in the holding stage is 450 ° C. or more and 560 ° C. or less, and the holding time Is a method for producing an aluminum alloy clad material characterized in that, during the hot rolling stage, the time during which the temperature of the first brazing material is 400 ° C. or more is 5 minutes or more.
An aluminum alloy clad material comprising an aluminum alloy core material, a first brazing material clad on one surface of the core material, and a second brazing material clad on the other surface of the core material, wherein the core material is Si : 0.05 to 1.50 mass%, Fe: 0.05 to 2.00 mass%, Mn: 0.5 to 2.0 mass%, the balance being made of an aluminum alloy composed of Al and inevitable impurities, One brazing material contains Si: 2.5-7.0 mass%, Fe: 0.05-1.20 mass%, Zn: 0.5-8.0 mass%, Mn: 0.3-2.0 mass% And the second brazing material contains Si: 2.5 to 13.0 mass%, Fe: 0.05 to 1.20 mass%, and the balance is made of an aluminum alloy composed of the balance Al and inevitable impurities. consists l and aluminum alloys consisting of unavoidable impurities, the density is 1.0 × 10 5 of Al-Mn-based intermetallic compound having a 0.1μm or more circle-equivalent diameter in the first brazing material before heating the brazing and the number / mm 2 or more, and wherein the presence density of the Al-Mn intermetallic compound having a 2μm or more equivalent circle diameter at said first brazing material after heating the brazing of 300 pieces / mm 2 or more Aluminum alloy clad material.
The first brazing material is Cu: 0.05-0.60 mass%, Ti: 0.05-0.30 mass%, Zr: 0.05-0.30 mass%, Cr: 0.05-0.30 mass%. And V: The aluminum alloy clad material according to claim 6, comprising an aluminum alloy further containing one or more selected from 0.05 to 0.30 mass%.
The first brazing material is made of an aluminum alloy further containing one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. The aluminum alloy clad material according to 7.
The core material is Mg: 0.05 to 0.50 mass%, Cu: 0.05 to 1.50 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: The aluminum alloy according to any one of claims 6 to 8, further comprising one or more selected from 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass%. Aluminum alloy clad material.
The second brazing material is Mn: 0.05 to 2.00 mass%, Cu: 0.05 to 1.50 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass%. 10. An aluminum alloy further comprising one or more selected from Cr: 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass%. The aluminum alloy clad material according to Item.
The second brazing material is made of an aluminum alloy further containing one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. The aluminum alloy clad material according to any one of 10.
A method for producing an aluminum alloy clad material according to any one of claims 6 to 11, wherein the aluminum alloy for the core material, the first brazing material and the second brazing material are respectively casted, A hot rolling step in which the ingots of the first brazing material and the second brazing material are each hot-rolled to a predetermined thickness, and a first brazing material having a predetermined thickness by hot rolling on one surface of the core material ingot. The other surface is clad with a second brazing material having a predetermined thickness by hot rolling to make a clad material, the hot clad rolling step for hot rolling the clad material, and the hot clad rolled clad A cold rolling step of cold rolling the material, and one or more annealing steps of annealing the clad material in one or both of the cold rolling step and after the cold rolling step, the first brazing material Hot rolling process Including a heating stage, a holding stage, and a hot rolling stage. In the heating stage, the rate of temperature increase until reaching 400 ° C. is 30 ° C./h or more, and from reaching 400 ° C. to reaching the holding temperature in the holding stage. The heating rate is 60 ° C./h or less, the holding temperature in the holding stage is 450 ° C. or more and 560 ° C. or less, the holding time is 1 hour or more, and the temperature of the first brazing material is 400 ° C. in the hot rolling stage. The method for producing an aluminum alloy clad material characterized in that the above time is 5 minutes or more.
An aluminum alloy clad material comprising an aluminum alloy core material, a first brazing material clad on one surface of the core material, and a sacrificial anode material clad on the other surface of the core material, wherein the core material is Si: 0.05 to 1.50 mass%, Fe: 0.05 to 2.00 mass%, Mn: 0.5 to 2.0 mass%, the balance being made of an aluminum alloy composed of Al and inevitable impurities, The brazing material contains Si: 2.5 to 7.0 mass%, Fe: 0.05 to 1.20 mass%, Zn: 0.5 to 8.0 mass%, Mn: 0.3 to 2.0 mass%. The sacrificial anode material is made of Zn: 0.5 to 8.0 mass%, Si: 0.05 to 1.50 mass%, Fe: 0.05. An Al—Mn intermetallic compound containing 2.00 mass%, comprising an aluminum alloy composed of the balance Al and inevitable impurities, and having a circle-equivalent diameter of 0.1 μm or more in the first brazing material before heat of brazing. The abundance density is 1.0 × 10 5 pieces / mm 2 or more, and the existence density of Al—Mn-based intermetallic compounds having an equivalent circle diameter of 2 μm or more in the first brazing material after the brazing addition heat is 300 pieces / An aluminum alloy clad material having a thickness of 2 mm or more.
The first brazing material is Cu: 0.05-0.60 mass%, Ti: 0.05-0.30 mass%, Zr: 0.05-0.30 mass%, Cr: 0.05-0.30 mass%. The aluminum alloy clad material according to claim 13, wherein the clad material is made of an aluminum alloy further containing one or more selected from V: 0.05 to 0.30 mass%.
The first brazing material is made of an aluminum alloy further containing one or two selected from Na: 0.001 to 0.050 mass% and Sr: 0.001 to 0.050 mass%. 14. The aluminum alloy clad material according to 14.
The core material is Mg: 0.05 to 0.50 mass%, Cu: 0.05 to 1.50 mass%, Ti: 0.05 to 0.30 mass%, Zr: 0.05 to 0.30 mass%, Cr: The aluminum alloy further comprising one or more selected from 0.05 to 0.30 mass% and V: 0.05 to 0.30 mass%, according to any one of claims 13 to 15. Aluminum alloy clad material.
The sacrificial anode material is Ni: 0.05 to 2.00 mass%, Mn: 0.05 to 2.00 mass%, Mg: 0.05 to 3.00 mass%, Ti: 0.05 to 0.30 mass%, It consists of an aluminum alloy further containing one or more selected from Zr: 0.05 to 0.30 mass%, Cr: 0.05 to 0.30 mass%, and V: 0.05 to 0.30 mass%. The aluminum alloy clad material according to any one of claims 13 to 16.
A method for producing an aluminum alloy clad material according to any one of claims 13 to 17, wherein the aluminum alloy for the core material, the first brazing material and the sacrificial anode material are cast, respectively. A hot rolling process in which the ingots of the first brazing material and the sacrificial anode material are each hot-rolled to a predetermined thickness, and the first brazing material having a predetermined thickness by hot rolling on one surface of the core material ingot, A clad process in which a sacrificial anode material having a predetermined thickness by hot rolling is clad on the surface to form a clad material, a hot clad rolling process in which the clad material is hot rolled, and a hot clad rolled clad material are cooled. Including a cold rolling step for cold rolling, and one or more annealing steps for annealing the clad material in one or both of the cold rolling step and in the middle of the cold rolling step. Rolling mill Includes a heating stage, a holding stage, and a hot rolling stage. In the heating stage, the rate of temperature rise until reaching 400 ° C. is 30 ° C./h or more, and from reaching 400 ° C. to reaching the holding temperature in the holding stage. The heating rate is 60 ° C./h or less, the holding temperature in the holding stage is 450 ° C. or more and 560 ° C. or less, the holding time is 1 hour or more, and the temperature of the first brazing material is 400 in the hot rolling stage. A method for producing an aluminum alloy clad material characterized in that the time at which the temperature is not lower than 5 ° C is 5 minutes or longer.
A heat exchanger using the aluminum alloy cladding material according to any one of claims 1 to 4 for at least a flow path forming component, wherein at least one surface of the first brazing material surface has a chloride ion concentration. A heat exchanger which is exposed to a solution of 1200 ppm or less.
A heat exchanger using the aluminum alloy clad material according to any one of claims 6 to 11 and 13 to 17 for at least a flow path forming component, wherein the first brazing material surface has a chloride ion concentration of 1200 ppm. A heat exchanger which is exposed to the following solution.