JP5101812B2 - High corrosion resistance tube for heat exchanger, heat exchanger and method for producing the same - Google Patents

Description

  The present invention relates to a high corrosion resistance tube for a heat exchanger and a heat exchanger, which can reduce the corrosion depth of the tube and has excellent corrosion resistance.

  In this specification, the term “aluminum” is used to include aluminum and its alloys. Further, in this specification, the expression “Al” means aluminum (a metal simple substance).

As an aluminum heat exchanger, a structure in which a plurality of flat tubes are laminated in the thickness direction with fins interposed therebetween, and a hollow header is connected to both ends of these tubes in a known manner is known. The flat tube and the fin are joined and integrated by brazing. If such an aluminum heat exchanger continues to be used as it is, pitting corrosion will occur in the tube, and this will reach the inner surface of the tube and penetrate it, and the function as a heat exchanger will be impaired. In order to prevent such pitting corrosion, it is conventional to apply Zn to the surface of the tube, diffuse Zn by heat treatment during brazing, form a Zn diffusion layer, and perform sacrificial corrosion protection by the presence of this Zn diffusion layer. (For example, see Patent Documents 1 and 2).
JP-A-4-15496 JP-A-9-137245

  In the techniques described in Patent Documents 1 and 2 above, a sprayed layer is formed by spraying an Al—Zn alloy on the surface of the tube core material. When corrosion progresses, not only this sprayed layer but also the tube is formed. The Zn diffusion layer formed by diffusing Zn in the core material also becomes corrosive, and there is a problem that the corrosive allowance (corrosion depth) is large. Therefore, it has been required to further improve the corrosion resistance of the tube by reducing the corrosion margin in the tube for heat exchanger.

  The present applicant has previously filed a patent application regarding a high corrosion resistance tube for a heat exchanger that can reduce the corrosion depth of the tube (Japanese Patent Application No. 2004-170659).

  The present invention has been made in view of such technical background, and is a heat exchanger tube and heat exchanger that can reduce the corrosion depth (corrosion allowance) of the tube and maintain excellent corrosion resistance over a long period of time. And its manufacturing method.

  In order to achieve the above object, the present invention provides the following means.

[1] In a heat exchanger tube in which a sacrificial corrosion layer is provided on the surface of an aluminum tube core,
The tube core material includes Mn: 1.0 to 1.7% by mass, Cu: more than 0.2 and 0.2% by mass or less, and the balance is made of aluminum composed of Al and inevitable impurities.
The sacrificial corrosion layer contains Zn: 0.1 to 5 mass%, Fe: more than 0 to 0.2 mass% or less, Si: more than 0 to 0.2 mass% or less, the balance being Al and inevitable A high corrosion resistance tube for a heat exchanger, characterized by being made of aluminum made of impurities.

  [2] The highly corrosion-resistant tube for heat exchangers according to item 1 above, wherein the Fe content in the tube core material exceeds 0 and is 0.6% by mass or less.

  [3] The high corrosion resistance tube for a heat exchanger according to the above item 1 or 2, wherein the Si content in the tube core material is more than 0 and 0.3 mass% or less.

  [4] The high corrosion-resistant tube for a heat exchanger according to any one of items 1 to 3, wherein the sacrificial corrosion layer has a thickness of 10 to 80 μm.

  [5] The high corrosion resistance tube for a heat exchanger according to any one of the above items 1 to 4, wherein the sacrificial corrosion layer has a surface roughness (Ry) of 20 to 50 μm.

  [6] The high corrosion-resistant tube for a heat exchanger according to any one of items 1 to 5, wherein the sacrificial corrosion layer is formed by spraying an Al—Zn alloy.

  [7] The high corrosion resistance tube for a heat exchanger according to any one of the above items 1 to 5, wherein the sacrificial corrosion layer is formed by spraying an aluminum wire and an Al—Zn alloy wire.

  [8] The high corrosion-resistant tube for a heat exchanger according to the above item 6 or 7, wherein the thermal spraying is arc thermal spraying.

  [9] A plurality of tubes each having a sacrificial corrosion layer provided on the surface of an aluminum tube core are laminated with fins interposed therebetween, and the tubes and the fins are joined together by brazing. In the heat exchanger in which a hollow header is connected in communication with both ends of the tube, the high corrosion resistant tube for a heat exchanger according to any one of the preceding items 1 to 8 is used as the tube. A heat exchanger characterized by

  [10] Mn: 1.0 to 1.7% by mass, Cu: more than 0 and not more than 0.2% by mass, with the balance Zn on the surface of the aluminum tube core made of Al and inevitable impurities: A sacrificial corrosion layer containing 0.1 to 5% by mass, Fe: 0 to 0.2% by mass, Si: 0 to 0.2% by mass, and the balance consisting of Al and inevitable impurities is formed. A process of manufacturing an aluminum tube, a process of assembling fins to the tube, a process of applying flux in the assembled state and drying, and heating the tube and fins at a predetermined temperature after the drying A heat exchanger manufacturing method comprising the step of attaching and joining.

[11] The method for manufacturing a heat exchanger as recited in the aforementioned Item 10, wherein the flux application amount is set to 5 to 20 g / m ² .

  In the invention of [1], a steep potential gradient can be formed in the vicinity of the interface between the sacrificial corrosion layer and the tube core material, thereby preventing the progress of corrosion at the boundary region between the sacrificial corrosion layer and the tube core material. (Corrosion does not reach the Zn diffusion layer in the tube core) and the corrosion depth (corrosion allowance) can be reduced, that is, the corrosion depth is very shallow, so a tube with excellent corrosion resistance is provided. it can. Furthermore, the Cu content in the aluminum tube core is more than 0 and 0.2% by mass or less, the Zn content in the sacrificial corrosion layer is 0.1 to 5% by mass, and the Fe content is more than 0. Since the content of Si is specified to be 0.2% by mass or less and the Si content is more than 0 and 0.2% by mass or less, the sacrificial corrosion layer is excellent in corrosion resistance and has a long life as a sacrificial corrosion layer. Excellent corrosion resistance can be maintained.

  In the invention of [2], since the Fe content in the tube core material exceeds 0 and is 0.6% by mass or less, the corrosion resistance of the tube core material can be further improved.

  In the invention of [3], since the Si content in the tube core material is more than 0 and 0.3% by mass or less, the corrosion resistance of the tube core material can be further improved.

  In the invention of [4], since the thickness of the sacrificial corrosion layer is defined as 10 to 80 μm, the duration of the anticorrosion effect can be further extended.

  In the invention of [5], since the surface roughness (Ry) of the sacrificial corrosion layer is 20 to 50 μm, the corrosion resistance of the tube can be further improved, and the tube and the fin can be brazed in a better state. it can.

  In the invention of [6], since the sacrificial corrosion layer is formed by spraying an Al—Zn alloy, it is possible to provide a high-quality tube at a low cost with high production efficiency.

  In the invention of [7], since the sacrificial corrosion layer is formed by spraying an aluminum wire and an Al—Zn alloy wire, a pseudo alloy layer of Al and Al—Zn is formed in the sacrificial corrosion layer. Further, the presence of Al spray particles around the Al—Zn spray particles enables cathodic protection to work in a very small range, and a longer long-term corrosion resistance can be obtained.

  In the invention of [8], since the arc spraying is adopted as the spraying method, the productivity can be further improved.

  In the invention of [9], a steep potential gradient can be formed in the vicinity of the interface between the sacrificial corrosion layer and the tube core material, thereby preventing the progress of corrosion at the boundary region between the sacrificial corrosion layer and the tube core material. Since the corrosion depth (corrosion allowance) of the tube can be reduced, a heat exchanger with excellent corrosion resistance can be provided. Furthermore, the Cu content in the aluminum tube core is more than 0 and 0.2% by mass or less, the Zn content in the sacrificial corrosion layer is 0.1 to 5% by mass, and the Fe content is more than 0. The sacrificial corrosion layer is excellent in corrosion resistance and has a long life as a sacrificial corrosion layer because it is defined as 0.2 mass% or less and the Si content is more than 0 and 0.2 mass% or less. Can provide high quality heat exchanger with excellent quality.

  In the invention of [10], it is possible to manufacture a high-quality heat exchanger having excellent durability performance provided with a tube having excellent corrosion resistance.

  In the invention of [11], a heat exchanger provided with a tube having further excellent corrosion resistance can be manufactured.

  FIG. 1 is a front view showing a heat exchanger according to an embodiment of the present invention. This heat exchanger (1) is used as a condenser and evaporator for a refrigeration cycle in a car air conditioner for an automobile, and constitutes a multiflow type heat exchanger.

  That is, this heat exchanger (1) is composed of a plurality of flat tubes along a horizontal direction as a heat exchange conduit between a pair of left and right hollow headers (4) (4) along a vertical direction arranged in parallel. (2) are arranged in parallel with both ends communicating with both hollow headers (4) and (4), and corrugated fins (3) between these tubes (2) and outside the outermost tube. ) And a side plate (10) is arranged outside the outermost corrugated fin (3).

  As shown in FIGS. 2 and 3, the tube (2) is made of a hollow extruded material of aluminum, and the inside thereof is divided into a plurality of refrigerant flow paths (2b) by partition walls (2a) continuously extending in the length direction. It is divided. This tube (2) consists of a tube core material (6) made of a hollow extruded material of aluminum and a sacrificial corrosion layer (7) formed on the surface of the tube core material (6). The corrugated fin (3) is made of an aluminum brazing material clad with a brazing material. Then, the tube (2) and the fin (3) are heated in the furnace in a state where the tubes (2) and the fins (3) are alternately laminated and assembled (temporarily assembled), and the tubes (2) and the fins (3) are brazed. Are brazed and joined.

  In the present invention, the sacrificial corrosion layer (7) does not mean an Al-Zn layer formed by diffusing Zn into the aluminum tube core material, but on the aluminum tube core material. Means an applied Al—Zn alloy layer (this alloy layer corrodes preferentially over the tube core material during corrosion) and is particularly suitable as such a sacrificial corrosion layer (7) Is a surface sprayed layer newly formed by spraying on the surface of an aluminum tube core. Also in the present invention, after brazing, there is a Zn diffusion layer in the vicinity of the surface sprayed layer in the tube core material by the diffusion of Zn from the surface sprayed layer. In the present invention, the Zn diffusion layer is not defined as a “sacrificial corrosion layer” (not a “sacrificial corrosion layer”). Conventionally, generally, the Zn diffusion layer in the tube core material is often called a sacrificial corrosion layer.

  In the heat exchanger (1), the tube core (6) contains Mn: 1.0 to 1.7% by mass, Cu: 0 to 0.2% by mass or less, with the balance being Al and It is made of aluminum made of inevitable impurities. The sacrificial corrosion layer (7) contains Zn: 0.1 to 5% by mass, Fe: 0 to 0.2% by mass, Si: 0 to 0.2% by mass, The balance is made of aluminum and inevitable impurities.

  In the present invention, the Mn content in the aluminum tube core (6) needs to be set to 1.0 to 1.7% by mass. Mn in the tube core material (6) made of aluminum is a metal element necessary for providing a steep potential gradient in the vicinity of the interface between the tube core material (6) and the sacrificial corrosion layer (7). If the amount is less than 0.0% by mass, a steep potential gradient cannot be imparted, and if the Mn content exceeds 1.7% by mass, a coarse intermetallic compound is produced, resulting in poor workability. Especially, it is preferable that Mn content in the said aluminum tube core material (6) is set to 1.3-1.65 mass%.

  Moreover, Cu content in the said aluminum tube core material (6) needs to be set to 0.2 mass% or less exceeding 0. If the Cu content exceeds 0.2% by mass, Cu diffuses from the tube core material (6) to the sacrificial corrosion layer (7) and lowers the function of the sacrificial corrosion layer (7). Especially, it is preferable that Cu content in the said aluminum tube core material (6) is set to 0.18 mass% or less exceeding 0.

  The Fe content in the aluminum tube core (6) is preferably set to more than 0 and not more than 0.6% by mass. Fe in the aluminum tube core (6) is a metal element that affects corrosion resistance, and the corrosion resistance of the tube core (6) is further improved by defining the Fe content to 0.6 mass% or less. Can do. Especially, it is more preferable that the Fe content in the aluminum tube core (6) is set to more than 0 and 0.45% by mass or less.

  Moreover, it is preferable that Si content in the said aluminum tube core material (6) is set to 0.3 mass% or less exceeding 0. Si in the aluminum tube core (6) is a metal element that affects the corrosion resistance, and the corrosion resistance of the tube core (6) is further improved by defining the Si content to 0.3% by mass or less. Can do. Especially, it is more preferable that Si content in the said aluminum tube core material (6) is set to 0.2 mass% or less exceeding 0.

  Other impurity elements in the aluminum tube core (6) may contain impurity elements such as Mg, Pb, Bi, Ni, etc., but the content of impurity elements such as Mg, Pb, Bi, Ni, etc. Is preferably set to more than 0 and 0.01% by mass or less.

  In this invention, Zn content in the said sacrificial corrosion layer (7) needs to be set to 0.1-5 mass%. Zn in the sacrificial corrosion layer (7) is a metal element necessary for surface corrosion of the sacrificial corrosion layer (7). When the Zn content is less than 0.1% by mass, pitting corrosion occurs in the tube. If the content exceeds 5% by mass, the sacrificial corrosion layer (7) corrodes early and long-term corrosion protection cannot be maintained. Especially, it is preferable that Zn content in the said sacrificial corrosion layer (7) is set to 0.5-4 mass%.

Further, the Fe content in the sacrificial corrosion layer (7) needs to be set to more than 0 and not more than 0.2% by mass, and the Si content must be set to more than 0 and not more than 0.2% by mass. It is impurities other than Zn in the sacrificial corrosion layer (7) that greatly affect the corrosion resistance of the sacrificial corrosion layer (7). In particular, since Fe and Si are metal elements that are most easily mixed as impurities in ordinary Al materials, the contents of these Fe and Si must be defined. When the Fe content exceeds 0.2% by mass, the corrosion starts as Al ₃ Fe, and the corrosion resistance is lowered. When the Si content exceeds 0.2% by mass, Si is tube core material by brazing heat treatment. The effect as a sacrificial corrosion layer (giving a steep potential gradient in the vicinity of the interface between the tube core material and the sacrificial corrosion layer) because it diffuses into (6) and forms an intermetallic compound with Mn of the tube core material (6). It becomes difficult to obtain. The Fe content in the sacrificial corrosion layer (7) is preferably set to more than 0 and 0.15% by mass or less, and the Si content in the sacrificial corrosion layer (7) is more than 0 to 0.1%. It is preferable to set the mass% or less. Other impurity elements in the sacrificial corrosion layer (7) may contain, for example, impurity elements such as Cu, Cr, Mg, Pb, Bi, etc., but impurities such as Cu, Cr, Mg, Pb, Bi, etc. The content is preferably set to more than 0 and 0.01% by mass or less.

  The thickness of the sacrificial corrosion layer (7) is preferably set to 10 to 80 μm. When the thickness is 10 μm or more, the duration of the anticorrosion effect can be further extended, and when the thickness is 80 μm or less, the sacrificial corrosion layer (7) can be reliably prevented from being cracked or peeled off.

  The surface roughness (Ry) of the surface (7a) of the sacrificial corrosion layer (7) is preferably 20 to 50 μm. When Ry is 20 μm or more, the melt flux at the time of brazing sufficiently soaks into the irregularities on the surface of the tube (2), so that the corrosion resistance can be further improved, and when Ry is 50 μm or less, the brazing material becomes a tube. (2) The tube (2) and the fin (3) can be brazed in a better state without being absorbed by the surface irregularities. Among these, the surface roughness (Ry) of the sacrificial corrosion layer (7) is more preferably 25 to 45 μm. The surface roughness (Ry) is Ry (maximum roughness after roughness curve conversion) defined in JIS B0601-1994.

  Although the formation method of the said sacrificial corrosion layer (7) is not specifically limited, For example, a clad material, thermal spraying, plating, vapor deposition, sputtering etc. are mentioned. Among these, the sacrificial corrosion layer (7) is preferably formed by thermal spraying, and in this case, there is an advantage that productivity can be improved. When thermal spraying is employed, it is preferable to form a sacrificial corrosion layer (7) by spraying an Al—Zn alloy. In this case, the preferred content of Zn in the Al—Zn alloy is 4 to 12% by mass. is there. More preferably, thermal spraying of an aluminum wire and an Al—Zn alloy wire is more preferable. In this case, the suitable content of Zn in the Al—Zn alloy is in the range of 4 to 20% by mass.

  When the Al—Zn alloy is sprayed, the degree of Zn evaporation varies depending on the spraying equipment, spraying conditions, and the like, so the alloy composition of the sacrificial corrosion layer (7) varies depending on the spraying equipment and spraying conditions. Therefore, in order to form the predetermined sacrificial corrosion layer (7), for example, in flame spraying and arc spraying, arc spraying has a higher spraying temperature and Zn tends to evaporate. In this case, in the Al—Zn alloy, It is better to increase the Zn content.

  The thermal spraying method is not particularly limited, and examples thereof include arc spraying and flame spraying. Further, the thermal spraying may be performed while scanning the spray gun with respect to the tube, or may be sprayed with a fixed spray gun while feeding the coiled aluminum material. Alternatively, the tube may be extruded from the extruder and sprayed continuously immediately after that. In this case, there is an advantage that the production efficiency can be improved. The spraying conditions are not particularly limited. The thermal spraying is preferably performed in a non-oxidizing atmosphere such as a nitrogen atmosphere, an argon atmosphere, or an atmosphere having a low oxygen concentration in order to prevent oxidation of the thermal spray layer formed by thermal spraying (oxidation of the sacrificial corrosion layer). Of these, thermal spraying is preferably performed in a nitrogen atmosphere or an argon atmosphere.

  When spraying by arc spraying, it is preferable to arc spray aluminum wire and Al—Zn alloy wire. In this case, a pseudo alloy layer of Al and Al—Zn is formed, and Al—Zn spray particles are surrounded by Al. Due to the presence of the spray particles, cathodic protection works in a very small range, and a longer long-term corrosion resistance can be obtained.

  The heat exchanger (1) of this invention is manufactured as follows, for example. That is, first, the surface of the aluminum tube core (6) containing Mn: 1.0 to 1.7% by mass, Cu: more than 0.2 and 0.2% by mass or less, with the balance being Al and inevitable impurities. In addition, Zn: 0.1 to 5% by mass, Fe: more than 0 to 0.2% by mass or less, Si: more than 0 to 0.2% by mass or less, the balance being Al and inevitable impurities A corrosive layer (7) is formed to produce an aluminum tube (2). Next, the tube (2) and the fin (3) are brazed and joined by heating at a predetermined temperature in a furnace with the fin (3) assembled to the tube (2) (see FIG. 2). Can be manufactured.

  A method for forming the sacrificial corrosion layer (7) is not particularly limited, and examples thereof include cladding materials, thermal spraying, plating, vapor deposition, and sputtering.

  In the above manufacturing method, the tube (2) and the fin (3) may be brazed by any method. For example, using fins made of an aluminum brazing material clad with brazing material, the tube and fins may be brazed and joined by heating and melting of the brazing material, or after flux is applied to the joint and dried, Brazing and joining may be performed by heating in an inert gas atmosphere such as nitrogen.

The flux application amount is preferably set to 5 to ²⁰ g / m ² . Conventionally, it has been generally considered that a coating amount of flux of about 1 to 3 g / m ² is sufficient. On the other hand, in the present invention, since the flux melted at the time of brazing penetrates into the sacrificial corrosion layer (7), the flux exists in the sacrificial corrosion layer (7), and therefore the flux does not become a site of corrosion. , Inhibit the progress of corrosion. It is preferable to set the flux coating amount to 5 to 20 g / m ² in order to sufficiently enhance the effect of suppressing the progress of such corrosion, that is, the flux coating amount is set to 5 to ²⁰ g / m ² . When the flux application amount is 5 g / m ² or more, the effect of suppressing the progress of corrosion can be enhanced more sufficiently, and when it is 20 g / m ² or less, unnecessary application waste can be eliminated and the cost can be reduced. Can also be reduced. Especially, it is especially preferable to set the application amount of the flux to 7 to 13 g / m ² .

  The heating temperature (heating temperature during brazing) is preferably set in the range of 550 to 620 ° C. By setting to such a range, the heat exchanger of this invention can be manufactured efficiently and stably with high quality.

  When brazing in the furnace, other heat exchanger components such as headers (4) (4), side plates (10) (10), etc. are temporarily assembled together, and the entire heat exchanger is brazed simultaneously. It is recommended to make it. Thus, these other components may be made of a brazing material, or a brazing material may be interposed only at the joint between the members.

  Next, specific examples of the present invention will be described.

<Examples 1 to 23, Comparative Examples 1 to 7>
Using an aluminum alloy (containing the metals shown in Tables 1 and 3), tube width: 16 mm, tube thickness (height): 3 mm, wall thickness: 0.5 mm, number of hollow parts: 4 flat tubes (core material) ) Was extruded. And, on the flat surfaces of the front and back of the flat tube (core material) (6) continuously extruded from the extruder, Al—Zn is applied from a thermal spray nozzle (arc sprayer) disposed above and below at a position immediately after the extrusion. A sacrificial corrosion layer (7) was formed by spraying an alloy (see Tables 1 and 3 for detailed metal composition) to obtain a tube (2). In Examples 19 to 23, an Al wire and an Al—Zn alloy wire were arc sprayed.

  Next, the flat tube (2) and corrugated fins (3) made of an aluminum brazing material clad with a brazing material are alternately laminated (see FIG. 2), and the core portion of the heat exchanger is assembled (temporarily assembled). ), The headers (4) and (4), the side plates (10) and (10), etc. were also temporarily assembled together. Next, a suspension obtained by suspending a fluoride-based flux in water is applied to the core part, dried, and then brazed by heating at 600 ° C. for 10 minutes in a nitrogen gas atmosphere furnace. A multi-flow type heat exchanger as shown in FIG. 1 was manufactured.

  The structure of the tube of the heat exchanger thus manufactured (the metal species and content of the tube core material, the metal species and content of the sacrificial corrosion layer, the surface roughness Ry of the sacrificial corrosion layer, the thickness of the sacrificial corrosion layer) Etc.) are shown in Tables 1-4.

  The corrosion resistance of the tube was examined for each heat exchanger obtained as described above. These results are shown in Tables 2 and 4. The evaluation method is as follows.

<Corrosion test>
A CCT test according to ASTM D1141 was performed. A CCT test was carried out for 400 hours with one cycle of 0.5 hour spraying with acetic acid aqueous solution and 1.5 hours wet. As a result, the maximum corrosion depth is approximately the same as the thickness of the sacrificial corrosion layer (up to the thickness of the sacrificial corrosion layer + 10 μm). Is approximately the same as the thickness of the sacrificial corrosion layer (up to the thickness of the sacrificial corrosion layer + 10 μm), and “○” indicates that the corrosion resistance was good in this corrosion test. The maximum corrosion depth is greater than the thickness of the sacrificial corrosion layer. Large (thickness of sacrificial corrosion layer + thickness of 10 μm or more) and smaller than the thickness of the Zn diffusion layer is “△”, and pitting corrosion occurs and the corrosion depth is 200 μm or more as “×”. did.

  As is clear from Tables 1 to 4, the heat exchanger tubes and heat exchangers of Examples 1 to 23 of the present invention were excellent in corrosion resistance.

  On the other hand, in Comparative Examples 1 and 3 to 7 that depart from the specified range of the present invention, the corrosion resistance was inferior. In Comparative Example 2, since the Mn content in the tube core material exceeded the specified range of the present invention, the extrudability when extruding the tube core material was poor and could not be extruded in a good state. .

It is a front view which shows the heat exchanger which concerns on one Embodiment of this invention. It is a perspective view which shows the joining state of a tube and a fin. It is sectional drawing of the tube for heat exchangers.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heat exchanger 2 ... Tube 3 ... Fin 4 ... Header 6 ... Tube core material 7 ... Sacrificial corrosion layer 7a ... Surface

Claims (9)

In a heat exchanger tube in which a sacrificial corrosion layer is provided on the surface of an aluminum tube core,
The tube core material includes Mn: 1.0 to 1.7% by mass, Cu: more than 0.2 and 0.2% by mass or less, and the balance is made of aluminum composed of Al and inevitable impurities.
The sacrificial corrosion layer contains Zn: 0.1 to 5 mass%, Fe: more than 0 to 0.2 mass% or less, Si: more than 0 to 0.2 mass% or less, the balance being Al and inevitable Consists of aluminum made of impurities,
A high corrosion resistance tube for a heat exchanger, wherein the sacrificial corrosion layer has a surface roughness (Ry) of 20 to 50 μm. In a heat exchanger tube in which a sacrificial corrosion layer is provided on the surface of an aluminum tube core,
The tube core material includes Mn: 1.0 to 1.7% by mass, Cu: more than 0.2 and 0.2% by mass or less, and the balance is made of aluminum composed of Al and inevitable impurities.
The sacrificial corrosion layer contains Zn: 0.1 to 5 mass%, Fe: more than 0 to 0.2 mass% or less, Si: more than 0 to 0.2 mass% or less, the balance being Al and inevitable Consists of aluminum made of impurities,
The sacrificial corrosion layer is formed by spraying an Al—Zn alloy having a Zn content of 4 to 12% by mass ,
A high corrosion resistance tube for a heat exchanger, wherein the sacrificial corrosion layer has a surface roughness (Ry) of 20 to 50 μm . In a heat exchanger tube in which a sacrificial corrosion layer is provided on the surface of an aluminum tube core,
The tube core material includes Mn: 1.0 to 1.7% by mass, Cu: more than 0.2 and 0.2% by mass or less, and the balance is made of aluminum composed of Al and inevitable impurities.
The sacrificial corrosion layer contains Zn: 0.1 to 5 mass%, Fe: more than 0 to 0.2 mass% or less, Si: more than 0 to 0.2 mass% or less, the balance being Al and inevitable Consists of aluminum made of impurities,
The sacrificial corrosion layer is formed by spraying an aluminum wire and an Al-Zn alloy wire having a Zn content of 4 to 20% by mass ,
A high corrosion resistance tube for a heat exchanger, wherein the sacrificial corrosion layer has a surface roughness (Ry) of 20 to 50 μm . The high corrosion-resistant tube for a heat exchanger according to claim 2 or 3 , wherein the thermal spraying is arc spraying. A plurality of tubes each having a sacrificial corrosion layer provided on the surface of an aluminum tube core are laminated with fins interposed therebetween, and the tubes and the fins are joined and integrated by brazing. In addition, in a heat exchanger in which a hollow header is connected to both ends of the tube,
The heat exchanger according to any one of claims 1 to 4 , wherein the tube is a high corrosion resistance tube for a heat exchanger. Mn: 1.0 to 1.7% by mass, Cu: more than 0 and not more than 0.2% by mass, with the balance of aluminum and inevitable impurities on the surface of the aluminum tube core, Zn: 0.1 ~ 5% by mass, Fe: more than 0 and 0.2% by mass or less, Si: more than 0 and 0.2% by mass or less, the balance is made of Al and inevitable impurities, and the surface roughness (Ry) is Forming an aluminum tube by forming a sacrificial corrosion layer of 20-50 μm;
Assembling fins to the tube;
Applying and drying flux in the assembled state;
A method of manufacturing a heat exchanger, comprising the step of brazing and joining the tube and the fin by heating at a predetermined temperature after the drying. Mn: 1.0 to 1.7% by mass, Cu: more than 0 and not more than 0.2% by mass, with the balance of Zn on the surface of the aluminum tube core made of Al and inevitable impurities. By spraying 4 to 12% by mass of an Al—Zn alloy, Zn: 0.1 to 5% by mass, Fe: 0 to more than 0.2% by mass, Si: 0 to more than 0.2% by mass It contained the following, Ri Do the balance is Al and inevitable impurities, a step of fabricating the aluminum tube surface roughness (Ry) is caused to form a sacrificial corrosion layer Ru 20~50μm der,
Assembling fins to the tube;
Applying and drying flux in the assembled state;
A method of manufacturing a heat exchanger, comprising the step of brazing and joining the tube and the fin by heating at a predetermined temperature after the drying. Mn: 1.0 to 1.7% by mass, Cu: more than 0 and not more than 0.2% by mass, and the balance of aluminum wire and Zn on the surface of the aluminum tube core made of Al and inevitable impurities By spraying an Al—Zn alloy wire having a content of 4 to 20% by mass, Zn: 0.1 to 5% by mass, Fe: 0 to more than 0.2% by mass, Si: 0 to more than 0 containing .2% by mass or less, Ri Do the balance is Al and inevitable impurities, a step of fabricating the aluminum tube surface roughness (Ry) is caused to form a sacrificial corrosion layer Ru 20~50μm der,
Assembling fins to the tube;
Applying and drying flux in the assembled state;
A method of manufacturing a heat exchanger, comprising the step of brazing and joining the tube and the fin by heating at a predetermined temperature after the drying. The method for manufacturing a heat exchanger as claimed in any one of claims 6-8 to set the coating amount of the flux 5 to 20 g / m ^2.

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