JP2022186330A - Method for welding dissimilar metal materials and method for producing heat exchanger - Google Patents

Abstract

To provide a method for welding dissimilar metals that can prevent the occurrence of voids during welding and can also prevent the weld strength from decreasing and a method for producing a heat exchanger.SOLUTION: A method for welding dissimilar metal materials includes the step for using a sintered wire 3, which is a sintered mixture of flux powder 31 and aluminum alloy powder 32, as an electrode, and melting the sintered wire 3 and the aluminum material 1 by arc welding, while welding the molten aluminum material 1 to unmolten another metal material 2 different from the aluminum material 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for welding dissimilar metal materials and a method for manufacturing a heat exchanger, and more particularly to a method for welding dissimilar metal materials and a method for manufacturing a heat exchanger for welding an aluminum material and another metal material.

Conventionally, when dissimilar metal materials are welded, it is known that a fragile intermetallic compound is formed at the interface between the dissimilar metal materials. Therefore, there is known a method of welding dissimilar metal materials in which welding is performed so as not to form a brittle intermetallic compound (see, for example, Patent Document 1).

The above Patent Document 1 discloses a method of welding an aluminum material to a steel material while melting the flux-containing wire and the aluminum material by arc welding using a flux-cored wire coated with an aluminum material using a flux as a core material. Have been described.

In Patent Literature 1, the use of flux spreads over the interface between the steel material and the aluminum material during welding, thereby suppressing the formation of intermetallic compounds. In Patent Document 1, an aluminum material and a steel material are joined by a bead formed by melting the aluminum material and the flux-cored wire.

Japanese Patent No. 4037109

However, in a flux-filled wire coated with a coating material such as that disclosed in Patent Document 1, seams are formed in the coating material, so moisture enters the interior through the seams and the flux absorbs moisture. Therefore, there is a problem that the moisture absorbed by the heat during welding evaporates and voids are generated in the bead, resulting in a decrease in welding strength.

The present invention has been made to solve the above problems, and one object of the present invention is to suppress the occurrence of voids during welding and reduce the weld strength. It is an object of the present invention to provide a method for welding dissimilar metals and a method for manufacturing a heat exchanger capable of suppressing .

In order to solve the above problems, the inventor of the present invention has made intensive studies on wires used for welding, and as a result, has found the following configuration capable of achieving the above objects. In the method for welding dissimilar metal materials according to the first aspect of the present invention, a sintered wire obtained by sintering a mixture of flux powder and aluminum alloy powder is used as an electrode, and the sintered wire and the aluminum material are welded by arc welding. It includes a step of welding the molten aluminum material to another unmelted metal material of a different type from the aluminum material while being melted.

In the method for welding dissimilar metal materials according to the first aspect of the present invention, as described above, a sintered wire obtained by sintering a mixture of flux powder and aluminum alloy powder is used as an electrode. As a result, unlike the case of using a welding wire coated with aluminum foil with flux as a core material, a seam is not formed on the surface, so moisture does not enter the welding wire and the flux absorbs moisture. can be suppressed. As a result, it is possible to suppress the formation of voids in the molten bead of the aluminum material and the sintered wire due to the evaporation of moisture absorbed by the flux during welding. In addition, since the ratio of the flux powder mixed with the aluminum alloy powder can be easily adjusted, the formation of intermetallic compounds can be suppressed and the generation of voids can be suppressed by adjusting the ratio of the flux powder. . As a result, it is possible to suppress the generation of voids during welding and to suppress the decrease in weld strength.

In the method for welding dissimilar metal materials according to the first aspect, preferably, in the welding step, the content of a low-melting element, which is an element having a melting point lower than that of aluminum including magnesium, zinc, phosphorus, potassium, and sulfur, is A sintered wire with a content of 0.1% by mass or less is used as an electrode. Here, if low-melting elements containing magnesium, zinc, phosphorus, potassium, and sulfur, which have a melting point lower than that of aluminum, are unevenly distributed in the bead, the low-melting-point elements at the interface between the aluminum and the low-melting-point elements will be affected by the shrinkage stress during bead solidification. separated from the aluminum and cracked. Therefore, by reducing the amount of the low-melting-point element, it is possible to suppress the occurrence of cracks in the beads. As a result, the welding strength between the aluminum material and the other metal material can be further improved.

In this case, preferably, in the welding step, both of the magnesium contents are 0.1% by mass or less, and the magnesium content of the aluminum material is lower than the magnesium content of the sintered wire. Welding is performed using a binding wire and an aluminum material. With this configuration, the amount of magnesium contained in the beads can be reduced, so cracks in the beads can be further suppressed. In addition, since the aluminum material melts more than the sintered wire, the amount of magnesium contained in the bead can be effectively reduced by making the amount of magnesium contained in the aluminum material smaller than that in the sintered wire. .

In the method for welding dissimilar metal materials according to the first aspect, preferably, in the welding step, a sintered wire coated with a coating material composed of an aluminum alloy separately from the aluminum alloy powder is used as the electrode. According to this structure, the sintered wire is covered with the covering material, so that the outer diameter of the sintered wire can be made uniform with high accuracy.

In the method for welding dissimilar metal materials according to the first aspect, preferably, the sintered wire is formed to have a substantially constant outer diameter in the longitudinal direction, and the step of welding includes feeding the sintered wire by a feeding device. while arc welding the aluminum material and other metal materials. With this configuration, the outer diameter of the sintered wire automatically sent out by the sending device can be made uniform, so that the amount of sintered wire used for welding can be made constant. It is possible to suppress the occurrence of welding unevenness caused by different wire sizes.

In the method for welding dissimilar metal materials according to the first aspect, preferably, in the welding step, the aluminum material is welded to another metal material made of steel material having a higher strength than the aluminum material. According to this structure, the mechanical strength of the aluminum material can be improved by welding the aluminum material to the steel material having high strength.

In this case, preferably, the welding step welds the aluminum material to another metal material made of stainless steel. With this configuration, the mechanical strength of the aluminum material can be improved by welding the aluminum material to the stainless steel material.

In the method for welding dissimilar metal materials according to the first aspect, preferably, the aluminum material is the heat exchanger main body, and the other metal material is a reinforcing member made of a metal material having a higher strength than the aluminum material. Yes, and the welding step comprises arc welding the heat exchanger body and the reinforcing member using the sintered wire as an electrode. According to this structure, since the heat exchanger main body is made of an aluminum material, the heat conductivity can be increased, so that heat can be efficiently exchanged between the refrigerant and the object to be cooled. . Moreover, the heat exchanger main body can be reinforced by welding a reinforcing member made of a metal material having a higher strength than an aluminum material to the heat exchanger main body.

A method for manufacturing a heat exchanger according to the second aspect of the present invention uses a sintered wire obtained by sintering a mixture of flux powder and aluminum alloy powder as an electrode, and arc welding the sintered wire and the aluminum material. While melting the constructed heat exchanger body, the molten heat exchanger body is welded to an unmelted reinforcing member made of a metal material having a higher strength than an aluminum material.

In the method for manufacturing a heat exchanger according to the second aspect, as described above, a sintered wire obtained by sintering a mixture of flux powder and aluminum alloy powder is used as the electrode. As a result, unlike the case of using a welding wire coated with aluminum foil with flux as a core material, a seam is not formed on the surface, so moisture does not enter the welding wire and the flux absorbs moisture. can be suppressed. As a result, it is possible to suppress the formation of voids in the molten bead of the aluminum material and the sintered wire due to the evaporation of moisture absorbed by the flux during welding. In addition, since the ratio of the flux powder mixed with the aluminum alloy powder can be easily adjusted, the formation of intermetallic compounds can be suppressed and the generation of voids can be suppressed by adjusting the ratio of the flux powder. . As a result, it is possible to suppress the generation of voids during welding, and to suppress the decrease in the welding strength between the heat exchanger main body and the reinforcing member.

ADVANTAGE OF THE INVENTION According to the present invention, a method for welding dissimilar metals and a method for manufacturing a heat exchanger are provided, which are capable of suppressing the generation of voids during welding and suppressing a decrease in weld strength. be able to.

It is a figure for demonstrating the welding method of dissimilar metals of this invention. 1 is a schematic diagram of a sintered wire according to a first embodiment of the present invention; FIG. It is a figure for demonstrating the manufacturing method of a sintered wire. It is a figure which shows an example of a heat exchanger. 1 is a block diagram showing a dual refrigeration cycle; FIG. It is a figure for demonstrating the structure of a heat exchanger. Figure 5 is a cross-sectional view along line 100-100 of Figure 4; FIG. 2 is a diagram of a bead generated by welding using a conventional flux-cored wire and a bead generated by welding using a sintered wire of the present invention; FIG. 4 is a schematic diagram of a sintered wire according to a second embodiment of the present invention;

[First embodiment]
A first embodiment embodying the present invention will be described below with reference to the drawings.

As shown in FIG. 1, in the welding method of the present invention, an aluminum material 1 and another metal material 2 are welded by arc welding using a sintered wire 3 as an electrode.

In the first embodiment, an aluminum material 1 and another metal material 2 are welded using MIG welding (metal inert gas welding). Specifically, an arc is generated between the electrode (sintered wire 3 ) and the aluminum material 1 to be welded while supplying an inert gas, which is a shielding gas, from the welding torch 4 . Then, while the sintered wire 3 and the aluminum material 1 are melted by using the generated arc as a heat source, the melted aluminum material 1 is welded to the other metal material 2 that is not melted. A bead 1a is formed by the molten aluminum material 1 and the molten sintered wire 3, and the aluminum material 1 and another metal material 2 are welded. In MIG welding, an electrode (sintered wire 3) is fed from a welding torch 4 with a constant size and welded. The welding torch 4 is an example of the "sending device" described in the claims.

The aluminum material 1 is made of pure aluminum or an aluminum alloy. A1000 series (for example, A1100, JIS standard) is used as pure aluminum. As the aluminum alloy, for example, A6063 (JIS standard) is used.

The aluminum material 1 preferably contains little or no low-melting elements, such as magnesium, zinc, phosphorus, potassium, and sulfur, which are elements having a melting point lower than that of aluminum. The content of the low melting point element is preferably 0.1% by mass or less. In particular, the magnesium content is preferably 0.1% by mass or less, more preferably 0.001% by mass. Moreover, the content of magnesium contained in the aluminum material 1 is preferably smaller than the content of magnesium contained in the sintered wire 3 .

The other metal material 2 is composed of a metal different from aluminum having greater strength than the aluminum material 1 . Further, the other metal material 2 is composed of a metal having a higher melting point than the aluminum material 1, and is not melted by heat during arc welding. The other metal material 2 is made of steel material. As the steel material, for example, a stainless steel material such as SUS304 (JIS standard) is used.

As shown in FIG. 2, the sintered wire 3 is cylindrical. The sintered wire 3 is formed to have a substantially constant outer diameter R in the longitudinal direction. The outer diameter R of the sintered wire 3 is designed according to the size of the diameter of the delivery portion of the welding torch 4 .

As shown in FIG. 3, the sintered wire 3 is manufactured by mixing flux powder 31 and aluminum alloy powder 32 and sintering the mixture. In FIG. 3, the flux powder 31 is indicated by black circles, and the aluminum alloy powder 32 is indicated by white circles. The flux powder 31 exists dispersedly throughout.

The sintered wire 3 is formed by mixing and sintering the flux powder 31 and the aluminum alloy powder 32, followed by extrusion and wire drawing. The sintered flux powder 31 and aluminum alloy powder 32 are formed into a cylindrical sintered wire 3 by extrusion. At this time, since the outer diameter of the extruded sintered wire 3 may vary, the outer diameter R ( 2) is molded to have a substantially constant size. In addition, the outer diameter R becomes smaller by performing wire drawing.

The flux powder 31 is composed of, for example, a halide such as potassium fluoride powder, or aluminum oxide powder. The flux powder 31 preferably contains little or no low-melting elements having a melting point lower than that of aluminum, such as magnesium, zinc, phosphorus, potassium, and sulfur. This is because if the low-melting point element is unevenly distributed in the bead, the low-melting point element separates from the aluminum at the interface between the aluminum and the low-melting point element due to shrinkage stress during solidification of the bead, resulting in cracking. In particular, the magnesium content is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.001% by mass or less. The content of flux powder 31 in sintered wire 3 may be, for example, 5% or more and less than 15%.

A case where the welding method of the present invention is used for the manufacturing method of the heat exchanger 5 will be described.

(Structure of heat exchanger)
As shown in FIG. 4, the heat exchanger 5 has an annular shape. The heat exchanger 5 is used in a two-system compression-expansion binary refrigeration cycle.

As shown in FIG. 5, in the two-system compression-expansion binary refrigeration cycle, the first refrigerant circulates in the first stage and the second refrigerant circulates in the second stage. In the dual refrigeration cycle, the first and second stages each include an evaporator, a compressor, a condenser, and an expansion section, and instead of the first-stage evaporator and the second-stage condenser, one A heat exchanger 5 is provided that combines a first-stage evaporator and a second-stage condenser.

In the first stage of the refrigeration cycle, the vapor-phase first refrigerant is compressed in the first compressor 6 to change into a high-temperature, high-pressure refrigerant. The first compressor 6 is, for example, a compressor, and compresses gas-phase refrigerant by movement of a piston.

The first refrigerant, which has become high temperature and high pressure in the first compressor 6, is supplied to the first condenser 7, exchanges heat with air or liquid, is cooled, and changes to a high pressure liquid phase refrigerant. do. Then, the first refrigerant becomes a low-pressure, low-temperature gas-liquid two-phase refrigerant when passing through the first expansion portion 8 . Then, the gas-liquid two-phase first refrigerant is supplied to the heat exchanger 5 . In the heat exchanger 5, the first refrigerant exchanges heat with the second refrigerant, and changes from gas-liquid two-phase to gas phase. After that, the gas-phase refrigerant is supplied to the first compressor 6 .

In the second stage of the refrigeration cycle, the second refrigerant exchanges heat with the first refrigerant in the heat exchanger 5, is condensed, and changes into a high-pressure liquid-phase refrigerant. Then, the second refrigerant becomes a low-pressure, low-temperature gas-liquid two-phase refrigerant when passing through the second expansion portion 9 . After being supplied to the evaporator 10, the second refrigerant exchanges heat with the air or liquid to be cooled, and changes from the gas-liquid two-phase state to the gas phase. The gas-phase refrigerant is supplied to the second compressor 11 and compressed to change into a high-temperature, high-pressure liquid-phase refrigerant. The second refrigerant having a high temperature and a high pressure in the second compressor 11 is supplied to the heat exchanger 5 .

As shown in FIG. 6, the heat exchanger 5 includes a heat exchanger body 50 and a reinforcing member 52 made of stainless steel. The heat exchanger body 50 includes a housing 51, a lid member 55, and flat tube microchannels 56 (see FIG. 7). The heat exchanger 5 is provided with a first flow path 51 a and a second flow path 51 b inside a housing 51 . The first coolant flows from the bottom (Z2 side) to the top (Z1 side) in the first flow path 51a. Also, the second coolant flows through the second flow path 51b from above (Z1 side) to below (Z2 side). The lid member 55 is an example of the "heat exchanger main body" in the claims.

The housing 51 is made of steel. A first header 53 and a second header 54 are attached to the housing 51 . The first header 53 is provided on the upper side of the housing 51 , and the second coolant is supplied to the housing 51 via the first header 53 . The second header 54 is provided on the lower side of the housing 51 , and the second refrigerant flows from the housing 51 to the evaporator 10 via the second header 54 .

The lid member 55 is provided on the upper side (Z1 side) inside the housing 51 and is configured to separate the first header 53 and the housing 51 from each other. A space through which the first refrigerant flows and a space through which the second refrigerant flows are separated by the lid member 55 . Further, the lid member 55 is provided on the lower side (Z2 side) inside the housing 51 and is configured to separate the second header 54 and the housing 51 from each other. Therefore, the space through which the first refrigerant flows and the space through which the second refrigerant flows are separated by the lid member 55 . The lid member 55 is made of the aluminum material 1 .

As shown in FIG. 7, the second flow path 51b (see FIG. 6) is formed by a microchannel 56 of a flat tube. A flat-tube microchannel 56 is inserted into the lid member 55 on the first header 53 (see FIG. 6) side, and the second fluid flowing from above is supplied to the flat-tube microchannel 56 . A flat tube microchannel 56 is inserted into the cover member 55 on the second header 54 side to collect the second refrigerant flowing from above and distribute it to the evaporator 10 . The microchannel 56 is constructed from an aluminum material 1 .

Based on FIG. 6, heat exchange between the first refrigerant and the second refrigerant will be described. In FIG. 6 , the flow of the first refrigerant is indicated by solid line arrows, and the flow of the second refrigerant is indicated by broken line arrows. The first coolant flows into the housing 51 through an inlet 57 provided on the lower side surface of the housing 51 . Then, it flows upward along the outer peripheral surface of the second flow path 51b. Then, the high-temperature second refrigerant that has flowed in from above through the first header 53 flows through the inside of the second flow path 51b, so that heat is exchanged on the outer peripheral surface of the second flow path 51b. The refrigerant evaporates, and the first refrigerant flows to the first compressor 6 from the outflow port 58 provided on the upper side surface of the housing 51 . Meanwhile, the second refrigerant is cooled and flows from the second header 54 to the evaporator 10 .

The reinforcing member 52 is welded to the lower surface of the lid member 55 on the first header 53 side and the upper surface of the lid member 55 on the second header 54 side. The reinforcing member 52 is also welded to the housing 51 . The reinforcing member 52 has an annular shape.

(Method for manufacturing heat exchanger)
An arc is generated between the sintered wire 3 and the lid member 55 while the lid member 55 and the reinforcing member 52 are in contact with each other, and the lid member 55 is melted and welded to the reinforcing member 52 . After welding the housing 51 and the reinforcing member 52 together, the first header 53 and the second header 54 are attached to the housing 51 .

(Comparison between conventional flux-cored wire and sintered wire of the present application)
As shown in FIG. 8, a bead when welding is performed using a conventional flux-cored wire with a core made of flux as an electrode, and a bead when welding is performed using the sintered wire 3 of the present invention as an electrode of the bead was observed. As shown in FIG. 8(A), when the conventional flux-cored wire was used, voids were generated, but when the sintered wire 3 was used as shown in FIG. I couldn't. From the above, the inventors have found that the use of the sintered wire 3 as an electrode can suppress the generation of voids.

(Effect of the first embodiment)
The following effects can be obtained in the first embodiment.

In the first embodiment, the method for welding dissimilar metal materials is to use, as an electrode, a sintered wire 3 obtained by sintering a mixture of flux powder 31 and aluminum alloy powder 32, and arc welding the sintered wire 3 and aluminum. A step of welding the molten aluminum material 1 to another unmelted metal material 2 of a different kind from the aluminum material 1 while melting the material 1 is provided. As a result, unlike the case of using a welding wire coated with aluminum foil with flux as a core material, a seam is not formed on the surface, so moisture does not enter the welding wire and the flux absorbs moisture. can be suppressed. As a result, it is possible to suppress the generation of voids in the molten bead of the aluminum material 1 and the sintered wire 3 due to the evaporation of moisture absorbed by the flux during welding. In addition, since the ratio of the flux powder 31 mixed with the aluminum alloy powder 32 can be easily adjusted, by adjusting the ratio of the flux powder 31, the formation of intermetallic compounds is suppressed and the generation of voids is suppressed. be able to. As a result, it is possible to suppress the generation of voids during welding and to suppress the decrease in weld strength.

In addition, in the first embodiment, the welding step includes sintering the content of the low-melting element, which is an element having a melting point lower than that of aluminum including magnesium, zinc, phosphorus, potassium, and sulfur, of 0.1% by mass or less. The connection wire 3 is used as an electrode. Here, if low-melting elements containing magnesium, zinc, phosphorus, potassium, and sulfur, which have a melting point lower than that of aluminum, are unevenly distributed in the beads 1a, shrinkage stress during solidification of the beads 1a causes the interface between the aluminum and the low-melting elements to The low melting point element separates from the aluminum and cracks form. Therefore, by reducing the amount of the low melting point element, it is possible to suppress the occurrence of cracks in the bead 1a. As a result, the welding strength between the aluminum material 1 and the other metal material 2 can be further improved.

Further, in the first embodiment, in the welding process, the content of magnesium is 0.1% by mass or less, and the content of magnesium in the aluminum material 1 is higher than the content of magnesium in the sintered wire 3. Welding is performed using a sintered wire 3 and an aluminum material 1, which are also small. As a result, the amount of magnesium contained in the beads 1a can be reduced, so that the occurrence of cracks in the beads 1a can be further suppressed. In addition, since the aluminum material 1 has a larger melting amount than the sintered wire 3, by making the amount of magnesium contained in the aluminum material 1 smaller than that of the sintered wire 3, the amount of magnesium contained in the bead 1a can be effectively reduced. can be reduced to

In the first embodiment, the sintered wire 3 is shaped to have a substantially constant outer diameter R in the longitudinal direction. Arc welding is performed with another metal material 2 . As a result, the outer diameter R of the sintered wire 3 automatically sent out by the welding torch 4 can be made uniform, so that the amount of the sintered wire 3 used for welding can be made constant. It is possible to suppress the occurrence of welding unevenness caused by the wires 3 having different sizes.

Moreover, in 1st Embodiment, the process to weld welds the aluminum material 1 to the other metal material 2 comprised by the steel material whose intensity|strength is larger than the aluminum material 1. As shown in FIG. Thereby, the mechanical strength of the aluminum material 1 can be improved by welding the aluminum material 1 to a steel material with high strength.

Moreover, in 1st Embodiment, the process to weld welds the aluminum material 1 to the other metal material 2 comprised by a stainless steel material. Thus, by welding the aluminum material 1 to the stainless steel material, the mechanical strength of the aluminum material 1 can be improved.

Further, in the first embodiment, the aluminum material 1 is the cover member 55, and the other metal material 2 is the reinforcing member 52 made of a metal material having a higher strength than the aluminum material 1, and the welding process is and arc welding the cover member 55 and the reinforcing member 52 using the sintered wire 3 as an electrode. Since the lid member 55 is made of the aluminum material 1, the heat conductivity can be increased, and heat exchange can be efficiently performed between the refrigerant and the object to be cooled. Further, by welding the reinforcement member 52 made of a metal material having a higher strength than the aluminum material 1 to the lid member 55, the lid member 55 can be reinforced.

Further, in the first embodiment, the method for manufacturing the heat exchanger 5 uses the sintered wire 3 obtained by sintering a mixture of the flux powder 31 and the aluminum alloy powder 32 as an electrode, and arc welding the sintered wire 3. 3 and the aluminum material 1 are melted, the melted lid member 55 is welded to the unmelted reinforcing member 52 composed of a metal material having greater strength than the aluminum material 1 . As a result, unlike the case of using a welding wire coated with aluminum foil with flux as a core material, a seam is not formed on the surface, so moisture does not enter the welding wire and the flux absorbs moisture. can be suppressed. As a result, it is possible to suppress the generation of voids in the molten bead of the aluminum material 1 and the sintered wire 3 due to the evaporation of moisture absorbed by the flux during welding. In addition, since the ratio of the flux powder 31 mixed with the aluminum alloy powder 32 can be easily adjusted, by adjusting the ratio of the flux powder 31, the formation of intermetallic compounds is suppressed and the generation of voids is suppressed. be able to. As a result, it is possible to suppress the occurrence of voids during welding, and it is possible to suppress a decrease in the welding strength between the lid member 55 and the reinforcing member 52 .

[Second embodiment]
Next, a second embodiment will be described with reference to FIG. In this second embodiment, a covering material 30 is provided on the sintered wire 3 of the first embodiment. In addition, in the figure, the same code|symbol is attached|subjected to the structure similar to the said 1st Embodiment.

As shown in FIG. 9, the sintered wire 3 according to the second embodiment of the present invention is coated with a covering material 30 made of an aluminum alloy different from the aluminum alloy powder 32 contained in the sintered wire 3 . Coating material 30 preferably contains little or no low-melting elements, elements that have a lower melting point than aluminum, including magnesium, zinc, phosphorus, potassium, and sulfur. The content of the low melting point element is preferably 0.1% by mass or less. In particular, the content of magnesium is preferably 0.1% by mass or less.

Other configurations of the second embodiment are the same as those of the first embodiment.

(Effect of Second Embodiment)
In the second embodiment, as in the first embodiment, the method of welding dissimilar metal materials uses, as an electrode, a sintered wire 3 obtained by sintering a mixture of flux powder 31 and aluminum alloy powder 32. It includes a step of welding the molten aluminum material 1 to another unmelted metal material 2 of a different type from the aluminum material 1 while melting the sintered wire 3 and the aluminum material 1 by arc welding. As a result, unlike the case of using a welding wire coated with aluminum foil with flux as a core material, a seam is not formed on the surface, so moisture does not enter the welding wire and the flux absorbs moisture. can be suppressed. As a result, it is possible to suppress the generation of voids in the molten bead of the aluminum material 1 and the sintered wire 3 due to the evaporation of moisture absorbed by the flux during welding. In addition, since the ratio of the flux powder 31 mixed with the aluminum alloy powder 32 can be easily adjusted, by adjusting the ratio of the flux powder 31, the formation of intermetallic compounds is suppressed and the generation of voids is suppressed. be able to. As a result, it is possible to suppress the generation of voids during welding and to suppress the decrease in weld strength.

In addition, in the second embodiment, as described above, the welding step uses the sintered wire 3 coated with the coating material 30 made of an aluminum alloy separately from the aluminum alloy powder 32 as the electrode. As a result, since the sintered wire 3 is covered with the covering material 30, the outer diameter R of the sintered wire 3 can be adjusted with high accuracy.

Other effects of the second embodiment are the same as those of the first embodiment.

[Modification]
The embodiments disclosed this time should be considered illustrative and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications (modifications) within the scope and meaning equivalent to the scope of the claims.

For example, in the above-described first and second embodiments, the example in which the other metal material is made of steel is shown, but the present invention is not limited to this. According to the invention, the other metallic material may consist of silver, copper, titanium, chromium or nickel.

Also, in the above-described first and second embodiments, an example is shown in which the other metal material is stainless steel material, but the present invention is not limited to this. In the present invention, the other metal material may be a steel material that does not contain chromium and nickel, unlike stainless steel material.

Moreover, although the example which welds an aluminum material and another metal material using MIG welding was shown in the said 1st Embodiment and 2nd Embodiment, this invention is not limited to this. In the present invention, TIG welding (Tungsten inert gas welding) or laser welding may be used to weld the aluminum material and other metal materials.

Further, in the above-described first and second embodiments, an example is shown in which the cover member is welded to the reinforcing member, but the present invention is not limited to this. In the present invention, for example, when the housing is made of aluminum, it may be used to weld the housing and the reinforcing member.

Further, in the above-described first and second embodiments, an example is shown in which the cover member is welded to the reinforcing member, but the present invention is not limited to this. The present invention may be used, for example, when welding a reinforcing member to a housing of a cooling device.

1 aluminum material 2 other metal material 3 sintered wire 4 welding torch (delivering device)
5 Heat Exchanger 30 Coating Material 31 Flux Powder 32 Aluminum Alloy Powder 52 Reinforcement Member 55 Lid Member (Heat Exchange Body)

Claims (9)

A sintered wire obtained by mixing and sintering a flux powder and an aluminum alloy powder is used as an electrode, and the sintered wire and the aluminum material are melted by arc welding, and the melted aluminum material is different from the aluminum material. A method of welding dissimilar metal materials comprising welding to other unmelted metal materials of the type. In the welding step, the sintered wire having a content of 0.1% by mass or less of a low-melting element, which is an element having a melting point lower than that of aluminum containing magnesium, zinc, phosphorus, potassium, and sulfur, is used as an electrode. The method for welding dissimilar metal materials according to claim 1. In the welding step, the sintered wire has a magnesium content of 0.1% by mass or less, and the magnesium content of the aluminum material is lower than the magnesium content of the sintered wire. 3. The method for welding dissimilar metal materials according to claim 2, wherein the welding is performed using the aluminum material and the aluminum material. The dissimilar metal material according to any one of claims 1 to 3, wherein the welding step uses, as an electrode, the sintered wire coated with a coating material made of an aluminum alloy separately from the aluminum alloy powder. welding method. The sintered wire is molded to have a substantially constant outer diameter in the longitudinal direction,
The method for welding dissimilar metal materials according to any one of claims 1 to 4, wherein the welding step arc-welds the aluminum material and the other metal material while feeding the sintered wire by a feeding device. . The dissimilar metal material according to any one of claims 1 to 5, wherein the welding step welds the aluminum material to the other metal material made of steel material having a higher strength than the aluminum material. welding method. 7. The method of welding dissimilar metal materials according to claim 6, wherein said welding step welds said aluminum material to said other metal material made of stainless steel. The aluminum material is a heat exchanger body,
The other metal material is a reinforcing member made of a metal material having a higher strength than the aluminum material,
The dissimilar metals according to any one of claims 1 to 7, wherein the welding step comprises arc welding the heat exchanger body and the reinforcing member using the sintered wire as an electrode. Material welding method. A sintered wire obtained by mixing and sintering a flux powder and an aluminum alloy powder is used as an electrode, and the heat exchanger main body composed of the sintered wire and the aluminum material is melted by arc welding, and the melted said A method of manufacturing a heat exchanger, wherein the heat exchanger main body is welded to a reinforcing member that is not melted and is made of a metal material having a higher strength than the aluminum material.

Images