Method for manufacturing dissimilar material bonded structure, and dissimilar material bonded structure

Abstract

Provided is a method for manufacturing a dissimilar material bonded structure, which does not require a special adjustment of welding conditions and is capable of suppressing the occurrence of pores. A method for producing a dissimilar material bonded structure in which an aluminum alloy plate (11) and a steel plate (21) are bonded, the method comprising: a step in which a low-temperature sprayed coating (12) is formed on at least a part of the surface of the aluminum alloy plate (11) by low-temperature spraying of a metal powder containing at least one selected from the group consisting of pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy, and a step in which the low-temperature sprayed coating (12) is formed on at least a part of the surface of the aluminum alloy plate (11) by low-temperature spraying of the metal powder containing at least one selected from the group consisting of pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy; a step for superimposing the aluminum alloy plate (11) and the steel plate (21) such that the low-temperature sprayed coating (12) faces the steel plate (21); and a step for performing laser welding from the opposite side of the surface of the steel plate (21) that faces the aluminum alloy plate (11). The metal powder is powdered from a molten metal in a vacuum or inert gas atmosphere.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a dissimilar material joined structure and a dissimilar material joined structure. Background Art

[0002] In recent years, for the purpose of weight reduction of vehicle structures, there has been an increasing demand for dissimilar material joined structures in which lightweight aluminum or aluminum alloy materials (hereinafter sometimes simply referred to as aluminum alloy materials) are joined to steel materials. As a method for joining dissimilar materials to each other, there are various methods. For example, there is a method in which a cold spray coating (hereinafter sometimes referred to as a low-temperature spray coating or a CS (Cold Spray) coating) is formed in advance on the surface of an aluminum alloy material, and the steel and the coating are laser welded.

[0003] However, according to the above joining method, pores may be generated in the welded metal due to the gas in the CS coating, and these pores cause a decrease in the joint strength.

[0004] Therefore, for example, in Patent Document 1, a method for manufacturing a dissimilar material joined structure capable of manufacturing a dissimilar material joined structure with fewer pores and excellent joint strength is proposed. The method for manufacturing a dissimilar material joined structure includes: a step of forming a low-temperature spray coating on at least a part of the surface of an aluminum alloy material by low-temperature spraying of a specified metal powder; a step of laminating the aluminum alloy material and the steel material so that the low-temperature spray coating faces the steel material; and a step of joining the aluminum alloy material and the steel material by laser welding from the steel material side. Moreover, the joining step is performed under welding conditions in which a molten part is formed in the steel material, the low-temperature spray coating, and the aluminum alloy material.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-30308 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, since the manufacturing method described in Patent Document 1 performs the joining step under welding conditions in which even the aluminum alloy material is melted, it is necessary to appropriately control the conditions during laser welding, and the welding conditions for melting the aluminum alloy material as the base material are limited. In addition, in the case where the aluminum alloy material as the base material is a die-cast material containing many pores, there is a concern that pores may be generated due to melting a large amount of the aluminum alloy material. Therefore, there is a demand for the development of a method for manufacturing a dissimilar material joined structure that can suppress the generation of pores even when the allowable range of welding conditions is set wide.

[0010] The present invention has been made in view of such problems, and an object thereof is to provide a method for manufacturing a dissimilar material joined structure that does not require adjustment of special welding conditions and can suppress the generation of pores, and a dissimilar material joined structure obtained by this joining method and having excellent joining strength.

[0011] Means for solving the problems

[0012] The above object of the present invention is achieved by the following structure (1) regarding the method for manufacturing a dissimilar material joined structure.

[0013] (1) A method for manufacturing a dissimilar material joined structure, which is a method for manufacturing a dissimilar material joined structure in which a non-ferrous metal member is joined to a steel material, characterized by comprising: a step of forming a low-temperature sprayed coating on at least a part of the surface of the non-ferrous metal member by low-temperature spraying of metal powder, the metal powder containing at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy; a step of laminating the non-ferrous metal member and the steel material such that the low-temperature sprayed coating faces the steel material; and a step of performing laser welding from the opposite side of the surface of the steel material facing the non-ferrous metal member; the metal powder being metal powder atomized from molten metal in a vacuum or an inert gas atmosphere.

[0014] In addition, a preferred embodiment of the present invention regarding the method for manufacturing a dissimilar material joined structure relates to the following structures (2) and (3).

[0015] (2) The method for manufacturing a dissimilar material joined structure according to (1), characterized in that the metal powder is metal powder manufactured by a method selected from a gas atomization method, a disk atomization method, a plasma atomization method, and a plasma rotating electrode method.

[0016] (3) The method for manufacturing a dissimilar material joined structure according to (1) or (2), characterized in that the hydrogen content in the metal powder is 16 ppm or less.

[0017] In addition, the above object of the present invention is achieved by the following structure (4) or (5) regarding the dissimilar material joined structure.

[0018] (4) A dissimilar material joint structure is a dissimilar material joint structure formed by joining a non-ferrous metal component and a steel material. It is characterized in that on at least a part of the surface of the non-ferrous metal component, a low-temperature sprayed coating film composed of metal powder is formed. The metal powder contains at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy. The non-ferrous metal component and the steel material are laminated in such a manner that the low-temperature sprayed coating film faces the steel material. From the surface of the steel material on the side opposite to the non-ferrous metal component side, a welding metal for joining the steel material and the low-temperature sprayed coating film is formed. The hydrogen content in the low-temperature sprayed coating film is 16 ppm or less.

[0019] (5) A dissimilar material joint structure is a dissimilar material joint structure formed by joining a non-ferrous metal component and a steel material. It is characterized in that on at least a part of the surface of the non-ferrous metal component, a low-temperature sprayed coating film composed of metal powder is formed. The metal powder contains at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy. The non-ferrous metal component and the steel material are laminated in such a manner that the low-temperature sprayed coating film faces the steel material. From the surface of the steel material on the side opposite to the non-ferrous metal component side, a welding metal for joining the steel material and the low-temperature sprayed coating film is formed. The low-temperature sprayed coating film is composed of at least one powder selected from gas atomized powder, disk atomized powder, plasma atomized powder, and powder manufactured by the plasma rotating electrode method.

[0020] Advantages of the Invention

[0021] According to the present invention, it is possible to provide a method for manufacturing a dissimilar material joint structure that does not require adjustment of special welding conditions and can suppress the generation of pores. In addition, according to the present invention, it is possible to provide a dissimilar material joint structure obtained by this joining method and having excellent joining strength. Description of the Drawings

[0022] Figure 1A It is a cross-sectional view showing the process of forming a low-temperature sprayed coating film in the method for manufacturing a dissimilar material joint structure according to an embodiment of the present invention.

[0023] Figure 1B It is a cross-sectional view showing a dissimilar material joint structure manufactured by the method for manufacturing a dissimilar material joint structure according to an embodiment of the present invention.

[0024] Figure 2 It is a photograph substituting for the drawing showing gas atomized powder manufactured by the gas atomization method.

[0025] Figure 3 It is a photograph substituting for the drawing showing water atomized powder manufactured by the water atomization method.

[0026] Figure 4 It is a diagram showing the joint part of a dissimilar material joint structure manufactured by the methods of the inventive example and the comparative example. Detailed Description of the Invention

[0027] Hereinafter, embodiments of the dissimilar material joint structure and its manufacturing method according to the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited to the embodiments described below, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

[0028] The present inventor has found that when joining dissimilar materials of non-ferrous metal parts and steel, by using metal powder with a lower hydrogen content manufactured by a manufacturing method different from that of conventional metal powder as a material for forming a low-temperature sprayed coating, the generation of pores can be suppressed.

[0029] Hereinafter, with reference to the drawings, the manufacturing method of the dissimilar material joint structure and the dissimilar material joint structure according to the embodiments of the present invention will be described in detail.

[0030] [Manufacturing Method of Dissimilar Material Joint Structure]

[0031] Figure 1A It is a cross-sectional view showing the process of forming a low-temperature sprayed coating in the manufacturing method of the dissimilar material joint structure according to the embodiment of the present invention. Figure 1B It is a cross-sectional view showing a dissimilar material joint structure manufactured by the manufacturing method of the dissimilar material joint structure according to the embodiment of the present invention. Refer to Figure 1A and Figure 1B , first, the manufacturing method of the dissimilar material joint structure according to the embodiment of the present invention will be described.

[0032] [Preparation of Materials]

[0033] In the present embodiment, non-ferrous metal parts and steel are used as materials for manufacturing the dissimilar material joint structure. As Figure 1A and Figure 1B shown, in the present embodiment, an aluminum alloy plate 11 is used as the non-ferrous metal part, and a steel plate 21 is used as the steel. In addition, the non-ferrous metal part means a part made of non-ferrous metal, and a part made of one selected from aluminum or aluminum alloy, magnesium or magnesium alloy, and titanium or titanium alloy can be used.

[0034] The type of steel is not particularly limited, and the content of components other than iron can be variously designed according to the performance of the required structure.

[0035] [Process of Forming Low-Temperature Sprayed Coating]

[0036] First, as shown in Figure 1A , on at least a part of the surface of the aluminum alloy plate 11, a low-temperature sprayed coating 12 is formed by low-temperature spraying of a metal powder (not shown). As the metal powder used in the low-temperature spraying, any metal powder that forms a low-temperature sprayed coating made of the same material as the steel plate 21 or a material that is easily joined to the steel plate 21 can be selected. Specifically, a metal powder containing at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy is used. In addition, in the present embodiment, as the metal powder, a metal powder formed by powdering molten metal in a vacuum or an inert gas environment is used. The properties of such a metal powder will be described in detail later.

[0037] <Process of laminating the aluminum alloy plate and the steel plate>

[0038] Next, as shown in Figure 1B , the aluminum alloy plate 11 and the steel plate 21 are laminated in such a manner that the low-temperature sprayed coating 12 faces the steel plate 21.

[0039] <Process of performing laser welding>

[0040] Then, for the region of the aluminum alloy plate 11 where the low-temperature sprayed coating 12 is formed, laser welding is performed from the opposite side of the surface of the steel plate 21 that faces the aluminum alloy plate 11. Thereby, a weld metal 23 that joins the steel plate 21 and the low-temperature sprayed coating 12 is formed, and a dissimilar material joined structure can be manufactured.

[0041] When joining dissimilar materials such as the aluminum alloy plate 11 and the steel plate 21, a method of forming a low-temperature sprayed coating 12 made of a material that is easily joined to the steel plate 21 on the surface of the aluminum alloy plate 11 and joining the low-temperature sprayed coating 12 and the steel plate 21 by laser welding is well-known. However, the low-temperature sprayed coating formed on the surface of the aluminum alloy plate 11 by a general method is gasified by laser heat during the process of performing laser welding, and this gas invades the weld metal, generating pores.

[0042] In the present embodiment, since a specific low-temperature sprayed coating 12 is formed, generation of pores can be suppressed during the subsequent process of performing laser welding. Regarding the metal powder used in the present embodiment and the low-temperature sprayed coating formed by this metal powder, differences from conventional metal powders and low-temperature sprayed coatings will be described in more detail while being cited.

[0043] (Metal powder)

[0044] Generally, when forming a low-temperature sprayed coating, metal powder (water atomized powder) manufactured by the water atomization method is used. The present inventors found that hydrogen in the low-temperature sprayed coating vaporizes due to the heat during laser welding, which causes the generation of pores, and various studies have been conducted on methods for reducing the hydrogen content in the low-temperature sprayed coating. As a result, it has been found that, as described above, it is effective to use metal powder formed by powdering molten metal in a vacuum or an inert gas environment. Examples of methods for manufacturing such metal powder include the gas atomization method, the disk atomization method, the plasma atomization method, and the plasma rotating electrode method, etc.

[0045] The so-called gas atomization method is a method in which a metal material composed of a desired component for forming a low-temperature sprayed coating is melted, and the molten metal is atomized by spraying an inert gas at high pressure. In addition, the disk atomization method is a method in which molten metal obtained by melting a metal material comes into contact with a rotating disk, and is atomized by centrifugal force. The plasma atomization method is a method in which plasma is sprayed onto a metal wire composed of a desired component to melt the metal, and the molten metal is atomized. The plasma rotating electrode method is a method in which a metal material composed of a desired component rotates at high speed, the metal material is melted by irradiating plasma onto the metal material, and the obtained molten metal is atomized by centrifugal force.

[0046] In this specification, the metal powder manufactured by the gas atomization method may sometimes be referred to as gas atomized powder, and the metal powder manufactured by the disk atomization method may sometimes be referred to as disk atomized powder. In addition, the metal powder manufactured by the plasma atomization method may sometimes be referred to as plasma atomized powder, and the metal powder manufactured by the plasma rotating electrode method may sometimes be referred to as PREP (Plasma Rotating Electrode Process) powder.

[0047] Regarding the above-mentioned gas atomized powder, disk atomized powder, plasma atomized powder, and PREP powder, since melting and solidification are carried out in a vacuum or an inert gas environment, the hydrogen content can be significantly reduced compared with water atomized powder. Therefore, by low-temperature spraying a metal powder manufactured by a method selected from the gas atomization method, the disk atomization method, the plasma atomization method, and the plasma rotating electrode method on the surface of the aluminum alloy plate 11, a low-temperature sprayed coating 12 with a reduced hydrogen content can be formed.

[0048] In order to suppress the generation of pores in the welded metal 23 during laser welding, the hydrogen content in the metal powder used when forming the low-temperature sprayed coating 12 is preferably 16 ppm or less, more preferably 14 ppm or less, further preferably 12 ppm or less, and particularly preferably 10 ppm or less.

[0049] In addition, the appearances of the gas atomized powder, disk atomized powder, plasma atomized powder, and PREP powder produced by the above method are also different from those of the water atomized powder. Figure 2 is a substitute photograph of the gas atomized powder produced by the gas atomization method, Figure 3 is a substitute photograph of the water atomized powder produced by the water atomization method. Figure 2 The gas atomized powder shown and Figure 3 the water atomized powder shown have the same composition and average particle size.

[0050] As Figure 2 shown, since the gas atomized powder 1 is atomized into molten metal powder while cutting the molten metal by jetting gas, the cooling rate during the manufacturing process becomes slow, and it becomes a smooth, roughly spherical shape due to surface tension. In addition, each gas atomized powder 1 is independent, and there are no adhered fine particles on the surface. The disk atomized powder, plasma atomized powder, and PREP powder also become the same shape. In contrast, as Figure 3 shown, the water atomized powder 2 is a powder atomized by jetting water at high pressure onto the molten metal. Since it is rapidly cooled and solidified, it does not become a spherical shape and has irregularities on the surface.

[0051] (Low-temperature spraying coating)

[0052] Since the low-temperature spraying coating 12 formed by the method of this embodiment uses the metal powder produced by the above specific method, the hydrogen content is lower than that of the low-temperature spraying coating obtained by using the water atomized powder. Therefore, after laminating the aluminum alloy plate 11 and the steel plate 21, in the process of performing laser welding from the upper surface of the steel plate 21, even when the low-temperature spraying coating 12 becomes high temperature due to laser heat, the gas generated from the low-temperature spraying coating 12 can be significantly reduced. As a result, the generation of pores in the obtained welded metal 23 can be suppressed.

[0053] In order to suppress the generation of pores in the welded metal 23 during laser welding, the hydrogen content in the low-temperature spraying coating 12 is 16 ppm or less, preferably 14 ppm or less, more preferably 12 ppm or less, and further preferably 10 ppm or less, the same as the hydrogen content of the metal powder.

[0054] In addition, the surface of the low-temperature spraying coating 12 obtained by low-temperature spraying at least one powder selected from the gas atomized powder, disk atomized powder, plasma atomized powder, and PREP powder is in a state where the shape of the metal powder remains. That is, if the outermost surface of the low-temperature spraying coating 12 is observed by an electron microscope or the like, characteristic spherical particles can be confirmed.

[0055] As described in detail above, according to the method for manufacturing the dissimilar material joining structure according to the present embodiment, since a low-temperature sprayed coating with a lower hydrogen content than the conventional method can be formed, in the process of performing laser welding, a weld metal with reduced porosity can be formed. In addition, the penetration depth of the weld metal formed by the manufacturing method according to the present embodiment may penetrate the low-temperature sprayed coating 12 and reach the aluminum alloy plate 11, or may not reach the aluminum alloy plate 11. Therefore, it is not necessary to strictly adjust the laser welding conditions to suppress the generation of pores, and the allowable range of manufacturing conditions can be increased.

[0056] Furthermore, when the aluminum alloy plate 11 (non-ferrous metal component) serving as the base material contains many pores, if the penetration depth of the weld metal is designed not to reach the aluminum alloy plate 11, the generation of pores can be further suppressed.

[0057] [Dissimilar material joining structure]

[0058] Next, the dissimilar material joining structure according to the present embodiment will be described below using Figure 1B The dissimilar material joining structure according to the present embodiment can be manufactured by the method for manufacturing the dissimilar material joining structure according to the present embodiment described above. Therefore, the description of the parts that overlap with the description in the above manufacturing method will be omitted or simplified.

[0059] As Figure 1B shown, the dissimilar material joining structure 10 is manufactured by joining the aluminum alloy plate 11 and the steel plate 21. Specifically, on a part of the surface of the aluminum alloy plate 11, a low-temperature sprayed coating 12 is formed, and the aluminum alloy plate 11 and the steel plate 21 are laminated so that the low-temperature sprayed coating 12 faces the steel plate 21. Then, the weld metal 23 penetrates the steel plate 21 from the surface of the steel plate 21 on the side opposite to the aluminum alloy plate 11 side and reaches the low-temperature sprayed coating 12, and is formed to join the steel plate 21 and the low-temperature sprayed coating 12.

[0060] In addition, in the present embodiment, the hydrogen content in the low-temperature sprayed coating 12 is 16 ppm or less. Regarding the low-temperature sprayed coating 12 as described above, its hydrogen content is preferably 14 ppm or less, more preferably 12 ppm or less, and further preferably 10 ppm or less. In addition, when the dissimilar material joining structure 10 according to the present embodiment is coated with a coating or the like and other processes are performed after manufacturing, sometimes the hydrogen content in the low-temperature sprayed coating 12 increases. Therefore, the hydrogen content in the low-temperature sprayed coating 12 in the dissimilar material joining structure 10 according to the present embodiment is set to a value measured within 90 days after manufacturing and before performing a process that changes the hydrogen content in the low-temperature sprayed coating 12 on the dissimilar material joining structure 10.

[0061] In addition, the low-temperature sprayed coating 12 of the dissimilar material joining structure 10 according to other embodiments is composed of at least one powder selected from gas atomized powder, disk atomized powder, plasma atomized powder, and PREP powder. The metal powder that is the material of the low-temperature sprayed coating 12 is as described above. Further, after forming the low-temperature sprayed coating 12 using the above-specified metal powder and manufacturing the dissimilar material joining structure 10, if the steel plate 21 is peeled off from the aluminum alloy plate 11, characteristic spherical metal powders can be confirmed on the surface of the low-temperature sprayed coating 12.

[0062] Example

[0063] Hereinafter, with respect to the method for manufacturing the dissimilar material joining structure of the present invention, invention examples and comparative examples will be specifically described.

[0064] <Manufacture of Dissimilar Material Joining Structure>

[0065] First, an aluminum alloy plate 11 and a steel plate 21 are prepared, and a low-temperature sprayed coating 12 is formed by low-temperature spraying iron powder on a part of the surface of the aluminum alloy plate 11 under the conditions shown below. Next, the steel plate is stacked on the aluminum alloy plate so that the low-temperature sprayed coating 12 faces the steel plate 21. Then, laser welding is performed from above the steel plate under the conditions shown below to join the aluminum alloy plate 11 and the steel plate 21.

[0066] (Low-temperature Spraying Conditions)

[0067] Apparatus: High-temperature and high-pressure type

[0068] Material of aluminum alloy plate: 7204 aluminum alloy (plate thickness 3 mm)

[0069] Metal powder: Gas atomized iron powder (average particle size 43 μm) or water atomized iron powder (average particle size 43 μm)

[0070] Gas type: Nitrogen

[0071] Gas pressure: 5 MPa

[0072] Gas temperature: 1000 °C

[0073] Film thickness of low-temperature sprayed coating: 2 mm

[0074] (Laser Welding Conditions)

[0075] Upper plate: 1470 MPa grade steel plate (plate thickness 1.4 mm)

[0076] Lower plate: Aluminum alloy plate formed with the above low-temperature sprayed coating

[0077] Welding Machine: Fiber Laser (YLS-6000 manufactured by IPG photonics)

[0078] Laser Output: 2750W

[0079] Welding Speed: 4 (m / min)

[0080] Spot Diameter: 0.3mm

[0081] <Evaluation Method for Dissimilar Material Joint Structure>

[0082] Take cross-sectional photos of the obtained joints and observe the pores in the weld metal. In addition, using analysis software (Image J), calculate the porosity through the following formula.

[0083] Porosity (%) = Total pore area × 100 / Weld metal area

[0084] Show the types of metal powders used and the calculation results of porosity in Table 1 below, and show the taken cross-sectional photos in Figure 4 in.

[0085] [Table 1]

[0086] Table 1

[0087]

[0088] As shown in Table 1 above and Figure 4 shown, in the inventive example, since the low-temperature sprayed coating 12 is formed using gas atomized iron powder, the hydrogen content in the low-temperature sprayed coating 12 is within the range specified by the present invention. Therefore, the porosity generated in the weld metal 23 joining the low-temperature sprayed coating 12 and the steel plate 21 is significantly reduced, and a sound weld metal can be obtained. As a result, a dissimilar material joint structure with excellent joint strength can be obtained.

[0089] On the other hand, in the comparative example, since the low-temperature sprayed coating 12 is formed using water atomized iron powder, the hydrogen content in the low-temperature sprayed coating 12 deviates from the range specified by the present invention and becomes a higher value. Therefore, pores 30 are generated in the weld metal 23, and a dissimilar material joint structure with excellent joint strength cannot be obtained.

[0090] In addition, although there are differences between the hydrogen content in the metal powder and the hydrogen content in the low-temperature sprayed coating in both the inventive example and the comparative example, theoretically, it can be considered that in the case of forming a low-temperature sprayed coating by low-temperature spraying of metal powder, the hydrogen content before and after low-temperature spraying does not change. Therefore, it can be considered that these differences are caused by measurement errors.

[0091] As described above, various embodiments have been explained. Needless to say, the present invention is not limited to such examples. Obviously, those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it should be understood that they naturally also belong to the technical scope of the present invention. In addition, the constituent elements in the above embodiments can be arbitrarily combined without departing from the gist of the invention.

[0092] In addition, this application is based on a Japanese patent application (Japanese Patent Application No. 2022-185208) filed on November 18, 2022, the content of which is incorporated herein by reference.

[0093] 10 Dissimilar material joining structure

[0094] 11 Aluminum alloy plate

[0095] 12 Low-temperature sprayed coating

[0096] 21 Steel plate

[0097] 23 Weld metal

[0098] 30 Air hole

Claims

1. A method for manufacturing a dissimilar material joined structure, which is a method for manufacturing a dissimilar material joined structure by joining a non-ferrous metal component and a steel material, characterized in that: It has: A step of forming a low-temperature sprayed coating on at least a part of the surface of the non-ferrous metal component by low-temperature spraying of metal powder, the metal powder containing at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy; A step of laminating the non-ferrous metal component and the steel material such that the low-temperature sprayed coating faces the steel material; and A step of performing laser welding from the opposite side of the surface of the steel material facing the non-ferrous metal component; The metal powder is a metal powder atomized from molten metal in a vacuum or an inert gas environment.

2. The method for manufacturing a dissimilar material joined structure according to claim 1, characterized in that: The metal powder is a metal powder manufactured by a method selected from a gas atomization method, a disk atomization method, a plasma atomization method, and a plasma rotating electrode method.

3. The method for manufacturing a dissimilar material joined structure according to claim 1 or 2, characterized in that: The hydrogen content in the metal powder is 16 ppm or less.

4. A dissimilar material joined structure, which is a dissimilar material joined structure formed by joining a non-ferrous metal component and a steel material, characterized in that: On at least a part of the surface of the non-ferrous metal component, a low-temperature sprayed coating composed of metal powder is formed, the metal powder containing at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy; The non-ferrous metal component and the steel material are laminated such that the low-temperature sprayed coating faces the steel material; On the surface of the steel material on the side opposite to the non-ferrous metal component side, a weld metal joining the steel material and the low-temperature sprayed coating is formed; The hydrogen content in the low-temperature sprayed coating is 16 ppm or less.

5. A dissimilar material joined structure, which is a dissimilar material joined structure formed by joining a non-ferrous metal component and a steel material, characterized in that: On at least a part of the surface of the non-ferrous metal component, a low-temperature sprayed coating composed of metal powder is formed, the metal powder containing at least one selected from pure iron, carbon steel, stainless steel, nickel, nickel alloy, cobalt, and cobalt alloy; The non-ferrous metal component and the steel material are laminated such that the low-temperature sprayed coating faces the steel material; On the surface of the steel material on the side opposite to the non-ferrous metal component side, a weld metal joining the steel material and the low-temperature sprayed coating is formed; The low-temperature sprayed coating is composed of at least one powder selected from gas atomized powder, disk atomized powder, plasma atomized powder, and powder manufactured by the plasma rotating electrode method.

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