JP2021167013A - Welded joined body, manufacturing method therefor, and filler material - Google Patents

Abstract

To ensure weld strength equal to or higher than conventional weld strength by controlling production of a compound between brittle metals in a weld portion between an iron-based metal member and an aluminum-based metal member and to reduce costs by increasing the degree of freedom in welding temperature, thereby making a manufacturing yield high in comparison with a conventional manufacturing yield.SOLUTION: A welded joined body includes: an iron-based metal member 101; an aluminum-based metal member 102; and a welding metal portion 103 for joining the iron-based metal member 101 and the aluminum-based metal member 102. In the welded joined body, an aluminum-based solid solution phase 105 is formed between the welding metal portion 103 and the aluminum-based metal member 102, a region where brittle phases 104 are dispersed is formed between the welding metal portion 103 and the aluminum-based solid solution phase 105. The central portion of the welding metal portion 103 contains nickel, copper, iron and aluminum. The content of nickel is 14-71% by mass, the content of copper is 20 to 69% by mass, and the content of aluminum is 16% or less by mass.SELECTED DRAWING: Figure 1

Description

The present invention relates to a welded joint, a method for producing the same, and a filler metal.

In recent years, from the viewpoint of energy saving, weight reduction of structural members of transportation machines (for example, automobiles, railroad vehicles, ships) has been required. Attempts have been made to apply an aluminum alloy-based metal member (hereinafter referred to as "Al-based metal member") as the structural member. However, from the viewpoint of mechanical strength and cost required for the structural member, it is difficult to use all metal members as Al-based metal members, and conventionally used iron-based metal members (hereinafter, "Fe-based metal"). It is being considered to be combined with "members").

However, it is known that when a Fe-based metal member and an Al-based metal member are directly welded, a fragile intermetallic compound is generated in a welded portion (for example, a weld bead). Specifically, there is a problem that a brittle intermetallic compound (for example, Al ₁₃ Fe ₄ phase, Al ₅ Fe ₂ phase) is formed in a thick layer in the bonding interface region, and sufficient welding strength cannot be obtained. Here, the fragile intermetallic compound is called an Intermetallic compound (IMC).

In particular, corrosion-resistant high-strength Fe-based metal members (for example, stainless steel members) and corrosion-resistant high-strength Al-based metal members (for example, A3000-based to A7000-based Al alloy members) are high due to the formation of a passivation film on the surface. Although corrosion resistance is ensured, the passivation film becomes an impeding factor at the time of welding and joining. For the purpose of removing the passivation film (oxide film), a larger amount of heat than usual is often applied during welding, but as a result, the amount of brittle intermetallic compound produced increases, which is a negative effect. Circulation is likely to occur.

Against such a background, various techniques for firmly joining the Fe-based metal member and the Al-based metal member have been proposed.

For example, in Patent Document 1, in a method of joining an iron-based material and an aluminum-based material by spot welding, a Cu alloy layer is arranged on the bonded surface on the iron-based material side, and the bonded surface on the aluminum-based material side. Discloses a technique for applying and joining a fluoride-based flux.

Further, in Patent Document 2, when joining different materials of a steel material and an aluminum alloy material which are dissimilar metals, a third material made of a metal different from these materials is interposed between these two materials, and the above two materials are provided. A technique for causing eutectic melting and joining between at least one of the materials and a third material is disclosed.

Further, in Patent Document 3, a laser beam is irradiated at the joint between the aluminum-based metal material and the iron-based metal material containing zinc at least a part of the surface to elute zinc and aluminum, and the laser is used. Pressurized by a roller in the direction in which the light irradiation surfaces come into contact with each other, an alloy layer in which zinc is solid-dissolved in aluminum is formed at the interface between the iron-based metal material and the aluminum-based metal material, and is composed of zinc, aluminum, and iron. A method for producing a dissimilar metal conjugate in which an intermetal compound composed of two or more kinds of metal elements selected from the group is dispersed in an alloy layer is disclosed.

Non-Patent Document 1 describes the relationship between the limit gap comparison that can be joined when a gap is provided between the plates and the tensile shear load of the joint in the lap fillet joint with respect to the hybrid welding work on two thin plates of aluminum alloy. It is disclosed. In this document, it is described that laser welding and arc (Mig) welding are hybridized.

Japanese Unexamined Patent Publication No. 2004-351507 Japanese Unexamined Patent Publication No. 2006-175502 Japanese Patent No. 5165339

Kobe Steel Technical Report / Vol.54 No.2 (Aug. 2004)

According to Patent Document 1, an iron system capable of obtaining stable and high bonding strength by suppressing the formation of fragile metal-to-metal compounds generated in the welded portion by a simple means without significantly modifying the conventional spot welding equipment. It is said that it is possible to provide a spot welding joining method and a joining joint between a material and an aluminum-based material.

However, the technique described in Patent Document 1 is premised on spot welding, that is, overlay welding of relatively thin plates and welding of relatively small heat capacity of the welded portion, and welding of relatively thick members. When applied to welding in which the heat capacity of the welded portion is relatively large, the maximum temperature reached of the welded portion rises or the solidification rate (cooling rate) decreases, causing grain boundary cracks in the welded portion. There is a concern that a brittle metal-to-metal compound may be formed. Further, since spot welding is not a line joining but a point joining, it is considered that it is difficult to apply it when performing a process for ensuring airtightness by welding.

On the other hand, according to Patent Document 2, by joining a third metal material that causes a passivation reaction with Al by interposing it between the steel material and the aluminum alloy material, the formation of intermetallic compounds in the joining process is suppressed. However, it is said that the oxide film at the bonding interface can be removed, and a method for bonding dissimilar metals capable of strong bonding can be provided.

However, in the technique described in Patent Document 2, in order to suppress the formation of intermetallic compounds in the welding process, it is necessary to control the welding interface temperature to be equal to or higher than the eutectic point and lower than the melting point of the base aluminum alloy material. , It is required to precisely control the maximum temperature reached of the welded part within a narrow temperature range. In other words, due to the difficulty of precise control of the weld temperature, there is a concern that the manufacturing yield will decrease (and thus the cost will increase).

Further, according to Patent Document 3, it is possible to provide a bonded body of dissimilar metals provided with a bonded portion having high shear strength and peel strength by positively utilizing an intermetallic compound.

However, the bonded body described in Patent Document 3 is limited to a galvanized steel sheet, and it is considered difficult to use an Fe-based metal member without zinc plating. Further, since the zinc plating is thin on the order of 10 μm, the welded joint is limited to the lap joint.

An object of the present invention is to control the formation of a brittle metal-to-metal compound in a welded portion in a welded joint (welded joint) between an iron-based metal member and an aluminum-based metal member to secure welding strength equal to or higher than that of the conventional one. At the same time, the degree of freedom in welding temperature is increased to increase the manufacturing yield and reduce the cost as compared with the conventional case.

The welded joint of the present invention includes an iron-based metal member, an aluminum-based metal member, and a welded metal portion for joining the iron-based metal member and the aluminum-based metal member, and the welded metal portion and the aluminum-based metal member. An aluminum-based solid solution phase is formed between them, a region in which a brittle phase is dispersed is formed between the weld metal portion and the aluminum-based solid solution phase, and the central portion of the weld metal portion is made of nickel or copper. , Iron and aluminum, the nickel content is 14-71% by mass, the copper content is 20-69% by mass, and the aluminum content is 16% by mass or less.

According to the present invention, in a welded joint (welded joint) between an iron-based metal member and an aluminum-based metal member, the formation of brittle metal-to-metal compounds in the welded portion is controlled to secure welding strength equal to or higher than the conventional one. In addition, the degree of freedom in welding temperature can be increased to increase the manufacturing yield and reduce the cost as compared with the conventional case.

It is a schematic cross-sectional view which shows the weld part after welding in a welding experiment. It is a schematic cross-sectional view which shows the composition analysis position of the weld metal part of the welded joint produced by lap fillet welding. It is a schematic cross-sectional view which shows the composition analysis position of the weld metal part of the welded joint produced by fillet welding. 6 is a cross-sectional image showing a welded portion formed in the welding experiment of Example 1. It is an enlarged SEM image of a part of the welded part of FIG. It is a flow chart which shows the welding method of an Example.

The present invention relates to a welding technique for metal members, and more particularly to a bonded body in which an Fe-based metal member and an Al-based metal member are firmly welded.

(Basic idea of the present invention)
The present inventor suppresses the continuous formation of undesired metal-to-metal compounds at the weld in the welded joint of Fe-based metal / Al-based metal using a filler metal (welding material), and has a degree of freedom in welding temperature. It was considered that an alloy based on an element having high compatibility with the metal to be welded metal member (particularly, an Fe-based metal having a higher melting point than the Al-based metal) is desirable as a welding material.

Specifically, as a filler material, an alloy containing Ni and Cu (hereinafter referred to as "Ni-Cu alloy") was selected so as to have high compatibility with Fe-based metals. As a result, in Al, the metal-metal compounds of Al—Fe, Al—Cu and Al—Ni produced by the reaction of the three elements of Ni and Cu of the filler metal and Fe of the metal to be welded are dispersed in the Al-based metal. It will be easier. In other words, the formation of different intermetallic compounds of Al—Fe, Al—Cu and Al—Ni makes it difficult for continuous formation of intermetallic compounds to occur. As the filler material, a welding rod, a welding wire, or the like is used.

Further, the present invention has been made by controlling the Al content in the central portion of the welded metal portion in which Al of the metal to be welded member is diffused. The present invention has been completed by diligent research and examination based on the technical idea.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The present invention is not limited to the embodiments taken up here, and can be appropriately combined and improved without departing from the technical idea of the present invention. In addition, the same reference numerals may be given to parts having the same meaning, and duplicate description may be omitted.

[Welding experiment]
(Preparation of samples of Examples 1 to 7 and Comparative Examples 1 to 6)
The sample is a welded joint in which an Fe-based metal member and an Al-based metal member are joined by a filler metal (hereinafter, also referred to as "Fe-based metal / Al-based metal welded joint").

As the filler material, a wire made of a Ni—Cu alloy was mainly used. The diameter of the wire is 1.2 mm.

As the Fe-based metal member to be the metal member to be welded, a mild steel plate (width 100 mm × length 200 mm × thickness 2 mm) was mainly used. As the Al-based metal member, an Al alloy plate (A6061 or A7N01, width 100 mm × length 200 mm × thickness 3 mm) was used.

The material of the Fe-based metal member is not limited to the examples, and for example, carbon steel, high-strength steel, stainless steel, and the like can be used.

As the Fe-based metal member of the example, a plated one is also used. Specifically, it is hot-dip galvanizing (GI) and alloyed hot-dip galvanizing (GA). In addition, it may be plated with aluminum or an aluminum alloy. With or without plating, strong welding is possible.

The welding method is lap fillet welding using wires.

FIG. 1 schematically shows a cross section of a welded portion after welding in a welding experiment.

In this figure, the upper plate is the Fe-based metal member 101, and the lower plate is the Al-based metal member 102.

The welded portion between the Fe-based metal member 101 and the Al-based metal member 102 includes a welded metal portion 103, a brittle phase 104, and an Al solid solution phase 105 (aluminum solid solution phase). The weld metal portion 103 is a portion where the filler metal is melt-solidified, and is a phase formed of a Cu—Ni alloy containing Fe and Al. The embrittlement phase 104 is made of an Al—Fe alloy, an Al—Cu alloy, or an Al—Ni alloy. The Al solid solution phase 105 contains at least Fe and Cu.

The welding method is not particularly limited as long as there is a method using a filler metal, and DC MIG welding, DC pulse MIG welding, AC MIG welding, AC pulse MIG welding, short-circuit transition type MIG welding, etc. may be used. .. A low heat input welding process includes cold metal transfer (CMT). CMT, unlike MIG, is a process in which the arc disappears and is pulled back when the wire reaches the molten pool. A current-voltage waveform that is a mixture of MIG and CMT may be used.

This time, we adopted a welding method that mixes MIG and CMT. Welding conditions vary depending on the thickness of the member, but this time, since the thickness of the lower plate is 3 mm, the current is 100 to 150 A, the wire feeding speed is about 5.6 m / min, and the welding speed is 100 cm / min. It was a minute. The shield gas is argon gas, and its supply rate is 20 L / min.
The welding machine used was a TransPuls Synergic 5000 CMT manufactured by Fronius, and the wire feeder used was a VR 7000 CMT manufactured by Fronius. Here, the welding speed means the speed at which the wire passes through the portion to be welded by the welding machine.

(Investigation of properties of Fe-based metal / Al-based metal welded joints)
(1) Microstructure Observation and Composition Analysis of Welded Metal Part A test piece for microstructure observation was collected from Fe-based metal / Al-based metal welded joints, which are samples of Examples 1 to 7 and Comparative Examples 1 to 6. Using an optical microscope and a scanning electron microscope-energy dispersive X-ray analyzer (SEM-EDX), the test piece was observed for microstructure of the cross section of the welded metal portion and the composition of the welded metal portion was analyzed.

In the composition analysis of the welded metal portion, a surface analysis was performed on one location in the center of the welded metal portion in a region of 50 μm square, and the content of each component was measured. Here, the areas targeted for surface analysis are defined as follows.

FIG. 2 is a schematic cross-sectional view showing a composition analysis position of a welded metal portion of a welded joint produced by lap fillet welding. Since the configuration of this figure is the same as that of FIG. 1, the description of each part will be omitted.

As shown in FIG. 2, at the position of the central portion in the thickness direction (the position of the midpoint of the line segment indicating the thickness t) in the cross section of the Fe-based metal member 101, the thickness of the weld metal portion 103 is set to the Fe-based metal. The longitudinal direction of the member 101 was measured, and the region 206 to be surface-analyzed was determined centering on the midpoint of the line segment indicating the thickness of the weld metal portion 103. Therefore, the midpoint, which is the center of the region 206, coincides with the center of gravity of the square region of 50 μm square. The line segment including the center of the region 206 overlaps with the extension line drawn from the central portion in the thickness direction of the cross section of the Fe-based metal member 101 to the inside of the welded metal portion 103 in the longitudinal direction of the Fe-based metal member 101. In other words, In other words, it is a line segment showing the thickness of the welded metal portion 103 drawn inside the welded metal portion 103 in the longitudinal direction.

Therefore, in the case of lap fillet welding, the central portion of the weld metal portion is the region 206 in FIG.

Although it is not used as a sample in the above composition analysis, when a welded joint produced by fillet welding is used as a sample, it is desirable to determine the region to be surface-analyzed as follows.

FIG. 3 is a schematic cross-sectional view showing the composition analysis position of the welded metal portion of the welded joint produced by fillet welding.

In this figure, the thickness of the Fe-based metal member 301 is sufficiently larger than that of the welded metal portion 303, and unlike FIGS. 1 and 2, the welded metal portion 303 does not reach the upper surface portion of the Fe-based metal member 301. It has become. Therefore, the center of the region 306 to be the target of the surface analysis is determined to coincide with the midpoint of the line segment 307 indicating the throat thickness. Here, the "throat thickness" is the case where a perpendicular line is drawn from the innermost part (the other apex of the triangle) of the welded metal part with respect to the straight line connecting the two points at both ends on the surface of the welded metal part in the cross-sectional view. It is the length of the perpendicular line (line segment) of.

In this figure, the other configurations are the same as those in FIG. 1, and the welded joint includes an Al-based metal member 302, an embrittlement phase 304, and an Al solid solution phase 305.

Therefore, in the case of fillet welding, the center of the region 306, which is the central portion of the weld metal portion, is defined as the midpoint of the line segment 307 in FIG. This midpoint coincides with the center of gravity of a 50 μm square area.

(2) Measurement of Weld Strength Test pieces for tensile test were collected from Fe-based metal / Al-based metal welded joints of Examples 1 to 7 and Comparative Examples 1 to 6. The test piece was subjected to a tensile shear test using a universal material testing machine. The tensile strength (welding strength) of the welded portion is a test piece subjected to lap fillet welding by YAG-Mig hybrid welding without providing a gap between two thin aluminum alloy plates described in Non-Patent Document 1. Based on 400 N / mm (10000 N / 25 mm width), which is the result of measuring the tensile shear breaking load using Less than was judged as "failed".

Table 1 shows the composition of the filler metal, the composition of the metal member, and the composition of the central portion of the welded metal portion and the welding strength in Examples 1 to 7 and Comparative Examples 1 to 6.

FIG. 4 is a cross-sectional image showing a welded portion formed in the welding experiment of Example 1.

This figure shows the configuration of the part corresponding to FIG.

In FIG. 4, the Fe-based metal member 401 and the Al-based metal member 402 are joined via the welded metal portion 403. Although not shown in FIG. 1, the Fe-based metal heat-affected zone 406 is formed in the region of the Fe-based metal member 401 adjacent to the welded metal portion 403. Further, an Al solid solution phase 405 (a portion where the base metal is melt-solidified during welding) is formed in a region of the Al-based metal member 402 adjacent to the welded metal portion 403. It is considered that this is because a part of the filler component is diffused into the Fe-based metal heat-affected zone 406 and the Al solid solution phase 405.

Region 408 is a portion to be further magnified and observed.

FIG. 5 is an enlarged SEM image of a part (region 408) of the welded portion of FIG.

As shown in FIG. 5, there is a region in which the embrittlement phase 504 is dispersed in the Al solid solution phase 505 between the welded metal portion 503 and the Al-based metal member (reference numeral 402 in FIG. 4). Undesirably continuously formed embrittlement phases were not observed, including areas other than region 408.

The continuously formed embrittlement phase was not observed in other examples.

As described above, in the test piece of the example, the embrittlement phase is discontinuous, so that it is considered that the strength is high.

From FIG. 4, it is considered that the thickness of the region where the embrittled phase is dispersed is approximately 100 to 500 μm.

Further, from FIG. 5, the embrittlement phase 504 has a length of 0.1 to 2.0 μm on the minor axis of the cross section with respect to the total value of the area of the cross section, which is 90% based on the area of the cross section. It is considered that this is the above.

As a result of further observing the region where the embrittled phase is dispersed in the Al solid solution phase, the embrittled phase is in the form of particles, and its size (average particle size) becomes smaller toward the Al-based metal member side. I understood. In other words, the size of the embrittled phase (average particle size) increases toward the weld metal portion. Here, the average particle size is calculated from the dimensions of the particles observed in the cross section, and may be defined by the length of the minor axis, or the average value may be calculated based on the area of the cross section. .. This is because the contribution of the size of the fine particles becomes large when the number is averaged.

The distribution of such an embrittled phase is schematically represented as the embrittled phase 104 also in FIG. 1 and the like.

As shown in Table 1, in Examples 1 to 7, the aluminum content of the region 206 (FIG. 2), which is the central portion of the weld metal portion, is 16% by mass or less.

Further, the welding strengths as a result of the tensile test for the test pieces of Examples 1 to 7 are all acceptable, and it can be seen that the test pieces of Examples 1 to 7 have sufficient welding strength.

The filler metal (wire) used in Examples 1 to 7 is a Ni—Cu alloy having a nickel content in the range of 30 to 80% by mass.

As shown in this table, the central part of the weld metal part contains nickel, copper, iron and aluminum, the nickel content is 14 to 71% by mass, and the copper content is 20 to 69% by mass. , The content of aluminum is 16% by mass or less.

The central portion of the weld metal portion further contains one or more elements selected from the group consisting of manganese, silicon, titanium, tin, zinc and magnesium, and the total content of these elements is 5% by mass. It is as follows. In addition, these elements are derived from a filler material or a metal member. Therefore, depending on the filler material or the metal member, the content may be out of the range.

The filler material further contains one or more elements selected from the group consisting of iron, manganese, silicon, titanium, aluminum and carbon, and the total content of these elements is 5% by mass or less.

As described above, in the welding experiment, the laminating fillet welding of the metal member to be welded with a thickness of 2 mm is performed, and no special temperature control is performed. This means that there are no particular restrictions on the welding temperature.

Therefore, according to Examples 1 to 7, it is possible to provide a welded joint of Fe-based metal / Al-based metal having a higher manufacturing yield (that is, lower cost) than the prior art.

On the other hand, in the test piece of Comparative Example 1 in which the aluminum content in the central portion of the weld metal portion exceeded 16% by mass, it was confirmed from the results of visual observation that cracks were locally present in the weld metal portion. .. The test piece of Comparative Example 1 failed the welding strength in the tensile test. This is because when the aluminum content in the weld metal portion containing nickel and copper as main components exceeds 16% by mass, the ductility (flexibility) of the weld metal portion decreases. In Comparative Example 1, the welding conditions were a current of 150 A, a wire feeding speed of 5.6 m / min, and a welding speed of 70 cm / min. Since the welding speed was slower than that of the example, the amount of heat input was large. From this, it is considered that a large amount of aluminum was mixed in the weld metal part.

From the results of Examples 1 to 7 and Comparative Example 1, the welding speed is preferably 80 to 120 cm / min, and more preferably 90 to 110 cm / min.

In summary, the process of welding the iron-based metal member and the aluminum-based metal member using the filler metal (welding process) is indispensable. In addition to this, it is desirable that there is a step (metal member installation step) in which the iron-based metal member and the aluminum-based metal member are installed so as to be in contact with each other at least partially before welding. Even if there is a gap in the entire range of the welding target portion, there is no problem as long as the gap is such that welding with the filler metal is possible and the strength after welding is equal to or higher than the desired value.

FIG. 6 is a flow chart showing a welding method of the embodiment.

As shown in this figure, the welding method of the embodiment includes a metal member installation step (S110) and a welding step (S120).

Further, the fillering material (wire) used in Comparative Examples 2 to 6 has a nickel content outside the range of 30 to 80% by mass, and has a composition different from that of the fillering material used in Examples 1 to 7. ing. In the test pieces of Comparative Examples 2 to 6, continuous formation of the embrittlement phase was confirmed in the interface region between the welded metal portion and the Al-based metal member by SEM observation. Further, the test pieces of Comparative Examples 2 to 6 failed the welding strength in the tensile test.

In Examples 1 to 7, it is considered that the desired result was obtained because the embrittled phase generated in the interface region between the welded metal portion and the Al-based metal member was dispersed and formed.

From the results of Examples 1 to 7 and Comparative Example 1, the aluminum content in the central portion of the weld metal portion is preferably 15% by mass or less, and more preferably 14.6% by mass or less.

In addition, for comparison, MIG welding was performed using A4043WY (Si: 6.0% by mass), which is a filler metal (wire) made of an aluminum alloy. As a result, the welding strength failed in the tensile test. Further, as a result of detailed SEM observation of this test piece, the embrittled phase in the interface region between the welded metal portion and the Fe-based metal member has a large variation of 1 to 15 μm in thickness and is continuously formed. It was confirmed that there was. It was difficult to control the temperature.

Instead of the welding method of the example, welding was performed using FSW (friction stir welding). Here, FSW is a method of generating frictional heat by pressing a cylindrical tool having a protrusion on the tip while rotating it against the base material, and causing plastic flow around the joint portion to join the joint. As a result, the welding strength failed in the tensile test. Further, as a result of detailed SEM observation, it was confirmed that the embrittled phase in the interface region between the joint portion and the Fe-based metal member has a large variation of 5 to 20 μm in thickness and is continuously formed. .. It was difficult to control the frictional heat.

The above-described embodiments and examples have been described for the purpose of assisting the understanding of the present invention, and the present invention is not limited to the specific configurations described. For example, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. That is, the present invention can delete, replace a part of the configurations of the embodiments and examples of the present specification with other configurations, and add other configurations.

101, 301, 401: Fe-based metal member, 102, 302, 402: Al-based metal member, 103, 303, 403, 503: Welded metal part, 104, 304, 504: Embrittled phase, 105, 305, 405, 505: Al solid solution phase, 206, 306, 408: region, 307: line segment, 406: Fe-based metal heat-affected zone.

Claims (10)

Iron-based metal members and
Aluminum-based metal parts and
A welded metal portion for joining the iron-based metal member and the aluminum-based metal member is included.
An aluminum-based solid solution phase is formed between the welded metal portion and the aluminum-based metal member.
A region in which the embrittlement phase is dispersed is formed between the weld metal portion and the aluminum-based solid solution phase.
The central portion of the weld metal portion contains nickel, copper, iron and aluminum, the nickel content is 14 to 71% by mass, the copper content is 20 to 69% by mass, and the aluminum content. Is 16% by mass or less, a welded joint. The central portion of the weld metal portion further contains one or more elements selected from the group consisting of manganese, silicon, titanium, tin, zinc and magnesium, and the total content of these elements is 5% by mass. The welded joint according to claim 1, which is as follows. It has a structure in which the iron-based metal member and the aluminum-based metal member are welded and joined using a filler metal.
The welded joint according to claim 1, wherein the filler metal is an alloy containing nickel and copper and has a nickel content of 30 to 80% by mass. The filler material further contains one or more elements selected from the group consisting of iron, manganese, silicon, titanium, aluminum and carbon, and the total content of these elements is 5% by mass or less. The welded joint according to claim 3. The welded joint according to claim 1, wherein the average particle size of the particles in the embrittlement phase is larger toward the weld metal portion side. Including the process of welding an iron-based metal member and an aluminum-based metal member using a filler metal.
The filler metal is an alloy containing nickel and copper, and has a nickel content of 30 to 80% by mass.
A method for producing a welded joint, wherein the central portion of the welded metal portion formed between the iron-based metal member and the aluminum-based metal member has an aluminum content of 16% by mass or less. The method for manufacturing a welded joint according to claim 6, further comprising a step of installing the iron-based metal member and the aluminum-based metal member so as to be in contact with each other before the welding. The method for manufacturing a welded joint according to claim 6, wherein the welding speed in the welding is 80 to 120 cm / min. A welded joint including an iron-based metal member, an aluminum-based metal member, and a welded metal portion for joining the iron-based metal member and the aluminum-based metal member, and the aluminum in the central portion of the welded metal portion. A filler metal which is an alloy containing nickel and copper and is used for welding and joining when producing a material having a content of 16% by mass or less.
A filler material having a nickel content of 30 to 80% by mass. The solution according to claim 9, further containing one or more elements selected from the group consisting of iron, manganese, silicon, titanium, aluminum and carbon, and the total content of these elements is 5% by mass or less. Addition material.

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