JP2019150840A - Different material coupling joint and different material joint method - Google Patents

Abstract

To provide a different material coupling joint and a different material joint method which enable a favorable bead appearance while suppressing a decrease in tensile strength by reducing large blow holes in a weld metal when welding a ferrous material and an aluminum-based material through braze welding using an aluminum-based wire.SOLUTION: A different material coupling joint, configured by butt-joining a ferrous material with an aluminum-based material through braze welding using an aluminum-based wire, is a different material coupling joint characterized in that a deposit metal containing aluminum is formed at a butt part of the ferrous material with the aluminum-based material, and in that a route gap of the ferrous material from the aluminum-based material is 0.5 mm or more and 2.0 mm or less.SELECTED DRAWING: Figure 1

Description

  INDUSTRIAL APPLICABILITY The present invention is suitable as a structural member for transportation fields such as automobiles, railway vehicles, and ships, machine parts, building structures, and the like. The present invention relates to a dissimilar joint and a dissimilar material joining method between aluminum and an aluminum material.

  Various structural materials for automobiles use some aluminum-based materials to reduce their weight. For this reason, development of a method for joining different materials of iron-based materials and aluminum-based materials is desired. .

As a method of joining the same kind of materials, generally, arc welding such as TIG (Tungsten Inert Gas) welding and MIG (Metal Inert Gas) welding, and fusion welding methods such as laser welding are generally used. In dissimilar joining of aluminum materials and iron materials, there is a difference in the melting temperature of both materials, so the aluminum material on the side with the lower melting point is melted, and the iron material is hardly melted. Blaze welding is known for bonding. However, a brittle Al-Fe intermetallic compound such as FeAl ₃ or Fe ₂ Al ₅ is easily formed relatively thick at the interface between the aluminum-based material and the iron-based material, and this is between the aluminum-based material and the iron-based material. Therefore, it has been difficult to obtain a stable joint strength by the above-mentioned blaze welding method.

  For this reason, as an example of applying MIG (Metal Inert Gas) welding to dissimilar material joining, a flux-cored wire (FCW) which is an aluminum-based welding material having an effect of removing an oxide film is used as an electrode wire, and pure aluminum is used. And a bare steel plate are MIG welded using a DC pulse power source (see Non-Patent Document 1). However, when MIG welding is applied to dissimilar material joining, the DC pulse MIG needs to reduce the current, so that the arc becomes unstable and spatter is likely to occur, and the cleaning action for removing the oxide film is insufficient. There are problems such as.

  Dissimilar material joining methods for solving the above problems are disclosed in Patent Documents 1 and 2 and Non-Patent Document 2. That is, although a flux-cored wire (FCW), which is an aluminum-based welding material, is used, the flux and wire components are adjusted, and an AC pulse power source is used to provide a bare steel plate or a surface-treated galvanized steel plate, and an aluminum material. A method has been developed to realize jointing between the two by blaze welding. This is because the flux in the wire removes the surface treatment components of the steel plate and cleans it, and prevents the temperature at the joint interface from becoming high due to the endothermic effect associated with the evaporation of the flux. It is possible to suppress the generation of compounds.

JP 7-148571 A JP 10-314933 A

“Survey Research on Melting Process Aluminum / Steel Dissimilar Material Joining Techniques” p75-93, 2002 Results Report (March 2003), Osaka University Research Institute for Joining Science Journal of the Japan Welding Society Vol.22, No.2, p315-322 (2004)

However, when brazing welding using an aluminum-based welding material (wire) is performed as a method of joining different materials of an iron-based material and an aluminum-based material, it is formed between the iron-based material and the aluminum-based material. There is a drawback that large blowholes tend to remain in the molten metal. When many large blowholes remain in the weld metal, there are problems such as a decrease in tensile strength and fatigue strength of the joint joint and a failure to obtain a good bead appearance.
Moreover, when it joins using the above-mentioned flux-cored wire (FCW), there also exists a problem that a blowhole will remain still more easily with the evaporation gas of the material component combined with the flux and the flux.

  The present invention has been made in view of the above-described problems, and its purpose is to join an iron-based material and an aluminum-based material by braze welding using an aluminum-based wire including a flux-cored wire. An object of the present invention is to provide a dissimilar joint joint and a dissimilar material joining method capable of obtaining a good bead appearance while suppressing a decrease in tensile strength of the joint joint by reducing large blow holes in the weld metal.

  The dissimilar joint joint of the present invention that solves the above problems is a dissimilar joint joint in which an iron-based material and an aluminum-based material are butt-joined by braze welding using an aluminum-based wire, the iron-based material and the aluminum A weld metal containing aluminum is formed at a butt portion of the system material, and a route gap between the iron system material and the aluminum system material is 0.5 mm or more and less than 2.0 mm.

  Moreover, the dissimilar material joining method of the present invention that solves the above-mentioned problem is a dissimilar material joining method in which an iron-based material and an aluminum-based material are butt-joined by blaze welding using an aluminum-based wire, the iron-based material and the above-mentioned A route gap of the aluminum-based material is set to 0.5 mm or more and less than 2.0 mm, and a weld metal containing aluminum is formed at a butt portion between the iron-based material and the aluminum-based material.

  Moreover, the dissimilar joint joint of the present invention that solves the above-mentioned problems is a dissimilar joint joint in which an iron-based material and an aluminum-based material are lap-joined by braze welding using an aluminum-based wire, and the ferrous material and A weld metal containing aluminum is formed in the overlapping portion of the aluminum-based material, and the aluminum-based material has a groove in the overlapping portion, and a groove angle of the groove is 30 ° or more. It is 50 degrees or less.

  Moreover, the dissimilar material joining method of the present invention that solves the above-mentioned problems is a dissimilar material joining method in which an iron-based material and an aluminum-based material are joined by lap welding using an aluminum-based wire, A groove having a groove angle of not less than 30 ° and not more than 50 ° is provided, and a weld metal containing aluminum is formed in an overlapping portion of the iron-based material and the aluminum-based material.

  According to the present invention, when joining an iron-based material and an aluminum-based material by blaze welding using an aluminum-based wire, the tensile strength of the joint joint can be reduced by reducing large blow holes in the weld metal. It is possible to provide a dissimilar material joint and a dissimilar material joining method capable of obtaining a good bead appearance while suppressing the decrease.

FIG. 1 is a schematic cross-sectional view of the vicinity of a joint joint that is butt-joined by the dissimilar material joining method according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the vicinity of a joint joint that is lap-joined by the dissimilar material joining method according to the second embodiment. FIG. 3 is a schematic cross-sectional view showing an aspect of a butt joint test used in Example 1 described later. FIG. 4A is a cross-sectional photograph showing a state of a blow hole in a weld metal in a butt joint of an Al alloy material and a steel material according to Comparative Example 1-1. FIG. 4B is a cross-sectional photograph showing the state of the blowhole in the weld metal in the butt joint of the Al alloy material and the steel material according to Comparative Example 1-2. FIG. 4C is a cross-sectional photograph showing the state of the blowhole in the weld metal in the butt joint of the Al alloy material and the steel material according to Comparative Example 1-3. FIG. 4D is a cross-sectional photograph showing the state of the blowhole in the weld metal in the butt joint of the Al alloy material and the steel material according to Example 1-1. FIG. 4E is a cross-sectional photograph showing the state of the blowhole in the weld metal in the butt joint of the Al alloy material and the steel material according to Example 1-2. FIG. 4F is a cross-sectional photograph showing the state of the blowhole in the weld metal in the butt joint of the Al alloy material and the steel material according to Example 1-3. FIG. 5A is a cross-sectional photograph showing a state of a blow hole in a weld metal in a butt joint of an Al alloy material and a steel material according to Comparative Example 1-6. FIG. 5B is a cross-sectional photograph showing the state of the blowhole in the weld metal in the butt joint of the Al alloy material and the steel material according to Example 1-4. FIG. 6A is a schematic cross-sectional view showing an aspect of a lap joint test (without groove processing) used in Example 2 described later. FIG. 6B is a schematic cross-sectional view showing an aspect of a lap joint test (with groove processing) used in Example 2 described later. FIG. 7A is a cross-sectional photograph showing the state of blowholes in the weld metal in the lap joint of the Al alloy material and steel material according to Comparative Example 2-1. FIG. 7B is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Comparative Example 2-2. FIG. 7C is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Comparative Example 2-3. FIG. 7D is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 2-1. FIG. 7E is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 2-2. FIG. 7F is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 2-3. FIG. 8A is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Comparative Example 2-4. FIG. 8A is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Comparative Example 2-5. FIG. 8C is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Comparative Example 2-6. FIG. 8D is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 2-4. FIG. 8E is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 2-5. FIG. 8F is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 2-6. FIG. 9A is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Comparative Example 3. FIG. 9B is a cross-sectional photograph showing the state of the blowhole in the weld metal in the lap joint of the Al alloy material and the steel material according to Example 3.

  Hereinafter, a dissimilar material joint and a dissimilar material joining method according to an embodiment (this embodiment) of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
First, the dissimilar material joint and the dissimilar material joining method according to the first embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view of the vicinity of a joint joint that has been butt-joined by the dissimilar material joining method according to the present embodiment. The dissimilar material joint (butt joint) of this embodiment is formed by butt-joining the iron-based material 1 and the aluminum-based material 2 by blaze welding with the weld metal 3 interposed therebetween.

  The butt joint is performed using MIG using a MIG welding machine as a heat source, for example. MIG welding is a joining method in which a wire acting as a filler metal is fed from a welding torch at a constant speed and is fed to generate an arc between the wire and the base material, so that air does not enter the joint. In addition, an inert gas is generated from the gas nozzle. An aluminum-based wire is used. Further, the welding conditions at the time of butt joining are not particularly limited as long as the aluminum-based wire can be appropriately melted. However, from the viewpoint of obtaining high joint strength (tensile strength) in the butt joint, the welding speed is preferably more than 300 mm / min and less than 500 mm / min.

  The weld metal 3 is formed by melting an aluminum wire that is a filler material at the time of butt joining and a part of the aluminum material 2. When the iron-based material 1 is, for example, a galvanized steel sheet, a part of the galvanized layer is melted and vaporized to form the weld metal 3. However, the iron-based material 1 (steel plate or the like) having a higher melting point than the aluminum-based material 2 or the galvanized layer forms the weld metal 3 without being melted, so that the growth of intermetallic compounds is reduced.

  Next, features of the present embodiment will be described.

  In the case where different materials of the iron-based material 1 and the aluminum-based material 2 are butt-joined, a method by blaze welding using an aluminum-based welding material (aluminum-based wire) is generally applied. However, when performing blaze welding using an aluminum-based wire, a large blow hole may remain in the weld metal 3 formed between the iron-based material 1 and the aluminum-based material 2. If many large blowholes remain in the weld metal 3, problems such as a decrease in tensile strength and fatigue strength of the joint joint and a failure to obtain a good bead appearance occur.

  Therefore, in this embodiment, when different materials are butt-joined, the root gap G between the iron-based material 1 and the aluminum-based material 2 is set to 0.5 mm or more and less than 2.0 mm, and the iron-based material 1 and the aluminum-based material 2 are set. The weld metal 3 containing aluminum is formed at the butting portion 4. Here, the root gap G is a predetermined gap provided between the iron-based material 1 and the aluminum-based material 2 in order to promote the penetration of the weld metal 3 and increase the bonding strength.

By setting the root gap G between the iron-based material 1 and the aluminum-based material 2 to 0.5 mm or more, gas generated during blaze welding (vaporization of components such as flux contained in the wire, and surface components of steel plates and aluminum are reduced. Since the vaporized gas H ₂ , Mg, etc. that reacts with the wire or the flux easily escapes from the inside of the weld metal 3 before solidification, it can be suppressed that many large blowholes remain in the weld metal 3. As a result, it is possible to effectively prevent problems such as a decrease in the tensile strength of the joint joint and a failure to obtain a good bead appearance.
In order to obtain the above action more effectively, the root gap G is preferably 0.5 mm or more, and more preferably 0.8 mm or more.

However, if the root gap G is too large, when the iron-based material 1 and the aluminum-based material 2 are blazed, the molten metal 3 does not conform to the iron-based material 1 side, and the weld metal 3 may melt away. There is. As a result, since dissimilar material joining may not be possible, the root gap G is set to less than 2.0 mm.
In order to obtain the above action more effectively, the root gap G is preferably less than 1.5 mm, and more preferably less than 1.2 mm. Most preferably, the root gap G is 1.0 mm.

Further, the aluminum-based material 2 has a groove at the abutting portion 4, and the groove angle θ of the groove is preferably 30 ° or more and 50 ° or less. By providing a groove in the aluminum-based material 2 in a range where the groove angle θ is 30 ° or more and 50 ° or less, the amount of melting of the aluminum-based material 2 that melts during blaze welding is reduced, and aluminum that causes blowholes Since the amount of vaporization of the components contained in the system material 2 or the surface components such as the oxide film can be suppressed, it can be further suppressed that many large blowholes remain in the weld metal 3.
In order to obtain the above action more effectively, the groove angle θ is preferably 30 ° or more, and more preferably 40 ° or more.

  However, if the groove angle θ is excessively increased, an undercut problem occurs at the bead end portion on the aluminum-based material 2 side. Therefore, the groove angle θ is set to 60 ° or less. In order to obtain the above action more effectively, the groove angle θ is preferably 55 ° or less, and more preferably 50 ° or less. Most preferably, the groove angle θ = 45 °.

On the iron-based material 1 side, a groove may be provided in the butt portion 4, but it is not particularly necessary.
In the case where a groove is provided in the aluminum-based material 2, the shape of the groove is not particularly limited, but it is preferable to use a so-called ladle groove having a slope on the surface near the heat source during butt joining.
When a groove is provided in the aluminum-based material 2, a root surface may be left (the root surface exceeds 0 mm).

The welding wire material used in the present embodiment is not particularly limited as long as it is an aluminum-based material, and is appropriately selected according to the welded joint and welding conditions. For example, A4043-WY, A4047-WY, A5356-WY, A5183-WY, and the like specified by JIS are listed as examples, but not limited thereto.
More preferably, a cylindrical skin material comprising 1.7 to 2.7% by mass of Si, 0.05 to 0.25% by mass of Ti, and the balance being aluminum and an aluminum alloy that is an unavoidable impurity. And 7-15% by mass of AlF ₃ filled in the skin material, with the balance being a KAlF-based flux and a flux that is an impurity, and the filling rate of the flux is 2.5 to 2.5 per total mass of the wire The use of a flux-cored wire that is 20% by weight is desired.

The wires include both solid wires and flux-cored wires (FCW). Among these, the flux-cored wire is obtained by filling a cylindrical aluminum alloy sheath with a flux, and a part of the aluminum-based material 2 is melted by heating with a heat source such as MIG at the time of joining. At this time, the flux melts together with the aluminum alloy sheath. In this case, the surface of the iron-based material 1 does not melt because the flux wets and spreads (in the case of a galvanized steel sheet, only the surface galvanized layer melts).
And, the wettability of the surface of the iron-based material 1 is improved in the melting portion, and the molten aluminum alloy that covers the surface of the iron-based material 1 is smoothly covered. As a result, the aluminum-based material 2 and the iron-based material 1 are firmly adhered to each other, and as a result, compared with wires using other aluminum-based materials, for example, the above-described wires defined by JIS and its improved materials. A strong interfacial bonding force can be obtained.

  Examples of the iron-based material 1 used in the present embodiment include steel materials such as ordinary steel and high-tensile steel (HITEN; HTSS). Etc. can be used. In the present embodiment, the type and shape of the steel material used for the joint is not particularly limited, and is appropriately used for a structural member, such as a steel plate, a steel shape member, a steel pipe, etc. Shapes and materials can be used. In addition, if it is a range which does not inhibit the dissimilar material joining method of this embodiment, plating (plated steel plate), such as zinc, and various surface treatments may be performed.

Examples of the aluminum material 2 used in the present embodiment include an aluminum material such as a pure aluminum material or an aluminum alloy material. The aluminum-based material 2 used in the present embodiment is not particularly limited in the type or shape of the alloy, and depending on the required characteristics as each structural member, a widely used plate material such as rolling, extrusion, etc. A shape material, a forging material, a casting material, etc. are selected suitably.
In addition, although 5000 type | system | group (Al-Mg type | system | group), 6000 type | system | group (Al-Mg-Si type | system | group) etc. can be mentioned as a kind of aluminum alloy, In this embodiment, any alloy can be used.

  However, in a 5000 series aluminum alloy having a relatively low boiling point Mg (magnesium) content over 6000 series, the amount of Mg that is vaporized and gasified during blaze welding also increases. For this reason, when a 5000 series aluminum alloy is used as the aluminum series material 2, the blowholes remaining in the weld metal 3 can also be increased. Therefore, the dissimilar material joint and the dissimilar material joining method of this embodiment are particularly 5000. This is effective when using an aluminum alloy.

There is no particular limitation on the thickness _{t 1} of an iron-based material 1, generally those 1.0mm~5.0mm is used. Moreover, it not particularly limited with respect to the thickness _{t 2} of the aluminum-based material 2, generally those 1.0mm~5.0mm is used.

<Second Embodiment>
Subsequently, a dissimilar material joint and a dissimilar material joining method according to the second embodiment of the present invention will be described. FIG. 2 is a schematic cross-sectional view of the vicinity of a joint joint that is lap-joined by the dissimilar material joining method according to the present embodiment. The dissimilar joint joint (lap joint) of the present embodiment is formed by lap joining the iron-based material 1 and the aluminum-based material 2 by blaze welding with the weld metal 3 interposed therebetween. The lap joining can be performed by the same method as in the first embodiment. Further, the formation process of the weld metal 3 is the same as that in the first embodiment.

  Next, features of the present embodiment will be described.

  As described in the first embodiment, when different materials of the iron-based material 1 and the aluminum-based material 2 are lap-joined by braze welding using an aluminum-based wire, the iron-based material 1 and the aluminum-based material are used. In some cases, a large blow hole may remain in the weld metal 3 formed between the two.

Therefore, in this embodiment, when different materials are lap-joined, a groove having a groove angle θ of 30 ° or more and 50 ° or less is provided for the aluminum-based material 2, and the iron-based material 1 and the aluminum-based material 2 are overlapped. The weld metal 3 containing aluminum is formed in the part 5.
By providing a groove in the aluminum-based material 2 in a range where the groove angle θ is 30 ° or more and 50 ° or less, the amount of melting of the aluminum-based material 2 that melts during blaze welding is reduced, and aluminum that causes blowholes The melting amount of the oxide film of the system material 2 can be suppressed. As a result, it is possible to effectively suppress many large blowholes remaining in the weld metal 3.
In order to obtain the above action more effectively, the groove angle θ is preferably 30 ° or more, and more preferably 40 ° or more.

  However, if the groove angle θ is excessively increased, an undercut problem occurs at the bead end portion on the aluminum-based material 2 side. Therefore, the groove angle θ is set to 60 ° or less. In order to obtain the above action more effectively, the groove angle θ is preferably 55 ° or less, and more preferably 50 ° or less. Most preferably, the groove angle θ = 45 °. In addition, although it is not necessary to provide a groove | channel in the butt | matching part 4 in the iron-type material 1 side, you may provide in particular. Moreover, when providing a groove | channel in the aluminum-type material 2, you may make it leave a route surface (a route surface shall be over 0 mm).

Further, the root gap G between the iron-based material 1 and the aluminum-based material 2 is preferably set to 0.5 mm or more and less than 2.0 mm. By setting the root gap G between the iron-based material 1 and the aluminum-based material 2 to 0.5 mm or more, gas generated during blaze welding (vaporization of components such as flux contained in the wire, and surface components of steel plates and aluminum are reduced. The vaporized gas H ₂ , Mg, etc. that reacts with the wire or the flux easily escapes from the inside of the weld metal 3 before solidification, so that it is more effectively suppressed that many large blowholes remain in the weld metal 3. be able to.
In order to obtain the above action more effectively, the root gap G is preferably 0.5 mm or more, and more preferably 0.8 mm or more.

However, if the root gap G is too large, when the iron-based material 1 and the aluminum-based material 2 are blazed, the molten metal 3 does not conform to the iron-based material 1 side, and the weld metal 3 may melt away. There is. As a result, dissimilar material joining may not be possible, and even if it can be joined, the tensile strength of the joint joint may be reduced. Therefore, the root gap G is preferably set to less than 2.0 mm.
In order to obtain the above action more effectively, the root gap G is more preferably less than 1.5 mm, and still more preferably less than 1.2 mm. Most preferably, the root gap G is 1.0 mm.

  The overlap allowance between the iron-based material 1 and the aluminum-based material 2 when performing the lap joining is not particularly limited, but is generally set in a range of 3.0 mm to 7.0 mm.

  In addition, about the detail of the welding wire raw material used in this embodiment, the iron-type material 1, and the aluminum-type material 2, since it is the same as that of 1st Embodiment, description is abbreviate | omitted.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples, and can be implemented with modifications within a range that can be adapted to the gist of the present invention, all of which are included in the technical scope of the present invention. Is done.

<Example 1>
Tests on butt joints in iron-based materials and aluminum-based materials were conducted. The welding conditions are as shown in Table 1 and are common to all Examples and Comparative Examples except for the welding speed. Note that the welding conditions described here are merely examples, and the present embodiment is not limited to the following welding conditions.
Further, as shown in Table 2, SS400 is used as an iron-based material (steel material), and A5052 which is a 5000-series aluminum alloy or A6022 which is a 6000-series aluminum alloy is used as an aluminum-based material (Al alloy material). The butt joint was carried out after setting the welding speed to each condition shown in Table 2. In addition, the cross-sectional schematic which shows the aspect of the butt-joining test in a present Example is shown in FIG.

Other common conditions are shown below.
Welding wire made by Nice Co., Ltd. AluS4M φ1.2mm
Welder DW300 + made by Daihen Co., Ltd.
Mode: Soft aluminum
Polarity / process: AC / pulse
Overhang length: 15mm
Shielding gas: Ar 20L / min
Welding method Automatic (DX100 + MH6)
Groove shape of aluminum material 45 ° shaped groove, root surface 1mm
Welding length about 200mm
In addition, when providing a root gap, after welding the workpiece | work both ends, this welding was implemented.
The standard of AluS4M is a cylindrical skin material made of aluminum alloy containing 1.7 to 2.7% by mass of Si and 0.05 to 0.25% by mass of Ti with the balance being aluminum and unavoidable impurities. And 7-15% by mass of AlF ₃ filled in the skin material, with the balance being a KAlF-based flux and a flux that is an impurity, and the filling rate of the flux is 2.5 to 2.5 per total mass of the wire It is a flux-cored wire that is 20 mass%.

In Table 2, the evaluation results for the bead appearance, surface defects, maximum test force and tensile strength are shown. The bead appearance was examined by visually observing the vertical cross-sectional shape in the longitudinal direction of the butt joint and measuring the bead width. Further, the surface defects were examined by checking the presence or absence of pore defects on the surface of the weld bead. Furthermore, the investigation of the tensile test was performed by processing the butt joint into a test piece described in JIS No. 5 and conducting a tensile test, and evaluating the tensile strength (N / mm) and the maximum test force (N).
In the investigation of the bead appearance, bead width, maximum test force, and tensile strength, 25 mm wide samples were collected by water jet (WJ) processing at three locations, 15 mm from the both ends in the weld bead direction and the central position. . The values of the bead width, the maximum test force and the tensile strength in Table 2 were the average values of three points on the welding start side, the sample center, and the welding end side.

  In Table 2, Example 1-1 to Example 1-4 (in the case of root gap = 1.0 mm) satisfying the requirements of the present invention have almost good or good bead appearance and no surface defects. Excellent maximum test force and tensile strength.

In addition, in Example 1-1 to Example 1-3 and Comparative Example 1-1 to Comparative Example 1-3 (in the case of root gap = 0 mm), each of the example and the comparative example at the same welding speed was compared. As for the improvement margin of the tensile strength of the Example with respect to the comparative example, Example 1-2 was the largest among Examples 1-1 to 1-3.
Tensile strength of Example 1-1 (134 N / mm) / Tensile strength of Comparative Example 1-1 (80 N / mm) = 1.68 times Tensile strength of Example 1-2 (171 N / mm) / Tensile strength of Comparative Example 1-2 (66 N / mm) = about 2.59 times Tensile strength of Example 1-3 (202 N / mm) / Tensile strength of Comparative Example 1-3 (143 N / mm) = About 1.41 times This is considered to be because Example 1-2 satisfies the conditions of more preferable welding speeds of more than 300 mm / min and less than 500 mm / min.

  Moreover, the improvement margin of the tensile strength with respect to Comparative Example 1-6 of Example 1-4 using a 6000 series aluminum alloy is the tensile strength (198 N / mm) of Example 1-4 / comparative example 1-6. Tensile strength (176 N / mm) = about 1.13 times. Based on this result, as described above, the dissimilar material joint and the dissimilar material joining method of the present embodiment are particularly when a 5000 series aluminum alloy is used. It is understood that it is effective.

On the other hand, Comparative Example 1-1 to Comparative Example 1-3 and Comparative Example 1-6 (in the case of root gap = 0 mm) that do not satisfy the requirements of the present invention had no problems in bead appearance or surface defects, but the maximum Test strength and tensile strength were inferior.
Further, in Comparative Examples 1-4 and 1-5 (when the root gap = 2.0 mm) that does not satisfy the requirements of the present invention, the weld metal derived from the welding wire is sufficient to the iron-based material side at the time of butt joining. First of all, as a result of melting away, a good bead shape could not be obtained. For this reason, in Comparative Examples 1-4 and Comparative Examples 1-5, a tensile test was not performed, and “bead width”, “maximum test force (N)”, and “tensile strength (N / mm) in Table 2 were used. ) "Is"-".

  Subsequently, with respect to Example 1-1 to Example 1-4, Comparative Example 1-1 to Comparative Example 1-3, and Comparative Example 1-6, the state of the blowhole in the weld metal was changed to a microscope (magnification: 20 times). , Apparatus name: The result confirmed by Keyence Corporation VHX-6000) is shown.

4A to 4C are cross-sectional photographs showing the state of blowholes in the weld metal in the butt joints of Al alloy materials and steel materials according to Comparative Examples 1-1 to 1-3, respectively. 4D to 4F are cross-sectional photographs showing states of blow holes in the weld metal in the butt joints of the Al alloy material and the steel material according to Example 1-1 to Example 1-3, respectively. In addition, these photographs have shown the cross section of the sample center part in a weld bead direction.
For example, when Example 1-1 is compared with Comparative Example 1-1 where the test conditions other than the route gap conditions are the same, blowholes in the weld metal (with a large number of black circles in FIGS. 4A and 4D). When attention is paid to the portion shown, it can be seen that the larger blowholes are reduced in Example 1-1. Similarly, in the comparison between Example 1-2 and Comparative Example 1-2, the comparison between Example 1-3 and Comparative Example 1-3, and the comparison between Example 1-4 and Comparative Example 1-6, the Examples It can be seen that large blowholes are reduced in the butt joint.
In FIGS. 4B and 4C, the steel material is not shown in the drawing because the steel material has been peeled off when the cross-sectional photograph is confirmed.

<Example 2>
Tests on lap jointing of iron-based materials and aluminum-based materials were conducted. The welding conditions are as shown in Table 3, and were common to all examples and comparative examples. Note that the welding conditions described here are merely examples, and the present embodiment is not limited to the following welding conditions.
Moreover, as shown in Table 4, CR980 or SS400 is used as an iron-based material (steel material), and A5052 which is a 5000-series aluminum alloy or A6022 which is a 6000-series aluminum alloy is used as an aluminum-based material (Al alloy material). The above lap joining was carried out with the presence or absence of groove processing and the root gap in the system material set to the conditions shown in Table 4. 6A (without groove processing) and FIG. 6B (with groove processing) are schematic cross-sectional views showing aspects of the lap joint test in this example.

Other common conditions are shown below.
Welding wire made by Nice Co., Ltd. AluS4M φ1.2mm
Welder DW300 + made by Daihen Co., Ltd.
Polarity / process: AC / pulse
Mode: Soft aluminum
Overhang length: 15mm
Shielding gas: Ar 20L / min
Welding method Automatic (DX100 + MH6)
Groove shape when a groove is provided in an aluminum-based material 45 ° -shaped groove, root surface 1 mm
Overlap 5mm
Welding length about 200mm
In addition, when providing a root gap, after welding the workpiece | work both ends, this welding was implemented.
The AluS4M standard is as described in the first embodiment.

  Table 4 shows the evaluation results for the bead appearance, surface defects, maximum test force, and tensile strength. In addition, since these evaluation methods are common with Example 1, description is abbreviate | omitted.

  In Table 4, Examples 2-1 to 1-6 (with groove processing) satisfying the requirements of the present invention have good bead appearance, no surface defects, and maximum test force and tensile strength. It was excellent.

In addition, when compared with an example (with groove processing) and a comparative example (without groove processing) in the same aluminum-based material and root gap, the improvement margin of the tensile strength of the example with respect to the comparative example is the example. 2-1 and Example 2-2 were larger than Example 2-3, and Example 2-4 and Example 2-5 were larger than Example 2-6.
Tensile strength of Example 2-1 (359 N / mm) / tensile strength of comparative example 1-1 (126 N / mm) = about 2.85 times Tensile strength of Example 2-2 (349 N / mm) / Tensile strength (171 N / mm) of Comparative Example 2-2 = about 2.04 times Tensile strength (273 N / mm) of Example 2-3 / Tensile strength (143 N / mm) of Comparative Example 2-3 = About 1.91 times Tensile strength of Example 2-4 (261 N / mm) / tensile strength of Comparative Example 2-4 (217 N / mm) = about 1.20 times Tensile strength of Example 2-5 ( 304 N / mm) / tensile strength of Comparative Example 2-5 (226 N / mm) = about 1.35 times Tensile strength of Example 2-6 (244 N / mm) / tensile strength of Comparative Example 2-6 ( 235 N / mm) = about 1.04 times. This is because Example 2-1, Example 2-2, Example 2-4 and Example 2-5 are preferable Tsu believed to be due to satisfy the 0.5mm or more but less than 2.0mm is a condition flop.

  Moreover, the improvement margin of the tensile strength of Example 2-1 using Example 5000 alloy which used 5000 series aluminum alloy is the tensile strength of Example 2-4 to Example 2-6 using 6000 series aluminum alloy. In view of the fact that it is considerably larger than the improvement allowance, as described above, it is understood that the dissimilar material joint and the dissimilar material joining method of this embodiment are particularly effective when a 5000 series aluminum alloy is used.

  On the other hand, Comparative Examples 2-1 to 2-6, which do not satisfy the requirements of the present invention, included those having no problem in bead appearance or surface defects. In either case, the maximum test force and tensile strength were included. It was inferior.

  Then, about Example 2-1 to Example 2-6 and Comparative Example 2-1 to Comparative Example 2-6, the state of the blowhole in the weld metal was set to a microscope (magnification: 20 times, apparatus name: (stock) ) The result confirmed by Keyence VHX-6000) is shown.

7A to 7C are cross-sectional photographs showing states of blow holes in the weld metal in the butt joints of the Al alloy material and the steel material according to Comparative Examples 2-1 to 2-3, respectively. 7D to 7F are cross-sectional photographs showing the state of blowholes in the weld metal in the butt joints of the Al alloy material and the steel material according to Example 2-1 to Example 2-3, respectively.
8A to 8C are cross-sectional photographs showing blowhole states in the weld metal in the butt joints of an Al alloy material and a steel material according to Comparative Examples 2-4 to 2-6, respectively.
8D to 8F are cross-sectional photographs showing states of blow holes in the weld metal in the butt joints of the Al alloy material and the steel material according to Examples 2-4 to 2-6, respectively.
For example, when Example 2-1 and Comparative Example 2-1 in which the aluminum-based material is common in 5000 series and the conditions of the route gap are the same are compared, blow holes in the weld metal (in FIGS. 7A and 7D). In the case of Example 2-1, it is understood that larger blowholes are reduced. Similarly, a comparison between Example 2-2 and Comparative Example 2-2, a comparison between Example 2-3 and Comparative Example 2-3, a comparison between Example 2-4 and Comparative Example 2-4, and Example 2- 5 and Comparative Example 2-5 and Comparative Example 2-6 and Comparative Example 2-6 also show that large blowholes are reduced in the lap joint of Example.

<Example 3>
As in Example 2, a test for lap joining in an iron-based material and an aluminum-based material was performed. The welding conditions are as shown in Table 5, and are common to the examples and comparative examples. Note that the welding conditions described here are merely examples, and the present embodiment is not limited to the following welding conditions.
Further, as shown in Table 6, using SS400 as an iron-based material (steel material) and using A5052 which is a 5000-series aluminum alloy as an aluminum-based material (Al alloy material), the presence / absence of the groove processing and the route in the aluminum-based material The lap joining was performed after setting the gaps to the conditions shown in Table 6. In Example 3, all the conditions except the presence / absence of groove processing in the example and the comparative example were the same. Other common conditions are the same as those in the second embodiment, and thus the description thereof is omitted.

  In Table 6, the evaluation results for the bead appearance, surface defects, maximum test force and tensile strength are shown. In addition, since these evaluation methods are common with Example 1, description is abbreviate | omitted.

  In Table 6, Example 3 (with groove processing) satisfying the requirements of the present invention had good bead appearance, no surface defects, and excellent maximum test force and tensile strength. On the other hand, Comparative Example 3 (without groove processing) that did not satisfy the requirements of the present invention had good bead appearance and no surface defects, but was inferior in maximum test force and tensile strength. From this result, even when each condition other than the presence or absence of the groove processing in the aluminum-based material was common, it was confirmed that the tensile strength was improved by providing the groove processing.

  Similarly, in Example 3 and Comparative Example 3, the state of the blowhole in the deposited metal was confirmed by a microscope (magnification: 20 times, device name: VHX-6000 manufactured by Keyence Corporation). 3 (see FIG. 9B) was found to have reduced larger blowholes than Comparative Example 3 (see FIG. 9A).

As described above, the following items are disclosed in this specification.
[1] A dissimilar joint joint in which an iron-based material and an aluminum-based material are butt-joined by blaze welding using an aluminum-based wire,
A weld metal containing aluminum is formed at the butt portion of the iron-based material and the aluminum-based material,
A dissimilar joint joint, wherein a root gap between the iron-based material and the aluminum-based material is 0.5 mm or more and less than 2.0 mm.
[2] The dissimilar material joint according to [1], wherein the aluminum-based material has a groove at the abutting portion, and a groove angle of the groove is 30 ° or more and 50 ° or less. Fittings.
[3] The dissimilar joint joint according to [1] or [2], wherein the aluminum material is made of a 5000 aluminum alloy.
[4] The dissimilar joint joint according to any one of [1] to [3], wherein the aluminum-based material has a plate thickness of 1.0 mm to 5.0 mm.
[5] A dissimilar material joining method in which an iron-based material and an aluminum-based material are butt-joined by blaze welding using an aluminum-based wire,
A route gap between the iron-based material and the aluminum-based material is set to 0.5 mm or more and less than 2.0 mm, and a weld metal containing aluminum is formed at a butt portion between the iron-based material and the aluminum-based material. Dissimilar material joining method.
[6] The dissimilar material joining method according to [5], wherein a groove having a groove angle of 30 ° or more and 50 ° or less is provided to the aluminum-based material, and the weld metal is formed.
[7] The dissimilar material joining method according to [5] or [6], wherein a 5000 series aluminum alloy is used as the aluminum series material.
[8] The dissimilar material joining method according to any one of [5] to [7], wherein a plate thickness of the aluminum-based material is 1.0 mm to 5.0 mm.
[9] The dissimilar material joining method as described in any one of [5] to [8] above, wherein MIG is used as a heat source for the butt joining.
[10] A dissimilar joint joint in which an iron-based material and an aluminum-based material are lap-joined by braze welding using an aluminum-based wire,
In the overlap portion of the iron-based material and the aluminum-based material, a weld metal containing aluminum is formed,
The aluminum-based material has a groove in the overlapped portion, and a groove angle of the groove is 30 ° or more and 50 ° or less.
[11] The dissimilar joint joint according to [10], wherein a root gap between the iron-based material and the aluminum-based material is 0.5 mm or more and less than 2.0 mm.
[12] The dissimilar joint joint according to [10] or [11], wherein the aluminum material is made of a 5000 aluminum alloy.
[13] The dissimilar joint joint according to any one of [10] to [12], wherein a thickness of the aluminum-based material is 1.0 mm or greater and 5.0 mm or less.
[14] A dissimilar material joining method in which an iron-based material and an aluminum-based material are lap-joined by blaze welding using an aluminum-based wire,
A groove having a groove angle of not less than 30 ° and not more than 50 ° is provided for the aluminum-based material, and a weld metal containing aluminum is formed in an overlapping portion of the iron-based material and the aluminum-based material. Dissimilar material joining method.
[15] The dissimilar material joining method according to [14], wherein a root gap between the iron-based material and the aluminum-based material is set to 0.5 mm or more and less than 2.0 mm, and the weld metal is formed.
[16] The dissimilar material joining method described in [14] or [15] above, wherein a 5000 series aluminum alloy is used as the aluminum series material.
[17] The dissimilar material joining method according to any one of [14] to [16], wherein a plate thickness of the aluminum-based material is 1.0 mm to 5.0 mm.
[18] The dissimilar material joining method according to any one of the above [14] to [17], wherein MIG is used as a heat source for the lap joining.

DESCRIPTION OF SYMBOLS 1 Iron-type material 2 Aluminum-type material 3 Weld metal 4 Butt part 5 Overlap part G Root gap (theta) Groove angle t ₁ Thickness of iron-type material t ₂ Thickness of aluminum-type material

Claims (18)

An iron-based material and an aluminum-based material are dissimilar joint joints butt-joined by blaze welding using an aluminum-based wire,
A weld metal containing aluminum is formed at the butt portion of the iron-based material and the aluminum-based material,
A dissimilar joint joint, wherein a root gap between the iron-based material and the aluminum-based material is 0.5 mm or more and less than 2.0 mm.   2. The dissimilar joint joint according to claim 1, wherein the aluminum-based material has a groove in the butt portion, and a groove angle of the groove is 30 ° or more and 50 ° or less.   The dissimilar joint according to claim 1 or 2, wherein the aluminum material is made of a 5000 aluminum alloy.   4. The dissimilar joint joint according to claim 1, wherein a thickness of the aluminum-based material is 1.0 mm or greater and 5.0 mm or less. A dissimilar material joining method in which an iron-based material and an aluminum-based material are butt-joined by blaze welding using an aluminum-based wire,
A route gap between the iron-based material and the aluminum-based material is set to 0.5 mm or more and less than 2.0 mm, and a weld metal containing aluminum is formed at a butt portion between the iron-based material and the aluminum-based material. Dissimilar material joining method.   The dissimilar material joining method according to claim 5, wherein a groove having a groove angle of 30 ° or more and 50 ° or less is provided to the aluminum-based material to form the weld metal.   The dissimilar material joining method according to claim 5 or 6, wherein a 5000 series aluminum alloy is used as said aluminum series material.   The dissimilar material joining method according to any one of claims 5 to 7, wherein a plate thickness of the aluminum-based material is 1.0 mm or more and 5.0 mm or less.   The dissimilar material joining method according to any one of claims 5 to 8, wherein MIG is used as a heat source for the butt joining. An iron-based material and an aluminum-based material are dissimilar joints joined by lap welding using an aluminum-based wire,
In the overlap portion of the iron-based material and the aluminum-based material, a weld metal containing aluminum is formed,
The aluminum-based material has a groove in the overlapped portion, and a groove angle of the groove is 30 ° or more and 50 ° or less.   The dissimilar joint joint according to claim 10, wherein a root gap between the iron-based material and the aluminum-based material is 0.5 mm or more and less than 2.0 mm.   The dissimilar joint according to claim 10 or 11, wherein the aluminum material is made of a 5000 aluminum alloy.   The dissimilar joint joint according to any one of claims 10 to 12, wherein a plate thickness of the aluminum-based material is 1.0 mm or greater and 5.0 mm or less. A dissimilar material joining method in which an iron-based material and an aluminum-based material are joined together by blazing welding using an aluminum-based wire,
A groove having a groove angle of not less than 30 ° and not more than 50 ° is provided for the aluminum-based material, and a weld metal containing aluminum is formed in an overlapping portion of the iron-based material and the aluminum-based material. Dissimilar material joining method.   The dissimilar material joining method according to claim 14, wherein a root gap between the iron-based material and the aluminum-based material is set to 0.5 mm or more and less than 2.0 mm to form the weld metal.   The dissimilar material joining method according to claim 14 or 15, wherein a 5000 series aluminum alloy is used as said aluminum series material.   The dissimilar material joining method according to any one of claims 14 to 16, wherein a plate thickness of the aluminum-based material is 1.0 mm or more and 5.0 mm or less. The dissimilar material joining method according to any one of claims 14 to 17, wherein MIG is used as a heat source in the overlap joining.

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