JP2018034167A - Arc-welding method for jointing different materials, joint assisting member, and different-material welded joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arc-welding method for jointing different materials, joint assisting member, and different-material welded joint capable of jointing different materials such as an aluminum alloy or a magnesium alloy, and a steel, securing strong and highly reliable quality, using inexpensive arc-welding equipment, as well as applicable either to an open cross-section structure or a closed cross-section structure with no restriction.SOLUTION: A different-material welded joint comprises: an upper plate 10 made of an aluminum alloy or a magnesium alloy; and a lower steel plate 20 made of a steel. The upper plate comprises: a hole 11 with a non-circular shape having different longitudinal and lateral lengths, and facing a surface superposed with the lower plate 20. The different-material welded joint further comprises a steel joint assisting member 30 having a circular hole part 33 with a non-circular shape having different longitudinal and lateral lengths. The hoe part in the steel joint assisting member is arranged on the upper plate 10 so as to be coaxial with the hole provided in the upper plate, as well as so as to have directions a, bof their respective longitudinal axes coincided with each other. The hole part in the joint assisting member is filled with a weld metal 40 made of an iron alloy or Ni alloy. In addition, a molten part W is formed of the weld metal, and respective parts of the molten lower plate and joint assisting member.SELECTED DRAWING: Figure 1B

Description

  The present invention relates to an arc welding method for joining dissimilar materials, a joining auxiliary member, and a dissimilar material welding joint.

For transportation equipment such as automobiles, the purpose is (a) consumption of petroleum fuel, which is a finite resource, (b) CO ₂ , which is a global warming gas generated by combustion, and (c) travel costs. As a result, improvement in driving fuel consumption is always required. In addition to improving power system technology such as the use of electric drive, reducing the weight of the vehicle body is one of the measures. For weight reduction, there is a means of replacing steel, which is currently the main material, with lightweight materials such as aluminum alloy, magnesium alloy, and carbon fiber. However, there are issues such as high costs and insufficient strength to replace everything with these lightweight materials. As a solution, a so-called multi-material design method that combines steel and lightweight materials in the right place is drawing attention. Have been bathed.

  In order to combine steel and the above lightweight materials, there are inevitably places where they are joined. It is known that welding, which is easy with steels, aluminum alloys, and magnesium alloys, is extremely difficult with different materials. The reason for this is that an intermetallic compound (IMC), which is extremely brittle, is formed in the melt-mixed portion of steel and aluminum or magnesium, and the melt-mixed portion is easily broken by an external stress such as tension or impact. . For this reason, welding methods such as resistance spot welding and arc welding cannot be adopted for dissimilar material joining, and other joining methods are generally used. For joining steel and carbon fiber, welding cannot be used because the latter is not a metal.

  As an example of the conventional dissimilar material joining technique, there is a means in which through holes are provided in both a steel material and a lightweight material and restrained from above and below with bolts and nuts. As another example, a means is known in which a caulking member is inserted from one side under a strong pressure and restrained by a caulking effect (see, for example, Patent Document 1).

  Furthermore, as another example, the steel joint member is pushed into the aluminum alloy material as a punch, and the hole and the joint member are temporarily restrained, then overlapped with the steel material, and sandwiched with both copper electrodes from above and below, Means for resistance-welding a steel material and a joining member by momentarily applying pressure and high current have been proposed (see, for example, Patent Document 2).

  As another example, means for directly joining aluminum alloy and steel materials using a friction stir welding tool has been developed. (For example, refer to Patent Document 3).

JP 2002-174219 A JP 2009-285678 A Japanese Patent No. 5044128

  However, the joining method using a bolt and a nut cannot be applied because a nut and a lightweight material constitute a closed cross-section structure (see FIG. 26A), and a nut cannot be inserted. Further, even in the case of a joint having an applicable open cross-section structure (see FIGS. 26B and 26C), there is a problem that it takes time to turn the nut and the efficiency is poor.

  Moreover, although the joining method described in Patent Document 1 is a relatively easy method, there is a problem that it cannot be inserted when the strength of the steel is high, and the joining strength depends on the frictional force and the rigidity of the caulking member. Therefore, there is a problem that high joint strength cannot be obtained. In addition, there is a problem that it cannot be applied to a closed cross-sectional structure because it is necessary to press down from both the front and back sides with a jig when inserting.

  Furthermore, the joining method described in Patent Document 2 cannot be applied to a closed cross-sectional structure, and the resistance welding method has a problem that the equipment is very expensive.

  The joining method described in Patent Document 3 applies pressure to the steel material surface while causing the aluminum alloy material to plastically flow in a low temperature region, while preventing both materials from melting and preventing the formation of intermetallic compounds. There is a research result that steel and carbon fiber can be joined, because it is said that metal bond strength is obtained. However, this joining method cannot be applied to a closed cross-sectional structure, and requires a high pressure, so that there is a problem that it is mechanically large and expensive. Also, the bonding force is not so high.

  Therefore, the existing dissimilar material joining technology has one or more problems such as (i) the member or groove shape is limited to an open cross-sectional structure, (ii) low joint strength, (iii) high equipment cost. have. For this reason, in order to spread multi-material design combining various materials, (i ′) applicable to both open and closed section structures, (ii ′) sufficiently high joint strength and reliability However, there is a need for a new technology that is easy to use and has all the elements of (iii ') low cost.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to use an aluminum alloy (hereinafter also referred to as “Al alloy”) or a magnesium alloy (hereinafter also referred to as “Mg alloy”) and a dissimilar steel material. Arc welding methods and joints for dissimilar materials that can be used with low-cost arc welding equipment that is already popular in the world, and can be joined with strong and reliable quality, and can be applied to both open and closed cross-section structures without restrictions. It is to provide an auxiliary member and a dissimilar material welded joint.

Here, when it is going to melt-join Al alloy or Mg alloy, and steel, the production | generation of an intermetallic compound (IMC) is unavoidable as mentioned above. On the other hand, it is obvious scientifically and practically that welding between steels shows the highest joint strength and reliability.
Therefore, the present inventors have devised means for achieving the joining of different materials by using welding between steels as a coupling force and further using a binding force.

Therefore, the above object of the present invention is achieved by the following configuration.
(1) An arc welding method for joining different materials for joining a first plate made of an aluminum alloy or a magnesium alloy and a second plate made of steel,
Forming a non-circular hole having different vertical and horizontal lengths in the first plate;
Superimposing the first plate and the second plate;
A steel joining auxiliary member in which non-circular hole portions having different vertical and horizontal lengths are formed, the hole portions being coaxial with the holes provided in the first plate, and the long-axis directions thereof coincide with each other. Arranging on the first plate;
The hole of the joining auxiliary member is filled with a weld metal by any of the following methods (a) to (e), and the second plate is inserted through the weld metal in the hole of the first plate. And welding the joining auxiliary member;
Arc welding method for dissimilar materials joining.
(A) A gas shielded arc welding method using a welding wire from which an iron alloy or Ni alloy weld metal is obtained as a melting electrode.
(B) Non-gas arc welding method using the welding wire as a melting electrode.
(C) Gas tungsten arc welding method using the welding wire as a non-melting electrode filler.
(D) A plasma arc welding method using the welding wire as a non-melting electrode filler.
(E) A coated arc welding method in which a coated arc welding rod from which the weld metal of an iron alloy or Ni alloy is obtained is used as a melting electrode.
(2) The second plate has a bulge formed by drawing,
The dissimilar material joining arc welding method according to (1), wherein, in the overlapping step, the bulging portion of the second plate is disposed in the hole of the first plate.
(3) A step of applying an adhesive over the entire circumference of the at least one overlapping surface of the first plate and the second plate before the overlapping step. Further, the arc welding method for joining different materials according to (1) or (2).
(4) In the arrangement step, an adhesive is applied to at least one opposing surface between the joining auxiliary member and the first plate facing the joining auxiliary member. (1) to (3) The arc welding method for joining dissimilar materials according to any one of the above.
(5) Any of (1) to (4), wherein an adhesive is applied to a boundary portion between the joining auxiliary member and the surface of the first plate during the arrangement step or after the filling welding step. The arc welding method for joining dissimilar materials as described in the above.
(6) The long axis side length _PSX of the hole portion of the joining auxiliary member is 50% or more and 100% or less with _respect to the long axis side length BDX of the hole of the first plate. (5) The arc welding method for joining different materials according to any one of (5).
(7) The minor axis side length _PSY of the hole portion of the joining auxiliary member is 50% or more and 100% or less with _respect to the minor axis side length _BDY of the hole of the first plate. The arc welding method for joining different materials according to any one of (6).
(8) Any one of (1) to (7), wherein the long axis side length P _DX of the joining auxiliary member is 105% or more with _respect to the long axis side length B _DX of the hole of the first plate. The arc welding method for joining dissimilar materials described in 1.
(9) Any of (1) to (8), wherein the minor axis side length P _DY of the joining auxiliary member is 105% or more with _respect to the minor axis side length B _DY of the hole of the first plate. The arc welding method for joining dissimilar materials described in 1.
(10) The thickness P _H of the joining auxiliary member is 50% or more and 150% or less of the plate thickness B _H of the first plate, for joining different materials according to any one of (1) to (9). Arc welding method.
(11) In the filling welding step, surplus is formed on the surface of the joining auxiliary member, and the major axis side length W _{DX of the} surplus is equal to the major axis side length of the hole of the joining auxiliary member. to P _SX, a 105% or more, (1) to a dissimilar materials bonded for arc welding method according to any one of (10).
(12) wherein in the filling welding process, the excess prime on the surface of the bonding auxiliary member is formed, and short shaft length W _DY of the excess prime is short shaft length of the hole portion of the auxiliary bonding member to P _SY, a 105% or more, (1) to a dissimilar materials bonded for arc welding method according to any one of (11).
(13) The first plate includes a plurality of holes, and the joining auxiliary member includes the plurality of holes.
The plurality of hole portions of the joining auxiliary member and the plurality of holes provided in the first plate are arranged coaxially and respectively in the same long axis direction;
The plurality of holes of the joining auxiliary member are respectively filled with weld metal, and the second plate and the joining auxiliary member are welded via the weld metal in the hole of the upper plate. 12) The arc welding method for joining dissimilar materials according to any one of the above.

(14) Used in the arc welding method for joining different materials according to any one of (1) to (13),
A joining auxiliary member made of steel and formed with non-circular holes having different vertical and horizontal lengths.

(15) A dissimilar material welded joint comprising: a first plate made of an aluminum alloy or a magnesium alloy; and a second plate made of steel arc-welded to the first plate,
The first plate has non-circular holes with different vertical and horizontal lengths facing the overlapping surface with the second plate,
It further comprises a steel joining auxiliary member in which non-circular holes having different vertical and horizontal lengths are formed,
The joining auxiliary member is disposed on the first plate so that the hole portion is coaxial with a hole provided in the first plate and the major axis directions thereof coincide with each other.
The hole portion of the joining auxiliary member is filled with a weld metal of an iron alloy or an Ni alloy, and is melted by the weld metal, the melted second plate, and a part of the joining auxiliary member. Dissimilar material welded joint is formed.
(16) The dissimilar material welded joint according to (15), wherein a bulging portion formed on the second plate is disposed in the hole of the first plate.
(17) The overlapping surface of at least one of the first plate and the second plate is provided with an adhesive provided over the entire circumference around the hole, (15) or (16 ) Dissimilar material welded joints.
(18) In any one of (15) to (17), comprising an adhesive provided on at least one facing surface between the joining auxiliary member and the first plate facing the joining auxiliary member. The dissimilar welded joint described.
(19) The dissimilar material welded joint according to any one of (15) to (18), comprising an adhesive provided at a boundary portion between the joining auxiliary member and the surface of the first plate.
(20) The long axis side length P _SX of the hole portion of the auxiliary joining member is 50% or more and 100% or less with _respect to the long axis side length B _DX of the hole of the first plate. (19) The dissimilar material welded joint according to any one of (19).
(21) The minor axis side length _PSY of the hole portion of the auxiliary joining member is 50% or more and 100% or less with _respect to the minor axis side length _BDY of the hole of the first plate. (20) The dissimilar material welded joint according to any one of (20).
(22) Any one of (15) to (21), wherein the long axis side length P _DX of the joining auxiliary member is 105% or more with _respect to the long axis side length B _DX of the hole of the first plate. The dissimilar material welded joint described in 1.
(23) Any of (15) to (22), wherein the minor axis side length P _DY of the joining auxiliary member is 105% or more with _respect to the minor axis side length B _DY of the hole of the first plate. The dissimilar material welded joint described in 1.
(24) Thickness _{P H} of the auxiliary bonding member, the first is less than 150% more than 50% of the thickness _{B H} plate (15) Dissimilar according to any one of - (23) Welded joints.
(25) A surplus is formed on the surface of the joining auxiliary member, and the major axis side length W _{DX of the} surplus is 105 to the major axis side length P _SX of the hole of the joining auxiliary member. % Dissimilar weld joint according to any one of (15) to (24).
(26) remaining prime on the surface of the joining auxiliary member is formed, and short shaft length W _DY of the excess prime is to short shaft length P _SY of the hole portion of the auxiliary bonding member, 105 % Dissimilar weld joint according to any one of (15) to (25).

  According to the present invention, a dissimilar material of an aluminum alloy or a magnesium alloy and steel can be joined with an inexpensive arc welding equipment with a strong and reliable quality, and both an open sectional structure and a closed sectional structure can be used. Applicable without limitation.

It is a perspective view of a dissimilar material welded joint according to an embodiment of the present invention. It is sectional drawing of the dissimilar-material welded joint along the Ib-Ib line | wire of FIG. 1A. It is sectional drawing of the dissimilar material welded joint along the Ic-Ic line | wire of FIG. 1A. It is a figure which shows the drilling operation | work of the arc welding method for dissimilar material joining of this embodiment. It is a figure which shows the superimposition operation | work of the arc welding method for dissimilar material joining of this embodiment. It is a figure which shows the insertion operation | work of the arc welding method for different material joining of this embodiment. It is a figure which shows the welding operation | work of the arc welding method for dissimilar material joining of this embodiment. It is a front view of the 1st modification of a joining auxiliary member. It is a front view of the 2nd modification of a joining auxiliary member. It is a front view of the 3rd modification of a joining auxiliary member. It is a front view of the 4th modification of a joining auxiliary member. It is a front view of the 5th modification of a joining auxiliary member. It is a front view of the 6th modification of a joining auxiliary member. It is sectional drawing which shows the dissimilar material welded joint in which no surplus is formed. It is sectional drawing which shows the state which the external stress of the plate | board thickness direction (three-dimensional direction) acted on the dissimilar material welded joint of FIG. 4A. It is sectional drawing which shows the state which the external stress of the plate | board thickness direction (three-dimensional direction) acted on the dissimilar material welded joint of FIG. 1B. It is sectional drawing of the dissimilar material welded joint for demonstrating penetration of a weld metal. It is sectional drawing of the dissimilar material welded joint for demonstrating penetration of a weld metal. It is a perspective view of the dissimilar material welding joint as a comparative example which piled up and welded the upper board made from aluminum, and the lower board made from steel. It is sectional drawing of the dissimilar material welded joint of FIG. 7A. FIG. 7B is a cross-sectional view illustrating a state in which shear tension is applied to the dissimilar material welded joint in FIG. 7A. It is a perspective view which shows the dissimilar material welded joint of FIG. 8A. It is sectional drawing which shows the state which the up-and-down peeling tension acted on the dissimilar material welded joint of FIG. 7A. It is a perspective view which shows the dissimilar material welded joint of FIG. 9A. It is a perspective view of the dissimilar material welding joint as a comparative example which piled up and welded the aluminum upper board and steel lower board which have a hole. It is sectional drawing of the dissimilar material welded joint of FIG. 10A. FIG. 10B is a cross-sectional view showing a state in which shear tension is applied to the dissimilar material welded joint in FIG. 10A. It is a perspective view which shows the state which shear tension acted on the dissimilar material welded joint of FIG. 10A, and the junction part shifted | deviated nearly 90 degrees. It is sectional drawing which shows the state which the up-and-down peeling tension acted on the dissimilar material welded joint of FIG. 10A. It is a perspective view which shows the dissimilar material welded joint of FIG. 12A. It is sectional drawing of the dissimilar material welded joint of this embodiment. It is sectional drawing which followed the XIII-XIII line | wire of FIG. 13A. It is sectional drawing of the upper board which shows the state before the arc welding in which a space | gap exists between an upper board and a lower board, a lower board, and a joining auxiliary member. It is sectional drawing of the dissimilar material welded joint which shows the state after arc welding with a heat contraction force. It is a top view of the upper board for explaining the dimensional relationship of a joining auxiliary member, and a joining auxiliary member. It is sectional drawing along the major axis direction of the upper board, lower board, and joining auxiliary member for demonstrating the dimensional relationship of a joining auxiliary member. It is sectional drawing along the minor-axis direction of the upper board, lower board, and joining auxiliary member for demonstrating the dimensional relationship of a joining auxiliary member. It is sectional drawing which shows the state which the stress of the shear direction acted on the dissimilar material welded joint whose diameter of the hole part of a joining auxiliary member is too small. It is sectional drawing which shows the state which the up-and-down peeling stress acted on the dissimilar material welded joint whose diameter of the hole part of a joining auxiliary member is too small. It is a perspective view of the upper board and lower board for demonstrating the 1st modification of the arc welding method for different material joining. It is sectional drawing of the upper board and lower board for demonstrating the 1st modification of the arc welding method for different material joining. It is a perspective view of the upper board and lower board for demonstrating the 2nd modification of the arc welding method for dissimilar materials joining. It is sectional drawing of the upper board and lower board for demonstrating the 2nd modification of the arc welding method for different material joining. It is a perspective view of the upper board, lower board, and joining auxiliary member for demonstrating the 3rd modification of the arc welding method for different material joining. It is sectional drawing of the upper board, lower board, and joining auxiliary member for demonstrating the 3rd modification of the arc welding method for different material joining. In a 3rd modification, it is a figure which shows the state in which the arc welding is performed in the sideways attitude | position. It is a perspective view of the dissimilar material welding joint for demonstrating the 4th modification of the arc welding method for dissimilar material joining. It is sectional drawing of the dissimilar material welding joint for demonstrating the 4th modification of the arc welding method for dissimilar material joining. It is the top view, side view, and bottom view which show the joining auxiliary member of Drawing 1A and Drawing 1B. It is the top view, side view, and bottom view which show the 7th modification of a joining auxiliary member. It is the top view, side view, and bottom view which show the 8th modification of a joining auxiliary member. It is sectional drawing for demonstrating the 5th modification of the arc welding method for different material joining, and a different material welded joint. It is a figure which shows the state before drawing a bulging part to the lower board of FIG. It is a figure which shows the state after the bulging part was drawn by the lower board of FIG. It is a perspective view which shows the closed cross-section structure to which the dissimilar material welded joint of this embodiment was applied. It is a perspective view which shows the open cross-section structure by the L-shaped board and the flat plate to which the dissimilar material welded joint of this embodiment was applied. It is a perspective view showing the open section structure by two flat plates to which the dissimilar material welded joint of this embodiment was applied. It is a perspective view which shows the closed cross-section structure to which the dissimilar material welded joint of this embodiment was applied, using the joining auxiliary member which has a some hole part. It is a perspective view which shows the open cross-section structure by an L-shaped board and a flat plate to which the dissimilar material welded joint of this embodiment was applied, using the joining auxiliary member which has a some hole part. It is a perspective view which shows the open cross-section structure by two flat plates to which the dissimilar material welded joint of this embodiment was applied, using the joining auxiliary member which has a some hole part. It is the front view and sectional drawing which show an example of the joining auxiliary member which has a some hole part. It is the front view and sectional drawing which show the other example of the joining auxiliary member which has a some hole part. It is the front view and sectional drawing which show the further another example of the joining auxiliary member which has a some hole part.

  Hereinafter, an arc welding method for joining dissimilar materials, a joining auxiliary member, and a dissimilar material welding joint according to an embodiment of the present invention will be described in detail based on the drawings.

  The arc welding method for dissimilar material joining of the present embodiment includes an upper plate 10 (first plate) made of aluminum alloy or magnesium alloy and a lower plate 20 (second plate) made of steel, which are superposed on each other. The dissimilar material welded joint 1 as shown in FIG. 1A to FIG. 1C is obtained by joining by the arc welding method mentioned later through the steel joining auxiliary member 30.

  The upper plate 10 is provided with a hole 11 that penetrates in the plate thickness direction and faces the overlapping surface of the lower plate 20. As shown in FIG. 2A, the hole 11 is formed in a non-circular shape having different vertical and horizontal lengths.

The joining auxiliary member 30 is formed with non-circular hole portions 33 having different vertical and horizontal lengths. In addition, it is preferable that the hole 33 of the joining auxiliary member 30 has a similar shape to the hole 11 of the upper plate 10. The joining auxiliary member 30 is arranged on the upper plate 10 so that the hole 33 is coaxial with the hole 11 provided in the upper plate 10 and the long axis directions a _x and b _x (see FIG. 2C) coincide with each other. Has been.
In addition, the external shape of the joining auxiliary member 30 is not limited to the rounded rectangle as shown in FIG. 2A, and can be any shape as long as the hole 11 of the upper plate 10 is closed after welding. For example, it may be a rectangle shown in FIGS. 3A and 3F, an oval connecting two circles shown in FIG. 3B, an ellipse shown in FIG. 3C, a circle shown in FIG. 3D, or a polygon shown in FIG. 3F.
Further, the shape of the hole 33 is not limited to a rounded rectangle as shown in FIGS. 2A and 3E, and may be an arbitrary shape. For example, it may be a rectangle shown in FIGS. 3A and 3D, an oval connecting two circles shown in FIG. 3B, or an ellipse shown in FIGS. 3C and 3F.
Furthermore, the outer diameter shape of the joining auxiliary member 30 may be similar to the shape of the hole 33 as shown in FIGS. 2A and 3A to 3C, and as shown in FIGS. 3D to 3F, It may be similar to the shape.

  Further, the hole 33 of the joining auxiliary member 30 is filled with a weld metal 40 of an iron alloy or Ni alloy in which a filler material (welding material) is melted by arc welding, and is melted with the weld metal 40. The molten plate W is formed by the lower plate 20 and a part of the joining auxiliary member 30. Therefore, the fusion | melting part W is also arrange | positioned also in the hole 11 of the upper board 10, and has welded the joining auxiliary member 30 and the lower board 20, and, thereby, the upper board 10 and the lower board 20 are joined. .

Hereinafter, the arc welding method for joining dissimilar materials constituting the dissimilar material welded joint 1 will be described with reference to FIGS. 2A to 2D.
First, as shown in FIG. 2A, a hole making operation for making a hole 11 in the upper plate 10 is performed (step S1). Next, as shown in FIG. 2B, a superposition operation for superposing the upper plate 10 and the lower plate 20 is performed (step S2). Further, as shown in FIG. 2C, the joining auxiliary member 30 is arranged so that the hole 33 is coaxial with the hole 11 provided in the upper plate 10 and the major axis directions a _x and b _x coincide with each other. 10 (step S3). Then, as shown in FIG. 2D, (a) a molten metal gas shielded arc welding method, (b) a non-gas arc welding method, (c) a gas tungsten arc welding method, and (d) a plasma arc welding method, which will be described in detail below. (E) The upper plate 10 and the lower plate 20 are joined by performing any arc welding operation of the covered arc welding method (step S4). FIG. 2D shows a case where (a) arc welding work is performed using the melting electrode type gas shielded arc welding method.

  Specific methods of the drilling operation in step S1 include a) punching using a punch, b) press punching using a die, c) cutting by laser, plasma, water jet method, and the like.

  Further, the arc welding operation in step S4 joins the joining auxiliary member 30 and the lower plate 20 via the weld metal 40 in the hole 11 of the upper plate 10, and fills the hole 33 provided in the joining auxiliary member 30. Is needed to do. Therefore, it is indispensable to insert a filler material (welding material) serving as a filler for arc welding. Specifically, the filler metal is melted and the weld metal 40 is formed by the following four arc welding methods.

(A) The melting electrode type gas shielded arc welding method is a welding method generally referred to as MAG (Mig) or MIG (Mig), and uses a solid wire or a flux-cored wire as a filler and arc generating melting electrode, and CO _2. , Ar, and He are used to form a sound weld by shielding the weld from the atmosphere with a shielding gas such as Ar, He.

  (B) The non-gas arc welding method is also called a self-shielded arc welding method, which uses a special flux-cored wire as a filler and arc-generating electrode, and on the other hand, eliminates the need for shielding gas and forms a sound weld. is there.

(C) The gas tungsten arc welding method is a kind of gas shielded arc welding method but is a non-melting electrode type and is generally called TIG (tig). As the shielding gas, an inert gas of Ar or He is used. An arc is generated between the tungsten electrode and the base material, and the filler wire is fed to the arc from the side.
Generally, the filler wire is not energized, but there is also a hot wire type TIG that energizes to increase the melting rate. In this case, no arc is generated in the filler wire.

  (D) The plasma arc welding method is the same as TIG in principle, but is a welding method in which the arc is contracted and the arc force is increased by making the gas double system and speeding up.

  (E) The coated arc welding method is an arc welding method using a coated arc welding rod in which a flux is applied to a metal core wire as a filler, and does not require a shielding gas.

As for the material of the filler material (welding material), as long as the weld metal 40 is an Fe alloy, a commonly used welding wire or welding rod can be applied. Note that a Ni alloy is applicable because it does not cause a problem in welding with iron.
Specifically, as JIS, (a) Z3312, Z3313, Z3317, Z3318, Z3321, Z3323, Z3334, (b) Z3313, (c) Z3316, Z3321, Z3334, (d) Z3211, Z3221, Z3223, Z3224, AWS (American Welding Society): (a) A5.9, A5.14, A5.18, A5.20, A5.22, A5.28, A5.29, A5.34, (b) A5.20, c) Standard materials such as A5.9, A5.14, A5.18, A5.28, (d) A5.1, A5.4, A5.5, and A5.11 are in circulation.

These arc welding methods are used to fill the hole portion 33 of the joining auxiliary member 30 with a filler material. The target position of the filler wire or the welding rod is the long axis direction of the hole portion 33 of the joining auxiliary member 30 as welding progresses. a. Move along _x .

  It is desirable that the weld metal 40 fills the hole 33 of the joining auxiliary member 30 and further forms a surplus Wa on the surface of the joining auxiliary member 30 (see FIGS. 1B and 1C). If no extra space is formed, that is, as shown in FIG. 4A, the hole 33 remains in appearance after welding, the bonding strength is insufficient particularly for external stress in the plate thickness direction (three-dimensional direction). (See FIG. 4B). For this reason, as shown in FIG. 5, by forming the surplus Wa, deformation of the joining auxiliary member 30 is suppressed against external stress in the plate thickness direction (three-dimensional direction), and high joining strength is obtained. It is done.

On the other hand, for the penetration on the opposite side to the surplus side, it is necessary that the lower plate 20 is appropriately melted as shown in FIG. 6A. In addition, as shown to FIG. 6B, even if it melts to the state where the weld metal 40 is formed exceeding the plate | board thickness of the lower board 20, and what is called a back wave appears, there is no problem.
However, if the lower plate 20 is not melted and only the weld metal 40 is on it, high strength cannot be obtained. Moreover, it is necessary to weld so that the weld metal 40 may melt deeply and the weld metal 40 and the lower plate 20 may not melt.
By the above operation, the upper plate 10 made of Al alloy or Mg alloy and the lower plate 20 made of steel are joined with high strength.

  Hereinafter, the role of the steel joining auxiliary member 30 used in the arc welding method will be described.

First, without using a joining auxiliary member, as shown in FIGS. 7A and 7B, an aluminum upper plate 10 and a steel lower plate 20 are simply overlapped, and a steel or nickel alloy welding wire is formed from the upper plate side. When arc welding is performed by holding arc welding with a fixed point for a fixed time, the formed weld metal 40a is aluminum and steel or an alloy of aluminum, steel and nickel. This alloy exhibits an intermetallic compound (IMC) that is brittle because of its high aluminum content. Even if such a dissimilar weld joint 100a seems to be joined at first glance, if a tensile stress is applied in the lateral direction (shear tension), the weld metal 40a is easily broken as shown in FIGS. 8A and 8B. And it will come off. Even when tensile stress is applied in the longitudinal direction (peeling tension), as shown in FIGS. 9A and 9B, the weld metal 40a is broken, or the boundary between the weld metal 40a and the upper plate 10 or the weld metal 40a The boundary portion of the lower plate 20 breaks, and the upper plate 10 comes off and the bonding is released.
Even if the upper plate 10 made of aluminum and the lower plate 20 made of steel are simply overlapped and attempted to be welded through in this way, the entire portion of the weld metal 40a becomes an intermetallic compound. However, it is not practical as a welded joint.

Further, as shown in FIGS. 10A and 10B, a method is conceivable in which a hole 11 having an appropriate size is formed in the upper plate 10 and a welding material of steel or nickel alloy is melted so as to fill the hole 11.
In this case, since the weld metal 40b formed of the steel and the welding material which is the lower plate 20 formed at the initial stage of welding does not melt aluminum, an intermetallic compound is not generated, and it has high strength and toughness. And is firmly coupled to the lower plate 20. In addition, the weld metal 40b formed in the hole 11 formed in the upper plate 10 has a very small proportion of aluminum melting, and the generation of intermetallic compounds is greatly suppressed, particularly in the central portion. Have. However, as long as it is limited to the vicinity of the hole 11 provided in the upper plate 10, a metal compound layer of aluminum and steel or aluminum and nickel is formed. When a shear tensile stress is applied to such a dissimilar material welded joint 100b as shown in FIG. 11A, the lower plate side is firmly metal-bonded, and thus can withstand high stress. On the other hand, although the intermetallic compound is formed around the hole on the upper plate side, since it cannot be separated and moved in shape, the base materials of the upper plate 10 and the lower plate 20 are initially deformed. . For this reason, compared with the dissimilar material welded joint 100a of FIG. 7A and FIG. However, when the deformation of the base material progresses and the joint portion is inclined near 90 ° as shown in FIG. If it becomes like this, the intermetallic compound formed in the peripheral part of the hole 11 will peel, and the upper board 10 will come out easily from a welding part. In other words, the improvement is insufficient. This result is, of course, the same in the vertical tension direction test as shown in FIGS. 12A and 12B.

  Due to the problems in the two dissimilar welded joints 100a and 100b, the joining auxiliary member 30 of this embodiment is used so as to withstand the tensile stress in the shearing direction and the stress in the vertical peeling direction. That is, as shown in FIGS. 2A to 2D, a hole is formed in the upper plate 10, and a steel joining auxiliary member 30 having a hole 33 in the center is placed on the same axis, and the upper plate 10 and the bonding member are joined. The weld metal 40 is formed by arc welding so as to fill the inside of the auxiliary member 30. If it does in this way, it will be in the state where the joining auxiliary member 30, the weld metal 40, and the lower board 20 are weld-joined by the strong metal bond as a cross section. The greatest role of the joining auxiliary member 30 which is wider than the hole 11 provided in the upper plate 10 is resistance to vertical peeling stress. As shown in FIG. 5, it is possible to prevent a phenomenon in which the interface between the upper plate 10 and the weld metal 40 is peeled off by applying an appropriately sized joining auxiliary member 30. Generally, the weld metal 40 breaks after sufficiently plastic deformation. It should be noted that the joining auxiliary member 30 does not adversely affect the initial stress even with respect to the tensile stress in the shear direction, and further, the peeling stress after the welded portion is inclined by 90 ° (see FIG. 11B) due to the base material deformation. The phenomenon that the interface between the upper plate 10 and the weld metal 40 is peeled off due to the change is prevented.

Further, the hole 33 of the joining auxiliary member 30 is filled with the weld metal in the hole 11 having the major axis and the minor axis provided in the upper plate 10, and thus the major axis and the minor axis are similar to the hole 11 of the upper plate 10. It has a non-circular shape with an axis. The lower plate 20 and the joining auxiliary member 30 are joined, but the upper plate 10 is not metallicly joined. However, as shown in FIGS. 13A and 13B, the weld metal 40 melted into the hole 11 of the upper plate 10 has a non-circular penetration shape. Therefore, even if a force F _R to the rotational direction in a plane acts, the lower plate 20 and the auxiliary bonding member 30 can be prevented from being rotated relative to the top plate 10.

Although described in detail later, the auxiliary bonding member 30, to increase the strength against external stress as the area is large and the thickness P _H is larger thickness direction (three dimensional directions), desirable. However, if it is larger than necessary, it may cause an increase in weight or excessive protrusion from the surface of the upper plate 10, resulting in aesthetic appearance deterioration and interference with other adjacent members. For this reason, the size of the joining auxiliary member 30 is determined according to the required design.

Further, as will be described in detail later, the size (P _SX , P _SY ) of the hole 33 of the auxiliary joining member 30 is the same as or smaller than the size (P _DX , P _DY ) of the hole 11 provided in the upper plate 10. There must be. If the size (P _SX , P _SY ) of the hole portion 33 of the joining auxiliary member 30 is larger, a large amount of Al alloy or Mg alloy is melted by hitting the arc that is at a very high temperature, and a large amount is formed in the formed weld metal 40. This is because an intermetallic compound is formed and is easily embrittled. Also, during arc welding, Al and Mg evaporate, generating a large amount of spatter and fumes and polluting the surrounding environment. It is important in this welding method that Al and Mg are not melted or evaporated as much as possible. Therefore, it is necessary that the weld metal 40 is not exposed until it reaches the height of the joining auxiliary member 30.

  Further, the joining auxiliary member 30 plays a role of minimizing a gap (gap) g generated on the overlapping surface when the upper plate 10 made of Al alloy or Mg alloy and the lower plate 20 made of steel are overlapped ( 14A). In the arc welding process, since the weld metal 40 is thermally contracted, a force acts in a direction in which the lower plate 20 and the joining auxiliary member 30 approach each other. As a result, even if there is some gap g before welding, as shown in FIG. 14B, the gap g decreases after welding and the design accuracy of the joint is increased.

  The material of the steel joining auxiliary member 30 is not particularly limited as long as it is pure iron and an iron alloy, and examples thereof include mild steel, carbon steel, and stainless steel.

  Moreover, the various dimensions of the joining auxiliary member 30 are set as follows in relation to the upper plate 10 as shown in FIGS. 15 to 16B.

・ Long axis side length P _SX and short axis side length P _{SY of the} hole
The long axis side length P _SX of the hole 33 is designed to be 50% or more and 100% or less with _respect to the long axis side length B _DX of the hole 11 of the upper plate 10. Further, the short axis side length _PSY of the hole 33 is designed to be 50% or more and 100% or less with _respect to the short axis side length BDY of the hole 11 of the upper plate 10. As described above, the size of the hole 33 of the auxiliary joining member 30 must be the same as or smaller than the size of the hole 11 formed in the upper plate 10 (that is, 100% or less). However, it is not desirable that the size of the hole 33 is too small. When the major axis side length P _SX and the minor axis side length P _SY of the hole 33 are less than 50% of the major axis side length B _DX and the minor axis side length B _{DY of the} hole 11, FIG. As shown, a gap is formed between the weld metal 40 to be formed and the hole wall of the upper plate 10, and when a stress in the shearing direction is applied, a large positional deviation is likely to occur. Also, as shown in FIG. 17B, the joining assisting member 30 is easily deformed and easily pulled out against the vertical peeling stress. For these reasons, the major axis side length P _SX and the minor axis side length P _SY of the hole 33 of the joining auxiliary member 30 are the major axis side length B _DX and the minor axis side of the hole 11 formed in the upper plate 10. It is desirable that the length B _{DY is} 50% or more for each.

・ Long axis side length _PDX and short axis side length _{PDY of the} joining auxiliary member
The long axis side length P _DX of the joining auxiliary member 30 is designed to be 105% or more with _respect to the long axis side length B _DX of the hole 11 of the upper plate 10. Further, the minor axis side length P _DY of the joining auxiliary member 30 is designed to be 105% or more with _respect to the minor axis side length B _DY of the hole 11 of the upper plate 10. As described above, the joining auxiliary member 30 plays a main role as a resistance force when an external stress in the thickness direction, in other words, a stress to be peeled off is applied. The joining auxiliary member 30 is desirable because the outer dimensions are larger and the thickness is larger, the strength is increased against external stress in the plate thickness direction (three-dimensional direction). If the major axis side length P _DX and the minor axis side length P _DY of the joining auxiliary member 30 are less than 105% of the major axis side length B _{DX and the} minor axis side length B _{DY of the} hole 11, the joining auxiliary member 30 However, when it is elasto-plastically deformed with respect to an external stress in the plate thickness direction, it is easy to obtain an apparent dimension equal to or smaller than the size of the hole 11 of the upper plate 10, and the upper plate 10 is likely to come off. That is, the joining auxiliary member 30 does not exhibit high resistance. Therefore, the major axis side length P _DX and the minor axis side length P _DY of the joining auxiliary member 30 are respectively set to 105% of the major axis side length B _{DX and the} minor axis side length B _DY of the hole 11 as lower limits. . More preferably, the major axis side length P _DX and the minor axis side length P _DY of the joining auxiliary member 30 are lower limits of 120% of the major axis side length B _{DX and the} minor axis side length B _DY of the hole 11, respectively. It is good to do. On the other hand, there is no need to provide an upper limit in terms of joint strength.

・ Thickness P _H of joining auxiliary member
The thickness P _H of the joining auxiliary member 30 is designed to be 50% or more and 150% or less of the plate thickness B _H of the upper plate 10. As mentioned above, the auxiliary bonding member 30 to increase the strength against external stress large external dimensions, and as the thickness P _H is larger thickness direction (three dimensional directions), desirable. By increasing the thickness P _H of the joining auxiliary member 30 in accordance with the plate thickness B _H of the upper plate 10 of the joint, a high resistance is exhibited. When the thickness P _H of the joining auxiliary member 30 is less than 50% of the plate thickness B _H of the upper plate 10, the joining auxiliary member 30 easily undergoes elasto-plastic deformation with respect to external stress in the plate thickness direction. When the apparent size is smaller than the size of the hole 11, the hole 11 is easily removed. That is, the joining auxiliary member 30 does not exhibit high resistance. Therefore, the thickness P _H of the joining auxiliary member 30 is set to 50% of the plate thickness B _H of the upper plate 10 as a lower limit. On the other hand, if the thickness P _H of the joining auxiliary member 30 exceeds 150% of the plate thickness B _H of the upper plate 10, there is no problem in the joint strength, but the overhanging shape results in poor appearance. Not only will the weight increase. Therefore, the thickness P _H of the joining auxiliary member 30 needs to be 150% or less of the plate thickness B _H of the upper plate 10.

Further, as shown in FIGS. 1B and 1C, when the surplus Wa is formed on the surface of the joining auxiliary member 30 in the filling welding process by the arc, the major axis side length W _{DX of the} surplus Wa is a short axis. The side length W _DY is set to 105% or more of the long axis side length P _SX and the short axis side length P _SY of the hole 33 of the joining auxiliary member 30.
As described above, the joining auxiliary member 30 has a role of exerting resistance against external stress in the plate thickness direction (three-dimensional direction), but does not exhibit high resistance unless the hole 33 is completely filled. When the hole 33 is not completely filled and the inner side surface of the hole 33 remains, the coupling area between the joining auxiliary member 30 and the weld metal 40 may be insufficient and may be easily detached. In order to increase the bonding area between the joining auxiliary member 30 and the weld metal 40, it is desirable to completely fill and form the surplus Wa. When the surplus Wa is formed, the major axis side length W _DX and the minor axis side length W _DY are the major axis side length P _SX and the minor axis side length P _SY of the hole 33 of the auxiliary joining member 30. Will be exceeded. The major axis side length W _DX and the minor axis side length W _DY of the surplus Wa are 105% or more of the major axis side length P _SX and the minor axis side length P _SY of the hole 33 of the auxiliary joining member 30, respectively. If this is the case, the overfill is surely formed, so this is the lower limit.

  In addition, about the plate | board thickness of the upper board 10 and the lower board 20, although it does not necessarily need to be limited, when construction efficiency and the shape as lap welding are considered, the board thickness of the upper board 10 is 4.0 mm or less. It is desirable to be. On the other hand, considering the heat input of arc welding, if the plate thickness is excessively thin, it will melt during welding and welding is difficult, so it is desirable that both the upper plate 10 and the lower plate 20 be 0.5 mm or more. .

  With the above configuration, the upper plate 10 can firmly join the aluminum alloy or the magnesium alloy, and the lower plate 20 can firmly join the steel material.

  Here, as a problem in the case of directly joining different kinds of metals, another problem is known in addition to the problem of forming the IMC. That is, when dissimilar metals come into contact with each other, it causes corrosion to accelerate in order to form a galvanic cell. Corrosion due to this cause (battery anode reaction) is called electrolytic corrosion. Corrosion proceeds when there is water on the surface where dissimilar metals are in contact with each other, so when this embodiment is applied to a place where water can easily enter as a joint, sealing to prevent ingress of water for the purpose of preventing electrolytic corrosion It is necessary to perform processing. Even in this bonding method, a plurality of surfaces where the Al alloy or Mg alloy is in contact with the steel are formed. Therefore, it is preferable to use a resin adhesive not only for the purpose of further improving the joint strength but also as a sealing material.

  For example, as in the first modification shown in FIGS. 18A and 18B, the adhesive 60 may be applied annularly around the welded portion around the welded surface at the joint surface of the upper plate 10 and the lower plate 20. In addition, as a method of applying the adhesive 60 over the entire periphery of the welded portion at the joint surface of the upper plate 10 and the lower plate 20, as in the second modification shown in FIGS. 19A and 19B, In this case, the rate of electrolytic corrosion of the upper plate 10, the lower plate 20, and the weld metal 40 can be reduced.

Moreover, you may apply | coat the adhesive agent 60 between the circumference | surroundings of the hole 11 of the upper board 10, and the lower surface of the joining auxiliary member 30 like the 3rd modification shown in FIG. 20A and 20B. Thereby, the electrolytic corrosion rate of the upper board 10, the joining auxiliary member 30, and the weld metal 40 can be lowered.
In this case, as a secondary effect, there is an operation of temporarily fixing the joining auxiliary member 30 to the upper plate 10 before arc welding. In particular, as shown in FIG. 21, when the arc welding is in a horizontal or upward posture, it is possible to prevent the joining auxiliary member 30 from falling due to gravity by applying the adhesive 60, and welding. Can be constructed properly.

  Furthermore, an adhesive 60 may be applied to a boundary portion between the joining auxiliary member 30 and the surface of the upper plate 10 as in a fourth modification shown in FIGS. 22A and 22B. As a result, the effect of reducing the electrolytic corrosion rate is obtained, and if the adhesive application is performed before arc welding, an operation of temporarily fixing the joining auxiliary member 30 to the upper plate 10 is obtained. In the third modification shown in FIGS. 20A and 20B, the application can be performed only before the welding process, but in the fourth modification shown in FIGS. 22A and 22B, the application can be performed before or after the welding process. It is.

In addition, the contact surface with the upper plate 10 of the joining auxiliary member 30 does not necessarily need to be a flat surface as shown in FIG. 23A. That is, as shown in FIGS. 23B and 23C, slits 34a and 34b may be provided on the contact surface of the joining auxiliary member 30 with the upper plate 10 as required. In particular, when a circumferential slit 34a, a grid-like slit 34b, or a radial slit (not shown) is provided on the contact surface side with the upper plate 10, the application of the adhesive 60 is applied to the gap between the slits 34a and 34b. Since it enters and does not escape, stable bonding is performed and the sealing effect is also ensured. Defining the thickness P _H of the auxiliary bonding member 30 in the case of such a non-planar surface is the largest part of the height.

Furthermore, a bulging portion 21 may be provided on the lower plate 20 as in a fifth modification shown in FIG.
Typically, the thickness of the upper plate 10 made of Al or Mg alloy may be large. When the plate thickness of the upper plate 10 is large, it is necessary to melt a lot of welding wires in the welding process and fill the hole portion 33 of the auxiliary joining member 30 beyond the hole 11 of the upper plate 10, and the amount of heat becomes excessive. The steel plate of the lower plate 20 is likely to melt away before the filling is completed. For this reason, if the bulging part 21 is provided by the drawing process about the lower board 20, since the volume of the hole 11 becomes small, it can be filled, preventing a melt-off defect.

  Further, in the fifth modified example, the bulging portion 21 of the lower plate 20 serves as a mark for aligning the upper plate 10 and the lower plate 20, and the bulging portion 21 of the lower plate 20 and the hole of the upper plate 10. 11 can be easily matched, leading to an improvement in the efficiency of the overlaying work.

  In the drawing process of the bulging portion 21, as shown in FIG. 25A, the periphery of the portion where the bulging portion 21 of the lower plate 20 is formed is constrained by the die 50. And as shown to FIG. 25B, the bulging part 21 is shape | molded by pressing the punch 51 by applying a pressure to the part in which the bulging part 21 is formed.

  Moreover, since the welding method of this embodiment can be said to be spot welding with a small joining area, when joining the overlapping portions J of practical members having a certain joining area, the welding method is shown in FIGS. 26A to 26C. As shown, multiple implementations may be performed. Thereby, strong joining is performed in the overlapping portion J. Although this embodiment can be used for an open cross-sectional structure as shown in FIGS. 26B and 26C, it can be suitably used particularly for a closed cross-sectional structure as shown in FIG. 26A.

  Moreover, when joining the overlapping part J of practical members, it is common to provide several joining parts in the area | region which adjoined from a viewpoint of ensuring intensity | strength and rigidity. In the joint as shown in FIG. 26A to FIG. 26C, the joining auxiliary member 30 is inserted one by one for every welding position. However, when there are a plurality of welding positions in the adjacent region, as shown in FIGS. 27A to 27C, the joining auxiliary member 30 </ b> A having a plurality of holes 33 matched to the distances of the plurality of welding positions is used. The workability of arrangement | positioning of the joining auxiliary member 30 can be improved.

28A to 28C show examples of the joining auxiliary member 30A having a plurality of holes 33, respectively. When such a joining auxiliary member 30A is used, a plurality of holes 11 are also formed in the upper plate 10, and a plurality of holes 33 of the joining auxiliary member 30A and a plurality of holes 11 provided in the upper plate 10 are provided. Are arranged on the same axis. And while filling the some hole part 33 of the joining auxiliary member 30 with the weld metal 40, the lower board 20 and the joining auxiliary member 30 are welded. In addition, in the rectangular joining auxiliary member 30A in FIG. 28B and the rounded quadrangular joining auxiliary member 30A in FIG. 28C, the dimension definition of the distances P _X and P _Y from the center of the hole 33 to one side of the square is described above. Using the long axis side length P _DX and the short axis side length P _DY given in relation to the upper plate 10, P _DX = 2 · P _X and P _DY = 2 · P _Y are given.

As described above, according to the arc welding method for dissimilar material joining according to the present embodiment, the step of forming the non-circular holes 11 having different vertical and horizontal lengths in the upper plate 10 and the step of overlapping the upper plate 10 and the lower plate 20 are performed. And the steel joining auxiliary member 30 in which the non-circular hole portions 33 having different vertical and horizontal lengths are formed, the hole portions 33 being coaxial with the holes 11 provided in the upper plate 10 and in the respective major axis directions. The hole 33 of the joining auxiliary member 30 is filled with the weld metal 40 by the step of arranging on the upper plate 10 so that a _x and b _x coincide with each other and the following methods (a) to (e): And welding the lower plate 20 and the joining auxiliary member 30 via the weld metal 40 in the hole 11 of the upper plate 10.

(A) A gas shielded arc welding method using a welding wire from which an iron alloy or Ni alloy weld metal 40 is obtained as a melting electrode.
(B) Non-gas arc welding method using the welding wire as a melting electrode.
(C) Gas tungsten arc welding method using the welding wire as a non-melting electrode filler.
(D) A plasma arc welding method using the welding wire as a non-melting electrode filler.
(E) A coated arc welding method in which a coated arc welding rod from which an iron alloy or Ni alloy weld metal 40 is obtained is used as a melting electrode.
As a result, the upper plate 10 of the Al alloy or Mg alloy and the lower plate 20 of the steel can be joined with low-cost arc welding equipment with strong and reliable quality, and the open cross-section structure can be changed to the closed cross-section structure. Can be applied without limitation.

  Further, the lower plate 20 has a bulging portion 21 formed by drawing, and the bulging portion 21 of the lower plate 20 is disposed in the hole 11 of the upper plate 10 in the overlapping process. Thereby, even when the plate | board thickness of the upper board 10 is large, a melt-off defect can be prevented and it can weld and the upper board 10 and the lower board 20 can be positioned easily.

  Further, before the overlapping step, a step of applying the adhesive 60 around the hole 11 is further provided on at least one overlapping surface of the upper plate 10 and the lower plate 20. Thereby, an adhesive agent can act as a sealing material besides joint strength improvement, and can reduce the electrolytic corrosion rate of the upper board 10, the lower board 20, and the weld metal 40. FIG.

  Further, in the arranging step, the adhesive 60 is applied to at least one facing surface between the joining assisting member 30 and the upper plate 10 facing the joining assisting member. Thereby, the electrolytic corrosion rate of the upper plate 10, the joining auxiliary member 30, and the weld metal 40 can be lowered.

  Further, the adhesive 60 is applied to the boundary portion between the joining auxiliary member 30 and the surface of the upper plate 10 during the arrangement step or after the filling and welding step. Thereby, the joining strength of the upper board 10 and the joining auxiliary member 30 can be improved. In addition, the effect | action which can temporarily fix the joining auxiliary member 30 will be acquired if the adhesive agent 60 is apply | coated in the case of an insertion process.

In addition, since the long axis side length P _SX of the hole 33 of the joining auxiliary member 30 is 50% or more and 100% or less with _respect to the long axis side length B _DX of the hole 11 of the upper plate 10, It is possible to prevent the intermetallic compound from being suppressed, the displacement due to the shear stress, and the upper plate 10 from coming off due to the vertical peeling stress.
Further, since the short axis side length P _SY of the hole 33 is 50% or more and 100% or less with _respect to the short axis side length B _DY of the hole 11 of the upper plate 10, the intermetallic compound in the weld metal 40 is formed. It is possible to prevent the displacement of the upper plate 10 due to the suppression and the shear stress, and the upper plate 10 from coming off due to the vertical peeling stress.

Moreover, since the major axis side length P _DX of the joining auxiliary member 30 is 105% or more with respect to the major axis side length B _DX of the hole 11 of the upper plate 10, the joining auxiliary member 30 is arranged outside the plate thickness direction. It can function as a resistance to stress.
In addition, since the minor axis side length P _DY of the joining auxiliary member 30 is 105% or more with respect to the minor axis side length B _DY of the hole 11 of the upper plate 10, the joining auxiliary member 30 is external to the plate thickness direction. It can function as a resistance to stress.

Further, since the thickness P _H of the joining auxiliary member 30 is 50% or more and 150% or less of the plate thickness B _H of the upper plate 10, the joining auxiliary member 30 has a plate thickness in consideration of appearance and weight increase. Can act as a resistance to external stress in the direction.

Further, in the filling welding process, the surplus Wa is formed on the surface of the joining auxiliary member, and the major axis side length W _{DX of the} surplus Wa is the major axis side length P of the hole 33 of the joining auxiliary member 30. Since it becomes 105% or more with respect to _SX , surplus Wa can function as a resistance force to the external stress of a plate | board thickness direction.
Further, in the filling welding process, excess prime Wa on the surface of the bonding auxiliary member is formed, and short shaft length W _DY of excess prime Wa is short shaft length P of the hole portion 33 of the auxiliary bonding member 30 Since it is 105% or more with respect to _SY , the surplus Wa can function as a resistance force to external stress in the thickness direction.

The upper plate 10 is provided with a plurality of holes 11, and the joining auxiliary member 30 includes a plurality of hole portions 33, and is provided in the plurality of hole portions 33 of the joining auxiliary member 30 and the upper plate 10. The plurality of holes 11 are arranged coaxially and the respective major axis directions a _x and b _x coincide with each other, and the plurality of holes 33 of the joining auxiliary member 30 are respectively filled with the weld metal 40 and The lower plate 20 and the joining auxiliary member 30 are welded through the weld metal 40 in the hole 11 of the plate 10. Thereby, when providing a some junction part, workability | operativity of arrangement | positioning of the joining auxiliary member 30 can be improved.

  Moreover, the joining auxiliary member 30 of the present embodiment is made of steel, and is formed with non-circular hole portions 33 having different vertical and horizontal lengths. Thereby, joining auxiliary member 30 is used suitably for the arc welding method for different material joining mentioned above.

Further, the dissimilar material welded joint 1 of the present embodiment includes an upper plate 10 made of an aluminum alloy or a magnesium alloy, and a steel lower plate 20 arc-welded to the upper plate 10, and the upper plate 10 It further includes a steel joining auxiliary member 30 that has non-circular holes 11 having different vertical and horizontal lengths facing the overlapping surface with the plate 20, and is formed with non-circular hole portions 33 having different vertical and horizontal lengths. The auxiliary member 30 is disposed on the upper plate 10 so that the hole 33 is coaxial with the hole 11 provided in the upper plate 10 and the major axis directions a _x and b _x coincide with each other. The hole 33 is filled with a weld metal 40 of iron alloy or Ni alloy, and a melted portion W is formed by the weld metal 40 and a part of the molten lower plate 20 and the joining auxiliary member 30. The
As a result, the dissimilar welded joint 1 including the upper plate 10 of Al alloy or Mg alloy and the lower plate 20 of steel is joined with a strong and reliable quality using an inexpensive arc welding equipment and opened. The present invention can be applied to both a cross-sectional structure and a closed cross-sectional structure without limitation.

  Note that the present invention is not limited to the above-described embodiments and examples, and modifications, improvements, and the like can be made as appropriate.

  Here, the effectiveness of this embodiment was confirmed using the following Examples A to E.

<Example A>
In Example A, a lap joint having a combination in which the upper plate 10 is an aluminum alloy A5083 having a plate thickness of 1.6 mm and the lower plate 20 is a 590 MPa class high-tensile steel plate having a plate thickness of 1.4 mm was used. In addition, this lap joint uses a JIS Z3312 G78A4MN5CM3T steel welding wire with a diameter of 1.2 mm, and an arc while moving the welding wire by a mag welding method using a mixed gas of Ar 80% + CO ₂ 20% as a shielding gas. Joined by welding.

  This welded joint 1 is subjected to a destructive test according to JIS Z3136 “Test specimen dimensions and test method for shear test of resistance spot and projection welded joint” and JIS Z3137 “Cross tensile test of resistance spot and projection welded joint”. It was. The long axis side of the hole 11 provided in the upper plate 10 and the long axis side of the hole portion 33 of the joining auxiliary member 30 are directed to the short side of the rectangular upper plate 10 as a test piece. Here, the tensile strength of Z3136 is represented as TSS, and the tensile strength of Z3137 is represented as CTS. As the pass / fail judgment values, TSS ≧ 8 kN and CTS ≧ 5 kN.

  Furthermore, as a preferable performance value, although not essential, JASO-CCT (Japan Automobile Standards Cyclic Corrosion Test), in which the welded joint is accelerated by repeated spraying with salt water → drying → wet, is conducted for 28 days, and then the destructive test is performed as well. To obtain post-corrosion TSS and post-corrosion CTS. The acceptable judgment value of these preferable performance values was 80% or more with respect to the value of the corrosion free test.

  In Table 1, the comparative example No. A1 to A5, this example No. Shown in A6 to A16.

  No. A <b> 1 is obtained by performing arc welding directly on the upper plate 10 without using a joining auxiliary member and without making a hole in the upper plate 10. Also, no adhesive is used. Since the steel welding wire and the aluminum base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, resulting in low TSS and CTS.

  No. In A 2, a rounded round hole 11 having a major axis length of 9.0 mm and a minor axis length of 7.0 mm is provided on the upper plate 10, but arc welding is performed without using the joining auxiliary member 30. No. Compared with A1, the amount of aluminum mixed in the weld metal is reduced, so the amount of intermetallic compounds is small and the degree of embrittlement is low, but still TSS and CTS are low.

  No. A3 is obtained by placing the joining auxiliary member 30 on the upper plate 10 which is not perforated and arc welding from above. The material of the joining auxiliary member 30 is JIS G3106 SM490C, and the outer shape is similar to the hole 11 of the upper plate 10 (hereinafter, the material of Example A is the same). Here, the joining auxiliary member 30 is not perforated. As a result, the joining auxiliary member 30 and the upper plate 10 could not penetrate into the lower plate 20 and could not be welded.

  No. A4 is obtained by placing the auxiliary joining member 30 on the upper plate 10 having a rounded rectangular shape with a major axis length of 9.0 mm and a minor axis length of 7.0 mm, and arc welding from above. Here, the joining auxiliary member 30 is not perforated. As a result, although it was possible to somehow penetrate the joining auxiliary member 30 and melt into the lower plate 20, the penetration width of the lower plate 20 was very small, and it was easily broken when subjected to a destructive test.

  No. A5 is obtained by placing the joining auxiliary member 30 on the upper plate 10 that is not perforated and arc welding from above. The joining auxiliary member 30 has a rounded rectangular hole having a major axis length of 9.0 mm and a minor axis length of 7.0 mm. As a result, the weld metal was No. As in A1, since the steel welding wire and the aluminum base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, resulting in low TSS and CTS.

On the other hand, no. In A6 to A16, a rounded rectangular joining auxiliary member 30 is placed on the upper plate 10 having a rounded rectangular shape with a major axis length of 9.0 mm and a minor axis length of 7.0 mm, and from above. Arc welded. The joining auxiliary member 30 is provided with a rounded rectangular hole having an appropriate size within the scope of the present invention. In these test bodies, the aluminum inflow of the weld metal 40 to be formed is suppressed to zero or extremely low due to the presence of the joining auxiliary member 30, and a high-quality weld metal is formed. Further, the penetration of the lower plate 20 becomes sufficiently large, and the joining auxiliary member 30 has a structure having a wide area with respect to the hole 11 of the upper plate 10, so that it is possible to prevent slipping off in the cross tension test and is high. CTS was also obtained. Furthermore, the test specimens (A7 to A9, A12 to A16) in which the metal room temperature rapid curing type two-component mixed adhesive is applied to an appropriate location have an effect of preventing electrolytic corrosion at the aluminum / steel interface, and CTS caused by corrosion. And the decrease in TSS was suppressed, and high post-corrosion CTS and TSS were exhibited. Specifically, no. For A6, no. A7, No. A8, No. It can be seen that the post-corrosion TSS and the post-corrosion CTS increase in order as the number of A9 and adhesive application points increases. No. A15 is the thickness P _H of the auxiliary bonding member 30 is beyond the most preferred range, the joint performance is good performance without any problem. However, this is an example that deviates from the most preferable range in that it requires a longer welding time than others and is not beautiful because it lacks in appearance and flatness.

<Example B>
In Example B, a combination lap joint was used in which the upper plate 10 was a magnesium alloy ASTM AZ31B having a plate thickness of 0.8 mm, and the lower plate 20 was a 780 MPa class high strength steel plate having a plate thickness of 1.0 mm. In addition, this lap joint is formed by a DC TIG welding method using Ar 100% gas as a shielding gas, and a tungsten electrode and a filler while inserting a steel welding wire of 1.0 mm in diameter as JIS Z3317 W55-1CM3 as a non-conducting filler. Joining was performed by arc welding while moving the wire.

  The weld joint 1 was subjected to a destructive test according to JIS Z3136 and JIS Z3137. The long axis side of the hole 11 provided in the upper plate 10 and the long axis side of the hole portion 33 of the joining auxiliary member 30 are directed to the short side of the rectangular upper plate 10 as a test piece. Here, the tensile strength of Z3136 is represented as TSS, and the tensile strength of Z3137 is represented as CTS. As the pass / fail judgment values, TSS ≧ 4 kN and CTS ≧ 3 kN.

  Furthermore, as a preferable performance value, although not essential, as in Example A, JASO-CCT is performed on the welded joint 1 for 28 days, and then a destructive test is performed in the same manner to perform post-corrosion TSS and post-corrosion CTS. Acquired. The acceptable judgment value of these preferable performance values was 80% or more with respect to the value of the corrosion free test.

  In Table 2, the comparative example No. B1 to B5, this example No. Shown in B6 to B17.

  No. B1 does not use a joining auxiliary member, does not make a hole in the upper plate 10, and performs direct arc welding on the upper plate 10. No adhesive is used. Since the steel welding wire and the magnesium base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, resulting in low TSS and CTS.

  No. B2 is provided with an elliptical hole 11 consisting of a semicircle-rectangle-semicircle having a major axis length of 7.0 mm and a minor axis length of 5.0 mm on the upper plate 10, but arc welding is performed without using a joining auxiliary member. It has been implemented. No. Compared to B1, the amount of magnesium alloy mixed in the weld metal is reduced, so the amount of intermetallic compounds is small and the degree of embrittlement is low, but still TSS and CTS are low.

  No. B3 is obtained by placing the joining auxiliary member 30 on the upper plate 10 that is not perforated and arc welding from above. The material of the joining auxiliary member 30 is JIS G3101 SS400, and the outer shape is circular (hereinafter, the material and outer diameter shape of Example B are the same). Here, the joining auxiliary member 30 is not perforated. As a result, although it was possible to somehow penetrate the joining auxiliary member 30 and the upper plate 10 and melt into the lower plate 20, the penetration width of the lower plate 20 was very small, and it was easily broken when subjected to a destructive test.

  No. B4 is No. The joining auxiliary member 30 is placed on the upper plate 10 in which the oval hole 11 similar to B2 is drilled, and arc welding is performed thereon. Here, the joining auxiliary member 30 is not perforated. As a result, although it was possible to somehow penetrate the joining auxiliary member 30 and melt into the lower plate 20, the penetration width of the lower plate 20 was very small, and it was easily broken when subjected to a destructive test.

  No. B5 is obtained by placing the joining auxiliary member 30 on the upper plate 10 that is not perforated and arc welding from above. The joining auxiliary member 30 is formed with a hole having a diameter of 3.8 mm. As a result, the weld metal was No. Similar to B1, since the steel welding wire and the magnesium alloy base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, resulting in low TSS and CTS.

  On the other hand, no. B6 to B17 are circular joining aids on the upper plate 10 in which an oblong hole 11 made of a semicircle-rectangle-semicircle having a major axis length of 7.0 mm × minor axis length of 5.0 mm is formed. The member 30 is placed and arc-welded from above. The joining auxiliary member 30 is provided with an oval hole having an appropriate size within the scope of the present invention. In these test bodies, the magnesium inflow of the weld metal 40 to be formed is suppressed to zero or extremely low due to the presence of the joining auxiliary member 30, and the high-quality weld metal 40 is formed. Further, the penetration of the lower plate 20 becomes sufficiently large, and the joining auxiliary member 30 has a structure having a wide area with respect to the hole 11 of the upper plate 10, so that it is possible to prevent slipping off in the cross tension test and is high. CTS was also obtained. Furthermore, in the specimens (B7 to B17) in which an adhesive is applied to an appropriate location, there is an action to prevent electrolytic corrosion at the magnesium alloy / steel interface, and a decrease in CTS and TSS due to corrosion is suppressed, and after high corrosion. CTS and TSS are shown. Specifically, no. For B6, no. B7, No. B8, No. It can be seen that the post-corrosion TSS and the post-corrosion CTS increase in order as the number of B9 and adhesive application points increases.

<Example C>
In Example C, a combination lap joint was used in which the upper plate 10 was an aluminum alloy A6061 with a plate thickness of 3.6 mm, and the lower plate 20 was a 400 MPa class steel plate with a plate thickness of 2.6 mm. The lap joint was joined by arc welding while moving the welding rod by a coated arc welding method using a JIS Z3224 ENi6062 Ni alloy-coated arc welding rod having a diameter of 4.0 mm. When the upper plate 10 is perforated, a deep drawing process using a punch is performed on the welded portion of the lower plate 20 to enter a height of 1.8 mm, that is, the center of the thickness of the hole 11 provided in the upper plate 10. Was processed as follows.

  The weld joint 1 was subjected to a destructive test according to JIS Z3136 and JIS Z3137. The long axis side of the hole 11 provided in the upper plate 10 and the long axis side of the hole portion 33 of the joining auxiliary member 30 are directed to the short side of the rectangular upper plate 10 as a test piece. Here, the tensile strength of Z3136 is represented as TSS, and the tensile strength of Z3137 is represented as CTS. As the pass / fail judgment values, TSS ≧ 9 kN and CTS ≧ 6 kN.

  Further, as a preferable performance value, although not essential, as in Examples A and B, JASO-CCT was performed on welded joint 1 for 28 days, and then a destructive test was performed in the same manner. CTS was obtained after corrosion. The acceptable judgment value of these preferable performance values was 80% or more with respect to the value of the corrosion free test.

  In Table 3, the comparative example No. C1-C5, this example No. Shown in C6-C13.

  No. C1 does not use a joining auxiliary member, does not make a hole in the upper plate 10, and performs arc welding directly on the upper plate 10. No adhesive is used. Since the Ni alloy welding rod and the aluminum base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, and had low TSS and CTS.

  No. In C2, an elliptical hole 11 having a major axis of 12.0 mm and a minor axis of 9.0 mm is provided on the upper plate 10, but arc welding is performed without using the joining auxiliary member 30. No. Compared to C1, the amount of aluminum alloy mixed in the weld metal decreases, so the amount of intermetallic compounds is small and the degree of embrittlement is low, but still TSS and CTS are low.

  No. C3 is obtained by placing the joining auxiliary member 30 on the upper plate 10 that is not perforated and arc welding from above. The material of the joining auxiliary member 30 is JIS G4051 S12C, and the outer diameter shape is a rounded square (hereinafter, the material of Example C and the outer diameter shape are the same). Here, the joining auxiliary member 30 is not perforated. As a result, the joining auxiliary member 30 and the upper plate 10 could not penetrate into the lower plate 20 and could not be welded.

  No. C4 is obtained by placing the joining auxiliary member 30 on the upper plate 10 having an elliptical hole having a major axis of 12.0 mm and a minor axis of 9.0 mm, and arc welding from above. Here, the joining auxiliary member 30 is not perforated. As a result, although it was possible to somehow penetrate the joining auxiliary member 30 and melt into the lower plate 20, the penetration width of the lower plate 20 was very small, and it was easily broken when subjected to a destructive test.

  No. C5 is obtained by placing the joining auxiliary member 30 on the upper plate 10 which is not perforated and arc welding from above. The joining auxiliary member 30 has a diameter of 7.0 mm. As a result, the weld metal was No. Similar to C1, since the Ni alloy welding rod and the magnesium alloy base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, resulting in low TSS and CTS.

  On the other hand, no. C6 to C13 are obtained by placing a rounded square joining auxiliary member 30 on the upper plate 10 having an elliptical hole having a major axis of 12.0 mm and a minor axis of 9.0 mm, and arc welding from above. . The joining auxiliary member 30 is provided with an oval hole having an appropriate size within the scope of the present invention. In these specimens, the aluminum inflow of the weld metal formed is suppressed to zero or extremely low due to the presence of the joining auxiliary member 30, and a high-quality weld metal is formed. Further, the penetration of the lower plate 20 becomes sufficiently large, and the joining auxiliary member 30 has a structure having a wide area with respect to the hole 11 of the upper plate 10, so that it is possible to prevent slipping off in the cross tension test and is high. CTS was also obtained. Although the plate thickness of the upper plate 10 is relatively thick at 3.6 mm, the distance between the joining auxiliary member 30 and the lower plate 20 is reduced at the welded portion by deep drawing of the lower plate 20, improving the welding efficiency and preventing the falling-off. The effect was obtained. Furthermore, in the test body (No. C7 to C11) in which an adhesive is applied to an appropriate location, there is an action to prevent electrolytic corrosion at the aluminum / steel interface, and the decrease in CTS and TSS due to corrosion is suppressed, resulting in high corrosion. Post CTS and TSS were shown.

<Example D>
In Example D, a combination lap joint was used in which the upper plate 10 was an aluminum alloy A6N01 having a plate thickness of 1.2 mm, and the lower plate 20 was an SPCC steel plate having a plate thickness of 1.2 mm. The lap joint was joined by arc welding while moving the welding wire by a self-shielded arc welding method using a JIS Z3313 T49YT4-0NA steel flux cored wire having a diameter of 1.2 mm.

  The weld joint 1 was subjected to a destructive test according to JIS Z3136 and JIS Z3137. The long axis side of the hole 11 provided in the upper plate 10 and the long axis side of the hole portion 33 of the joining auxiliary member 30 are directed to the short side of the rectangular upper plate 10 as a test piece. Here, the tensile strength of Z3136 is represented as TSS, and the tensile strength of Z3137 is represented as CTS. As the pass / fail judgment values, TSS ≧ 6 kN and CTS ≧ 4 kN.

  Further, although not essential, as a preferable performance value, as in Examples A, B, and C, JASO-CCT is performed on welded joint 1 for 28 days, and then a destructive test is performed in the same manner. TSS and post-corrosion CTS were obtained. The acceptable judgment value of these preferable performance values was 80% or more with respect to the value of the corrosion free test.

  In Table 4, the comparative example No. D1 to D2, this example No. Shown at D3-D5.

  No. D <b> 1 is obtained by performing arc welding directly on the upper plate 10 without using a joining auxiliary member and without making a hole in the upper plate 10. No adhesive is used. Since the steel welding wire and the aluminum base material were melted and mixed, the formed weld metal was an extremely brittle intermetallic compound, and had low TSS and CTS.

  No. In D2, a rectangular hole 11 of 9.0 mm × 6.0 mm is provided in the upper plate 10, but arc welding is performed without using the joining auxiliary member 30. No. Compared with D1, since the amount of aluminum alloy mixed in the weld metal decreases, the amount of intermetallic compounds is small and the degree of embrittlement is low, but still TSS and CTS are low.

  On the other hand, no. D3 to D5 are obtained by mounting a circular joining auxiliary member 30 obtained by processing a JIS G3106 SM490A material on an upper plate 10 having a rectangular hole of 9.0 mm × 6.0 mm and arc welding from above. It is. The joining auxiliary member 30 is provided with a rectangular hole having an appropriate size within the scope of the present invention. In these test bodies, the aluminum inflow of the weld metal 40 to be formed is suppressed to zero or extremely low due to the presence of the joining auxiliary member 30, and the high-quality weld metal 40 is formed. Further, the penetration of the lower plate 20 becomes sufficiently large, and the joining auxiliary member 30 has a structure having a wide area with respect to the hole 11 of the upper plate 10, so that it is possible to prevent slipping off in the cross tension test and is high. CTS was also obtained. Furthermore, the test body No. which applied the adhesive material to an appropriate location. In D4 and D5, there was an effect of preventing electrolytic corrosion at the aluminum-steel interface, and the decrease in CTS and TSS due to corrosion was suppressed, and high post-corrosion CTS and TSS were shown. Specifically, the test body No. Compared to D3, No. 3 coated with adhesive. D4 has improved CTS and TSS after corrosion.

<Example E>
In Example E, a combination lap joint was used in which the upper plate 10 was an aluminum alloy A7N01 having a plate thickness of 4.0 mm, and the lower plate 20 was a 1180 MPa class high-tensile steel plate having a plate thickness of 3.0 mm. A bulging portion 21 having a height of 2.0 mm was formed at a portion to be welded of the lower plate 20 by drawing. In addition, this lap joint uses a JIS Z3321 YS309L stainless steel welding wire with a diameter of 1.2 mm, and is a welding wire by a plasma arc welding method in which shielding gas: Ar 99% + H ₂ 1% and plasma gas: Ar 100%. It was joined by arc welding while moving.

  This welded joint 1 is subjected to a destructive test according to JIS Z3136 “Test specimen dimensions and test method for shear test of resistance spot and projection welded joint” and JIS Z3137 “Cross tensile test of resistance spot and projection welded joint”. It was. The long axis side of the hole 11 provided in the upper plate 10 and the long axis side of the hole portion 33 of the joining auxiliary member 30 are directed to the short side of the rectangular upper plate 10 as a test piece. Here, the tensile strength of Z3136 is represented as TSS, and the tensile strength of Z3137 is represented as CTS. As the pass / fail judgment values, TSS ≧ 10 kN and CTS ≧ 8 kN.

  Furthermore, as a preferable performance value, although not essential, as in Examples A to D, JASO-CCT was performed on the welded joint 1 for 28 days, and after that, a destructive test was performed in the same manner. Post CTS was obtained. The acceptable judgment value of these preferable performance values was 80% or more with respect to the value of the corrosion free test.

  In Table 5, in this example, No. Shown at E1-E3.

  No. E1 to E3 are obtained by placing a rectangular joining auxiliary member 30 made of SUS304 stainless steel on the top plate 10 having a rounded rectangular hole of 21.0 mm × 18.0 mm and arc welding from above. is there. The joining auxiliary member 30 is provided with a rounded rectangular hole having an appropriate size within the scope of the present invention. In these test bodies, the aluminum inflow to the weld metal 40 to be formed is suppressed to zero or extremely low by the presence of the joining auxiliary member 30, and a high-quality weld metal is formed. Further, the penetration of the lower plate 20 becomes sufficiently large, and the joining auxiliary member 30 has a structure having a wide area with respect to the hole 11 of the upper plate 10, so that it is possible to prevent slipping off in the cross tension test and is high. CTS was also obtained. Although the plate thickness of the upper plate 10 is comparatively thick at 4.0 mm, the distance between the auxiliary joining member 30 and the lower plate 20 is reduced at the welded portion by deep drawing of the lower plate 20 to improve the welding efficiency and prevent the metal from falling off. The effect was obtained. Furthermore, the test body No. which applied the adhesive material to an appropriate location. E1 and E3 have the effect of preventing electrolytic corrosion at the aluminum-steel interface, and the decrease in CTS and TSS due to corrosion was suppressed, and high post-corrosion CTS and TSS were shown. Specifically, the test body No. with no adhesive was used. For E2, no. E3 is coated with an adhesive, and the post-corrosion TSS and post-corrosion CTS are improved.

DESCRIPTION OF SYMBOLS 10 Upper plate 11 Hole 20 Lower plate 30 Joining auxiliary member 33 Hole 40 Weld metal W Melting part Wa Extra pile

Claims (26)

An arc welding method for joining different materials for joining a first plate made of an aluminum alloy or a magnesium alloy and a second plate made of steel,
Forming a non-circular hole having different vertical and horizontal lengths in the first plate;
Superimposing the first plate and the second plate;
A steel joining auxiliary member in which non-circular hole portions having different vertical and horizontal lengths are formed, the hole portions being coaxial with the holes provided in the first plate, and the long-axis directions thereof coincide with each other. Arranging on the first plate;
The hole of the joining auxiliary member is filled with a weld metal by any of the following methods (a) to (e), and the second plate is inserted through the weld metal in the hole of the first plate. And welding the joining auxiliary member;
Arc welding method for dissimilar materials joining.
(A) A gas shielded arc welding method using a welding wire from which an iron alloy or Ni alloy weld metal is obtained as a melting electrode.
(B) Non-gas arc welding method using the welding wire as a melting electrode.
(C) Gas tungsten arc welding method using the welding wire as a non-melting electrode filler.
(D) A plasma arc welding method using the welding wire as a non-melting electrode filler.
(E) A coated arc welding method in which a coated arc welding rod from which the weld metal of an iron alloy or Ni alloy is obtained is used as a melting electrode. The second plate has a bulge formed by drawing,
The arc welding method for dissimilar material joining according to claim 1, wherein, in the overlapping step, the bulging portion of the second plate is disposed in the hole of the first plate.   Before the superposition step, the method further comprises a step of applying an adhesive over the entire circumference of the at least one superposition surface of the first plate and the second plate around the hole. The arc welding method for joining dissimilar materials according to claim 1 or 2.   In the said arrangement | positioning process, an adhesive agent is apply | coated to at least one opposing surface between the said joining auxiliary member and the said 1st board facing this joining auxiliary member. The arc welding method for joining dissimilar materials described in 1.   5. The adhesive according to claim 1, wherein an adhesive is applied to a boundary portion between the joining auxiliary member and the surface of the first plate during the arranging step or after the filling welding step. Arc welding method for joining different materials. The long axis side length _PSX of the hole portion of the joining auxiliary member is 50% or more and 100% or less with _respect to the long axis side length BDX of the hole of the first plate. 2. An arc welding method for joining dissimilar materials according to item 1. The minor axis side length _PSY of the hole portion of the joining auxiliary member is 50% or more and 100% or less with _respect to the minor axis side length _BDY of the hole of the first plate. 2. An arc welding method for joining dissimilar materials according to item 1. The long axis side length P _DX of the joining auxiliary member is 105% or more with _respect to the long axis side length B _DX of the hole of the first plate, according to any one of claims 1 to 7. Arc welding method for joining dissimilar materials. 9. The short axis side length P _DY of the joining auxiliary member is 105% or more with _respect to the short axis side length B _DY of the hole of the first plate, according to claim 1. Arc welding method for joining dissimilar materials. The thickness P _H of the auxiliary bonding member, wherein at first 150% or less than 50% of the thickness B _H of the plate, dissimilar metals joint for arc welding method according to any one of claims 1-9 . In the filling welding step, a surplus is formed on the surface of the joining auxiliary member, and the major axis side length W _{DX of the} surplus is equal to the major axis side length P _SX of the hole of the joining auxiliary member. On the other hand, the arc welding method for dissimilar material joining according to any one of claims 1 to 10, which is 105% or more. In the filling welding process, excess prime is formed on the surface of the auxiliary bonding member, and short shaft length W _DY of the excess prime is a short shaft length P _SY of the hole portion of the auxiliary bonding member On the other hand, the arc welding method for joining dissimilar materials according to any one of claims 1 to 11, which is 105% or more. The first plate has a plurality of holes, and the joining auxiliary member includes a plurality of holes.
The plurality of hole portions of the joining auxiliary member and the plurality of holes provided in the first plate are arranged coaxially and respectively in the same long axis direction;
The plurality of holes of the joining auxiliary member are filled with weld metal, respectively, and the second plate and the joining auxiliary member are welded through the weld metal in the hole of the first plate. The arc welding method for joining different materials according to any one of -12. It is used for the arc welding method for dissimilar material joining according to any one of claims 1 to 13,
A joining auxiliary member made of steel and formed with non-circular holes having different vertical and horizontal lengths. A dissimilar weld joint comprising: a first plate made of an aluminum alloy or a magnesium alloy; and a second plate made of steel arc-welded to the first plate,
The first plate has non-circular holes with different vertical and horizontal lengths facing the overlapping surface with the second plate,
It further comprises a steel joining auxiliary member in which non-circular holes having different vertical and horizontal lengths are formed,
The joining auxiliary member is disposed on the first plate so that the hole portion is coaxial with a hole provided in the first plate and the major axis directions thereof coincide with each other.
The hole portion of the joining auxiliary member is filled with a weld metal of an iron alloy or an Ni alloy, and is melted by the weld metal, the melted second plate, and a part of the joining auxiliary member. Dissimilar material welded joint is formed.   The dissimilar material welded joint according to claim 15, wherein a bulging portion formed in the second plate is disposed in the hole of the first plate.   17. The dissimilar material according to claim 15, wherein the overlapping surface of at least one of the first plate and the second plate is provided with an adhesive provided over the entire circumference around the hole. Welded joints.   The dissimilar material according to any one of claims 15 to 17, further comprising an adhesive provided on at least one facing surface between the joining auxiliary member and the first plate facing the joining auxiliary member. Welded joints.   The dissimilar material welded joint according to any one of claims 15 to 18, comprising an adhesive provided at a boundary portion between the joining auxiliary member and the surface of the first plate. Long shaft length _{P SX} of the hole portion of the auxiliary bonding member is 100% or less than 50% with respect to the first long shaft length _{B DX} of the hole in the plate, one of the claim 15 to 19 The dissimilar material welded joint according to claim 1. 21. The short axis side length P _SY of the hole portion of the joining auxiliary member is 50% or more and 100% or less with _respect to the short axis side length B _DY of the hole of the first plate. The dissimilar material welded joint according to claim 1. The major axis side length P _DX of the joining auxiliary member is 105% or more with respect to the major axis side length B _DX of the hole of the first plate, according to any one of claims 15 to 21. Dissimilar material welded joint. The minor axis side length P _DY of the joining auxiliary member is 105% or more with _respect to the minor axis side length B _DY of the hole of the first plate, according to any one of claims 15 to 22. Dissimilar material welded joint. The thickness _{P H} of the auxiliary bonding member, the first plate is not more than 150% more than 50% of the thickness _{B H} of the plate, dissimilar weld joint according to any one of claims 15 to 23. A surplus is formed on the surface of the joining auxiliary member, and the major axis side length W _{DX of the} surplus is 105% or more with respect to the major axis side length P _SX of the hole of the joining auxiliary member. The dissimilar material welded joint according to any one of claims 15 to 24. The excess prime on the surface of the bonding auxiliary member is formed, and short shaft length W _DY of the excess prime is to short shaft length P _SY of the hole portion of the auxiliary bonding member, and 105% or more The dissimilar material welded joint according to any one of claims 15 to 25.

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