JP4859732B2 - Dissimilar material MIG joint and dissimilar material MIG joining method - Google Patents

Description

  The present invention relates to a butt joint of dissimilar materials of a plated steel plate and an aluminum alloy plate and a joining method thereof.

  In structural materials such as automobiles, the use of aluminum alloy materials is spreading instead of steel materials for the purpose of weight reduction. However, since steel materials are excellent in terms of formability, material cost, etc., the adoption of tailored blank materials that take advantage of both aluminum alloy materials and steel materials has been studied. A tailored blank is a member in which different materials are joined together, and the technology of tailored blanks between steel materials has been put into practical use, but the tailored blank material of steel and aluminum alloy materials has not been put into practical use. It is.

  About the joining method of steel materials and aluminum alloy material, it describes in patent document 1 and patent document 2. FIG.

  In Patent Document 1, an initial stacking allowance between a steel plate and an aluminum alloy plate, a reduction ratio of the joint portion to the aluminum alloy plate, and a joint portion thickness of the aluminum alloy plate at the joint portion are defined. The manufacturing method of the tailored blank material which becomes is described.

  Moreover, in patent document 2, in order to implement | achieve the laser butt | matching of the board | plate material from which melting | fusing point differs, by enlarging the energy irradiated to the metal plate with a high melting | fusing point rather than the metal plate with a low melting | fusing point, The manufacturing method of the tailored blank material which becomes is described.

Japanese Patent Laid-Open No. 11-47946 JP 2005-254282 A

  However, in the joining method called mash seam joining described in Patent Document 1, the joint structure becomes a lap joint and cannot make a butt joint because of its principle. For this reason, there is a difficulty in formability when a press is used due to the step formed in the joint.

Moreover, in the laser joining described in Patent Document 2, butt joints between different materials are possible, but the apparatus is expensive, and when the steel plate is irradiated with a laser and melted, the steel plate is placed between the steel plate and the aluminum alloy plate. Since a thick intermetallic compound is produced, joint strength tends to be poor. Moreover, since the surface of a steel plate may be exposed, corrosion resistance tends to become low.
The present invention has been made in view of such problems, and provides a butt-joint joint between dissimilar materials having a joint strength and corrosion resistance in a butt joint between a plated steel plate and an aluminum alloy plate, and a joining method thereof. With the goal.

The dissimilar material MIG joint according to the present invention is a joint where a plated steel plate and an aluminum alloy plate are butt-joined by MIG welding , wherein the butt portion is a filler material, the plated layer of the plated steel plate and the aluminum alloy plate are It is covered with a weld metal formed by melting, and the plating layer does not remain in the region covered with the weld metal on the surface of the plated steel plate, and the plated steel plate in this region An intermetallic compound is partially generated in a portion of the surface on the side of the aluminum alloy plate, and an intermetallic compound is generated in a portion of the surface of the plated steel plate that is separated from the aluminum alloy plate in the region. It is characterized by not being.

  Moreover, you may comprise the dissimilar-material joining joint which concerns on this invention so that the said plated steel plate may be a zinc alloy type plated steel plate.

  Moreover, you may comprise the dissimilar-material joining joint which concerns on this invention so that the said plated steel plate may be an aluminum plated steel plate.

Dissimilar MiG bonding method according to the present invention, butt the plated steel sheet and aluminum alloy sheet, using an aluminum-based filler material to a bonding method for MIG arc welding, the aluminum alloy plate target position of the wire from the bonding position set in a range of side 0.1～3.2Mm, in the only one surface of the aluminum alloy plate and MIG arc welding, the filler metal plating layer and the butted portion by Tokeawa the aluminum alloy plate of the plated steel sheet A weld metal is formed so as to cover the surface of the plated steel plate, and the region covered with the weld metal on the surface of the plated steel plate has no remaining plating layer, and the plated steel plate in this region An intermetallic compound is partially generated on the surface of the aluminum alloy plate side of the surface, and the surface of the plated steel sheet in the region The spaced side portions from aluminum alloy plate so as not generated intermetallic compound, characterized in that joining between the plated steel sheet and the aluminum alloy plate.

  Moreover, you may comprise the different material joining method which concerns on this invention so that the said plated steel plate may be a zinc alloy type plated steel plate.

  Moreover, you may comprise the dissimilar material joining method which concerns on this invention so that the said plated steel plate may be an aluminum plated steel plate.

According to the present invention, the intermetallic compound between steel and aluminum alloy plate during butt joint can be reduced to grow. As a result, since the steel plate and the plating layer-welded metal are firmly joined, a joint having high strength can be obtained as the whole joint.

  Moreover, since both butt surfaces are covered with the weld metal after the butt joining, the interface between the aluminum alloy plate and the steel plate is not exposed to the surface, and the electrolytic corrosion from the surrounding atmosphere can be reduced.

  As described above, it is possible to butt-join a plated steel plate and an aluminum alloy plate that ensure joint strength and have excellent corrosion resistance.

  Below, the butt-joint joint of the dissimilar materials which concerns on embodiment of this invention, and its joining method are demonstrated with reference to FIG. 1, FIG. 2, Table 1. FIG.

  FIG. 1 is a view showing a butt-joint joint between dissimilar materials and a joining method thereof according to an embodiment of the present invention, and is a cross-sectional view in the vicinity of a joint joint. As shown in the figure, the abutting surfaces of the steel plate 11 (hereinafter referred to as the zinc alloy-based plated steel plate 13) on which the zinc alloy-based plated layer 12 is applied and the aluminum alloy plate 10 do not cause a mistake. 18 are closely attached.

  The butt joint is performed by a MIG welder. MIG welding is a joining method in which a wire 15 serving as a filler material is fed from a welding torch 14 at a constant speed and is fed to generate an arc 17 between the wire 15 and the base material. An inert gas 16 is generated from a gas nozzle (not shown) so as not to be mixed. The wire 15 is made of aluminum, and the wire aiming position “a” is set in a predetermined range from the joining position “b” to the aluminum alloy plate 10 side, and is joined from only one side. This predetermined range is preferably 0.1 to 3.2 mm. The wire aiming position a is a numerical value of the position where the center of the wire 15 is on the workpiece when the wire 15 is protruded from the welding torch 14 by a certain amount.

  Next, the operation of the embodiment of the present invention will be described.

FIG. 2 is a cross-sectional view of the joint showing the situation where the butt joint between the zinc alloy-based plated steel plate 13 and the aluminum alloy plate 10 has been completed. The weld metal 20 is formed by melting an aluminum wire 15 serving as a filler material, a part of the aluminum alloy plate 10 and a part of the zinc alloy plating layer 12 at the time of butt joining. Since the weld metal is formed without melting the steel plate 11 having a higher melting point than the aluminum alloy or the zinc alloy, the growth of the intermetallic compound 19 is reduced.

  The butted surfaces of the zinc alloy-based plated steel plate 13 and the aluminum alloy plate 10 are covered with the weld metal 20. Therefore, since the interface between the aluminum alloy plate 10 and the steel plate 11 is not exposed on the surface, it is possible to reduce electrolytic corrosion from the surrounding atmosphere.

As described above, the bonding according to the present invention is a bonding method in which the growth of the intermetallic compound 19 is reduced. However, as a result of the bonding, also as an intermetallic compound between the aluminum alloy plate 10 and the steel plate 11 is partially generated, the intermetallic compound 19 is at a location away from the influence of heat is small wire position is not generated Since the steel plate 11 and the alloy zinc-based plating layer 12-the weld metal 20 are firmly joined, a joint having high strength can be obtained as the whole joint.

  In the present embodiment, the butt joint between the aluminum alloy plate 10 and the zinc alloy-based plated steel plate 13 has been described. However, an aluminum alloy-based plated layer can also be employed as the plated layer attached to the steel plate 11. In this case, since the aluminum alloy plating has good wettability with the droplets of the aluminum wire 15, stronger bonding can be realized.

  As described above, it is preferable to join from one side of the base material within the range of 0.1 to 3.2 mm from the joining position b to the aluminum alloy plate 10 side from the joining position b. According to the facts obtained from (test results).

  When the wire aiming position a is set to the steel plate 11 side from the joining position b to 0.1 mm from the aluminum alloy plate 10 side, the bead is drawn only on the steel plate 11 side, and the weld metal 20 is sufficiently spread to the aluminum alloy plate 10 side. Absent. Moreover, since the heat transmitted to the steel plate 11 side becomes excessive, the intermetallic compound 19 generated at the interface between the aluminum alloy plate 10 and the steel plate 11 is generated thick in a wide range. As a result, the joint strength is significantly reduced.

  On the contrary, when the wire aiming position “a” is set to the aluminum alloy plate 10 side further than the aluminum alloy plate 10 side of 3.2 mm from the joining position “b”, the aluminum alloy plate 10 side melts and butt joining becomes impossible.

  In addition, in order to obtain a good distribution of the weld metal 20 spreading on both sides of the base material, when joining from both sides of the base material, the thermal deformation of the base material becomes remarkably large. Therefore, construction from only one side of the base material is preferable.

  Next, examples of the present invention will be described.

  Table 1 below summarizes the test conditions of the examples of the present invention and the comparative examples to be compared and various evaluations of the joints in a list.

  The test was conducted by combining the following conditions.

Type of aluminum alloy plate: 6000 series (plate thickness 1.6 mm) or 5000 series (plate thickness 1.0 mm)
Types of steel plates: Alloyed galvanized material (plate thickness 1.0 mm), aluminum-plated material (plate thickness 1.0 mm), cold rolled bare specification (plate thickness 1.0 mm)
Wire aiming position: Aluminum alloy plate side from joining position, 1.0mm, 0.1mm, 2.0mm, 3.0mm, 3.2mm, 3.2mm
Bonding position: 0.5 mm on the steel plate side
In addition, in order to investigate the presence or absence of defects in the joint, a strength property test, a bending test, and a combined corrosion test (CCT) were performed.

  The strength characteristic test is passed if the manufactured tailored blank material is subjected to a tensile tester and the base metal side is broken, and is rejected if it is broken at the joint. This is because if the joint is broken, the joint is a weak point in strength.

  The bending test was performed when a specimen was collected from the tailored blank material and the joining line between the different materials and the bending center line were made to coincide with each other and when it was made to go straight. The test conditions were bending at 90 degrees with an inner radius of 15 mm, and checking for cracks and peeling.

  The combined corrosion test (CCT) was a 200 cycle or 300 cycle corrosion test in an accelerated test simulating actual corrosion.

  In Example 1, a MIG welder was used to perform bonding using an aluminum 4000 series welding wire φ1.2 mm. The bonding conditions were set such that the current value was 80 A and the bonding speed was 70 cpm. The materials to be joined are 1.6 mm of 6000 series aluminum alloy plate and 1.0 mm of galvanized steel sheet (mild steel), and the target position of the wire is 1.0 mm, 0.1 mm, 2.0 mm on the aluminum alloy plate side from the joining position. , 3.0 mm, and 3.2 mm.

  Comparative Example 1 was carried out in order to compare the test results with Example 1, and the testing machine and test conditions used were the same as in Example 1, and a new wire aiming position different from Example 1 was set. In addition, the steel sheet side grade was changed to a cold-rolled bare steel plate (soft steel), and the bondability was also confirmed.

  As shown in Table 1, butt joining of an aluminum alloy plate and an galvannealed steel plate performed under the conditions of Example 1 gave good results in each of the strength property test, bending test, and corrosion resistance test. It was. On the other hand, in the joining shown in Comparative Example 1, the aluminum alloy plate and the galvannealed steel plate could not be joined under the conditions (1) to (3). In (1), the aluminum side melted away. On the other hand, in (2) and (3), a bead was drawn only on the steel plate side, and bonding was not possible. In (4), good results were obtained in the evaluation of the strength characteristics and the bending test, but in the corrosion resistance test, electrocorrosion was observed in the vicinity of the joint.

  As described above, if the butt joint according to the present invention is used, the butt joint between the aluminum alloy plate 6000 series and the galvannealed steel sheet can ensure the joint strength and the good shape of the weld metal, and perform the joint with excellent corrosion resistance. Can do. However, the wire aiming position needs to be in the range of 0.1 to 3.2 mm on the aluminum alloy plate side from the joining position. When the wire aiming position was on the steel plate side than the above range, the bead was drawn only on the steel plate side, and the weld metal did not spread sufficiently to the aluminum alloy plate side. On the contrary, when the wire aiming position was set to the aluminum alloy plate side from the above range, the aluminum alloy plate side melted and butt joining could not be performed.

  Moreover, since the interface between the aluminum alloy material and the steel material is exposed on the surface, the aluminum alloy plate and the bare steel plate are easily affected by electric corrosion from the atmosphere, and are not excellent in corrosion resistance.

  In Example 2, a MIG welding machine was used to perform bonding using an aluminum 4000 series welding wire φ1.2 mm. The joining conditions were set such that the current value was 65 A and the joining speed was 70 cpm. The materials to be joined are 1.0 mm of 5000 series aluminum alloy plate and 1.0 mm of galvanized steel sheet (mild steel), and the target position of the wire is 1.0 mm, 0.1 mm, 2.0 mm on the aluminum alloy plate side from the joining position. , 3.0 mm, and 3.2 mm.

  Comparative Example 2 was carried out in order to compare the test results with Example 2, and the testing machine and test conditions used were the same as in Example 2, and a new wire target position different from Example 2 was set. In addition, the steel sheet side grade was changed to a cold-rolled bare steel plate (soft steel), and the bondability was also confirmed.

  As shown in Table 1, the butt joint between the aluminum alloy plate and the galvannealed steel plate performed under the conditions shown in Example 2 is a good result in each of the strength property test, the bending test, and the corrosion resistance test. was gotten. On the other hand, under the conditions shown in Comparative Example 2, the aluminum alloy plate and the galvannealed steel plate could not be joined under the conditions (1) to (3). The reason why the bonding could not be performed was the same as in Comparative Example 1. In (4), good results were obtained in the evaluation of the strength characteristics and the bending test, but in the corrosion resistance test, electrocorrosion was observed in the vicinity of the joint.

  As described above, if the butt joint according to the present invention is used, the butt joint between the aluminum alloy plate 5000 series and the alloyed galvanized steel sheet can ensure the joint strength and the good shape of the weld metal, and perform the joint with excellent corrosion resistance. Can do. However, the range in which the target position of the wire is set in order to ensure high-quality bonding, and the problem of bonding between the bare steel plate and the aluminum alloy plate 5000 series are described in Example 1 using the aluminum alloy plate 6000 series and The result was the same as that shown in Comparative Example 1.

  In Example 3, a MIG welder was used to join using an aluminum 4000 series welding wire φ1.2 mm. The joining conditions were set such that the current value was 80 A and the joining speed was 70 cpm. The materials to be joined are 1.6 mm of 6000 series aluminum alloy plate and 1.0 mm of aluminum plated steel plate (soft steel), and the target position of the wire is 1.0 mm, 0.1 mm, 2.0 mm, 3 mm on the aluminum alloy plate side from the joining position. It was carried out at a plurality of locations of 0.0 mm and 3.2 mm.

  Comparative Example 3 was carried out in order to compare the test results with Example 3, and the testing machine and test conditions used were the same as in Example 3, and a new wire aiming position different from Example 3 was set.

  As shown in Table 1, butt joining of an aluminum alloy plate and an aluminum-plated steel plate performed under the conditions shown in Example 3 gave good results in various tests such as strength property tests, bending tests, and corrosion resistance tests. It was. On the other hand, under the conditions shown in Comparative Example 3, the aluminum alloy plate and the aluminum plated steel plate could not be joined under the conditions (1) to (3). The reason why the bonding could not be performed was the same as in Comparative Example 1.

  As described above, when the butt joint according to the present invention is used, the butt joint of the aluminum alloy plate 6000 series with the aluminum-plated steel sheet can ensure the joint strength and the good shape of the weld metal, and can perform the joint with excellent corrosion resistance. . However, the range in which the target position of the wire was set in order to ensure high-quality bonding was the same as in Example 1 and Comparative Example 1 in which butt bonding was performed using an alloyed galvanized steel sheet.

  With respect to the corrosion resistance test, Example 3 can withstand the CCT 300 cycle, and the use of an aluminum-plated steel sheet was superior to the case of using an alloyed galvanized steel sheet as the steel sheet. This is because the wire used for bonding was made of aluminum, so that the wetness of the aluminum plating layer and the aluminum wire droplets was good.

  In Example 4, a MIG welder was used to join using an aluminum 4000 series welding wire φ1.2 mm. The joining conditions were set such that the current value was 65 A and the joining speed was 70 cpm. The material to be joined is 1.0 mm of a 5000 series aluminum alloy plate and 1.0 mm of an aluminum-plated steel plate (soft steel), and the target position of the wire is 1.0 mm, 0.1 mm, 2.0 mm, 3 mm on the aluminum alloy plate side from the joining position. It was carried out at a plurality of locations of 0.0 mm and 3.2 mm.

  Comparative Example 4 was carried out in order to compare the test results with Example 4, and the testing machine and test conditions used were the same as those of Example 4, and a new wire aiming position different from Example 4 was set.

  As shown in Table 1, butt joining of an aluminum alloy plate and an aluminum-plated steel plate performed under the conditions shown in Example 4 gave good results in various tests such as strength property tests, bending tests, and corrosion resistance tests. It was. On the other hand, under the conditions shown in Comparative Example 4, in (1) to (3), the aluminum alloy plate and the aluminum plated steel plate could not be joined. The reason why the bonding could not be performed was the same as in Comparative Example 1.

  As described above, when the butt joint according to the present invention is used, the butt joint of the aluminum alloy plate 5000 series with the aluminum-plated steel sheet can ensure the joint strength and the good shape of the weld metal, and the joint with excellent corrosion resistance. It can be carried out. However, the range in which the target position of the wire was set in order to ensure high-quality bonding was the same as in Example 1 and Comparative Example 1 in which butt bonding was performed using an alloyed galvanized steel sheet.

  Regarding the corrosion resistance test, since an aluminum-plated steel sheet was used as the steel sheet, it was able to withstand the CCT300 cycle as in Example 3.

It is sectional drawing of the joint joint part vicinity of the dissimilar material joining which concerns on embodiment of this invention. It is sectional drawing of the joint joint vicinity by which dissimilar material joining which concerns on embodiment of this invention was made | formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Aluminum alloy plate 11 Steel plate 12 Zinc alloy type plating layer 13 Zinc alloy type plating steel plate 14 Welding torch 15 Wire (aluminum wire)
16 Inert gas 17 Arc 18 Butting surface 19 Intermetallic compound 20 Weld metal a Wire aiming position b Joining position

Claims (6)

A welded joint in which a plated steel plate and an aluminum alloy plate are butt-joined by MIG welding , wherein the butt portion is covered with a filler metal, a welded metal formed by melting the plated layer of the plated steel plate and the aluminum alloy plate. In the region covered with the weld metal on the surface of the plated steel plate, the plating layer does not remain, and the aluminum alloy plate side portion of the surface of the plated steel plate in this region The dissimilar material MIG is characterized in that an intermetallic compound is partially generated and no intermetallic compound is generated in a portion of the surface of the plated steel plate in the region that is separated from the aluminum alloy plate. Joint joint . The dissimilar material MIG joint according to claim 1, wherein the plated steel sheet is a zinc alloy-based plated steel sheet. The dissimilar material MIG joint according to claim 1, wherein the plated steel sheet is an aluminum plated steel sheet. Butt plated steel sheet and aluminum alloy sheet, using an aluminum-based filler material to a bonding method for MIG arc welding, range target position of the wire from the joint position of the aluminum alloy plate side 0.1~3.2mm set, the only one side of an aluminum alloy plate and MIG arc welding, the filler material, welding so as to cover the surface of the plated steel sheet in the plating layer and the butted portion by Tokeawa the aluminum alloy plate of the plated steel sheet In the region where the metal is formed and covered with the weld metal on the surface of the plated steel plate, the plating layer does not remain, and the aluminum alloy plate side portion of the surface of the plated steel plate in this region Is a part of the surface of the plated steel plate in the region that is separated from the aluminum alloy plate while the intermetallic compound is partially generated Dissimilar MiG joining method characterized by the parts so as not generated intermetallic compound and bonding the aluminum alloy plate and the plated steel sheet. The dissimilar material MIG joining method according to claim 4, wherein the plated steel sheet is a zinc alloy-based plated steel sheet. 5. The dissimilar material MIG joining method according to claim 4, wherein the plated steel sheet is an aluminum plated steel sheet.

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