JP5957720B2 - Friction stir welding method - Google Patents

Description

  The present invention relates to a friction stir welding method.

  Patent Document 1 discloses a technique in which a friction stir welding is performed by inserting an inner corner friction stir welding rotary tool into the inner corners of two metal members abutted at right angles. FIG. 24 is a cross-sectional view showing a conventional friction stir welding method. In the conventional friction stir welding method, the abutting portion J formed by abutting the end surface of the metal member 101 and the side surface of the metal member 102 is friction stir welded by the inner corner friction stir welding rotary tool 110. The inner corner friction stir welding rotary tool 110 includes a pressing block 111 that has a triangular prism shape, and a stirring pin 112 that can rotate with respect to the pressing block 111 while passing through the pressing block 111. When joining, the stirring pin 112 is rotated in a state where the pressing block 111 is in contact with the side surfaces of the metal members 101 and 102.

JP-A-11-320128

  In the conventional friction stir welding, since the presser block 111 is joined to the metal members 101 and 102 while being pressed, the presser block 111 may cause the metal members 101 and 102 to be scraped. Moreover, since there is the pressing block 111, the joint portion could not be visually recognized.

  In addition, as shown in FIG. 24, it is conceivable to perform temporary bonding from the surface side constituting the outer corner before bonding the inner corners of the metal members 101 and 102. When the thickness of the metal members 101 and 102 is large, there is a problem that a gap is formed between the plasticized region Wa formed by temporary joining and the plasticized region Wb formed at the inner corner.

  From such a viewpoint, an object of the present invention is to provide a friction stir welding method capable of suitably joining while suppressing damage to metal members during joining.

In order to solve such a problem, the present invention provides a friction stir welding method for joining two metal members using a rotary tool provided with a stirring pin and connected to a rotating shaft of a friction stirrer, A spiral groove is engraved on the outer peripheral surface of the pin, and a butting process is performed in which the metal members are butted at an angle to form a butting portion, and the rotated stirring pin is inserted into the inner corner of the metal members A main joining step of performing friction stir welding of the abutting portion in a state where only the stirring pin of the rotating tool among the friction stirrer and the rotating tool is brought into contact with only both the metal members to generate friction heat ; , Including.

The present invention also relates to a friction stir welding method in which two metal members are joined using a rotary tool provided with a stir pin and connected to a rotating shaft of a friction stirrer, wherein the outer peripheral surface of the stir pin is spirally wound. Grooves are formed, and abutting step in which the metal members are abutted at an angle to form a butted portion, and the rotated stirring pin is inserted into an inner corner of the metal members, the friction stirrer and A first main joining step of performing friction stir welding of the abutting portion in a state where only the stirring pin of the rotating tool among the rotating tools is in contact with the two metal members, and the rotating stirring pin between the metal members. Of the friction stirrer and the rotary tool, only the stirring pin of the rotary tool is brought into contact with only the metal members to generate frictional heat. Frictional friction A second main bonding step for bonding, characterized in that it comprises a.

  According to this joining method, since only the stirring pin is brought into contact with the metal member, damage to the side surface of the metal member during joining can be suppressed. Moreover, since the pressing block is not used for the rotary tool as in the prior art, the joint portion can be visually recognized. Thereby, workability | operativity can be improved.

  Moreover, it is preferable to overlap the plasticization area | region formed at said 1st main joining process, and the plasticization area | region formed at said 2nd main joining process. According to this joining method, since the gap between the abutting portions is eliminated, airtightness and watertightness can be improved.

  In the abutting step, the side surface of one metal member and the end surface of the other metal member are abutted, and the angle of the inner corner formed by the side surface of the one metal member and the side surface of the other metal member is In the case of α, in the main joining step, a virtual reference in which the rotation center axis of the rotary tool inserted at the line of intersection of the side surfaces passes through the line of intersection and the side surface is α / 2 It is preferable to be located between a surface and the side surface of the one metal member.

  By tilting the rotary tool toward one of the metal members, the agitation pin can be inserted up to a deep position of the abutting portion, so that it can be joined to a deep position of the abutting portion.

  Moreover, it is preferable to include the temporary joining process which inserts the rotated rotary tool in the surface side which comprises the outer corner of the said metal members, and performs the temporary joining of the said abutting part before the said main joining process. According to this joining method, when performing this joining process, it can prevent that metal members separate.

  Moreover, in the said main joining process, it is preferable to overlap the plasticization area | region formed at the said temporary joining process, and the plasticization area | region formed at the said main joining process. According to this joining method, since the gap between the butt portions is eliminated by overlapping the plasticized regions, the airtightness and the watertightness can be improved.

  Further, it is preferable to perform overlay welding on the plasticized region formed in the main joining step. According to such a joining method, the metal shortage due to the main joining process can be supplemented.

  According to the friction stir welding method according to the present invention, it is possible to suitably bond while suppressing damage to the metal member during bonding.

(A) is the side view which showed the rotation tool for this joining of this embodiment, (b) is sectional drawing which showed the joining form of the rotation tool for this joining. (A) is the side view which showed the rotary tool for temporary joining of this embodiment, (b) is sectional drawing which showed the joining form of the rotary tool for temporary joining. (A) is the perspective view which showed the preparatory process which concerns on 1st embodiment, (b) is the perspective view which showed the preliminary process which concerns on 1st embodiment. It is the figure which showed this joining process which concerns on 1st embodiment, Comprising: (a) is a perspective view, (b) is sectional drawing. It is sectional drawing which showed the repair process which concerns on 1st embodiment. (A) is sectional drawing which shows the 1st main joining process which concerns on 2nd embodiment, (b) is sectional drawing which shows the 2nd main joining process which concerns on 2nd embodiment. It is the side view which showed the basic shape of the rotation tool for this joining used in an Example. It is a side view which shows 1 series and 2 series of the rotary tool for this joining used in an Example. It is a side view which shows 3 series and 4 series of the rotation tool for this joining used in an Example. (A) is a schematic diagram which shows the fillet part thickness reduction amount of an Example. (B) is a schematic diagram showing a screw cross-sectional area of the example. 2 is a cross-sectional view showing the results of 1 series and 2 series in Example 1. FIG. 3 is a cross-sectional view showing the results of 3 series and 4 series in Example 1. FIG. FIG. 6 is a cross-sectional view showing the results of 1 series and 2 series in Example 2. 6 is a cross-sectional view showing the results of 3 series and 4 series in Example 2. FIG. 4 is a graph showing a relationship between a screw cross-sectional area and a fillet thickness reduction in Example 1. It is the graph which showed the relationship between the screw cross-sectional area in Example 2, and a fillet part thickness reduction amount. Sectional drawing which shows the result at the time of setting the rotation speed of this rotation tool B-1 for Example 3 to 1000 rpm and setting the joining speed to 100 mm / min, 200 mm / min, 300 mm / min, 500 mm / min in Example 3. It is. In Example 3, sectional drawing which shows the result at the time of setting the rotation speed of this rotation tool C-1 for bonding to 1000 rpm, and setting the joining speed to 100 mm / min, 200 mm / min, 300 mm / min, 500 mm / min. It is. In Example 3, sectional drawing which shows the result at the time of setting the rotation speed of this rotation tool A-4 for bonding to 1000 rpm, and setting the joining speed to 100 mm / min, 200 mm / min, 300 mm / min, 500 mm / min. It is. In Example 3, it is sectional drawing which shows the result at the time of fixing a rotation speed to 1000 rpm and setting joining speed to 100 mm / min. In Example 3, it is sectional drawing which shows the result at the time of fixing rotation speed to 1000 rpm and setting joining speed to 200 mm / min. In Example 3, it is sectional drawing which shows the result at the time of fixing a rotational speed to 1000 rpm and setting joining speed to 300 mm / min. In Example 3, it is sectional drawing which shows the result at the time of fixing rotation speed to 1000 rpm and setting joining speed to 500 mm / min. It is sectional drawing which shows the conventional friction stir welding method.

  Embodiments of the present invention will be described in detail with reference to the drawings. First, the main joining rotary tool and the temporary joining rotary tool used in the present embodiment will be described.

  As shown in FIG. 1A, the main joining rotary tool F is composed of a connecting portion F1 and a stirring pin F2. The main rotating tool F for joining is formed of, for example, tool steel. The connection part F1 is a part connected to the rotating shaft D of the friction stirrer shown in FIG. The connecting portion F1 has a cylindrical shape, and is formed with screw holes B and B to which bolts are fastened.

  The stirring pin F2 hangs down from the connecting portion F1 and is coaxial with the connecting portion F1. The stirring pin F2 is tapered as it is separated from the connecting portion F1. A spiral groove F3 is formed on the outer peripheral surface of the stirring pin F2.

  As shown in FIG. 1 (b), when performing friction stir welding using the rotating tool F for main welding, only the rotating stirring pin F2 is inserted into the metal member 1 and connected to the metal members 1 and 2. It is moved away from the part F1. In other words, the friction stir welding is performed with the base end portion of the stirring pin F2 exposed. A plasticized region W is formed in the movement locus of the main rotating tool F for bonding by hardening the friction-stirred metal.

  As shown in FIG. 2A, the temporary bonding rotary tool G includes a shoulder portion G1 and a stirring pin G2. The temporary joining rotary tool G is made of, for example, tool steel. As shown in FIG. 2B, the shoulder portion G1 is a portion that is connected to the rotating shaft D of the friction stirrer and is a portion that holds the plastic fluidized metal. The shoulder portion G1 has a cylindrical shape. The lower end surface of the shoulder portion G1 has a concave shape in order to prevent the fluidized metal from flowing out.

  The stirring pin G2 is suspended from the shoulder portion G1, and is coaxial with the shoulder portion G1. The stirring pin G2 is tapered as it is separated from the shoulder portion G1. A spiral groove G3 is formed on the outer peripheral surface of the stirring pin G2.

  As shown in FIG. 2B, when friction stir welding is performed using the temporary welding rotary tool G, the rotated stirring pin G2 and the lower end of the shoulder portion G1 are inserted into the metal members 1 and 2. Move. A plasticized region w is formed in the movement locus of the temporary bonding rotary tool G by hardening the friction-stirred metal.

<First embodiment>
Next, the friction stir welding method according to the first embodiment of the present invention will be described. The first embodiment includes (1) a preparation process, (2) a preliminary process, (3) a main joining process, and (4) a repair process.

(1) Preparatory process A preparatory process is demonstrated with reference to FIG. The preparation process according to the present embodiment includes a butting process for butting the metal members 1 and 2 to be joined, a tab material arranging process for placing the tab material 3 at the end of the butting part J1 of the metal members 1 and 2, and a tab. A welding process in which the material 3 is temporarily joined to the metal members 1 and 2 by welding.

  In the abutting step, as shown in FIG. 3A, the side surface 1b of the metal member 1 to be joined and the end surface 2a of the metal member 2 are abutted, and the end surface 1a of the metal member 1 and the side surface 2c of the metal member 2 are abutted. And be on the same page. That is, in the abutting step, the metal members 1 and 2 are abutted vertically so as to be L-shaped when viewed from the side. The metal members 1 and 2 may be any metal that can be frictionally stirred, but in this embodiment, an aluminum alloy is used.

  In the tab material arranging step, as shown in FIG. 3B, the tab material 3 is arranged on one end side of the abutting portion J1 of the metal members 1 and 2, and the tab material 3 is placed on the side surface 1d of the metal member 1 and the metal member. 2 is brought into contact with the side surface 2d. It arrange | positions so that the surface 3a of the tab material 3, the side surface 2c of the metal member 2, and the end surface 1a of the metal member 1 may become flush | level.

  In the welding process, the metal members 1 and 2 and the tab material 3 are welded, and the metal members 1 and 2 and the tab material 3 are joined.

  When the preparation process is completed, the metal members 1 and 2 and the tab material 3 are placed on a frame of a friction stirrer (not shown) and restrained so as not to move using a jig (not shown) such as a clamp.

(2) Preliminary process
The preliminary process includes a temporary joining process of temporarily joining the abutting portions J1 of the metal members 1 and 2. Specifically, as shown in FIG. 3B, a temporary joining rotary tool G is inserted into the tab member 3, and the abutting portion J1 is formed from the outside of the metal members 1 and 2 (the surface side constituting the outer corner). Friction stir welding is performed. In the temporary bonding step, the temporary bonding rotary tool G is moved in a state where the lower surface of the shoulder portion G1 is pushed into the metal members 1 and 2, as shown in FIG. When all or part of the abutting portion J1 is joined, the tab material 3 is cut from the metal members 1 and 2. In this embodiment, the temporary joining step is performed by friction stir welding, but the metal members 1 and 2 may be temporarily joined by welding, for example.

(3) Main joining process
When the preliminary process is completed, a main joining process for fully joining the abutting portions J1 of the metal members 1 and 2 is executed. In the main joining step according to the present embodiment, first, as shown in FIG. 4A, the backing material T is disposed on the surfaces constituting the outer corners of the metal members 1 and 2. The backing material T is a metal member having an L shape in plan view, and is brought into contact with the side surface 1 c, the end surface 1 a of the metal member 1, and the side surface 2 c of the metal member 2. Then, the metal members 1 and 2 and the backing material T are placed on a frame of a friction stirrer (not shown) and restrained so as not to move using a jig (not shown) such as a clamp.

  Next, in the final joining step, the rotated main joining tool F is inserted into the inner corners of the metal member 1 and the metal member 2 (the corners composed of the side surface 1b and the side surface 2b), and the mating portion J1 is inserted. Friction stir welding is performed. In the main joining step, as shown in FIGS. 4A and 4B, the connecting portion F1 of the main welding rotary tool F and the metal members 1 and 2 are separated from each other, and only the stirring pin F2 is joined to the abutting portion J1. Insert into.

  Further, in the main joining step, as shown in FIG. 4B, the friction stir welding is performed by inclining the rotation center axis Fc of the main welding rotating tool F. That is, in the main joining step, the rotation center axis Fc of the main welding rotary tool F inserted at the intersection line C1 between the side surface 1b and the side surface 2b passes through the intersection line C1 and the angle formed between the side surface 1b and the side surface 2b is α. It is set so as to be positioned between the virtual reference plane C that becomes / 2 (α = 90 ° in the present embodiment) and the side surface 1b of the metal member 1. In the main joining step, the plasticized region W1 formed in the main joining step is overlapped with the plasticizing region w formed in the temporary joining step. The position of the rotation center axis Fc does not include a position overlapping the side surface 1b and the virtual reference plane C.

(4) Repair process
When the main joining process is completed, the repairing process is performed on the plasticized region W1 formed on the metal members 1 and 2 by the main joining process. In the repair process according to the present embodiment, overlay welding is performed on the upper surface of the plasticized region W1 as shown in FIG.

  By the main joining step, the upper surface (surface) of the plasticized region W1 tends to have a groove due to lack of metal, but the lack of metal can be replenished by overlay welding. As shown in FIG. 5, it is preferable that the side surface 1b of the metal member 1 and the side surface 2b of the metal member 2 are flush with the weld metal N formed by overlay welding. In addition, before performing build-up welding, the upper surface of the plasticization area | region W1 may be shaved, a recessed groove may be formed previously, and build-up welding may be performed to this recessed groove. Further, when the groove is relatively shallow, the overlay welding is omitted, and the side surface 1b of the metal member 1 and the side surface 2b of the metal member 2 are chamfered so that the groove formed by friction stir welding is formed. It may be removed.

  According to the friction stir welding according to the present embodiment described above, in the main joining step of joining the inner corners of the metal members 1 and 2, only the stirring pin F <b> 2 is brought into contact with the metal members 1 and 2. Damage to the side surface 1b of the metal member 1 and the side surface 2b of the metal member 2 can be suppressed. Moreover, since the holding block is not used as in the prior art, the joint portion can be visually recognized. Thereby, since a joining condition etc. can be grasped | ascertained, workability | operativity can be improved.

  Further, in the main joining step, airtightness and water tightness can be improved by overlapping the plasticized region w formed in the temporary joining step and the plasticized region W1 formed in the main joining step. Further, by performing the temporary joining step using the temporary joining rotary tool G smaller than the main joining rotational tool F, it is possible to prevent the metal members 1 and 2 from being separated in the final joining step.

  Further, in the main joining process, for example, when the main joining rotary tool F is tilted to one metal member 1 side, for example, the stirring pin F2 is inserted along the virtual reference plane C shown in FIG. That is, compared to the case where the angle between the side surfaces 1b and 2b and the rotation center axis Fc is 45 ° with respect to the metal members 1 and 2 that are vertical, the stirring pin is deeper than the abutting portion J1. F2 can be inserted. Thereby, it can join to the deep position of the abutting part J1.

  Moreover, the metal shortage in this joining process can be replenished by performing overlay welding on the plasticization area | region W2 formed at this joining process.

<Second embodiment>
Next, the friction stir welding method according to the second embodiment of the present invention will be described. The second embodiment includes (1) a preparation step, (2) a preliminary step, (3) a first main joining step, (4) a second main joining step, and (5) a repairing step. 2nd embodiment illustrates the case where the metal members 1 and 2 thicker than 1st embodiment are joined. The second embodiment is different from the first embodiment in that the main joining step is performed twice. Note that (1) the preparation step and (2) the preliminary step are the same as those in the first embodiment, and thus detailed description thereof is omitted.

(4) First Main Joining Process In the first main joining process, as shown in FIG. 6 (a), with respect to the abutting portion J1, in the same manner as the main joining process of the first embodiment described above. Then, the rotating tool F for main joining rotated at the inner corners of the metal members 1 and 2 is inserted to perform friction stir welding. In the second embodiment, since the thickness of the metal members 1 and 2 is large, even if the insertion angle of the rotation tool F for main bonding is inclined to the metal member 1 side, the plasticized region W1 formed in the main bonding step and The plasticized region w formed in the temporary joining process cannot be overlapped.

(5) Second Main Joining Step In the second main joining step, friction stir welding is performed using the main welding rotating tool F from the side of the surface constituting the outer corners of the metal members 1 and 2. Specifically, as shown in FIG. 6 (b), the stirring pin F2 of the rotating tool F for main joining rotated from the end surface 1a of the metal member 1 and the side surface 2c side of the metal member 2 is inserted, and the abutting portion J1 Move along. In the second main joining step, the connecting part F1 of the main joining rotary tool F is separated from the metal members 1 and 2, and only the stirring pin F2 is inserted into the abutting part J1. The plasticized region W2 formed in the second main joining step is overlapped with the plasticizing region W1 formed in the first main joining step. In the second main joining step of the present embodiment, the stirring pin F2 reaches the plasticizing region W1. Thereby, the butt | matching part J1 can be joined more reliably.

  In the second main joining process, friction stir welding may be performed by appropriately providing tab members on the metal members 1 and 2. You may utilize in the 2nd this joining process, without cutting and removing the tab material used in the case of a temporary joining process.

(6) Repairing process In the repairing process, in the same manner as the repairing process of the first embodiment, the plasticized region W1 formed in the first main joining process and the plasticized region W2 formed in the second main joining process. Overlay the top surface of the metal to replenish the missing metal.

  According to the second embodiment described above, substantially the same effect as the first embodiment can be obtained, and by performing the second main joining step, even if the metal members 1 and 2 are thick, Since friction stir welding can be performed over the entire length of the abutting portion J1, airtightness and watertightness can be improved. Further, according to the main rotating tool F for joining, the stirring pin F2 can be inserted to a deep position while suppressing a load applied to the friction stirrer.

  In addition, although the 2nd main joining process was performed using the rotation tool F for this joining in this embodiment, it is not limited to this, For example, it is a rotary tool provided with the shoulder part and the stirring pin, A long stirring pin may be used.

  Although the embodiments of the present invention have been described above, design changes can be made as appropriate without departing from the spirit of the present invention. For example, in the present embodiment, the metal members 1 and 2 are abutted at a right angle, but may be abutted as many times as long as the angle formed between the side surface 1b of the metal member 1 and the side surface 2b of the metal member 2 is other than 180 degrees. Further, for example, the end surfaces 1 a of the metal member 1 and the end surface 2 a of the metal member 2 may be cut out obliquely so that the metal members 1 and 2 are abutted.

  In the embodiment, as shown in FIG. 7, a total of 20 rotary tools for main joining having five types of pin angles (angles between the rotating shaft and the outer peripheral surface of the stirring pin) and four types of screw depth and screw pitch. Was prepared, and the bonding situation of each was investigated.

  As shown in FIG. 7, the metal member Z to be joined is made of an aluminum alloy, and has a V-shaped groove Za having a V-shaped cross section. The angle of the V-shaped groove Za is 90 degrees. In each Example, only the stirring pin of each rotary tool for main joining was inserted into the V-shaped groove Za at a predetermined depth and moved in the longitudinal direction of the V-shaped groove Za by a predetermined length. The insertion depth of the stirring pin was a common depth for each example.

  As shown in the vertical direction of FIGS. 8 and 9, the A series of the rotating tools for this joining has a pin angle of 9.5 degrees, the B series has a pin angle of 14 degrees, and the C series has a pin angle of 18 degrees. .4 degrees, the D series has a pin angle of 23 degrees, and the E series has a pin angle of 27.6 degrees.

  8 and 9, the 1 series has a screw depth of 0.4 mm and a screw pitch of 0.5 mm, and the 2 series has a screw depth of 1.0 mm and a screw pitch of 1.0 mm. The 3 series has a screw depth of 1.8 mm and a screw pitch of 2.0 mm, and the 4 series has a screw depth of 2.5 mm and a screw pitch of 3.0 mm. For example, as shown in FIG. 8, the “main joining rotating tool C-2” has a pin angle of 18.4 degrees, a screw depth of 1.0 mm, and a screw pitch of 1.0 mm.

Further, “fill thickness reduction amount (mm ² )” described later refers to the upper surface Z1 of the plasticized region W after the friction stir welding and the metal member Z, as shown in FIG. Means a cross-sectional area of a region surrounded by the side walls Z2 and Z2 of the V and the virtual extension line Z3 of the V-shaped groove Za. In addition, when a joining defect exists in the plasticization area | region W, the cross-sectional area of the area | region of this joining defect was also added as "fillet part thickness reduction amount (mm < ² >)".

Further, “screw cross-sectional area (mm ² )” described later is a section of a region surrounded by an imaginary line F4 passing through the outer peripheral surface of the stirring pin F2 and the spiral groove F3, as shown in FIG. It means the sum of areas (the part where hatches are drawn).

<Example 1>
In the first embodiment, the main welding rotation tools A-1 to A-4, the main welding rotation tools B-1 to B-4, the main welding rotation tools C-1 to C-4, and the main welding rotation are described. Using a total of 20 rotary tools for main welding, including tools D-1 to D-4 and rotary tools for main welding E-1 to E-4, set the rotation speed to 1000 rpm and the welding speed (moving speed) to 100 mm / min. Then, friction stir welding was performed.

  As shown in FIGS. 11 and 12, it can be seen that the cross-sectional area of the plasticized region W increases as the pin angle increases. Moreover, it turns out that the plasticization area | region W is formed in the deep position as the screw depth and screw pitch become large, and the fillet part thickness reduction amount becomes large.

  Moreover, as shown in FIG.11 and FIG.12, in this rotation tool A-1 for joining, the joining defect Q has generate | occur | produced. In the main rotating tool B-2 for bonding, the amount of thinning is large and bonding is poor. It can be seen that the joining conditions are generally good except for the rotating tools A-1 and B-2 for the joining.

  In the 4 series (A-4, B-4, C-4, D-4) shown in FIG. 12, it can be seen that the lower surface of the metal member Z is deformed so as to protrude downward. It can also be seen that many burrs are generated in the 1 and 4 series.

<Example 2>
In Example 2, friction stir welding was performed using the above-described 20 kinds of main rotating tools for welding and setting the number of rotations to 1000 rpm and the welding speed to 200 mm / min.

  As shown in FIG. 13 and FIG. 14, in this rotary tool for bonding A-1, B-1, C-1, D-1, B-2, C-2, a bonding defect Q is formed. Recognize. Moreover, it turns out that the thinning amount is large in this rotary tool A-2 for joining, and it becomes a joining defect. It can be seen that the other joining rotary tools have generally good joining conditions.

  When Example 1 and Example 2 are comprehensively observed, it can be seen that the rate of occurrence of the bonding defect Q is lower when the bonding speed is slower (Example 1). It can also be seen that as the screw depth and screw pitch increase, the amount of thinning increases, but the incidence of joint defects is low.

FIG. 15 is a graph showing the relationship between the screw cross-sectional area and the fillet thickness reduction in Example 1. FIG. 16 is a graph showing the relationship between the screw cross-sectional area and the fillet thickness reduction in Example 2. If the screw cross-sectional area is too small, the joining defect Q tends to occur. On the other hand, if the screw cross-sectional area is too large, the fillet thickness reduction amount tends to increase. Therefore, the screw cross-sectional area is preferably 50～180Mm ^2, more preferably a 100 to 150 mm ^2.

<Example 3>
In Example 3, the cross section of the plasticized region formed by moving the above-described 20 kinds of main welding rotary tools with respect to the flat metal member Z (no V-shaped groove) was observed. In Example 3, the rotational speed was fixed at 1000 rpm, and the joining speed was varied to 100 mm / min, 200 mm / min, 300 mm / min, and 500 mm / min.

FIG. 17 shows the results when the rotational speed of the main rotating tool B-1 is set to 1000 rpm and the welding speed is set to 100 mm / min, 200 mm / min, 300 mm / min, and 500 mm / min in Example 3. FIG.
FIG. 18 shows the results when the rotational speed of the main rotating tool C-1 is set to 1000 rpm and the welding speed is set to 100 mm / min, 200 mm / min, 300 mm / min, and 500 mm / min in Example 3. FIG.
FIG. 19 shows the results when the rotational speed of the main rotating tool A-4 is set to 1000 rpm and the welding speed is set to 100 mm / min, 200 mm / min, 300 mm / min, and 500 mm / min in Example 3. FIG.

  17 and 18, it can be seen that the bonding defect Q increases as the bonding speed increases. 17 to 19, it can be seen that the amount of burrs increases as the joining speed increases.

FIG. 20 is a cross-sectional view showing the results when the rotation speed is fixed at 1000 rpm and the joining speed is 100 mm / min in Example 3.
FIG. 21 is a cross-sectional view showing the results when the rotation speed is fixed at 1000 rpm and the joining speed is 200 mm / min in Example 3.
FIG. 22 is a cross-sectional view showing the results when the rotation speed is fixed at 1000 rpm and the joining speed is 300 mm / min in Example 3.
FIG. 23 is a cross-sectional view showing the results when the rotation speed is fixed at 1000 rpm and the joining speed is 500 mm / min in Example 3.

  20 to 23 comprehensively, it is understood that a slower joining speed is preferable and a larger screw depth and thread pitch are preferable.

DESCRIPTION OF SYMBOLS 1 Metal member 1a End surface 1b Side surface 1c Side surface 1d Side surface 2 Metal member 2a End surface 2b Side surface 2c Side surface 2d Side surface 3 Tab material C Virtual reference plane C1 Intersection line F Main rotation tool F1 Connection part F2 Stirring pin G Temporary bonding rotation tool G1 Shoulder part G2 Stirring pin J1 Butting part W1-W2 Plasticization area w Plasticization area

Claims (7)

A friction stir welding method for joining two metal members using a rotary tool provided with a stirring pin and connected to a rotating shaft of a friction stirrer,
A spiral groove is engraved on the outer peripheral surface of the stirring pin,
A butting step of butting the metal members at an angle to form a butting portion;
The rotated stirring pin was inserted into the inner corner of the metal members, and only the stirring pin of the rotating tool out of the friction stirrer and the rotating tool was brought into contact with only both the metal members to generate frictional heat . And a main joining step of performing friction stir welding of the butt portion in a state. A friction stir welding method for joining two metal members using a rotary tool provided with a stirring pin and connected to a rotating shaft of a friction stirrer,
A spiral groove is engraved on the outer peripheral surface of the stirring pin,
A butting step of butting the metal members at an angle to form a butting portion;
The rotated stirring pin was inserted into the inner corner of the metal members, and only the stirring pin of the rotating tool out of the friction stirrer and the rotating tool was brought into contact with only both the metal members to generate frictional heat . A first main joining step of performing friction stir welding of the butt portion in a state;
The rotated stirring pin is inserted into the surface side constituting the outer corner of the metal members, and only the stirring pin of the rotating tool among the friction stirring device and the rotating tool is in contact with the two metal members. A friction stir welding method comprising: a second main joining step of performing friction stir welding of the abutting portion.   The friction stir welding method according to claim 2, wherein the plasticized region formed in the first main joining step and the plasticized region formed in the second main joining step overlap each other. In the abutting step, the side surface of one metal member and the end surface of the other metal member are abutted, and the angle of the inner corner formed by the side surface of the one metal member and the side surface of the other metal member is α. If there is
In the main joining step, the rotation center axis of the rotary tool inserted at the intersection line between the side surfaces passes through the intersection line and the virtual reference plane having an angle of α / 2 with the side surface and the one of the The friction stir welding method according to any one of claims 1 to 3, wherein the friction stir welding method is located between a side surface of the metal member.   Before the main joining step, the method includes a temporary joining step in which a rotated rotary tool is inserted into a surface side constituting the outer corners of the metal members to temporarily join the abutting portions. The friction stir welding method according to any one of claims 4 to 4.   6. The friction stir welding method according to claim 5, wherein in the main joining step, the plasticized region formed in the temporary joining step and the plasticized region formed in the main joining step are overlapped.   The friction stir welding method according to any one of claims 1 to 6, wherein overlay welding is performed on the plasticized region formed in the main joining step.