WO2021182516A1 - Method for manufacturing welded structure - Google Patents

Method for manufacturing welded structure Download PDF

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Publication number
WO2021182516A1
WO2021182516A1 PCT/JP2021/009544 JP2021009544W WO2021182516A1 WO 2021182516 A1 WO2021182516 A1 WO 2021182516A1 JP 2021009544 W JP2021009544 W JP 2021009544W WO 2021182516 A1 WO2021182516 A1 WO 2021182516A1
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Prior art keywords
torch
auxiliary
welded structure
manufacturing
welding
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PCT/JP2021/009544
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French (fr)
Japanese (ja)
Inventor
正和 柴原
一樹 生島
佑太 三ツ井
新太郎 前田
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公立大学法人大阪
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Priority to JP2022507247A priority Critical patent/JPWO2021182516A1/ja
Publication of WO2021182516A1 publication Critical patent/WO2021182516A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/235—Preliminary treatment

Definitions

  • the present invention relates to a method for manufacturing a welded structure.
  • Patent Document 1 Japanese Unexamined Patent Publication No. 2015-199111 describes a method for manufacturing a welded structure.
  • the welded structure described in Patent Document 1 has a first member and a second member superposed on the first member.
  • the weld metal portion to which the first member and the second member are welded extends along the welding line direction.
  • the portions sandwiching the weld metal portion in the direction intersecting the welding line direction are referred to as the first portion and the second portion.
  • the weld metal portion is formed by irradiating the welded structure while moving the first laser along the welding line direction.
  • the second laser is irradiated to the first portion.
  • the first portion is not melted by the irradiation of the second laser.
  • the irradiation position of the first laser in the welding line direction and the irradiation position of the second laser in the welding line direction coincide with each other. According to the method for manufacturing a welded structure described in Patent Document 1, it is said that the occurrence of high temperature cracks (solidification cracks) in the weld metal portion can be suppressed.
  • Patent Document 1 the method for manufacturing a welded structure described in Patent Document 1 has room for improvement with respect to the occurrence of high-temperature cracks in the weld metal portion.
  • the present invention has been made in view of the above-mentioned problems of the prior art. More specifically, the present invention provides a method for manufacturing a welded structure capable of suppressing the occurrence of high temperature cracks.
  • the weld metal portion extending along the first direction and the weld metal portion intersecting with the first direction are sandwiched.
  • This is a method for manufacturing a welded structure having a first portion and a second portion.
  • the above-mentioned method for manufacturing a welded structure includes a step of forming a weld metal portion by moving a weld torch from one side in the first direction to the other side in the first direction along a first direction, and a welding torch.
  • the first and second parts by moving at least one auxiliary torch along the first direction from one side in the first direction to the other side in the first direction during at least a portion of the movement. It is provided with a step of heating at least one of the above so as not to melt.
  • Each of the positions of the at least one auxiliary torch in the first direction deviates from the position of the welding torch in the first direction.
  • At least one auxiliary torch may include a first auxiliary torch that heats the first portion and a second auxiliary torch that heats the second portion.
  • the first auxiliary torch and the second auxiliary torch may face each other in the second direction.
  • the first auxiliary torch and the second auxiliary torch may be located on one side in the first direction with respect to the welding torch.
  • a solidified brittle temperature region in which a liquid phase and a solid phase coexist is formed adjacent to one side of the molten pool formed by the welding torch in the first direction. May be good.
  • the first auxiliary torch and the second auxiliary torch may face the solidification brittle temperature region in the second direction.
  • At least one auxiliary torch may include a third auxiliary torch that heats the first portion and a fourth auxiliary torch that heats the second portion.
  • the third auxiliary torch and the fourth auxiliary torch may be located on the other side in the first direction with respect to the welding torch.
  • the third auxiliary torch and the fourth auxiliary torch may face each other in the second direction.
  • the occurrence of high temperature cracks in the weld metal portion can be suppressed.
  • FIG. 1 is a plan view of the welded structure according to the first embodiment.
  • FIG. 2 is a cross-sectional view taken along the line II-II of FIG.
  • the welded structure according to the first embodiment includes a first member 1, a second member 2, and a weld metal portion 3.
  • the first portion 7 and the second portion 8 in the welded structure according to the first embodiment are portions that sandwich the weld metal portion 3 in the second direction DR2 described later.
  • the first member 1 and the second member 2 are, for example, flat plate-shaped members.
  • the first member 1 and the second member 2 are made of, for example, steel.
  • the first member 1 and the second member 2 are, for example, rolled steel sheets (SM material) for welded structures specified in JIS standards (JIS G 3106: 2008).
  • the first member 1 and the second member 2 are made of the same material, for example.
  • the first member 1 and the second member 2 may be made of different materials.
  • the first member 1 and the second member 2 do not have to be made of steel.
  • the first member 1 and the second member 2 may be a non-ferrous alloy such as an aluminum (Al) alloy.
  • the weld metal portion 3 extends along the first direction DR1.
  • the first direction DR1 is the welding line direction.
  • the weld metal portion 3 is composed of a weld metal in which the molten first member 1 and the second member 2 are mixed (in the case where a welding material is used, the molten welding material is further mixed) and solidified. This is the part that is.
  • the weld metal portion 3 is sandwiched between the first member 1 and the second member 2 in the second direction DR2. That is, the first member 1 constitutes the first portion 7, and the second member 2 constitutes the second portion 8.
  • the second direction DR2 is a direction intersecting the first direction DR1.
  • the second direction DR2 is preferably orthogonal to the first direction DR1.
  • a heat-affected zone 4 is formed around the weld metal portion 3.
  • the heat-affected zone 4 is indicated by a dotted line.
  • the heat-affected zone 4 is a portion that is not melted due to heat input during welding, but whose metal structure and mechanical properties are changed from the base metal due to heat input during welding.
  • the heat-affected zone 4 has a width W.
  • the width W is the width of the heat-affected zone 4 in the second direction DR2.
  • the width W is wider than the case where the auxiliary heating step S22 is not performed in the welding step S2 (only the weld metal forming step S21 is performed in the welding step S2). Therefore, by measuring the width W, it can be determined whether both the weld metal forming step S21 and the auxiliary heating step S22 are performed.
  • FIG. 3 is a process diagram showing a method for manufacturing a welded structure according to the first embodiment.
  • the method for manufacturing a welded structure according to the first embodiment includes a preparation step S1 and a welding step S2.
  • the welding step S2 is performed after the preparation step S1.
  • the welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22.
  • FIG. 4 is a schematic view for explaining the preparation step S1 in the method for manufacturing the welded structure according to the first embodiment.
  • the first member 1 and the second member 2 are prepared.
  • the first member 1 has a first end surface 1a.
  • the first end surface 1a is an end surface of the first member 1 in the second direction DR2.
  • the second member 2 has a second end surface 2a.
  • the second end surface 2a is an end surface of the second member 2 in the second direction DR2.
  • the first member 1 and the second member 2 are butted so that the first end surface 1a and the second end surface 2a face each other in the second direction DR2.
  • the first member 1 and the second member 2 are fixed by temporary attachment. This temporary attachment is performed at a plurality of points along the first direction DR1.
  • FIG. 5 is a schematic view for explaining the welding step S2 in the method for manufacturing the welded structure according to the first embodiment.
  • the welding torch 5, the first auxiliary torch 6a, and the second auxiliary torch 6b are indicated by dotted lines.
  • the weld metal portion 3 is formed in the weld metal forming step S21.
  • the weld metal portion 3 is formed by moving the weld torch 5 along the first direction DR1.
  • the welding torch 5 is moved from one side (starting end side) in the first direction DR1 to the other side (ending end side) in the first direction DR1.
  • the welding torch 5 is arranged so as to straddle the first member 1 and the second member 2.
  • the first member 1 on the first end surface 1a side and the second member 2 on the second end surface 2a side are melted and solidified, and the weld metal portion 3 is formed.
  • the welding torch 5 is, for example, a welding torch of an arc welder.
  • the welding torch 5 is not limited to this, and may be, for example, a welding torch of a laser welding machine.
  • a molten pool 51 is formed in the vicinity of the welding torch 5.
  • the molten pool 51 is composed of a molten first member 1 and a second member 2 (when a welding material is used, the molten pool 51 further contains a molten welding material).
  • a solidification brittle temperature region 52 is formed adjacent to the start end side of the molten pool 51 in the first direction DR1.
  • the solidification brittle temperature region 52 is a region in which the solid phase and the liquid phase coexist. From another point of view, the temperature of the solidified brittle temperature region 52 exceeds the solidus temperature of the base material (first member 1 and the second member 2) and is lower than the liquidus temperature of the base material. It is an area that has become.
  • auxiliary heating step S22 is performed at least partly while the welding torch 5 is moving from the start end side to the end side along the first direction DR1.
  • first auxiliary torch 6a and the second auxiliary torch 6b move from the start end side to the end side along the first direction DR1.
  • the moving speed of the first auxiliary torch 6a and the second auxiliary torch 6b in the first direction DR1 is, for example, equal to the moving speed of the welding torch 5 in the first direction DR1.
  • the first auxiliary torch 6a heats the first member 1.
  • the second auxiliary torch 6b heats the second member 2. From another point of view, the position of the first auxiliary torch 6a in the second direction DR2 and the position of the second auxiliary torch 6b in the second direction DR2 deviate from the position of the welding torch 5 in the second direction DR2. There is.
  • the distance between the first auxiliary torch 6a and the welding torch 5 in the second direction DR2 is, for example, equal to the distance between the second auxiliary torch 6b and the welding torch 5 in the second direction DR2.
  • the output of the first auxiliary torch 6a and the second auxiliary torch 6b is smaller than the output of the welding torch 5. As a result, the first member 1 is not melted by heating the first auxiliary torch 6a, and the second member 2 is not melted by heating the second auxiliary torch 6b.
  • the position of the first auxiliary torch 6a in the first direction DR1 and the position of the second auxiliary torch 6b in the first direction DR1 are deviated from the positions of the welding torch 5 in the first direction DR1. More specifically, the first auxiliary torch 6a and the second auxiliary torch 6b are on the starting end side of the welding torch 5 in the first direction DR1.
  • the position of the first auxiliary torch 6a in the first direction DR1 and the position of the second auxiliary torch 6b in the first direction DR1 coincide with each other, for example. That is, the first auxiliary torch 6a and the second auxiliary torch 6b face each other in, for example, the second direction DR2.
  • the first auxiliary torch 6a and the second auxiliary torch 6b preferably face the solidification brittle temperature region 52 in the second direction DR2.
  • the first auxiliary torch 6a and the second auxiliary torch 6b are, for example, welding torches of an arc welder.
  • the first auxiliary torch 6a and the second auxiliary torch 6b are not limited to this, and may be, for example, a welding torch of a laser welding machine.
  • FIG. 6 is a schematic high temperature ductility curve of the solidification brittle temperature region 52 between the liquid phase temperature and the solid phase temperature.
  • the horizontal axis represents the temperature in the solidification brittleness temperature region 52
  • the vertical axis represents the strain applied to the solidification brittleness temperature region 52.
  • the high-temperature ductility curve (solid line) in FIG. 6 shows the limit strain at which high-temperature cracking occurs at a predetermined temperature.
  • T L and T S in FIG. 6 respectively show a liquidus temperature and a solidus temperature.
  • auxiliary heating is performed by the first auxiliary torch 6a and the second auxiliary torch 6b. Since the portion of the first member 1 heated by the first auxiliary torch 6a and the portion of the second member 2 heated by the second auxiliary torch 6b thermally expand, these portions are compressed into the solidification brittle temperature region 52. Stress is applied.
  • the position of the first auxiliary torch 6a in the second direction DR2 (the position of the second auxiliary torch 6b in the second direction DR2) is deviated from the position of the welding torch 5 in the second direction DR2 has been described.
  • the position of the first auxiliary torch 6a (second auxiliary torch 6b) in the second direction DR2 may coincide with the position of the welding torch 5 in the second direction DR2 (deformation example 2). ..
  • high temperature cracking is less likely to occur in the solidified brittle temperature region 52, as in the method for manufacturing the welded structure according to the first embodiment.
  • the structure of the welded structure according to the second embodiment is the same as the structure of the welded structure according to the first embodiment. Therefore, here, the description regarding the configuration of the welded structure according to the second embodiment will be omitted.
  • the method for manufacturing a welded structure according to the second embodiment includes a preparation step S1 and a welding step S2.
  • the welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22. Regarding these points, the method for manufacturing the welded structure according to the second embodiment is common to the method for manufacturing the welded structure according to the first embodiment.
  • the method for manufacturing the welded structure according to the second embodiment is different from the method for manufacturing the welded structure according to the first embodiment with respect to the details of the auxiliary heating step S22.
  • FIG. 7 is a schematic view for explaining the welding process S2 in the method for manufacturing the welded structure according to the second embodiment.
  • the welding torch 5, the third auxiliary torch 6c, and the fourth auxiliary torch 6d are indicated by dotted lines.
  • the third auxiliary torch 6c and the fourth auxiliary torch 6c and the fourth are replaced with the first auxiliary torch 6a and the second auxiliary torch 6b.
  • An auxiliary torch 6d is used.
  • the third auxiliary torch 6c and the fourth auxiliary torch 6d are moving from the start side to the end side along the first direction DR1.
  • the moving speed of the third auxiliary torch 6c and the fourth auxiliary torch 6d in the first direction DR1 is, for example, equal to the moving speed of the welding torch 5 in the first direction DR1.
  • the third auxiliary torch 6c heats the first member 1.
  • the fourth auxiliary torch 6d heats the second member 2. From another point of view, the position of the third auxiliary torch 6c in the second direction DR2 and the position of the fourth auxiliary torch 6d in the second direction DR2 deviate from the position of the welding torch 5 in the second direction DR2. There is.
  • the distance between the third auxiliary torch 6c and the welding torch 5 in the second direction DR2 is, for example, equal to the distance between the fourth auxiliary torch 6d and the welding torch 5 in the second direction DR2.
  • the output of the 3rd auxiliary torch 6c and the 4th auxiliary torch 6d is smaller than the output of the welding torch 5. As a result, the first member 1 is not melted by heating the third auxiliary torch 6c, and the second member 2 is not melted by heating the fourth auxiliary torch 6d.
  • the position of the third auxiliary torch 6c in the first direction DR1 and the position of the fourth auxiliary torch 6d in the first direction DR1 are deviated from the positions of the welding torch 5 in the first direction DR1. More specifically, the third auxiliary torch 6c and the fourth auxiliary torch 6d are on the terminal side of the welding torch 5 in the first direction DR1.
  • the position of the third auxiliary torch 6c in the first direction DR1 and the position of the fourth auxiliary torch 6d in the first direction DR1 coincide with each other, for example. That is, the third auxiliary torch 6c and the fourth auxiliary torch 6d face each other in, for example, the second direction DR2.
  • the first auxiliary torch 6a and the second auxiliary torch 6b are, for example, welding torches of an arc welder.
  • the first auxiliary torch 6a and the second auxiliary torch 6b are not limited to this, and may be, for example, a welding torch of a laser welding machine.
  • FIG. 8 is a schematic view showing in-plane rotational deformation of the first member 1 and the second member 2 that occur during the weld metal forming step S21.
  • the temperatures of the first member 1 and the second member rise significantly in the vicinity of the welding torch 5, while being separated from the welding torch 5. At the position, the temperatures of the first member 1 and the second member do not rise so much.
  • the third auxiliary torch 6c and the fourth auxiliary torch 6d heat the first member 1 and the second member 2 on the terminal side of the welding torch 5, respectively. Therefore, the difference in the amount of thermal expansion between the vicinity of the welding torch 5 and the position away from the welding torch 5 is reduced. As a result, the amount of in-plane deformation of the first member 1 and the second member 2 is reduced, and the tensile strain applied to the solidification brittle temperature region 52 is reduced. As described above, according to the method for manufacturing the welded structure according to the second embodiment, high temperature cracking is less likely to occur in the solidified brittle temperature region 52.
  • the third auxiliary torch 6c and the fourth auxiliary torch 6d heat the first member 1 and the second member 2 on the terminal side of the welding torch 5, respectively. Therefore, the temporary fixing on the terminal side of the welding torch 5 is preheated. That is, in the method for manufacturing a welded structure according to the second embodiment, the restraint against in-plane rotational deformation due to temporary fixing is weakened in advance.
  • the occurrence of high temperature cracking in the solidification brittle temperature region 52 can be further suppressed. ..
  • auxiliary heating step S22 is performed using the third auxiliary torch 6c and the fourth auxiliary torch 6d
  • either one of the third auxiliary torch 6c and the fourth auxiliary torch 6d may be used (modification example 2).
  • the third auxiliary torch 6c or the fourth auxiliary torch 6d is used, depending on the arrangement of the weld metal portion 3 (for example, when the weld metal portion 3 is near the end of the welded structure), It may not be possible to sufficiently suppress high temperature cracking.
  • both the third auxiliary torch 6c and the fourth auxiliary torch 6d are used, it is possible to stably suppress the occurrence of high temperature cracks regardless of the arrangement of the weld metal portion 3.
  • FIG. 9 is a plan view of the welded structure according to the third embodiment.
  • FIG. 10 is a cross-sectional view taken along the line XX of FIG.
  • the welded structure according to the third embodiment includes a first member 1, a second member 2, and a weld metal portion 3.
  • the structure of the welded structure according to the third embodiment is common to the structure of the welded structure according to the first embodiment.
  • the second member 2 is superposed on the first member 1.
  • the weld metal portion 3 is formed so as to penetrate the first member 1 and the second member 2. That is, in the welded structure according to the third embodiment, the portions of the first member 1 and the second member 2 adjacent to the weld metal portion 3 from one side in the second direction DR2 become the first portion 7. The portion of the first member 1 and the second member 2 adjacent to the weld metal portion 3 from the other side in the second direction DR2 is the second portion 8.
  • the structure of the welded structure according to the third embodiment is different from the structure of the welded structure according to the first embodiment.
  • the width of the first portion 7 in the second direction DR2 and the width of the second portion 8 in the second direction DR2 may be different from each other.
  • the method for manufacturing a welded structure according to the third embodiment includes a preparation step S1 and a welding step S2.
  • the welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22. Regarding these points, the method for manufacturing the welded structure according to the third embodiment is common to the method for manufacturing the welded structure according to the first embodiment.
  • the method for manufacturing the welded structure according to the third embodiment is the method for manufacturing the welded structure according to the first embodiment with respect to the details of the preparation step S1, the details of the weld metal forming step S21, and the details of the auxiliary heating step S22. Is different.
  • FIG. 11 is a schematic diagram for explaining the preparation step S1 in the method for manufacturing the welded structure according to the third embodiment.
  • the second member 2 is superposed on the first member 1.
  • FIG. 12 is a schematic view for explaining the welding step S2 in the method for manufacturing the welded structure according to the third embodiment.
  • the welding torch 5, the first auxiliary torch 6a and the second auxiliary torch 6b are indicated by dotted lines.
  • the weld torch 5 is moved from the start end side to the end side along the first direction DR1.
  • the weld metal portion 3 is formed so as to penetrate the first member 1 and the second member 2.
  • the first portion 7 (the first member 1 and the second member 2 adjacent to the weld metal portion 3 from one side in the second direction DR2) Part) is heated by the first auxiliary torch 6a
  • the second part 8 (the part of the first member 1 and the second member 2 adjacent to the weld metal part 3 from the other side in the second direction DR2) is the second. It is heated by the auxiliary torch 6b.
  • the first portion 7 is not melted by heating the first auxiliary torch 6a
  • the second portion 8 is not melted by heating the second auxiliary torch 6b.
  • the tensile strain applied to the solidification brittleness temperature region 52 is reduced (or solidification brittleness) by heating the first auxiliary torch 6a and the second auxiliary torch 6b. Since compressive strain is applied to the temperature region 52), high temperature cracking is less likely to occur in the solidified brittle temperature region 52.
  • FIG. 13 is a cross-sectional view of the welded structure according to the fourth embodiment.
  • FIG. 13 shows a cross-sectional view orthogonal to the extending direction (first direction DR1) of the weld metal portion 3.
  • the first member 1 has a thickness T1 and the second member 2 has a thickness T2.
  • the thickness T1 and the thickness T2 are 16 mm or more and 40 mm or more. That is, the welded structure according to the fourth embodiment is common to the welded structure according to the first embodiment in that it is a butt welded joint, but a thick plate is used as the first member 1 and the second member 2. It is different from the welded structure according to the first embodiment in that it is.
  • the method for manufacturing a welded structure according to the fourth embodiment includes a preparation step S1 and a welding step S2.
  • the welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22.
  • the method for manufacturing the welded structure according to the fourth embodiment is different from the method for manufacturing the welded structure according to the first embodiment.
  • the method for manufacturing the welded structure according to the fourth embodiment is different from the method for manufacturing the welded structure according to the first embodiment with respect to the details of the preparation step S1 and the welding step S2.
  • FIG. 14 is a cross-sectional view for explaining the preparation step S1 in the method for manufacturing the welded structure according to the fourth embodiment.
  • the end surface (second end surface 2a) on the first member 1 side constitutes a Y-shaped groove.
  • the groove composed of the first end surface 1a and the second end surface 2a is not limited to the Y groove.
  • the groove composed of the first end surface 1a and the second end surface 2a may be a V-shaped groove, an X-shaped groove, a K-shaped groove, or the like.
  • the welding step S2 (welded metal forming step S21 and auxiliary heating step S22) in the method for manufacturing a welded structure according to the fourth embodiment may be repeated a plurality of times. That is, the weld metal portion 3 of the welded structure according to the fourth embodiment may be formed by multi-layer welding.
  • the welding step S2 in the welding structure manufacturing method according to the fourth embodiment replaces the welding step S2 in the welding structure manufacturing method according to the first embodiment with the welding structure according to the second embodiment. Welding step S2 in the manufacturing method may be used.
  • FIG. 15 is a perspective view of the welded structure according to the fifth embodiment.
  • FIG. 15 shows a cross-sectional view of the weld metal portion 3 orthogonal to the extending direction.
  • FIG. 16 is a cross-sectional view of the welded structure according to the fifth embodiment.
  • the welded structure according to the fifth embodiment includes a first member 1, a second member 2, and a weld metal portion 3.
  • the first member 1 has a first end surface 1a and a first main surface 1b.
  • the second member 2 has a second end surface 2a and a second main surface 2b.
  • the second member 2 is arranged on the first member 1 (on the first main surface 1b) so that the second end surface 2a faces the first main surface 1b.
  • the weld metal portion 3 extends along the first direction DR1 and joins the first main surface 1b side of the first member 1 and the second end surface 2a side of the second member 2. That is, the welded structure according to the first embodiment is a butt joint, while the welded structure according to the fifth embodiment is a T joint.
  • the method for manufacturing a welded structure according to the fifth embodiment includes a preparation step S1 and a welding step S2.
  • the welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22.
  • the method for manufacturing the welded structure according to the fifth embodiment is different from the method for manufacturing the welded structure according to the first embodiment.
  • the method for manufacturing the welded structure according to the fifth embodiment is different from the method for manufacturing the welded structure according to the first embodiment with respect to the details of the preparation step S1 and the welding step S2.
  • the second member 2 is placed on the first member 1 (first main surface 1b) so that the second end surface 2a faces the first main surface 1b. Placed on).
  • FIG. 17 is a schematic view for explaining the welding step S2 in the method for manufacturing the welded structure according to the fifth embodiment.
  • the weld torch 5 is moved from one side of the first direction DR1 to the other side of the first direction DR1.
  • the first main surface 1b side of the first member 1 and the second end surface 2a side of the second member 2 are melted to form the weld metal portion 3.
  • the first auxiliary torch 6a and the second auxiliary torch 6b move from one side of the first direction DR1 toward the other side of the first direction DR1. , Moved with the welding torch 5. At this time, the first auxiliary torch 6a is heated so as not to melt the first main surface 1b, and the second auxiliary torch 6b is heated so as not to melt the second main surface 2b.
  • the first auxiliary torch 6a and the second auxiliary torch 6b are on one side of the welding torch 5 in the first direction DR1.
  • the positions of the first auxiliary torch 6a and the second auxiliary torch 6b in the first direction DR1 overlap with the positions of the solidification brittle temperature region 52 formed by the welding torch 5 in the first direction DR1.
  • a third auxiliary torch 6c and a fourth auxiliary torch 6d are used in place of the first auxiliary torch 6a and the second auxiliary torch 6b.
  • the third auxiliary torch 6c and the fourth auxiliary torch 6d may be used together with the first auxiliary torch 6a and the second auxiliary torch 6b.
  • the third auxiliary torch 6c and the fourth auxiliary torch 6d are the first main surface 1b and the first main surface 1b on the other side in the first direction DR1 from the welding torch 5, respectively.
  • the second main surface 2b is heated so as not to melt.

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Abstract

This method is for manufacturing a welded structure having a welded metal portion extending along a first direction, and a first portion and second portion which sandwich the welded metal portion therebetween in a second direction intersecting the first direction. This method for manufacturing a welded structure is provided with: a step for forming the welded metal portion by moving a welding torch along the first direction, from one side in the first direction to the other side in the first direction; and a step for moving one or more auxiliary torches along the first direction, from one side in the first direction to the other side in the first direction, and thereby heating but not melting the first portion and/or the second portion, during at least a portion of the time that the welding torch is moving. Each of the positions of the one or more auxiliary torches in the first direction is offset from the position of the welding torch in the first direction.

Description

溶接構造体の製造方法Welded structure manufacturing method
　本発明は、溶接構造体の製造方法に関する。 The present invention relates to a method for manufacturing a welded structure.
　特許文献１（特開２０１５－１９９１１１号公報）には、溶接構造体の製造方法が記載されている。特許文献１に記載の溶接構造体においては、第１部材と、第１部材上に重ね合わされた第２部材とを有している。第１部材と第２部材とが溶接されている溶接金属部は、溶接線方向に沿って延在している。溶接線方向に交差している方向において溶接金属部を挟み込んでいる部分を、第１部分及び第２部分とする。 Patent Document 1 (Japanese Unexamined Patent Publication No. 2015-199111) describes a method for manufacturing a welded structure. The welded structure described in Patent Document 1 has a first member and a second member superposed on the first member. The weld metal portion to which the first member and the second member are welded extends along the welding line direction. The portions sandwiching the weld metal portion in the direction intersecting the welding line direction are referred to as the first portion and the second portion.
　特許文献１に記載の溶接構造体を製造する際、溶接線方向に沿って第１レーザを移動させながら照射することにより、溶接金属部が形成される。第１レーザを移動させながら照射している際、第１部分には、第２レーザが照射されている。第２レーザの照射により、第１部分は、溶融していない。溶接線方向における第１レーザの照射位置と溶接線方向における第２レーザの照射位置とは、互いに一致している。特許文献１に記載の溶接構造体の製造方法によると、溶接金属部における高温割れ（凝固割れ）の発生が抑制できるとされている。 When manufacturing the welded structure described in Patent Document 1, the weld metal portion is formed by irradiating the welded structure while moving the first laser along the welding line direction. When irradiating while moving the first laser, the second laser is irradiated to the first portion. The first portion is not melted by the irradiation of the second laser. The irradiation position of the first laser in the welding line direction and the irradiation position of the second laser in the welding line direction coincide with each other. According to the method for manufacturing a welded structure described in Patent Document 1, it is said that the occurrence of high temperature cracks (solidification cracks) in the weld metal portion can be suppressed.
特開２０１５－１９９１１１号公報JP-A-2015-199111
　しかしながら、特許文献１に記載の溶接構造体の製造方法は、溶接金属部における高温割れの発生に関して、改善の余地がある。 However, the method for manufacturing a welded structure described in Patent Document 1 has room for improvement with respect to the occurrence of high-temperature cracks in the weld metal portion.
　本発明は、上記の従来技術の問題点に鑑みてなされたものである。より具体的には、本発明は、高温割れの発生を抑制可能な溶接構造体の製造方法を提供するものである。 The present invention has been made in view of the above-mentioned problems of the prior art. More specifically, the present invention provides a method for manufacturing a welded structure capable of suppressing the occurrence of high temperature cracks.
　本発明の一態様に係る溶接構造体の製造方法は、第１方向に沿って延在している溶接金属部と、第１方向に交差している第２方向において溶接金属部を挟み込んでいる第１部分及び第２部分とを有する溶接構造体の製造方法である。上記の溶接構造体の製造方法は、第１方向に沿って溶接トーチを第１方向における一方側から第１方向における他方側へと移動させることにより溶接金属部を形成する工程と、溶接トーチが移動している間の少なくとも一部において、第１方向に沿って少なくとも１つの補助トーチを第１方向における一方側から第１方向における他方側へと移動させることにより、第１部分及び第２部分の少なくとも一方を溶融しないように加熱する工程とを備えている。少なくとも１つの補助トーチの位置の第１方向における位置の各々は、溶接トーチの第１方向における位置とずれている。 In the method for manufacturing a welded structure according to one aspect of the present invention, the weld metal portion extending along the first direction and the weld metal portion intersecting with the first direction are sandwiched. This is a method for manufacturing a welded structure having a first portion and a second portion. The above-mentioned method for manufacturing a welded structure includes a step of forming a weld metal portion by moving a weld torch from one side in the first direction to the other side in the first direction along a first direction, and a welding torch. The first and second parts by moving at least one auxiliary torch along the first direction from one side in the first direction to the other side in the first direction during at least a portion of the movement. It is provided with a step of heating at least one of the above so as not to melt. Each of the positions of the at least one auxiliary torch in the first direction deviates from the position of the welding torch in the first direction.
　上記の溶接構造体の製造方法では、少なくとも１つの補助トーチに、第１部分を加熱する第１補助トーチ及び第２部分を加熱する第２補助トーチが含まれていてもよい。第１補助トーチ及び第２補助トーチは、第２方向において互いに対向していてもよい。第１補助トーチ及び第２補助トーチは、溶接トーチよりも第１方向における一方側に位置していてもよい。 In the above method for manufacturing a welded structure, at least one auxiliary torch may include a first auxiliary torch that heats the first portion and a second auxiliary torch that heats the second portion. The first auxiliary torch and the second auxiliary torch may face each other in the second direction. The first auxiliary torch and the second auxiliary torch may be located on one side in the first direction with respect to the welding torch.
　上記の溶接構造体の製造方法では、溶接トーチにより形成される溶融池の第１方向における一方側に、液相と固相とが共存している凝固脆性温度領域が隣接して形成されていてもよい。第１補助トーチ及び第２補助トーチは、第２方向において凝固脆性温度領域と対向していてもよい。 In the above method for manufacturing a welded structure, a solidified brittle temperature region in which a liquid phase and a solid phase coexist is formed adjacent to one side of the molten pool formed by the welding torch in the first direction. May be good. The first auxiliary torch and the second auxiliary torch may face the solidification brittle temperature region in the second direction.
　上記の溶接構造体の製造方法では、少なくとも１つの補助トーチに、第１部分を加熱する第３補助トーチ及び第２部分を加熱する第４補助トーチが含まれていてもよい。第３補助トーチ及び第４補助トーチは、溶接トーチよりも第１方向における他方側に位置していてもよい。第３補助トーチ及び第４補助トーチは、第２方向において互いに対向していてもよい。 In the above method for manufacturing a welded structure, at least one auxiliary torch may include a third auxiliary torch that heats the first portion and a fourth auxiliary torch that heats the second portion. The third auxiliary torch and the fourth auxiliary torch may be located on the other side in the first direction with respect to the welding torch. The third auxiliary torch and the fourth auxiliary torch may face each other in the second direction.
　本発明の一態様に係る溶接構造体及び溶接構造体の製造方法によると、溶接金属部における高温割れの発生を抑制できる。 According to the welded structure and the method for manufacturing the welded structure according to one aspect of the present invention, the occurrence of high temperature cracks in the weld metal portion can be suppressed.
第１実施形態に係る溶接構造体の平面図である。It is a top view of the welded structure which concerns on 1st Embodiment. 図１のＩＩ－ＩＩにおける断面図である。It is sectional drawing in II-II of FIG. 第１実施形態に係る溶接構造体の製造方法を示す工程図である。It is a process drawing which shows the manufacturing method of the welded structure which concerns on 1st Embodiment. 第１実施形態に係る溶接構造体の製造方法における準備工程Ｓ１を説明するための模式図である。It is a schematic diagram for demonstrating the preparation step S1 in the manufacturing method of the welded structure which concerns on 1st Embodiment. 第１実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。It is a schematic diagram for demonstrating the welding process S2 in the manufacturing method of the welding structure which concerns on 1st Embodiment. 液相線温度と固体相線温度との間における凝固脆性温度領域５２の模式的な高温延性曲線である。It is a typical high temperature ductility curve of the solidification brittle temperature region 52 between the liquid phase line temperature and the solid phase line temperature. 第２実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。It is a schematic diagram for demonstrating the welding process S2 in the manufacturing method of the welding structure which concerns on 2nd Embodiment. 溶接金属形成工程Ｓ２１を行っている間に生じる第１部材１及び第２部材２の面内回転変形を示す模式図である。It is a schematic diagram which shows the in-plane rotational deformation of the 1st member 1 and 2nd member 2 which occur while performing a weld metal forming step S21. 第３実施形態に係る溶接構造体の平面図である。It is a top view of the welded structure which concerns on 3rd Embodiment. 図９のＸ－Ｘにおける断面図である。9 is a cross-sectional view taken along the line XX of FIG. 第３実施形態に係る溶接構造体の製造方法における準備工程Ｓ１を説明するための模式図である。It is a schematic diagram for demonstrating the preparation step S1 in the manufacturing method of the welded structure which concerns on 3rd Embodiment. 第３実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。It is a schematic diagram for demonstrating the welding process S2 in the manufacturing method of the welding structure which concerns on 3rd Embodiment. 第４実施形態に係る溶接構造体の断面図である。It is sectional drawing of the welded structure which concerns on 4th Embodiment. 第４実施形態に係る溶接構造体の製造方法における準備工程Ｓ１を説明するための断面図である。It is sectional drawing for demonstrating the preparation step S1 in the manufacturing method of the welded structure which concerns on 4th Embodiment. 溶接金属部３が形成される前の第５実施形態に係る溶接構造体の斜視図である。It is a perspective view of the welded structure which concerns on 5th Embodiment before the weld metal part 3 is formed. 第５実施形態に係る溶接構造体の断面図である。It is sectional drawing of the welded structure which concerns on 5th Embodiment. 第５実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。It is a schematic diagram for demonstrating the welding process S2 in the manufacturing method of the welding structure which concerns on 5th Embodiment.
　本発明の実施形態を、図面を参照しながら説明する。以下の図面においては、同一又は相当する部分に同一の参照符号を付し、重複する説明を繰り返さない。 An embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and duplicate explanations will not be repeated.
　（第１実施形態に係る溶接構造体の構成）
　以下に、第１実施形態に係る溶接構造体の構成を説明する。 (Structure of welded structure according to the first embodiment)
The configuration of the welded structure according to the first embodiment will be described below.
　図１は、第１実施形態に係る溶接構造体の平面図である。図２は、図１のＩＩ－ＩＩにおける断面図である。図１及び２に示されるように、第１実施形態に係る溶接構造体は、第１部材１と、第２部材２と、溶接金属部３とを有している。第１実施形態に係る溶接構造体における第１部分７及び第２部分８は、後述する第２方向ＤＲ２において溶接金属部３を挟み込んでいる部分である。 FIG. 1 is a plan view of the welded structure according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. As shown in FIGS. 1 and 2, the welded structure according to the first embodiment includes a first member 1, a second member 2, and a weld metal portion 3. The first portion 7 and the second portion 8 in the welded structure according to the first embodiment are portions that sandwich the weld metal portion 3 in the second direction DR2 described later.
　＜第１部材１及び第２部材２＞
　第１部材１及び第２部材２は、例えば、平板状の部材である。第１部材１及び第２部材２は、例えば、鋼製である。第１部材１及び第２部材２は、例えば、ＪＩＳ規格（ＪＩＳ　Ｇ　３１０６：２００８）に規定されている溶接構造用圧延鋼板（ＳＭ材）である。第１部材１及び第２部材２は、例えば、同一材料により形成されている。第１部材１及び第２部材２は、互いに異なる材料により形成されていてもよい。第１部材１及び第２部材２は、鋼製である必要はない。第１部材１及び第２部材２は、例えばアルミニウム（Ａｌ）合金等の非鉄合金であってもよい。 <First member 1 and second member 2>
The first member 1 and the second member 2 are, for example, flat plate-shaped members. The first member 1 and the second member 2 are made of, for example, steel. The first member 1 and the second member 2 are, for example, rolled steel sheets (SM material) for welded structures specified in JIS standards (JIS G 3106: 2008). The first member 1 and the second member 2 are made of the same material, for example. The first member 1 and the second member 2 may be made of different materials. The first member 1 and the second member 2 do not have to be made of steel. The first member 1 and the second member 2 may be a non-ferrous alloy such as an aluminum (Al) alloy.
　＜溶接金属部３＞
　溶接金属部３は、第１方向ＤＲ１に沿って延在している。第１方向ＤＲ１は、溶接線方向である。溶接金属部３は、溶融した第１部材１及び第２部材２が混合されて（溶接材料が用いられている場合は、溶融した溶接材料がさらに混合されて）凝固した溶接金属により構成されている部分である。溶接金属部３は、第２方向ＤＲ２において、第１部材１と第２部材２とにより挟み込まれている。すなわち、第１部材１が第１部分７を構成しており、第２部材２が第２部分８を構成している。第２方向ＤＲ２は、第１方向ＤＲ１に交差している方向である。第２方向ＤＲ２は、好ましくは、第１方向ＤＲ１に直交している。 <Welded metal part 3>
The weld metal portion 3 extends along the first direction DR1. The first direction DR1 is the welding line direction. The weld metal portion 3 is composed of a weld metal in which the molten first member 1 and the second member 2 are mixed (in the case where a welding material is used, the molten welding material is further mixed) and solidified. This is the part that is. The weld metal portion 3 is sandwiched between the first member 1 and the second member 2 in the second direction DR2. That is, the first member 1 constitutes the first portion 7, and the second member 2 constitutes the second portion 8. The second direction DR2 is a direction intersecting the first direction DR1. The second direction DR2 is preferably orthogonal to the first direction DR1.
　＜熱影響部４＞
　溶接金属部３の周囲には、熱影響部４が形成されている。図２中において、熱影響部４は、点線により示されている。熱影響部４は、溶接時の入熱により溶融していないが、溶接時の入熱により金属組織及び機械的特性が母材から変化している部分である。熱影響部４は、幅Ｗを有している。幅Ｗは、第２方向ＤＲ２における熱影響部４の幅である。幅Ｗは、溶接工程Ｓ２において補助加熱工程Ｓ２２が行われなかった（溶接工程Ｓ２において溶接金属形成工程Ｓ２１のみが行われた）場合と比較して、広くなっている。そのため、幅Ｗを測定することにより、溶接金属形成工程Ｓ２１及び補助加熱工程Ｓ２２の双方が行われているかを判断することができる。 <Heat-affected zone 4>
A heat-affected zone 4 is formed around the weld metal portion 3. In FIG. 2, the heat-affected zone 4 is indicated by a dotted line. The heat-affected zone 4 is a portion that is not melted due to heat input during welding, but whose metal structure and mechanical properties are changed from the base metal due to heat input during welding. The heat-affected zone 4 has a width W. The width W is the width of the heat-affected zone 4 in the second direction DR2. The width W is wider than the case where the auxiliary heating step S22 is not performed in the welding step S2 (only the weld metal forming step S21 is performed in the welding step S2). Therefore, by measuring the width W, it can be determined whether both the weld metal forming step S21 and the auxiliary heating step S22 are performed.
　（第１実施形態に係る溶接構造体の製造方法）
　以下に、第１実施形態に係る溶接構造体の製造方法を説明する。 (Manufacturing method of welded structure according to the first embodiment)
The method of manufacturing the welded structure according to the first embodiment will be described below.
　図３は、第１実施形態に係る溶接構造体の製造方法を示す工程図である。図３に示されるように、第１実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１と、溶接工程Ｓ２とを有している。溶接工程Ｓ２は、準備工程Ｓ１の後に行われる。溶接工程Ｓ２は、溶接金属形成工程Ｓ２１と、補助加熱工程Ｓ２２とを有している。 FIG. 3 is a process diagram showing a method for manufacturing a welded structure according to the first embodiment. As shown in FIG. 3, the method for manufacturing a welded structure according to the first embodiment includes a preparation step S1 and a welding step S2. The welding step S2 is performed after the preparation step S1. The welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22.
　＜準備工程Ｓ１＞
　図４は、第１実施形態に係る溶接構造体の製造方法における準備工程Ｓ１を説明するための模式図である。図４に示されるように、準備工程Ｓ１においては、第１部材１及び第２部材２が準備される。第１部材１は、第１端面１ａを有している。第１端面１ａは、第２方向ＤＲ２における第１部材１の端面である。第２部材２は、第２端面２ａを有している。第２端面２ａは、第２方向ＤＲ２における第２部材２の端面である。 <Preparation step S1>
FIG. 4 is a schematic view for explaining the preparation step S1 in the method for manufacturing the welded structure according to the first embodiment. As shown in FIG. 4, in the preparation step S1, the first member 1 and the second member 2 are prepared. The first member 1 has a first end surface 1a. The first end surface 1a is an end surface of the first member 1 in the second direction DR2. The second member 2 has a second end surface 2a. The second end surface 2a is an end surface of the second member 2 in the second direction DR2.
　第１部材１及び第２部材２は、第１端面１ａ及び第２端面２ａが第２方向ＤＲ２において互いに対向するように突き合わされている。図示されていないが、第１部材１と第２部材２との間は、仮付けにより固定されている。この仮付けは、第１方向ＤＲ１に沿って複数点行われている。 The first member 1 and the second member 2 are butted so that the first end surface 1a and the second end surface 2a face each other in the second direction DR2. Although not shown, the first member 1 and the second member 2 are fixed by temporary attachment. This temporary attachment is performed at a plurality of points along the first direction DR1.
　＜溶接金属形成工程Ｓ２１＞
　図５は、第１実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。なお、図５中において、溶接トーチ５、第１補助トーチ６ａ及び第２補助トーチ６ｂは、点線により示されている。図５に示されるように、溶接金属形成工程Ｓ２１においては、溶接金属部３の形成が行われる。溶接金属部３の形成は、溶接トーチ５を第１方向ＤＲ１に沿って移動させることにより行われる。溶接トーチ５は、第１方向ＤＲ１における一方側（始端側）から第１方向ＤＲ１における他方側（終端側）へと移動される。溶接トーチ５は、第１部材１及び第２部材２を跨ぐように配置される。これにより、第１端面１ａ側にある第１部材１及び第２端面２ａ側にある第２部材２が溶融・凝固し、溶接金属部３が形成される。 <Welded metal forming step S21>
FIG. 5 is a schematic view for explaining the welding step S2 in the method for manufacturing the welded structure according to the first embodiment. In FIG. 5, the welding torch 5, the first auxiliary torch 6a, and the second auxiliary torch 6b are indicated by dotted lines. As shown in FIG. 5, in the weld metal forming step S21, the weld metal portion 3 is formed. The weld metal portion 3 is formed by moving the weld torch 5 along the first direction DR1. The welding torch 5 is moved from one side (starting end side) in the first direction DR1 to the other side (ending end side) in the first direction DR1. The welding torch 5 is arranged so as to straddle the first member 1 and the second member 2. As a result, the first member 1 on the first end surface 1a side and the second member 2 on the second end surface 2a side are melted and solidified, and the weld metal portion 3 is formed.
　溶接トーチ５は、例えば、アーク溶接機の溶接トーチである。但し、溶接トーチ５は、これに限られず、例えば、レーザ溶接機の溶接トーチであってもよい。 The welding torch 5 is, for example, a welding torch of an arc welder. However, the welding torch 5 is not limited to this, and may be, for example, a welding torch of a laser welding machine.
　溶接トーチ５が第１方向ＤＲ１に沿って始端側から終端側へと移動している際、溶接トーチ５の近傍には、溶融池５１が形成されている。溶融池５１は、溶融された第１部材１及び第２部材２により構成されている（溶接材料が用いられる場合、溶融池５１は、さらに溶融された溶接材料を含んでいる）。また、溶融池５１の第１方向ＤＲ１における始端側に隣接して、凝固脆性温度領域５２が形成されている。凝固脆性温度領域５２は、固相と液相とが共存している領域である。このことを別の観点から言えば、凝固脆性温度領域５２は、その温度が母材（第１部材１及び第２部材２）の固相線温度を超えて母材の液相線温度未満となっている領域である。 When the welding torch 5 is moving from the start end side to the end side along the first direction DR1, a molten pool 51 is formed in the vicinity of the welding torch 5. The molten pool 51 is composed of a molten first member 1 and a second member 2 (when a welding material is used, the molten pool 51 further contains a molten welding material). Further, a solidification brittle temperature region 52 is formed adjacent to the start end side of the molten pool 51 in the first direction DR1. The solidification brittle temperature region 52 is a region in which the solid phase and the liquid phase coexist. From another point of view, the temperature of the solidified brittle temperature region 52 exceeds the solidus temperature of the base material (first member 1 and the second member 2) and is lower than the liquidus temperature of the base material. It is an area that has become.
　＜補助加熱工程Ｓ２２＞
　補助加熱工程Ｓ２２は、溶接トーチ５が第１方向ＤＲ１に沿って始端側から終端側へと移動している間の少なくとも一部に行われる。補助加熱工程Ｓ２２においては、第１補助トーチ６ａ及び第２補助トーチ６ｂが、第１方向ＤＲ１に沿って始端側から終端側へと移動している。第１補助トーチ６ａ及び第２補助トーチ６ｂの第１方向ＤＲ１における移動速度は、例えば、溶接トーチ５の第１方向ＤＲ１における移動速度と等しい。 <Auxiliary heating step S22>
The auxiliary heating step S22 is performed at least partly while the welding torch 5 is moving from the start end side to the end side along the first direction DR1. In the auxiliary heating step S22, the first auxiliary torch 6a and the second auxiliary torch 6b move from the start end side to the end side along the first direction DR1. The moving speed of the first auxiliary torch 6a and the second auxiliary torch 6b in the first direction DR1 is, for example, equal to the moving speed of the welding torch 5 in the first direction DR1.
　第１補助トーチ６ａは、第１部材１を加熱している。第２補助トーチ６ｂは、第２部材２を加熱している。このことを別の観点から言えば、第２方向ＤＲ２における第１補助トーチ６ａの位置及び第２方向ＤＲ２における第２補助トーチ６ｂの位置は、第２方向ＤＲ２における溶接トーチ５の位置とずれている。第２方向ＤＲ２における第１補助トーチ６ａと溶接トーチ５との間の距離は、例えば、第２方向ＤＲ２における第２補助トーチ６ｂと溶接トーチ５との間の距離と等しい。 The first auxiliary torch 6a heats the first member 1. The second auxiliary torch 6b heats the second member 2. From another point of view, the position of the first auxiliary torch 6a in the second direction DR2 and the position of the second auxiliary torch 6b in the second direction DR2 deviate from the position of the welding torch 5 in the second direction DR2. There is. The distance between the first auxiliary torch 6a and the welding torch 5 in the second direction DR2 is, for example, equal to the distance between the second auxiliary torch 6b and the welding torch 5 in the second direction DR2.
　第１補助トーチ６ａ及び第２補助トーチ６ｂの出力は、溶接トーチ５の出力よりも小さい。その結果、第１補助トーチ６ａの加熱により第１部材１は溶融せず、第２補助トーチ６ｂの加熱により第２部材２は溶融しない。 The output of the first auxiliary torch 6a and the second auxiliary torch 6b is smaller than the output of the welding torch 5. As a result, the first member 1 is not melted by heating the first auxiliary torch 6a, and the second member 2 is not melted by heating the second auxiliary torch 6b.
　第１補助トーチ６ａの第１方向ＤＲ１における位置及び第２補助トーチ６ｂの第１方向ＤＲ１における位置は、溶接トーチ５の第１方向ＤＲ１における位置とずれている。より具体的には、第１補助トーチ６ａ及び第２補助トーチ６ｂは、第１方向ＤＲ１において、溶接トーチ５よりも始端側にある。 The position of the first auxiliary torch 6a in the first direction DR1 and the position of the second auxiliary torch 6b in the first direction DR1 are deviated from the positions of the welding torch 5 in the first direction DR1. More specifically, the first auxiliary torch 6a and the second auxiliary torch 6b are on the starting end side of the welding torch 5 in the first direction DR1.
　第１補助トーチ６ａの第１方向ＤＲ１における位置及び第２補助トーチ６ｂの第１方向ＤＲ１における位置は、例えば、互いに一致している。すなわち、第１補助トーチ６ａ及び第２補助トーチ６ｂは、例えば、第２方向ＤＲ２において互いに対向している。第１補助トーチ６ａ及び第２補助トーチ６ｂは、好ましくは、第２方向ＤＲ２において凝固脆性温度領域５２と対向している。 The position of the first auxiliary torch 6a in the first direction DR1 and the position of the second auxiliary torch 6b in the first direction DR1 coincide with each other, for example. That is, the first auxiliary torch 6a and the second auxiliary torch 6b face each other in, for example, the second direction DR2. The first auxiliary torch 6a and the second auxiliary torch 6b preferably face the solidification brittle temperature region 52 in the second direction DR2.
　第１補助トーチ６ａ及び第２補助トーチ６ｂは、例えば、アーク溶接機の溶接トーチである。但し、第１補助トーチ６ａ及び第２補助トーチ６ｂは、これに限られず、例えば、レーザ溶接機の溶接トーチであってもよい。 The first auxiliary torch 6a and the second auxiliary torch 6b are, for example, welding torches of an arc welder. However, the first auxiliary torch 6a and the second auxiliary torch 6b are not limited to this, and may be, for example, a welding torch of a laser welding machine.
　（第１実施形態に係る溶接構造体の製造方法の効果）
　以下に、第１実施形態に係る溶接構造体の製造方法の効果を説明する。 (Effect of Manufacturing Method of Welded Structure According to First Embodiment)
The effect of the method for manufacturing the welded structure according to the first embodiment will be described below.
　まず、溶接時における高温割れの発生メカニズムを説明する。図６は、液相線温度と固体相線温度との間における凝固脆性温度領域５２の模式的な高温延性曲線である。図６中において、横軸は凝固脆性温度領域５２の温度であり、縦軸は凝固脆性温度領域５２に加わる歪みである。図６中の高温延性曲線（実線）は、所定の温度における高温割れが発生する限界の歪みを示している。また、図６中のＴＬ及びＴＳは、それぞれ液相線温度及び固相線温度を示している。 First, the mechanism of high-temperature cracking during welding will be described. FIG. 6 is a schematic high temperature ductility curve of the solidification brittle temperature region 52 between the liquid phase temperature and the solid phase temperature. In FIG. 6, the horizontal axis represents the temperature in the solidification brittleness temperature region 52, and the vertical axis represents the strain applied to the solidification brittleness temperature region 52. The high-temperature ductility curve (solid line) in FIG. 6 shows the limit strain at which high-temperature cracking occurs at a predetermined temperature. Further, T L and T S in FIG. 6 respectively show a liquidus temperature and a solidus temperature.
　図６に示されるように、凝固脆性温度領域５２においては、溶融している金属の凝固に伴って（すなわち、温度が低下するに伴って）、引張歪みが増加していく（図６中の点線参照）。この点線が高温延性曲線の上方にある領域（図６中のハッチングされた領域を参照）を通過する場合、凝固脆性温度領域５２に高温割れが生じることになる。 As shown in FIG. 6, in the solidification brittle temperature region 52, the tensile strain increases as the molten metal solidifies (that is, as the temperature decreases) (in FIG. 6). See dotted line). When this dotted line passes through a region above the high temperature ductility curve (see the hatched region in FIG. 6), high temperature cracking will occur in the solidified brittle temperature region 52.
　第１実施形態に係る溶接構造体の製造方法においては、第１補助トーチ６ａ及び第２補助トーチ６ｂによる補助加熱が行われている。第１補助トーチ６ａにより加熱されている第１部材１の部分及び第２補助トーチ６ｂにより加熱されている第２部材２の部分が熱膨張するため、これらの部分から凝固脆性温度領域５２に圧縮応力が加わる。 In the method for manufacturing a welded structure according to the first embodiment, auxiliary heating is performed by the first auxiliary torch 6a and the second auxiliary torch 6b. Since the portion of the first member 1 heated by the first auxiliary torch 6a and the portion of the second member 2 heated by the second auxiliary torch 6b thermally expand, these portions are compressed into the solidification brittle temperature region 52. Stress is applied.
　この圧縮応力により、凝固脆性温度領域５２には加わる引張歪みが軽減される（又は、凝固脆性温度領域５２に圧縮歪みが加わる）ようになる（図６中の一点鎖線参照）。その結果、この一点鎖線が高温延性曲線の上方にある領域を通過しがたくなり、凝固脆性温度領域５２に高温割れが生じがたくなる。 Due to this compressive stress, the tensile strain applied to the solidification brittle temperature region 52 is reduced (or the compression strain is applied to the solidification brittle temperature region 52) (see the one-point chain line in FIG. 6). As a result, it becomes difficult for the alternate long and short dash line to pass through the region above the high temperature ductility curve, and high temperature cracking is less likely to occur in the solidification brittle temperature region 52.
　（変形例）
　上記においては、補助加熱工程Ｓ２２が第１補助トーチ６ａ及び第２補助トーチ６ｂを用いて行われる例を説明した。しかしながら、補助加熱工程Ｓ２２には、第１補助トーチ６ａ及び第２補助トーチ６ｂのいずれか一方が用いられてもよい（変形例１）。なお、第１補助トーチ６ａ及び第２補助トーチ６ｂのいずれか一方を用いる場合、溶接金属部３の配置によっては（例えば、溶接金属部３が溶接構造体の端部近傍にある場合等）、高温割れを十分に抑制できないことがある。他方で、第１補助トーチ６ａ及び第２補助トーチ６ｂの双方を用いる場合には、溶接金属部３の配置によらず安定して高温割れの発生を抑制することが可能となる。 (Modification example)
In the above, an example in which the auxiliary heating step S22 is performed by using the first auxiliary torch 6a and the second auxiliary torch 6b has been described. However, in the auxiliary heating step S22, either one of the first auxiliary torch 6a and the second auxiliary torch 6b may be used (modification example 1). When either the first auxiliary torch 6a or the second auxiliary torch 6b is used, depending on the arrangement of the weld metal portion 3 (for example, when the weld metal portion 3 is near the end of the welded structure), It may not be possible to sufficiently suppress high temperature cracking. On the other hand, when both the first auxiliary torch 6a and the second auxiliary torch 6b are used, it is possible to stably suppress the occurrence of high temperature cracks regardless of the arrangement of the weld metal portions 3.
　上記においては、第２方向ＤＲ２における第１補助トーチ６ａの位置（第２方向ＤＲ２における第２補助トーチ６ｂの位置）が第２方向ＤＲ２における溶接トーチ５の位置とずれている例を説明した。しかしながら、変形例１において、第２方向ＤＲ２における第１補助トーチ６ａ（第２補助トーチ６ｂ）の位置が、第２方向ＤＲ２における溶接トーチ５の位置と一致していてもよい（変形例２）。変形例１及び変形例２のいずれにおいても、第１実施形態に係る溶接構造体の製造方法と同様に、凝固脆性温度領域５２に高温割れが生じがたくなる。 In the above, an example in which the position of the first auxiliary torch 6a in the second direction DR2 (the position of the second auxiliary torch 6b in the second direction DR2) is deviated from the position of the welding torch 5 in the second direction DR2 has been described. However, in the first modification, the position of the first auxiliary torch 6a (second auxiliary torch 6b) in the second direction DR2 may coincide with the position of the welding torch 5 in the second direction DR2 (deformation example 2). .. In both the modified example 1 and the modified example 2, high temperature cracking is less likely to occur in the solidified brittle temperature region 52, as in the method for manufacturing the welded structure according to the first embodiment.
　（第２実施形態に係る溶接構造体の構成）
　第２実施形態に係る溶接構造体の構成は、第１実施形態に係る溶接構造体の構成と同様である。そのため、ここでは、第２実施形態に係る溶接構造体の構成に関する説明を省略する。 (Structure of welded structure according to the second embodiment)
The structure of the welded structure according to the second embodiment is the same as the structure of the welded structure according to the first embodiment. Therefore, here, the description regarding the configuration of the welded structure according to the second embodiment will be omitted.
　（第２実施形態に係る溶接構造体の製造方法）
　以下に、第２実施形態に係る溶接構造体の製造方法を説明する。ここでは、第１実施形態に係る溶接構造体の製造方法と異なる点を主に説明し、重複する説明は繰り返さない。 (Manufacturing method of welded structure according to the second embodiment)
The method of manufacturing the welded structure according to the second embodiment will be described below. Here, the points different from the method for manufacturing the welded structure according to the first embodiment will be mainly described, and the duplicated description will not be repeated.
　第２実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１と、溶接工程Ｓ２とを有している。溶接工程Ｓ２は、溶接金属形成工程Ｓ２１と、補助加熱工程Ｓ２２とを有している。これらの点に関して、第２実施形態に係る溶接構造体の製造方法は、第１実施形態に係る溶接構造体の製造方法と共通している。 The method for manufacturing a welded structure according to the second embodiment includes a preparation step S1 and a welding step S2. The welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22. Regarding these points, the method for manufacturing the welded structure according to the second embodiment is common to the method for manufacturing the welded structure according to the first embodiment.
　しかしながら、第２実施形態に係る溶接構造体の製造方法は、補助加熱工程Ｓ２２の詳細に関して、第１実施形態に係る溶接構造体の製造方法と異なっている。 However, the method for manufacturing the welded structure according to the second embodiment is different from the method for manufacturing the welded structure according to the first embodiment with respect to the details of the auxiliary heating step S22.
　図７は、第２実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。なお、図７中において、溶接トーチ５、第３補助トーチ６ｃ及び第４補助トーチ６ｄは、点線により示されている。図７に示されるように、第２実施形態に係る溶接構造体の製造方法における補助加熱工程Ｓ２２では、第１補助トーチ６ａ及び第２補助トーチ６ｂに代えて、第３補助トーチ６ｃ及び第４補助トーチ６ｄが用いられる。 FIG. 7 is a schematic view for explaining the welding process S2 in the method for manufacturing the welded structure according to the second embodiment. In FIG. 7, the welding torch 5, the third auxiliary torch 6c, and the fourth auxiliary torch 6d are indicated by dotted lines. As shown in FIG. 7, in the auxiliary heating step S22 in the method for manufacturing the welded structure according to the second embodiment, the third auxiliary torch 6c and the fourth auxiliary torch 6c and the fourth are replaced with the first auxiliary torch 6a and the second auxiliary torch 6b. An auxiliary torch 6d is used.
　第３補助トーチ６ｃ及び第４補助トーチ６ｄが、第１方向ＤＲ１に沿って始端側から終端側へと移動している。第３補助トーチ６ｃ及び第４補助トーチ６ｄの第１方向ＤＲ１における移動速度は、例えば、溶接トーチ５の第１方向ＤＲ１における移動速度と等しい。 The third auxiliary torch 6c and the fourth auxiliary torch 6d are moving from the start side to the end side along the first direction DR1. The moving speed of the third auxiliary torch 6c and the fourth auxiliary torch 6d in the first direction DR1 is, for example, equal to the moving speed of the welding torch 5 in the first direction DR1.
　第３補助トーチ６ｃは、第１部材１を加熱している。第４補助トーチ６ｄは、第２部材２を加熱している。このことを別の観点から言えば、第２方向ＤＲ２における第３補助トーチ６ｃの位置及び第２方向ＤＲ２における第４補助トーチ６ｄの位置は、第２方向ＤＲ２における溶接トーチ５の位置とずれている。第２方向ＤＲ２における第３補助トーチ６ｃと溶接トーチ５との間の距離は、例えば、第２方向ＤＲ２における第４補助トーチ６ｄと溶接トーチ５との間の距離と等しい。 The third auxiliary torch 6c heats the first member 1. The fourth auxiliary torch 6d heats the second member 2. From another point of view, the position of the third auxiliary torch 6c in the second direction DR2 and the position of the fourth auxiliary torch 6d in the second direction DR2 deviate from the position of the welding torch 5 in the second direction DR2. There is. The distance between the third auxiliary torch 6c and the welding torch 5 in the second direction DR2 is, for example, equal to the distance between the fourth auxiliary torch 6d and the welding torch 5 in the second direction DR2.
　第３補助トーチ６ｃ及び第４補助トーチ６ｄの出力は、溶接トーチ５の出力よりも小さい。その結果、第３補助トーチ６ｃの加熱により第１部材１は溶融せず、第４補助トーチ６ｄの加熱により第２部材２は溶融しない。 The output of the 3rd auxiliary torch 6c and the 4th auxiliary torch 6d is smaller than the output of the welding torch 5. As a result, the first member 1 is not melted by heating the third auxiliary torch 6c, and the second member 2 is not melted by heating the fourth auxiliary torch 6d.
　第３補助トーチ６ｃの第１方向ＤＲ１における位置及び第４補助トーチ６ｄの第１方向ＤＲ１における位置は、溶接トーチ５の第１方向ＤＲ１における位置とずれている。より具体的には、第３補助トーチ６ｃ及び第４補助トーチ６ｄは、第１方向ＤＲ１において、溶接トーチ５よりも終端側にある。 The position of the third auxiliary torch 6c in the first direction DR1 and the position of the fourth auxiliary torch 6d in the first direction DR1 are deviated from the positions of the welding torch 5 in the first direction DR1. More specifically, the third auxiliary torch 6c and the fourth auxiliary torch 6d are on the terminal side of the welding torch 5 in the first direction DR1.
　第３補助トーチ６ｃの第１方向ＤＲ１における位置及び第４補助トーチ６ｄの第１方向ＤＲ１における位置は、例えば、互いに一致している。すなわち、第３補助トーチ６ｃ及び第４補助トーチ６ｄは、例えば、第２方向ＤＲ２において互いに対向している。 The position of the third auxiliary torch 6c in the first direction DR1 and the position of the fourth auxiliary torch 6d in the first direction DR1 coincide with each other, for example. That is, the third auxiliary torch 6c and the fourth auxiliary torch 6d face each other in, for example, the second direction DR2.
　第１補助トーチ６ａ及び第２補助トーチ６ｂは、例えば、アーク溶接機の溶接トーチである。但し、第１補助トーチ６ａ及び第２補助トーチ６ｂは、これに限られず、例えば、レーザ溶接機の溶接トーチであってもよい。 The first auxiliary torch 6a and the second auxiliary torch 6b are, for example, welding torches of an arc welder. However, the first auxiliary torch 6a and the second auxiliary torch 6b are not limited to this, and may be, for example, a welding torch of a laser welding machine.
　（第２実施形態に係る溶接構造体の製造方法の効果）
　以下に、第２実施形態に係る溶接構造体の製造方法の効果を説明する。 (Effect of Manufacturing Method of Welded Structure According to Second Embodiment)
The effect of the method for manufacturing the welded structure according to the second embodiment will be described below.
　図８は、溶接金属形成工程Ｓ２１を行っている間に生じる第１部材１及び第２部材２の面内回転変形を示す模式図である。図８に示されるように、溶接金属形成工程Ｓ２１が行われている際、溶接トーチ５の近傍においては第１部材１及び第２部材の温度が大きく上昇する一方で、溶接トーチ５から離れた位置においては第１部材１及び第２部材の温度はあまり上昇しない。 FIG. 8 is a schematic view showing in-plane rotational deformation of the first member 1 and the second member 2 that occur during the weld metal forming step S21. As shown in FIG. 8, when the weld metal forming step S21 is being performed, the temperatures of the first member 1 and the second member rise significantly in the vicinity of the welding torch 5, while being separated from the welding torch 5. At the position, the temperatures of the first member 1 and the second member do not rise so much.
　その結果、溶接トーチ５の近傍と溶接トーチ５から離れた位置との間で熱膨張量に差異が生じ、終端側に近づくほど第１部材１と第２部材２との間隔が拡がるような面内回転変形（図８中の点線参照）が生じる。この面内回転変形により凝固脆性温度領域５２に引張歪みが加わり、当該引張歪みが凝固脆性温度領域５２における高温割れの原因の１つになる。 As a result, there is a difference in the amount of thermal expansion between the vicinity of the welding torch 5 and the position away from the welding torch 5, and the distance between the first member 1 and the second member 2 increases as the distance from the welding torch 5 approaches the end side. Internal rotational deformation (see dotted line in FIG. 8) occurs. Due to this in-plane rotational deformation, tensile strain is applied to the solidification brittle temperature region 52, and the tensile strain becomes one of the causes of high temperature cracking in the solidification brittle temperature region 52.
　第２実施形態に係る溶接構造体の製造方法においては、第３補助トーチ６ｃ及び第４補助トーチ６ｄが溶接トーチ５よりも終端側において第１部材１及び第２部材２をそれぞれ加熱しているため、溶接トーチ５の近傍と溶接トーチ５から離れた位置との間における熱膨張量の差異が減少する。その結果、第１部材１及び第２部材２の面内変形量が減少するとともに、凝固脆性温度領域５２に加わる引張歪みが小さくなる。このように、第２実施形態に係る溶接構造体の製造方法によると、凝固脆性温度領域５２に高温割れが生じがたくなる。 In the method for manufacturing a welded structure according to the second embodiment, the third auxiliary torch 6c and the fourth auxiliary torch 6d heat the first member 1 and the second member 2 on the terminal side of the welding torch 5, respectively. Therefore, the difference in the amount of thermal expansion between the vicinity of the welding torch 5 and the position away from the welding torch 5 is reduced. As a result, the amount of in-plane deformation of the first member 1 and the second member 2 is reduced, and the tensile strain applied to the solidification brittle temperature region 52 is reduced. As described above, according to the method for manufacturing the welded structure according to the second embodiment, high temperature cracking is less likely to occur in the solidified brittle temperature region 52.
　第１部材１と第２部材２との間に仮止めが行われている場合、溶接トーチ５の近傍と溶接トーチ５から離れた位置との間で熱膨張量に差異が生じても、仮止めにより第１部材１及び第２部材２の面内回転変形は抑制されている。しかしながら、溶接トーチ５が仮止めに接近して仮止めが溶融すれば、仮止めにより抑制されていた面内回転変形が急激に開放される結果、凝固脆性温度領域５２に大きな引張歪みが作用する。 When temporary fixing is performed between the first member 1 and the second member 2, even if there is a difference in the amount of thermal expansion between the vicinity of the welding torch 5 and the position away from the welding torch 5, it is temporarily fixed. In-plane rotational deformation of the first member 1 and the second member 2 is suppressed by the stopper. However, when the welding torch 5 approaches the temporary fixing and the temporary fixing melts, the in-plane rotational deformation suppressed by the temporary fixing is suddenly released, and as a result, a large tensile strain acts on the solidification brittle temperature region 52. ..
　第２実施形態に係る溶接構造体の製造方法においては、第３補助トーチ６ｃ及び第４補助トーチ６ｄが溶接トーチ５よりも終端側において第１部材１及び第２部材２をそれぞれ加熱しているため、溶接トーチ５よりも終端側にある仮止めが予熱されることになる。すなわち、第２実施形態に係る溶接構造体の製造方法においては、仮止めによる面内回転変形に対する拘束が、予め弱められている。 In the method for manufacturing a welded structure according to the second embodiment, the third auxiliary torch 6c and the fourth auxiliary torch 6d heat the first member 1 and the second member 2 on the terminal side of the welding torch 5, respectively. Therefore, the temporary fixing on the terminal side of the welding torch 5 is preheated. That is, in the method for manufacturing a welded structure according to the second embodiment, the restraint against in-plane rotational deformation due to temporary fixing is weakened in advance.
　その結果、溶接トーチ５が仮止めに接近して仮止めが溶融しても、面内回転変形が急激には開放されず、凝固脆性温度領域５２に加わる引張歪みが軽減される。このように、第２実施形態に係る溶接構造体の製造方法によると、第１部材１と第２部材２とが仮止めされている場合にも、凝固脆性温度領域５２に高温割れが生じがたくなる。 As a result, even if the welding torch 5 approaches the temporary fixing and the temporary fixing melts, the in-plane rotational deformation is not suddenly released, and the tensile strain applied to the solidification brittle temperature region 52 is reduced. As described above, according to the method for manufacturing the welded structure according to the second embodiment, even when the first member 1 and the second member 2 are temporarily fixed, high temperature cracks occur in the solidified brittle temperature region 52. I want to.
　（変形例）
　上記においては、第１補助トーチ６ａ及び第２補助トーチ６ｂに代えて第３補助トーチ６ｃ及び第４補助トーチ６ｄを用いる例を説明したが、第１補助トーチ６ａ及び第２補助トーチ６ｂと第３補助トーチ６ｃ及び第４補助トーチ６ｄとが併用されてもよい（変形例１）。第１実施形態に係る溶接構造体の製造方法と第２実施形態に係る溶接構造体の製造方法とでは、凝固脆性温度領域５２における高温割れの発生を抑制するメカニズムが異なる。そのため、第１補助トーチ６ａ及び第２補助トーチ６ｂと第３補助トーチ６ｃ及び第４補助トーチ６ｄとが併用されることにより、凝固脆性温度領域５２における高温割れの発生をさらに抑制することができる。 (Modification example)
In the above, an example in which the third auxiliary torch 6c and the fourth auxiliary torch 6d are used in place of the first auxiliary torch 6a and the second auxiliary torch 6b has been described. The 3 auxiliary torch 6c and the 4th auxiliary torch 6d may be used in combination (modification example 1). The mechanism for suppressing the occurrence of high-temperature cracks in the solidified brittle temperature region 52 differs between the method for manufacturing the welded structure according to the first embodiment and the method for manufacturing the welded structure according to the second embodiment. Therefore, by using the first auxiliary torch 6a and the second auxiliary torch 6b and the third auxiliary torch 6c and the fourth auxiliary torch 6d in combination, the occurrence of high temperature cracking in the solidification brittle temperature region 52 can be further suppressed. ..
　上記においては、補助加熱工程Ｓ２２が第３補助トーチ６ｃ及び第４補助トーチ６ｄを用いて行われる例を説明した。しかしながら、補助加熱工程Ｓ２２には、第３補助トーチ６ｃ及び第４補助トーチ６ｄのいずれか一方が用いられてもよい（変形例２）。なお、第３補助トーチ６ｃ及び第４補助トーチ６ｄのいずれか一方を用いる場合、溶接金属部３の配置によっては（例えば、溶接金属部３が溶接構造体の端部近傍にある場合等）、高温割れを十分に抑制できないことがある。他方で、第３補助トーチ６ｃ及び第４補助トーチ６ｄの双方を用いる場合には、溶接金属部３の配置によらず安定して高温割れの発生を抑制することが可能となる。 In the above, an example in which the auxiliary heating step S22 is performed using the third auxiliary torch 6c and the fourth auxiliary torch 6d has been described. However, in the auxiliary heating step S22, either one of the third auxiliary torch 6c and the fourth auxiliary torch 6d may be used (modification example 2). When either the third auxiliary torch 6c or the fourth auxiliary torch 6d is used, depending on the arrangement of the weld metal portion 3 (for example, when the weld metal portion 3 is near the end of the welded structure), It may not be possible to sufficiently suppress high temperature cracking. On the other hand, when both the third auxiliary torch 6c and the fourth auxiliary torch 6d are used, it is possible to stably suppress the occurrence of high temperature cracks regardless of the arrangement of the weld metal portion 3.
　上記においては、第２方向ＤＲ２における第３補助トーチ６ｃの位置（第２方向ＤＲ２における第４補助トーチ６ｄの位置）が第２方向ＤＲ２における溶接トーチ５の位置とずれている例を説明した。しかしながら、変形例２において、第２方向ＤＲ２における第３補助トーチ６ｃ（第４補助トーチ６ｄ）の位置が、第２方向ＤＲ２における溶接トーチ５の位置と一致していてもよい（変形例３）。変形例２及び変形例３のいずれにおいても、第２実施形態に係る溶接構造体の製造方法と同様に、凝固脆性温度領域５２に高温割れが生じがたくなる。 In the above, an example in which the position of the third auxiliary torch 6c in the second direction DR2 (the position of the fourth auxiliary torch 6d in the second direction DR2) is deviated from the position of the welding torch 5 in the second direction DR2 has been described. However, in the second modification, the position of the third auxiliary torch 6c (fourth auxiliary torch 6d) in the second direction DR2 may coincide with the position of the welding torch 5 in the second direction DR2 (modification example 3). .. In both the modified example 2 and the modified example 3, high temperature cracking is less likely to occur in the solidified brittle temperature region 52, as in the method for manufacturing the welded structure according to the second embodiment.
　（第３実施形態に係る溶接構造体の構成）
　以下に、第３実施形態に係る溶接構造体の構成を説明する。ここでは、第１実施形態に係る溶接構造体の構成と異なる点を主に説明し、重複する説明は繰り返さない。 (Structure of welded structure according to the third embodiment)
The configuration of the welded structure according to the third embodiment will be described below. Here, the points different from the configuration of the welded structure according to the first embodiment will be mainly described, and the overlapping description will not be repeated.
　図９は、第３実施形態に係る溶接構造体の平面図である。図１０は、図９のＸ－Ｘにおける断面図である。図９及び１０に示されるように、第３実施形態に係る溶接構造体は、第１部材１と、第２部材２と、溶接金属部３とを有している。この点に関して、第３実施形態に係る溶接構造体の構成は、第１実施形態に係る溶接構造体の構成と共通している。 FIG. 9 is a plan view of the welded structure according to the third embodiment. FIG. 10 is a cross-sectional view taken along the line XX of FIG. As shown in FIGS. 9 and 10, the welded structure according to the third embodiment includes a first member 1, a second member 2, and a weld metal portion 3. In this respect, the structure of the welded structure according to the third embodiment is common to the structure of the welded structure according to the first embodiment.
　しかしながら、第３実施形態に係る溶接構造体において、第２部材２は、第１部材１上に重ねられている。溶接金属部３は、第１部材１及び第２部材２を貫通するように形成されている。すなわち、第３実施形態に係る溶接構造体においては、第２方向ＤＲ２における一方側から溶接金属部３に隣接している第１部材１及び第２部材２の部分が第１部分７になっており、第２方向ＤＲ２における他方側から溶接金属部３に隣接している第１部材１及び第２部材２の部分が第２部分８になっている。これらの点に関して、第３実施形態に係る溶接構造体の構成は、第１実施形態に係る溶接構造体の構成と異なっている。 However, in the welded structure according to the third embodiment, the second member 2 is superposed on the first member 1. The weld metal portion 3 is formed so as to penetrate the first member 1 and the second member 2. That is, in the welded structure according to the third embodiment, the portions of the first member 1 and the second member 2 adjacent to the weld metal portion 3 from one side in the second direction DR2 become the first portion 7. The portion of the first member 1 and the second member 2 adjacent to the weld metal portion 3 from the other side in the second direction DR2 is the second portion 8. With respect to these points, the structure of the welded structure according to the third embodiment is different from the structure of the welded structure according to the first embodiment.
　なお、第３実施形態に係る溶接構造体において、第２方向ＤＲ２における第１部分７の幅と第２方向ＤＲ２における第２部分８の幅とは、互いに異なっていてもよい。 In the welded structure according to the third embodiment, the width of the first portion 7 in the second direction DR2 and the width of the second portion 8 in the second direction DR2 may be different from each other.
　（第３実施形態に係る溶接構造体の製造方法）
　以下に、第３実施形態に係る溶接構造体の製造方法を説明する。ここでは、第１実施形態に係る溶接構造体の製造方法と異なる点を主に説明し、重複する説明は繰り返さない。 (Manufacturing method of welded structure according to the third embodiment)
The method of manufacturing the welded structure according to the third embodiment will be described below. Here, the points different from the method for manufacturing the welded structure according to the first embodiment will be mainly described, and the duplicated description will not be repeated.
　第３実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１と、溶接工程Ｓ２とを有している。溶接工程Ｓ２は、溶接金属形成工程Ｓ２１と、補助加熱工程Ｓ２２とを有している。これらの点に関して、第３実施形態に係る溶接構造体の製造方法は、第１実施形態に係る溶接構造体の製造方法と共通している。 The method for manufacturing a welded structure according to the third embodiment includes a preparation step S1 and a welding step S2. The welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22. Regarding these points, the method for manufacturing the welded structure according to the third embodiment is common to the method for manufacturing the welded structure according to the first embodiment.
　しかしながら、第３実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１の詳細、溶接金属形成工程Ｓ２１の詳細及び補助加熱工程Ｓ２２の詳細に関して、第１実施形態に係る溶接構造体の製造方法と異なっている。 However, the method for manufacturing the welded structure according to the third embodiment is the method for manufacturing the welded structure according to the first embodiment with respect to the details of the preparation step S1, the details of the weld metal forming step S21, and the details of the auxiliary heating step S22. Is different.
　図１１は、第３実施形態に係る溶接構造体の製造方法における準備工程Ｓ１を説明するための模式図である。第３実施形態に係る溶接構造体の製造方法における準備工程Ｓ１では、第２部材２が、第１部材１上に重ねられる。 FIG. 11 is a schematic diagram for explaining the preparation step S1 in the method for manufacturing the welded structure according to the third embodiment. In the preparation step S1 in the method for manufacturing a welded structure according to the third embodiment, the second member 2 is superposed on the first member 1.
　図１２は、第３実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。図１２中において、溶接トーチ５、第１補助トーチ６ａ及び第２補助トーチ６ｂは、点線により示されている。図１２に示されるように、第３実施形態に係る溶接構造体の製造方法における溶接金属形成工程Ｓ２１では、第１方向ＤＲ１に沿って溶接トーチ５を始端側から終端側へと移動させることにより、第１部材１及び第２部材２を貫通するように溶接金属部３が形成される。 FIG. 12 is a schematic view for explaining the welding step S2 in the method for manufacturing the welded structure according to the third embodiment. In FIG. 12, the welding torch 5, the first auxiliary torch 6a and the second auxiliary torch 6b are indicated by dotted lines. As shown in FIG. 12, in the weld metal forming step S21 in the method for manufacturing a welded structure according to the third embodiment, the weld torch 5 is moved from the start end side to the end side along the first direction DR1. , The weld metal portion 3 is formed so as to penetrate the first member 1 and the second member 2.
　第３実施形態に係る溶接構造体の製造方法における補助加熱工程Ｓ２２では、第１部分７（第２方向ＤＲ２における一方側から溶接金属部３に隣接している第１部材１及び第２部材２の部分）が第１補助トーチ６ａにより加熱され、第２部分８（第２方向ＤＲ２における他方側から溶接金属部３に隣接している第１部材１及び第２部材２の部分）が第２補助トーチ６ｂにより加熱される。なお、第１補助トーチ６ａの加熱により第１部分７は溶融せず、第２補助トーチ６ｂの加熱により第２部分８は溶融しない。 In the auxiliary heating step S22 in the method for manufacturing a welded structure according to the third embodiment, the first portion 7 (the first member 1 and the second member 2 adjacent to the weld metal portion 3 from one side in the second direction DR2) Part) is heated by the first auxiliary torch 6a, and the second part 8 (the part of the first member 1 and the second member 2 adjacent to the weld metal part 3 from the other side in the second direction DR2) is the second. It is heated by the auxiliary torch 6b. The first portion 7 is not melted by heating the first auxiliary torch 6a, and the second portion 8 is not melted by heating the second auxiliary torch 6b.
　（第３実施形態に係る溶接構造体の製造方法の効果）
　第３実施形態に係る溶接構造体の製造方法においても、第１補助トーチ６ａの加熱及び第２補助トーチ６ｂの加熱により、凝固脆性温度領域５２に加わる引張歪みが軽減される（又は、凝固脆性温度領域５２に圧縮歪みが加わる）ことになるため、凝固脆性温度領域５２に高温割れが生じがたくなる。 (Effect of Manufacturing Method of Welded Structure According to Third Embodiment)
Also in the method for manufacturing a welded structure according to the third embodiment, the tensile strain applied to the solidification brittleness temperature region 52 is reduced (or solidification brittleness) by heating the first auxiliary torch 6a and the second auxiliary torch 6b. Since compressive strain is applied to the temperature region 52), high temperature cracking is less likely to occur in the solidified brittle temperature region 52.
　このように、第１補助トーチ６ａ及び第２補助トーチ６ｂを用いて第１部分７及び第２部分８を溶融させずに加熱しながら溶接トーチ５を用いて溶接金属部３を形成することにより凝固脆性温度領域５２における高温割れの発生を抑制する手法は、溶接の形式（突き合わせ溶接又は重ね溶接）に拠らず適用可能である。 In this way, by forming the weld metal portion 3 using the welding torch 5 while heating the first portion 7 and the second portion 8 without melting them using the first auxiliary torch 6a and the second auxiliary torch 6b. The method of suppressing the occurrence of high temperature cracks in the solidification brittle temperature region 52 is applicable regardless of the welding type (butt welding or lap welding).
　（第４実施形態に係る溶接構造体の構成）
　以下に、第４実施形態に係る溶接構造体の構成を説明する。ここでは、第１実施形態に係る溶接構造体の構成と異なる点を主に説明し、重複する説明は繰り返さない。 (Structure of welded structure according to the fourth embodiment)
The configuration of the welded structure according to the fourth embodiment will be described below. Here, the points different from the configuration of the welded structure according to the first embodiment will be mainly described, and the overlapping description will not be repeated.
　図１３は、第４実施形態に係る溶接構造体の断面図である。図１３には、溶接金属部３の延在方向（第１方向ＤＲ１）に直交する断面図が示されている。図１３に示されるように、第１部材１は厚さＴ１を有しており、第２部材２は厚さＴ２を有している。厚さＴ１及び厚さＴ２は、１６ｍｍ以上４０ｍｍ以上である。すなわち、第４実施形態に係る溶接構造体は、突き合わせ溶接継手である点に関して第１実施形態に係る溶接構造体と共通しているが、第１部材１及び第２部材２として厚板が用いられている点に関して第１実施形態に係る溶接構造体と異なっている。 FIG. 13 is a cross-sectional view of the welded structure according to the fourth embodiment. FIG. 13 shows a cross-sectional view orthogonal to the extending direction (first direction DR1) of the weld metal portion 3. As shown in FIG. 13, the first member 1 has a thickness T1 and the second member 2 has a thickness T2. The thickness T1 and the thickness T2 are 16 mm or more and 40 mm or more. That is, the welded structure according to the fourth embodiment is common to the welded structure according to the first embodiment in that it is a butt welded joint, but a thick plate is used as the first member 1 and the second member 2. It is different from the welded structure according to the first embodiment in that it is.
　（第４実施形態に係る溶接構造体の製造方法）
　以下に、第４実施形態に係る溶接構造体の製造方法を説明する。ここでは、第１実施形態に係る溶接構造体の製造方法と異なる点を主に説明し、重複する説明は繰り返さない。 (Manufacturing method of welded structure according to the fourth embodiment)
The method of manufacturing the welded structure according to the fourth embodiment will be described below. Here, the points different from the method for manufacturing the welded structure according to the first embodiment will be mainly described, and the duplicated description will not be repeated.
　第４実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１と、溶接工程Ｓ２とを有している。溶接工程Ｓ２は、溶接金属形成工程Ｓ２１と、補助加熱工程Ｓ２２とを有している。これらの点に関して、第４実施形態に係る溶接構造体の製造方法は、第１実施形態に係る溶接構造体の製造方法と異なっている。しかしながら、第４実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１及び溶接工程Ｓ２の詳細に関して、第１実施形態に係る溶接構造体の製造方法と異なっている。 The method for manufacturing a welded structure according to the fourth embodiment includes a preparation step S1 and a welding step S2. The welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22. Regarding these points, the method for manufacturing the welded structure according to the fourth embodiment is different from the method for manufacturing the welded structure according to the first embodiment. However, the method for manufacturing the welded structure according to the fourth embodiment is different from the method for manufacturing the welded structure according to the first embodiment with respect to the details of the preparation step S1 and the welding step S2.
　図１４は、第４実施形態に係る溶接構造体の製造方法における準備工程Ｓ１を説明するための断面図である。図１４に示されるように、第４実施形態に係る溶接構造体の製造方法における準備工程Ｓ１では、第１部材１の第２部材２側の端面（第１端面１ａ）と第２部材２の第１部材１側の端面（第２端面２ａ）とが、Ｙ形開先を構成している。但し、第１端面１ａ及び第２端面２ａにより構成されている開先は、Ｙ開先に限られない。第１端面１ａ及び第２端面２ａにより構成されている開先は、Ｖ形開先、Ｘ形開先、Ｋ形開先等であってもよい。 FIG. 14 is a cross-sectional view for explaining the preparation step S1 in the method for manufacturing the welded structure according to the fourth embodiment. As shown in FIG. 14, in the preparation step S1 in the method for manufacturing the welded structure according to the fourth embodiment, the end faces (first end faces 1a) of the first member 1 on the second member 2 side and the second member 2 The end surface (second end surface 2a) on the first member 1 side constitutes a Y-shaped groove. However, the groove composed of the first end surface 1a and the second end surface 2a is not limited to the Y groove. The groove composed of the first end surface 1a and the second end surface 2a may be a V-shaped groove, an X-shaped groove, a K-shaped groove, or the like.
　第４実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２（溶接金属形成工程Ｓ２１及び補助加熱工程Ｓ２２）は、複数回繰り返されてもよい。すなわち、第４実施形態に係る溶接構造体の溶接金属部３は、多層溶接により形成されてもよい。なお、第４実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２は、第１実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２に代えて、第２実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２が用いられてもよい。 The welding step S2 (welded metal forming step S21 and auxiliary heating step S22) in the method for manufacturing a welded structure according to the fourth embodiment may be repeated a plurality of times. That is, the weld metal portion 3 of the welded structure according to the fourth embodiment may be formed by multi-layer welding. The welding step S2 in the welding structure manufacturing method according to the fourth embodiment replaces the welding step S2 in the welding structure manufacturing method according to the first embodiment with the welding structure according to the second embodiment. Welding step S2 in the manufacturing method may be used.
　（第４実施形態に係る溶接構造体の製造方法の効果）
　第４実施形態に係る溶接構造体の製造方法によると、高温割れが特に生じやすい厚板を突き合わせ溶接する場合であっても、高温割れの発生を抑制することができる。 (Effect of Manufacturing Method of Welded Structure According to Fourth Embodiment)
According to the method for manufacturing a welded structure according to the fourth embodiment, it is possible to suppress the occurrence of high-temperature cracks even when butt-welding thick plates that are particularly prone to high-temperature cracks.
　（第５実施形態に係る溶接構造体の構成）
　以下に、第５実施形態に係る溶接構造体の構成を説明する。ここでは、第１実施形態に係る溶接構造体の構成と異なる点を主に説明し、重複する説明は繰り返さない。 (Structure of welded structure according to the fifth embodiment)
The configuration of the welded structure according to the fifth embodiment will be described below. Here, the points different from the configuration of the welded structure according to the first embodiment will be mainly described, and the overlapping description will not be repeated.
　図１５は、第５実施形態に係る溶接構造体の斜視図である。図１５には、溶接金属部３の延在方向に直交している断面図が示されている。図１６は、第５実施形態に係る溶接構造体の断面図である。図１５及び図１６に示されるように、第５実施形態に係る溶接構造体は、第１部材１と、第２部材２と、溶接金属部３とを有している。 FIG. 15 is a perspective view of the welded structure according to the fifth embodiment. FIG. 15 shows a cross-sectional view of the weld metal portion 3 orthogonal to the extending direction. FIG. 16 is a cross-sectional view of the welded structure according to the fifth embodiment. As shown in FIGS. 15 and 16, the welded structure according to the fifth embodiment includes a first member 1, a second member 2, and a weld metal portion 3.
　第１部材１は、第１端面１ａと、第１主面１ｂとを有している。第２部材２は、第２端面２ａと、第２主面２ｂとを有している。第２部材２は、第２端面２ａが第１主面１ｂに対向するように第１部材１上（第１主面１ｂ上）に配置されている。溶接金属部３は、第１方向ＤＲ１に沿って延在しており、第１部材１の第１主面１ｂ側と第２部材２の第２端面２ａ側とを接合している。すなわち、第１実施形態に係る溶接構造体が突き合わせ継手である一方、第５実施形態に係る溶接構造体は、Ｔ継手である。 The first member 1 has a first end surface 1a and a first main surface 1b. The second member 2 has a second end surface 2a and a second main surface 2b. The second member 2 is arranged on the first member 1 (on the first main surface 1b) so that the second end surface 2a faces the first main surface 1b. The weld metal portion 3 extends along the first direction DR1 and joins the first main surface 1b side of the first member 1 and the second end surface 2a side of the second member 2. That is, the welded structure according to the first embodiment is a butt joint, while the welded structure according to the fifth embodiment is a T joint.
　（第５実施形態に係る溶接構造体の製造方法）
　以下に、第５実施形態に係る溶接構造体の製造方法を説明する。ここでは、第１実施形態に係る溶接構造体の製造方法と異なる点を主に説明し、重複する説明は繰り返さない。 (Manufacturing method of welded structure according to the fifth embodiment)
The method of manufacturing the welded structure according to the fifth embodiment will be described below. Here, the points different from the method for manufacturing the welded structure according to the first embodiment will be mainly described, and the duplicated description will not be repeated.
　第５実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１と、溶接工程Ｓ２とを有している。溶接工程Ｓ２は、溶接金属形成工程Ｓ２１と、補助加熱工程Ｓ２２とを有している。これらの点に関して、第５実施形態に係る溶接構造体の製造方法は、第１実施形態に係る溶接構造体の製造方法と異なっている。しかしながら、第５実施形態に係る溶接構造体の製造方法は、準備工程Ｓ１及び溶接工程Ｓ２の詳細に関して、第１実施形態に係る溶接構造体の製造方法と異なっている。 The method for manufacturing a welded structure according to the fifth embodiment includes a preparation step S1 and a welding step S2. The welding step S2 includes a welding metal forming step S21 and an auxiliary heating step S22. Regarding these points, the method for manufacturing the welded structure according to the fifth embodiment is different from the method for manufacturing the welded structure according to the first embodiment. However, the method for manufacturing the welded structure according to the fifth embodiment is different from the method for manufacturing the welded structure according to the first embodiment with respect to the details of the preparation step S1 and the welding step S2.
　第５実施形態に係る溶接構造体の製造方法における準備工程Ｓ１では、第２部材２が、第２端面２ａが第１主面１ｂに対向するように第１部材１上（第１主面１ｂ上）に配置される。 In the preparation step S1 in the method for manufacturing a welded structure according to the fifth embodiment, the second member 2 is placed on the first member 1 (first main surface 1b) so that the second end surface 2a faces the first main surface 1b. Placed on).
　図１７は、第５実施形態に係る溶接構造体の製造方法における溶接工程Ｓ２を説明するための模式図である。図１７に示されるように、第５実施形態に係る溶接構造体の製造方法における溶接金属形成工程Ｓ２１では、溶接トーチ５を第１方向ＤＲ１の一方側から第１方向ＤＲ１の他方側へと移動されることにより、第１部材１の第１主面１ｂ側及び第２部材２の第２端面２ａ側を溶融させて溶接金属部３が形成される。 FIG. 17 is a schematic view for explaining the welding step S2 in the method for manufacturing the welded structure according to the fifth embodiment. As shown in FIG. 17, in the weld metal forming step S21 in the method for manufacturing a welded structure according to the fifth embodiment, the weld torch 5 is moved from one side of the first direction DR1 to the other side of the first direction DR1. As a result, the first main surface 1b side of the first member 1 and the second end surface 2a side of the second member 2 are melted to form the weld metal portion 3.
　第５実施形態に係る溶接構造体の製造方法における補助加熱工程Ｓ２２では、第１補助トーチ６ａ及び第２補助トーチ６ｂが、第１方向ＤＲ１の一方側から第１方向ＤＲ１の他方側に向かって、溶接トーチ５とともに移動される。この際、第１補助トーチ６ａは第１主面１ｂを溶融させないように加熱しており、第２補助トーチ６ｂは第２主面２ｂを溶融させないように加熱している。 In the auxiliary heating step S22 in the method for manufacturing a welded structure according to the fifth embodiment, the first auxiliary torch 6a and the second auxiliary torch 6b move from one side of the first direction DR1 toward the other side of the first direction DR1. , Moved with the welding torch 5. At this time, the first auxiliary torch 6a is heated so as not to melt the first main surface 1b, and the second auxiliary torch 6b is heated so as not to melt the second main surface 2b.
　第１補助トーチ６ａ及び第２補助トーチ６ｂは、溶接トーチ５よりも第１方向ＤＲ１における一方側にある。好ましくは、第１補助トーチ６ａ及び第２補助トーチ６ｂの第１方向ＤＲ１における位置は、溶接トーチ５により形成される凝固脆性温度領域５２の第１方向ＤＲ１における位置と重なっている。 The first auxiliary torch 6a and the second auxiliary torch 6b are on one side of the welding torch 5 in the first direction DR1. Preferably, the positions of the first auxiliary torch 6a and the second auxiliary torch 6b in the first direction DR1 overlap with the positions of the solidification brittle temperature region 52 formed by the welding torch 5 in the first direction DR1.
　なお、図示されていないが、第５実施形態に係る溶接構造体の製造方法では、第１補助トーチ６ａ及び第２補助トーチ６ｂに代えて第３補助トーチ６ｃ及び第４補助トーチ６ｄが用いられてもよく、第１補助トーチ６ａ及び第２補助トーチ６ｂとともに第３補助トーチ６ｃ及び第４補助トーチ６ｄが用いられてもよい。第３補助トーチ６ｃ及び第４補助トーチ６ｄが用いられる場合、第３補助トーチ６ｃ及び第４補助トーチ６ｄは、それぞれ、溶接トーチ５よりも第１方向ＤＲ１における他方側において第１主面１ｂ及び第２主面２ｂを溶融しないように加熱する。 Although not shown, in the method for manufacturing a welded structure according to the fifth embodiment, a third auxiliary torch 6c and a fourth auxiliary torch 6d are used in place of the first auxiliary torch 6a and the second auxiliary torch 6b. Alternatively, the third auxiliary torch 6c and the fourth auxiliary torch 6d may be used together with the first auxiliary torch 6a and the second auxiliary torch 6b. When the third auxiliary torch 6c and the fourth auxiliary torch 6d are used, the third auxiliary torch 6c and the fourth auxiliary torch 6d are the first main surface 1b and the first main surface 1b on the other side in the first direction DR1 from the welding torch 5, respectively. The second main surface 2b is heated so as not to melt.
　（第５実施形態に係る溶接構造体の製造方法の効果）
　第５実施形態に係る溶接構造体の製造方法によると、溶接によりＴ継手を形成する場合であっても、高温割れの発生を抑制することができる。 (Effect of Manufacturing Method of Welded Structure According to Fifth Embodiment)
According to the method for manufacturing a welded structure according to the fifth embodiment, it is possible to suppress the occurrence of high temperature cracks even when the T joint is formed by welding.
　（その他の実施形態）
　第５実施形態では、Ｔ継手を溶接により形成する場合について説明し、第１実施形態、第２実施形態及び第４実施形態では突き合わせ継手を溶接により形成する場合について説明し、第３実施形態では重ね継手を溶接により形成する場合について説明したが、本発明は、その他の継手（例えば、角継手）を溶接により形成する場合も適用可能である。 (Other embodiments)
In the fifth embodiment, a case where the T joint is formed by welding will be described, in the first embodiment, the second embodiment and the fourth embodiment, a case where the butt joint is formed by welding will be described, and in the third embodiment, the case where the butt joint is formed by welding will be described. Although the case where the lap joint is formed by welding has been described, the present invention is also applicable to the case where other joints (for example, square joints) are formed by welding.
　以上のように本発明の実施形態について説明を行ったが、上述の実施形態を様々に変形することも可能である。また、本発明の範囲は、上述の実施形態に限定されるものではない。本発明の範囲は、請求の範囲によって示され、請求の範囲と均等の意味及び範囲内での全ての変更を含むことが意図される。 Although the embodiment of the present invention has been described above, it is possible to modify the above-described embodiment in various ways. Moreover, the scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.
　１　第１部材、１ａ　第１端面、２　第２部材、２ａ　第２端面、３　溶接金属部、４　熱影響部、５　溶接トーチ、６ａ　第１補助トーチ、６ｂ　第２補助トーチ、６ｃ　第３補助トーチ、６ｄ　第４補助トーチ、７　第１部分、８　第２部分、５１　溶融池、５２　凝固脆性温度領域、１ｂ　第１主面、２ｂ　第２主面、ＤＲ１　第１方向、ＤＲ２　第２方向、Ｓ１　準備工程、Ｓ２　溶接工程、Ｓ２１　溶接金属形成工程、Ｓ２２　補助加熱工程、Ｗ　幅、Ｔ１，Ｔ２　厚さ。 1 1st member, 1a 1st end face, 2 2nd member, 2a 2nd end face, 3 Welded metal part, 4 Heat affected zone, 5 Welding torch, 6a 1st auxiliary torch, 6b 2nd auxiliary torch, 6c 3rd auxiliary Torch, 6d 4th auxiliary torch, 7 1st part, 8 2nd part, 51 molten pool, 52 solidification brittle temperature region, 1b 1st main surface, 2b 2nd main surface, DR1 1st direction, DR2 2nd direction, S1 preparation process, S2 welding process, S21 welding metal forming process, S22 auxiliary heating process, W width, T1, T2 thickness.

Claims (7)

  1. 　第１方向に沿って延在している溶接金属部と、前記第１方向に交差している第２方向において前記溶接金属部を挟み込んでいる第１部分及び第２部分とを有する溶接構造体の製造方法であって、
    　前記第１方向に沿って溶接トーチを前記第１方向における一方側から前記第１方向における他方側へと移動させることにより前記溶接金属部を形成する工程と、
    　前記溶接トーチが移動している間の少なくとも一部において、前記第１方向に沿って少なくとも１つの補助トーチを前記第１方向における一方側から前記第１方向における他方側へと移動させることにより、前記第１部分及び前記第２部分の少なくとも一方を溶融しないように加熱する工程とを備え、
    　前記少なくとも１つの補助トーチの位置の前記第１方向における位置の各々は、前記溶接トーチの前記第１方向における位置とずれている、溶接構造体の製造方法。     A welded structure having a weld metal portion extending along a first direction and a first portion and a second portion sandwiching the weld metal portion in a second direction intersecting the first direction. It is a manufacturing method of
    A step of forming the weld metal portion by moving the welding torch from one side in the first direction to the other side in the first direction along the first direction.
    By moving at least one auxiliary torch along the first direction from one side in the first direction to the other side in the first direction, at least in part while the welding torch is moving. A step of heating at least one of the first portion and the second portion so as not to melt is provided.
    A method for manufacturing a welded structure, wherein each of the positions of the at least one auxiliary torch in the first direction deviates from the position of the welding torch in the first direction.
  2. 　前記少なくとも１つの補助トーチには、前記第１部分を加熱する第１補助トーチ及び前記第２部分を加熱する第２補助トーチが含まれており、
    　前記第１補助トーチ及び前記第２補助トーチは、前記第２方向において互いに対向しており、
    　前記第１補助トーチ及び前記第２補助トーチは、前記溶接トーチよりも前記第１方向における一方側に位置している、請求項１に記載の溶接構造体の製造方法。     The at least one auxiliary torch includes a first auxiliary torch that heats the first portion and a second auxiliary torch that heats the second portion.
    The first auxiliary torch and the second auxiliary torch face each other in the second direction.
    The method for manufacturing a welded structure according to claim 1, wherein the first auxiliary torch and the second auxiliary torch are located on one side of the welding torch in the first direction.
  3. 　前記溶接トーチにより形成される溶融池の前記第１方向における一方側には、液相と固相とが共存している凝固脆性温度領域が隣接して形成されており、
    　前記第１補助トーチ及び前記第２補助トーチは、前記第２方向において前記凝固脆性温度領域と対向している、請求項２に記載の溶接構造体の製造方法。     A solidification brittle temperature region in which a liquid phase and a solid phase coexist is adjacent to one side of the molten pool formed by the welding torch in the first direction.
    The method for manufacturing a welded structure according to claim 2, wherein the first auxiliary torch and the second auxiliary torch face the solidification brittle temperature region in the second direction.
  4. 　前記少なくとも１つの補助トーチには、前記第１部分を加熱する第３補助トーチ及び前記第２部分を加熱する第４補助トーチが含まれており、
    　前記第３補助トーチ及び前記第４補助トーチは、前記溶接トーチよりも前記第１方向における他方側に位置しており、
    　前記第３補助トーチ及び前記第４補助トーチは、前記第２方向において互いに対向している、請求項１～請求項３のいずれか１項に記載の溶接構造体の製造方法。     The at least one auxiliary torch includes a third auxiliary torch that heats the first portion and a fourth auxiliary torch that heats the second portion.
    The third auxiliary torch and the fourth auxiliary torch are located on the other side of the welding torch in the first direction.
    The method for manufacturing a welded structure according to any one of claims 1 to 3, wherein the third auxiliary torch and the fourth auxiliary torch face each other in the second direction.
  5. 　前記第１部分は、第１部材であり、
    　前記第２部分は、第２部材である、請求項１～請求項４のいずれか１項に記載の溶接構造体の製造方法。     The first part is a first member and
    The method for manufacturing a welded structure according to any one of claims 1 to 4, wherein the second part is a second member.
  6. 　前記第１部材の厚さ及び前記第２部材の厚さは、１６ｍｍ以上４０ｍｍ以下であり、
    　前記第１部材の前記第２部材側の端面及び前記第２部材の前記第１部材側の端面は、開先を構成している、請求項５に記載の溶接構造体の製造方法。     The thickness of the first member and the thickness of the second member are 16 mm or more and 40 mm or less.
    The method for manufacturing a welded structure according to claim 5, wherein the end face of the first member on the second member side and the end face of the second member on the first member side form a groove.
  7. 　第１主面及び第１端面を含む第１部材と、第２主面及び第２端面を含み、かつ前記第２端面が前記第１主面と対向するように前記第１部材上に配置されている第２部材と、第１方向に沿って延在し、かつ前記第１部材及び前記第２部材を接合している溶接金属部とを有する溶接構造体の製造方法であって、
    　前記第１方向に沿って溶接トーチを前記第１方向における一方側から前記第１方向における他方側へと移動させることにより前記溶接金属部を形成する工程と、
    　前記溶接トーチが移動している間の少なくとも一部において、前記第１方向に沿って少なくとも１つの補助トーチを前記第１方向における一方側から前記第１方向における他方側へと移動させることにより、前記第１主面及び前記第２主面の少なくとも一方を溶融しないように加熱する工程とを備え、
    　前記少なくとも１つの補助トーチの位置の前記第１方向における位置の各々は、前記溶接トーチの前記第１方向における位置とずれている、溶接構造体の製造方法。      The first member including the first main surface and the first end surface, the second main surface and the second end surface are included, and the second end surface is arranged on the first member so as to face the first main surface. A method for manufacturing a welded structure having a second member, a welded metal portion extending along a first direction, and joining the first member and the second member.
    A step of forming the weld metal portion by moving the welding torch from one side in the first direction to the other side in the first direction along the first direction.
    By moving at least one auxiliary torch along the first direction from one side in the first direction to the other side in the first direction, at least in part while the welding torch is moving. A step of heating at least one of the first main surface and the second main surface so as not to melt is provided.
    A method for manufacturing a welded structure, wherein each of the positions of the at least one auxiliary torch in the first direction deviates from the position of the welding torch in the first direction.
PCT/JP2021/009544 2020-03-12 2021-03-10 Method for manufacturing welded structure WO2021182516A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0452079A (en) * 1990-06-21 1992-02-20 Sky Alum Co Ltd Method for preventing welding distortion of sheet metals
JPH09192839A (en) * 1996-01-19 1997-07-29 Mitsubishi Heavy Ind Ltd Method and device for automatic welding
WO2015198405A1 (en) * 2014-06-25 2015-12-30 株式会社日立製作所 Weld part structure

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0452079A (en) * 1990-06-21 1992-02-20 Sky Alum Co Ltd Method for preventing welding distortion of sheet metals
JPH09192839A (en) * 1996-01-19 1997-07-29 Mitsubishi Heavy Ind Ltd Method and device for automatic welding
WO2015198405A1 (en) * 2014-06-25 2015-12-30 株式会社日立製作所 Weld part structure

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