JP2016172262A - Electrogas arc welding method and electrogas arc welding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrogas arc welding method enabling the toughness of a heat-affected zone to be improved while suppressing incomplete fusion.SOLUTION: The electrogas arc welding method has a first movement step of moving a plurality of welding torches in a first direction and a second movement step of moving the plurality of welding torches in a second direction. The first movement step causes the top first torch 1 of the plurality of welding torches moving in the first direction to generate an arc 31 and causes a second torch 2 disposed rear of the first torch 1 in the first direction to move to pass through a molten pool 30 formed by the first torch 1 without generating the arc 31. The second movement step causes the second torch 2 to generate the arc 31, causes the top in the second direction to move, and causes the first torch 1 to move to pass through a molten pool 30 formed by the second torch 2 without generating the arc 31.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrogas arc welding method and an electrogas arc welding system.

  The electrogas arc welding method is a kind of vertical welding, in which welding is performed while preventing dripping of molten metal with a metal pad. In the electrogas arc welding method, a fixed water-cooled copper plating or a refractory solid flux or a sliding water-cooled copper plating is arranged on the back side of the groove, and a sliding water-cooled copper is placed on the front side of the groove. Arrange the padding material. In the electrogas arc welding method, the molten pool formed in the groove surrounded by the backside and front surface side metal or solid flux is shielded with gas, and the welding wire is fed and continuously fed while being fed. It is an arc welding method that finishes in one direction in the direction.

  As such an electrogas arc welding method, for example, Patent Document 1 discloses a method of supplying a welding wire, which is a flux-cored wire, and a filler wire to a molten pool. In the electrogas arc welding described in Patent Document 1, the filler wire is supplied to the molten pool generated by the arc generated from the welding wire, thereby lowering the temperature of the molten pool and improving the toughness of the weld heat affected zone. .

JP 2007-030019 A

  By the way, in the electrogas arc welding described in Patent Document 1 described above, the welding wire and the fuller wire are oscillated in the thickness direction while the positions of the welding wire and the fuller wire are fixed. Therefore, in the molten pool, welding is performed while the temperature on one side in the plate thickness direction where the filler wire is disposed is always lowered.

  However, when the temperature of the molten pool is lowered, the toughness of the heat affected zone is improved. On the other hand, if the temperature of the molten pool is excessively lowered, there is a possibility that poor fusion occurs.

  The present invention has been made to solve the above-described demand, and provides an electrogas arc welding method and an electrogas arc welding system capable of improving toughness of a heat-affected zone while suppressing poor fusion. It is.

In order to solve the above problems, the present invention proposes the following means.
An electrogas arc welding method according to a first aspect of the present invention is an electrogas arc welding method in which welding is performed while moving a plurality of welding torches within a groove of a member to be welded. A first moving step for moving the first welding step, and a second moving step for moving the plurality of welding torches moved in the first direction in a second direction different from the first direction. The moving step generates an arc on at least the first first torch among the plurality of welding torches that move in the first direction, and the second torch arranged behind the first torch in the first direction. The second moving step is performed by switching the welding torch that generates the arc, without passing the molten pool formed by the first torch without generating an arc. An arc is generated in the second torch to move the head in the second direction, and the second torch is passed through the molten pool formed by the second torch without generating an arc in the first torch. Move backward in the second direction.

  According to such a configuration, when welding in the first direction, an arc is generated in the first first torch to form a weld pool and weld, and the second torch passes through the weld pool. By doing so, the temperature of the molten pool can be reduced before it becomes higher than necessary. In addition, when welding in the second direction, the welding torch that generates the arc is switched, and an arc is generated in the leading second torch to form and weld the molten pool. By passing one torch, the temperature of the molten pool can be reduced before it becomes higher than necessary. That is, regardless of whether the welding torch moves in the first direction or the second direction, an arc is always generated in the leading welding torch to form a molten pool, and a welding arc torch without a trailing arc is generated. Can be exposed to the molten pool. Therefore, while reducing the heat input of the molten pool before it becomes higher than necessary in the rear welding torch, the frontmost welding torch where the arc is generated and the most rear side of the groove It is possible to directly apply a welding torch where an arc is generated to both.

  In the electrogas arc welding method, the second moving step generates an arc on both the first torch and the second torch over a predetermined time when the welding torch that generates the arc is switched. Also good.

  According to such a configuration, when switching the welding torch that generates the arc, the arc is generated from both the first torch and the second torch over a predetermined time, so that no arc is generated from all the welding torches. It is possible to prevent the welding torch from moving in the state. Therefore, an arc is not generated from the welding torch at the end portion of the groove, and the occurrence of poor fusion can be suppressed with high accuracy.

  In the electrogas arc welding method, the plurality of welding torches may be configured only by the first torch and the second torch.

  According to such a configuration, the number of welding torches inserted into the groove can be minimized by using only the first torch and the second torch as the welding torch. Therefore, it is possible to weld even a thin member to be welded so as to improve the toughness of the heat affected zone while suppressing poor fusion.

  In the electrogas arc welding method, at least one of the first torch and the second torch may be connected to a cathode of a welding power source using a wire with REM.

  According to such a configuration, by using a welding torch that uses a REM-containing wire and is connected to the cathode of the welding power source, it is possible to melt the wire without increasing the welding current while ensuring the stability of the generated arc. Since the speed can be increased, a heat input reduction effect can be expected.

  In the electrogas arc welding method, at least one of the first moving step and the second moving step may move the plurality of welding torches while stirring the molten pool.

  According to such a configuration, the wettability of the molten pool in the groove can be improved by moving the welding torch while stirring the molten pool.

  The electrogas arc welding system according to the second aspect of the present invention controls the plurality of welding torches in the electrogas arc welding system that performs welding while moving the plurality of welding torches within the groove of the member to be welded. A control unit, wherein the control unit adjusts a moving direction of the plurality of welding torches so as to move the plurality of welding torches in the first direction; A second movement control adjusting unit that adjusts the movement direction so as to move the plurality of moved welding torches in a second direction different from the first direction, and the first movement control unit includes the first movement control unit An arc is generated in at least the first first torch among the plurality of welding torches moving in the direction, and the second torch arranged rearward in the first direction with respect to the first torch. The second movement control unit switches the welding torch that generates the arc to generate the arc on the second torch without causing the arc to pass through the molten pool formed by the first torch. And moving the head in the second direction so as to pass through the molten pool formed by the second torch without generating an arc in the first torch. Move backwards.

  According to the present invention, an arc is always generated at the leading welding torch in the moving direction, and the temperature of the molten pool can be lowered by the welding torch disclosed in the publication that does not generate an arc, and the heat-affected zone is suppressed while suppressing poor fusion. The toughness can be improved.

It is a flowchart explaining the electrogas arc welding method in embodiment of this invention. It is a figure explaining the electrogas arc welding method in embodiment of this invention, Comprising: The figure (a) is a figure explaining a 1st movement process, The figure (b) is a figure explaining a 2nd movement process. is there. It is a block diagram explaining the electrogas arc welding system in the embodiment of the present invention. It is a figure explaining the relationship between the position of the 1st torch in the embodiment of the present invention, and the 2nd torch, and the current value supplied to the 1st torch and the 2nd torch, The figure (a) is with time progress. It is a figure which shows the position of a 1st torch and a 2nd torch, The figure (b) is a figure which shows the electric current value supplied to a 1st torch with time passage, The figure (c) is the figure with time passage. It is a figure which shows the electric current value supplied to a 2 torch.

Hereinafter, a first embodiment according to the present invention will be described with reference to FIGS.
The electrogas arc welding method S1 performs welding while moving a plurality of welding torches within the groove 40 of the thick welded member 4. In the electrogas arc welding method S1, a vertical groove 40 formed between two members to be welded 4 made of low-temperature steel, double-layered stainless steel, or the like passes through one pass from the lower side to the upper side in the vertical direction. Weld with. That is, the welding direction of the electrogas arc welding method S1 of the present embodiment is a direction from the lower side to the upper side in the vertical direction. The electrogas arc welding method S <b> 1 is performed by an electrogas arc welding system 100 that performs welding while oscillating two welding torches of the first torch 1 and the second torch 2 in the plate thickness direction of the member 4 to be welded. Here, the plate | board thickness direction of the to-be-welded member 4 in this embodiment is set as the horizontal direction which is a direction orthogonal to a welding direction.

  As shown in FIG. 1, the electrogas arc welding method S1 of the present embodiment includes a first moving step S10 for moving a plurality of welding torches in a first direction D1, and a plurality of welding torches moved in the first direction D1. And a second moving step S20 that moves the second direction D2 different from the first direction D1. In the electrogas arc welding method S1, the first moving step S10 and the second moving step S20 are repeatedly performed a plurality of times.

  Here, the first direction D1 is a moving direction when the welding torch is oscillated in the groove 40, and as shown in FIG. 2A, the member 4 to be welded which is one side in the plate thickness direction. It is the direction which goes to the surface 41 side of the to-be-welded member 4 which is the other side from the back surface 42 side. The second direction D2 is a moving direction when oscillating in the direction opposite to the first direction D1, and as shown in FIG. 2B, from the front surface 41 side to the back surface 42 side in the plate thickness direction. It is the direction to go.

  The welding torch generates an arc 31 from the tip of the welding wire 3 to be sent out by supplying a predetermined current. As shown in FIG. 2A, the welding torch includes a first torch 1 arranged at the head when the plurality of welding torches are moved in the first direction D1, and the plurality of welding torches in the second direction D2. And a second torch 2 that is different from the first torch 1 that is disposed at the top when moving toward. That is, the welding torch of the present embodiment is constituted by only two of the first torch 1 and the second torch 2. The first torch 1 is arranged in the groove 40 on the surface 41 side of the member 4 to be welded than the second torch 2. The first torch 1 is arranged away from the second torch 2 by a predetermined distance d. In the first torch 1 and the second torch 2, a wire containing REM (rare earth metal, Ce, La, Y) is used as the welding wire 3.

  In the first moving step S10, among the plurality of welding torches moving in the first direction D1, an arc 31 is generated in the first first torch 1 to move the head in the first direction D1, and the first torch 1 is moved. The second torch 2 disposed behind the first direction D1 is moved without generating the arc 31. The first moving step S10 is performed when the arc 31 is not generated on the first torch 1 and the arc 31 is generated on the second torch 2 as in the second moving step S20 described later. The welding torch that generates the arc 31 is switched based on a predetermined condition. Thereby, in the first movement step S10, the arc 31 is generated on the first torch 1 and the arc 31 is not generated on the second torch 2. In the first movement step S10 of the present embodiment, as shown in FIG. 2A, when moving in the first direction D1, the first torch 1 is moved to the head, and the second torch 2 is moved to the first torch. 1 is moved so as to pass through the molten pool 30 formed by 1. In the first moving step S10, the first torch 1 and the second torch 2 are moved while being vibrated. That is, in the first moving step S10, the second torch 2 moves while stirring the molten pool 30.

  In the second moving step S20, after the second moving step S20 is performed, the second torch 2 generates the arc 31 to move the head in the second direction D2, and the first torch 1 does not generate the arc 31 without generating the arc 31. The second torch 2 is moved behind in the second direction D2. In the second moving step S20, the arc 31 is not generated on the second torch 2 and the arc 31 is generated on the first torch 1 as after the first moving step S10. The welding torch that generates the arc 31 is switched based on the above. Thus, in the second moving step S20, the arc 31 is generated on the second torch 2 and the arc 31 is not generated on the first torch 1. In the second movement step S20 of the present embodiment, as shown in FIG. 2B, when moving in the second direction D2, the second torch 2 is moved to the head, and the first torch 1 is moved to the second torch. It moves so that the molten pool 30 formed by 2 may pass. In the second moving step S20, the first torch 1 and the second torch 2 are moved while being vibrated, as in the first moving step S10. That is, in the second moving step S20, the first torch 1 moves while stirring the molten pool 30.

  In the electrogas arc welding method S1 of the present embodiment, the first moving step S10 is performed again after the second moving step S20, and the first moving step S10 and the second moving step S20 are repeated a plurality of times according to the number of times of oscillation. Exit after implementing.

  Here, the predetermined conditions in the first moving step S10 and the second moving step S20 of the present embodiment are the first torch 1 and the first over a predetermined time when the welding torch that generates the arc 31 is switched. The arc 31 is generated from both the two torches 2. The predetermined time depends on various welding conditions such as the interval between the first torch 1 and the second torch 2, the time required to reliably form the molten pool 30, the size of the object to be welded, the size of the apparatus, and the like. What is necessary is just to set beforehand.

  Moreover, the electrogas arc welding system 100 which implements the electrogas arc welding method S1 of this embodiment is a fixing | fixed arrange | positioned at the back surface 42 side of the to-be-welded member 4, as shown to Fig.2 (a) and FIG.2 (b). A backing material 5 of the type and a sliding type backing metal 6 disposed on the surface 41 side are provided. That is, the electrogas arc welding system 100 is a one-side sliding copper plating type welding system.

  The backing material 5 is formed of a fixed water-cooled copper plating or a refractory solid flux. The backing material 5 is disposed so as to block the groove 40 from the back surface 42 side in a state where the backing material 5 is in contact with the back surface 42 of the member 4 to be welded.

  The face metal 6 is formed of a water-cooled copper metal. The face metal 6 is disposed so as to close the groove 40 from the surface 41 side in a state where the surface metal 6 can slide on the surface 41 of the member 4 to be welded. The surface stopper 6 is provided with a gas nozzle 61 capable of ejecting the gas G toward the groove 40. Moreover, the cooling metal W is distribute | circulated through the inside and the surface stopper 6 is cooled at the time of welding.

  As shown in FIG. 3, the electrogas arc welding system 100 of the present embodiment includes two welding torches, a first torch 1 and a second torch 2, a position measuring unit 110 that measures the position of the welding torch, and a welding torch. A power supply unit 130 for supplying current to the motor, a movement adjusting unit 120 for moving the welding torch, and a control unit 140 for controlling the welding torch via the power supply unit 130 and the movement adjusting unit 120 are provided.

  The position measurement unit 110 measures the positions of the plurality of welding torches in the groove 40 and sends a signal to the control unit 140. The position measuring unit 110 of the present embodiment sends a signal to the first movement control unit 141 of the control unit 140 described later when the leading welding torch among the plurality of welding torches reaches the most back surface 42 side of the groove 40. Send. The position measurement unit 110 sends a signal to the second movement control unit 142 of the control unit 140 described later when the leading welding torch among the plurality of welding torches reaches the most surface 41 side of the groove 40. That is, the position measurement unit 110 of the present embodiment sends a signal to the first movement control unit 141 when the second torch 2 reaches the back surface 42 side, and the first torch 1 when the first torch 1 reaches the front surface 41 side. A signal is sent to the second movement control unit 142. As the position measuring unit 110, for example, a weaver is used.

  The power supply unit 130 supplies a predetermined current necessary for generating the arc 31 to the first torch 1 and the second torch 2 in accordance with a signal from the control unit 140. The power supply unit 130 according to the present embodiment includes a first power supply unit 131 connected to the first torch 1 and a second power supply unit 132 connected to the second torch 2.

The first power supply unit 131 can supply a predetermined current necessary for generating the arc 31 to the first torch 1. As for the 1st power supply part 131, the cathode of the welding power supply is connected to the 1st torch 1, and the anode is connected to the to-be-welded member 4 (positive polarity). In the first power supply unit 131, the current value supplied by the control unit 140 is adjusted. The first power supply unit 131 of the present embodiment, by being turned ON, the current supplied to the first torch 1 and I _A, that is the OFF state, the current value supplied to the first torch 1 Is set to 0.

Similarly to the first power supply unit 131, the second power supply unit 132 can supply a prescribed current necessary for generating the arc 31 to the second torch 2. As for the 2nd power supply part 132, the cathode of the welding power supply is connected to the 2nd torch 2, and the anode is connected to the to-be-welded member 4 (positive polarity). In the second power supply unit 132, the current value supplied by the control unit 140 is adjusted. The second power supply unit 132 of the present embodiment, by being turned ON, the current supplied to the second torch 2 and I _B, it is in the OFF state, the current value supplied to the second torch 2 Is set to 0.

  The movement adjusting unit 120 moves a plurality of welding torches simultaneously in accordance with a signal from the control unit 140. The movement adjusting unit 120 of this embodiment synchronizes the movements of the first torch 1 and the second torch 2 and oscillates in the thickness direction simultaneously with the first torch 1 and the second torch 2. As shown in FIG. 2 (a), the movement adjusting unit 120 moves the first torch 1 to the head and the second torch 2 is formed by the first torch 1 when moving in the first direction D1. It moves so that it may pass through the molten pool 30. FIG. As shown in FIG. 2 (b), the movement adjusting unit 120 moves the second torch 2 to the head and moves the first torch 1 by the second torch 2 when moving in the second direction D2. It moves so that it may pass through the molten pool 30. FIG. That is, when moving so as to pass through the molten pool 30, the positions of the first torch 1 and the second torch 2 with respect to the welding direction are adjusted so that the tip of the welding wire 3 moves while being immersed in the molten pool 30. For example, the movement adjusting unit 120 moves the welding torch at an oscillating condition of 10 to 60 times / min. The movement adjusting unit 120 moves the first torch 1 and the second torch 2 while vibrating.

  The control unit 140 sends a signal to the power supply unit 130 and the movement adjustment unit 120 according to the movement direction to the welding torch in accordance with the signal from the position measurement unit 110. The control unit 140 of the present embodiment moves in the first direction D1 and the first movement control unit 141 that adjusts the moving direction of the plurality of welding torches so as to move the plurality of welding torches in the first direction D1. A second movement control unit 142 that adjusts the movement direction so as to move the plurality of welding torches in a second direction D2 different from the first direction D1.

  The first movement control unit 141 receives the signal from the position measurement unit 110 and performs the first movement process S10. The first movement control unit 141 of the present embodiment sends a signal to the movement adjustment unit 120 so as to move the first torch 1 and the second torch 2 in the first direction D1 by receiving a signal from the position measurement unit 110. . The first movement control unit 141 sends a signal to the first power supply unit 131 so that the arc 31 is generated in at least the first first torch 1 among the plurality of welding torches moving in the first direction D1, and the second torch. 2 to send a signal to the second power supply unit 132 so that the arc 31 is not generated. When the arc 31 is not generated on the first torch 1 and the arc 31 is generated on the second torch 2, the first movement control unit 141 generates the arc 31 based on a predetermined condition. Switch torch.

  The second movement control unit 142 receives the signal from the position measurement unit 110 and performs the second movement process S20. The second movement control unit 142 of the present embodiment sends a signal to the movement adjustment unit 120 so as to move the first torch 1 and the second torch 2 in the second direction D2 by receiving a signal from the position measurement unit 110. . The second movement control unit 142 sends a signal to the second power supply unit 132 so that at least the second torch 2 generates the arc 31 among the plurality of welding torches, and prevents the first torch 1 from generating the arc 31. A signal is sent to the first power supply unit 131. When the arc 31 is not generated in the second torch 2 and the arc 31 is generated in the first torch 1, the second movement control unit 142 generates the arc 31 based on a predetermined condition. Switch torch.

  Here, the electrogas arc welding method S1 using the electrogas arc welding system 100 will be specifically described.

  As shown in FIG. 4A, in the first torch 1 and the second torch 2, the groove 40 is oscillated in the plate thickness direction by the movement adjusting unit 120. Specifically, at time t1, the first torch 1 and the second torch 2 are positioned on the surface 41 side in a state of being separated by a distance d. Therefore, at time t1, a signal is sent from the position measurement unit 110 to the second movement control unit 142, and the second movement step S20 is performed from time t1 to time t3.

The second movement control unit 142 sends a signal to the first power supply unit 131 to cause the first torch 1 to generate the arc 31 over a predetermined time, and causes the second torch 2 to generate the arc 31. Send a signal to 132. In the present embodiment, the arc 31 is generated in the first torch 1 and the second torch 2 from time t1 to time t2 as the predetermined time. Therefore, as shown in FIGS. 4B and 4C, the first power supply 131 and the second power supply 132 are in the ON state from time t1 to time t2, and the first torch Currents I _A and I _B necessary for generating the arc 31 in the first and second torches 2 are respectively supplied.

  Thereafter, the second movement control unit 142 sends a signal to the first power supply unit 131 so that the arc 31 is not generated in the first torch 1. Therefore, during the period from time t2 to time t3, the first power supply unit 131 is turned off and only the second power supply unit 132 is turned on. As a result, the generation of the arc 31 from the first torch 1 is stopped, and the arc 31 is generated only from the second torch 2.

  The second movement control unit 142 also sends a signal to the movement adjustment unit 120, so that the movement adjustment unit 120 causes the first torch 1 and the second torch 2 to move from the front surface 41 side toward the rear surface 42 side in the second direction D2. Moved to. Thereby, the first torch 1 and the second torch 2 are moved toward the back surface 42 side by the movement adjusting unit 120, and reach the back surface 42 side at time t3.

  Next, at time t3, the first torch 1 and the second torch 2 are positioned on the back surface 42 side, so that a signal is sent from the position measuring unit 110 to the first movement control unit 141, and from time t3 to time t5, One transfer step S10 is performed.

  The first movement control unit 141 sends a signal to the second power supply unit 132 to generate the arc 31 in the second torch 2 over a predetermined time, and also generates the arc 31 in the first torch 1. Send a signal to 131. In the present embodiment, the arc 31 is generated in the first torch 1 and the second torch 2 from time t3 to time t4 as the predetermined time.

  In the present embodiment, the time from the time t3 that is the predetermined time in the first movement control unit 141 to the time t4 and the time from the time t1 that is the predetermined time in the second movement control unit 142 to the time t2 are the same. Length.

  Accordingly, as shown in FIGS. 4B and 4C, the first power supply 131 and the second power supply 132 are in the ON state from time t3 to time t4, and the first torch A current necessary for generating the arc 31 in the first and second torches 2 is supplied.

  Thereafter, the first movement control unit 141 sends a signal to the second power supply unit 132 so that the arc 31 is not generated in the second torch 2. Therefore, during the period from time t4 to time t5, the second power supply unit 132 is turned off, and only the first power supply unit 131 is turned on. As a result, the generation of the arc 31 from the second torch 2 is stopped, and the arc 31 is generated only from the first torch 1.

  The first movement control unit 141 also sends a signal to the movement adjustment unit 120 to move the first torch 1 and the second torch 2 from the back surface 42 side to the front surface 41 side in the first direction D1. . Thereby, the first torch 1 and the second torch 2 are moved toward the surface 41 side by the movement adjusting unit 120, and reach the surface 41 side at time t5.

  As described above, the first movement control unit 141 and the second movement control unit 142 repeatedly control the first torch 1 and the second torch 2 based on the signal from the position measurement unit 110, so that the first movement process. S10 and the second moving step S20 are repeatedly performed.

  According to the electrogas arc welding method S1 and the electrogas arc welding method S1 as described above, the weld pool 30 is formed by generating the arc 31 in the first first torch 1 when welding in the first direction D1. Then, the second torch 2 is passed through the molten pool 30 while welding. Therefore, the temperature of the molten pool 30 can be reduced by the second torch 2 before the temperature becomes higher than the temperature necessary for welding the groove 40. Further, when welding toward the second direction D2, the welding torch that generates the arc 31 is switched, and the welding pool 30 is formed and welded by generating the arc 31 on the leading second torch 2, The first torch 1 is passed through the molten pool 30. Therefore, the first torch 1 can reduce the temperature of the molten pool 30 before it becomes higher than the temperature necessary for welding the groove 40. That is, regardless of whether the welding torch moves in the first direction D1 or the second direction D2, the arc 31 is always generated in the leading welding torch to form the molten pool 30, and the rear arc 31 is generated. An unwelded welding torch can be exposed to the molten pool 30. Therefore, the front welding torch where the arc 31 is generated is reduced to the most surface 41 side of the groove 40 while reducing the heat input of the molten pool 30 before it becomes higher than necessary in the rear welding torch. The welding torch in which the arc 31 is generated can be directly applied to both the most back surface 42 side. Therefore, the temperature necessary for sufficient melting can be secured even at the end of the groove 40, and it is possible to suppress the occurrence of poor fusion on both the most surface 41 side and the most back surface 42 side of the groove 40. And can be welded. As a result, the thermal effect is a region that is exposed to high heat even when it does not melt in the vicinity of the groove 40 when performing welding while suppressing the occurrence of poor fusion due to the temperature of the molten pool 30 being too low. The toughness of the part can be improved.

  In addition, when the welding torch that generates the arc 31 is switched in the first moving step S10 and the second moving step S20, the arc 31 is generated from both the first torch 1 and the second torch 2 over a predetermined time. Therefore, when switching the welding torch that generates the arc 31, it is possible to prevent the welding torch from moving in a state where the arc 31 is not generated from all the welding torches. Therefore, it is possible to suppress with high accuracy the occurrence of poor fusion without generating the arc 31 from the welding torch at the end portion of the groove 40 such as the outermost surface 41 side or the rearmost surface 42 side of the groove 40. Can do.

  Further, by using only two welding torches, the first torch 1 and the second torch 2, the number of welding torches inserted into the groove 40 can be minimized. Therefore, it is possible to weld the thin member 4 to be welded so as to improve the toughness of the heat affected zone while suppressing poor fusion.

  In addition, by using the first torch 1 and the second torch 2 that are connected to the cathode of the welding power source using the REM-containing wire, the first torch 1 and the second moving step S20 are performed at the time of execution. The wire melting rate can be increased without increasing the welding current while ensuring the stability of the arc 31 generated from the second torch 2. Therefore, the effect of reducing the amount of heat input can be expected, and the occurrence of poor fusion can be suppressed with higher accuracy.

  Further, by vibrating the first torch 1 and the second torch 2, the molten pool 30 can be moved while being stirred. Thereby, the wettability of the molten pool 30 in the groove 40 can be improved. Therefore, it is possible to suppress the occurrence of poor fusion with higher accuracy.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

  The plurality of welding torches are not limited to the two configurations of the first torch 1 and the second torch 2, and may be three or more. At this time, the third torch is preferably disposed between the first torch 1 and the second torch 2.

  Moreover, in this embodiment, although it was set as the structure which each provides the power supply part 130 which supplies an electric current to the 1st torch 1 and the 2nd torch 2, it is not limited to such a structure. For example, only one power source may be provided, and the control unit 140 may be controlled to switch the current supply destination.

  Moreover, in this embodiment, in order to stir the molten pool 30, the welding torch itself was vibrated, However, It is not limited to such a structure, What is necessary is just to be able to stir the molten pool 30. For example, the weld pool 30 itself may be magnetically agitated by electromagnetic force from the outside of the welded member 4 by attaching a magnetic coil to the surface metal 6 or the like.

DESCRIPTION OF SYMBOLS S1 ... Electrogas arc welding method S10 ... 1st movement process S20 ... 2nd movement process 4 ... To-be-welded member 40 ... Groove 41 ... Front surface 42 ... Back surface 1 ... First torch 2 ... Second torch 3 ... Welding wire 31 ... Arc DESCRIPTION OF SYMBOLS 30 ... Molten pool 100 ... Electrogas arc welding system 5 ... Backing material 6 ... Surface metallurgy 61 ... Gas nozzle G ... Gas W ... Cooling water 110 ... Position measuring part 120 ... Movement adjustment part 130 ... Power supply part 131 ... First power supply part 132 ... Second power supply unit 140 ... Control unit 141 ... First movement control unit 142 ... Second movement control unit

Claims (6)

In the electrogas arc welding method of performing welding while moving a plurality of welding torches within the groove of the member to be welded,
A first moving step of moving the plurality of welding torches in a first direction;
A second moving step of moving the plurality of welding torches moved in the first direction toward a second direction different from the first direction;
The first moving step includes
Among the plurality of welding torches moving in the first direction, an arc is generated at least at the first first torch, and an arc is generated at the second torch arranged behind the first torch in the first direction. Without passing through the molten pool formed by the first torch,
The second moving step includes
The welding torch that generates the arc is switched, the arc is generated in the second torch, the head in the second direction is moved, and the melt formed by the second torch without generating the arc in the first torch. An electrogas arc welding method in which the second torch is moved rearward in the second direction so as to pass through a pond.   2. The electrogas arc welding method according to claim 1, wherein the second moving step generates an arc in both the first torch and the second torch over a predetermined time when the welding torch that generates the arc is switched. .   The electrogas arc welding method according to any one of claims 1 and 2, wherein the plurality of welding torches are configured only by the first torch and the second torch.   The electrogas arc welding method according to any one of claims 1 to 3, wherein at least one of the first torch and the second torch is connected to a cathode of a welding power source using a wire containing REM.   The electrogas arc welding method according to any one of claims 1 to 4, wherein at least one of the first moving step and the second moving step moves the plurality of welding torches while stirring the molten pool. . In an electrogas arc welding system that performs welding while moving a plurality of welding torches within a groove of a member to be welded,
A control unit for controlling the plurality of welding torches,
The controller is
A first movement control unit for adjusting a movement direction of the plurality of welding torches so as to move the plurality of welding torches in a first direction;
A second movement control adjuster that adjusts the moving direction so as to move the plurality of welding torches moved in the first direction in a second direction different from the first direction;
The first movement controller is
Among the plurality of welding torches moving in the first direction, an arc is generated at least at the first first torch, and an arc is generated at the second torch arranged behind the first torch in the first direction. Without passing through the molten pool formed by the first torch,
The second movement control unit is
The welding torch that generates the arc is switched, the arc is generated in the second torch, the head in the second direction is moved, and the melt formed by the second torch without generating the arc in the first torch. An electrogas arc welding system that moves rearward in the second direction relative to the second torch so as to pass through a pond.

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