JP6955453B2 - Overlay welding method - Google Patents

Description

The present disclosure relates to an overlay welding method in which the surface of a base metal is covered with a weld metal.

Overlay welding, in which the surface of the base metal is covered with weld metal, is known and is used in various fields. As one of the uses of overlay welding, for example, by overlay welding a weld metal such as stainless steel or Ni-based alloy to the surface of a base metal such as carbon steel or low alloy steel, the base metal becomes water. Corrosion resistance may be improved for places that come into contact with water or water vapor. Such overlay welding is performed, for example, in a cask for storing used fuel and storing it in water.

If the base metal is melted during welding, the base metal and the welding metal are mixed, so that Cr and Ni added to the welding metal are reduced. In clad welding, which is a type of overlay welding, such dilution can be suppressed by performing welding while weaving in a direction perpendicular to the welding direction. Patent Document 1 discloses an example of such clad welding, and in particular, when a certain weld bead is formed next to a preceding weld bead, it is locally localized in a region overlapping the end of the preceding weld bead. By forming a deep penetration portion in the surface, the occurrence of poor fusion is prevented.

Japanese Unexamined Patent Publication No. 2013-139058

In order to suppress the dilution rate in overlay welding, it is conceivable to suppress the amount of heat input of the welding torch to suppress the amount of melting of the base metal. However, if the amount of heat input to the welding torch is reduced, there is a high possibility that defects due to poor fusion will occur. Further, when overlay welding is performed according to the conventional rod-moving method using a low heat input welding torch, a large amount of time is spent to form a sufficient overlay layer.

At least one embodiment of the present invention has been made in view of the above circumstances, and an efficient build-up can be formed by using a welding torch with low heat input while suppressing the occurrence of defects due to poor fusion. It is an object of the present invention to provide a overlay welding method.

(1) The overlay welding method according to at least one embodiment of the present invention solves the above problems.
While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
The step of forming the second welding bead by carrying out the weaving is provided so that the locus of the welding torch with respect to the base metal includes the first rod pattern that goes in the direction opposite to the welding direction.

According to the method (1) above, when forming a welding bead along the welding direction by overlay welding, the locus of the welding torch includes a first rod pattern that goes in the direction opposite to the welding direction. Welding torch rods are carried out. By performing such a rod movement, the molten pool formed on the surface of the base metal is less likely to precede the welding torch. As a result, even when the amount of heat input to the welding torch is low, the required heat input to the base metal can be performed, and the occurrence of fusion defects can be effectively suppressed.

(2) In some embodiments, in the method (1) above,
The first rod pattern is directed toward the first weld bead.

According to the method (2) above, when the second welding bead is formed, the welding torch is moved in a first rod pattern so as to be directed toward the first welding bead. That is, the welding rod of the welding torch is made so that the welding torch rides on the previously formed welding bead. By performing such a rod movement, it is possible to promote the formation of an overlay layer in the thickness direction and shorten the time required for overlay welding while suppressing the occurrence of fusion failure with the first welding bead.

(3) In some embodiments, in the method (1) or (2) above,
In the step of forming the second welding bead, the weaving is performed so that the locus of the welding torch with respect to the base metal includes a second rod pattern traveling straight along the welding direction.

According to the method (3) above, when forming a welding bead along the welding direction by overlay welding, welding is performed so that the locus of the welding torch includes a second rod pattern that goes straight along the welding direction. The torch is lucked. By performing such a rod movement, it is possible to more effectively suppress the occurrence of fusion failure with the first welding bead.

(4) In some embodiments, in the method (3) above,
The second rod pattern is performed on the end of the first weld bead.

According to the method (4) above, it is possible to more effectively suppress the occurrence of fusion failure at the end of the first welding bead.

(5) In some embodiments, in any one of the above methods (1) to (4),
A step of starting the formation of the second weld bead with a higher amount of heat input than the step of forming the second weld bead is provided.

According to the method (5) above, by starting the formation of the second weld bead with a high amount of heat input, the occurrence of fusion failure at the bead start portion can be effectively suppressed.

(6) In some embodiments, in any one of the above methods (1) to (5),
A step of terminating the formation of the second weld bead with a higher heat input amount than the step of forming the second weld bead is provided.

According to the method (6) above, by completing the formation of the second weld bead with a high amount of heat input, it is possible to effectively suppress the occurrence of fusion failure at the end of the bead.

(7) In some embodiments, in the method (5) or (6) above,
In the step of starting the formation of the second welding bead or the step of ending the formation of the second welding bead, the weaving is carried out along the welding direction.

According to the method (7) above, weaving is performed along the welding direction at the bead start portion or bead end portion where welding is performed with a high heat input amount. That is, unlike the first rod pattern described above, the rod is not moved in the direction opposite to the welding direction.

(8) In some embodiments, in the method (7) above,
The step of forming the second welding bead is
The step of performing the weaving with the first amplitude and
The step of performing the weaving with a second amplitude larger than the first amplitude, and
Are included in order.

According to the method (8) above, when the welding torch rod including the first rod pattern is carried out, weaving with a small amplitude is performed, and then weaving with a large amplitude is performed. By performing weaving that increases the amplitude in this way, it is possible to effectively suppress the occurrence of fusion defects due to changes in the bar pattern.

(9) In some embodiments, in any one of the above methods (1) to (8),
The weaving is performed so that the amplitude in the first region on the side of the first weld bead from the center line of the second weld bead is smaller than the amplitude in the second region on the side opposite to the first region. NS.

According to the method (9) above, the inclination of the overlay formed in the second region can be made gentler than that of the overlay formed in the first region. As a result, when the weld bead is repeatedly formed, the overlap with the next weld bead to be formed can be satisfactorily formed.

(10) In some embodiments, in any one of the above methods (1) to (9),
The formation of the second weld bead ends on the side of the first weld bead from the center line of the second weld bead.

According to the method (10) above, the formation of the second weld bead ends on the side of the first weld bead from the center line of the second weld bead. As a result, the end portion of the second weld bead does not interfere with the formation of a further weld bead following the second weld bead. Therefore, when the welding bead is repeatedly formed, the overlap with the welding bead to be formed next can be satisfactorily formed.

(11) In some embodiments, in any one of the above methods (1) to (10),
The overlay welding is a clad welding in which the surface of the base metal is covered with the welding metal.

The above-mentioned methods (including the above-mentioned various forms) can be suitably applied to clad welding.

(12) In some embodiments, in any one of the above methods (1) to (11),
The overlay welding is carried out using a welding machine capable of switching between a low heat input welding mode and a pulse mode.

The above-mentioned method (including the above-mentioned various forms) can be preferably carried out by using a welding machine capable of switching between a low heat input welding mode and a pulse mode.

According to at least one embodiment of the present invention, it is possible to provide an overlay welding method capable of efficiently overlay forming while suppressing the occurrence of defects due to poor fusion by using a welding torch with low heat input.

This is an example of an apparatus configuration for carrying out the overlay welding method according to at least one embodiment of the present invention. It is a schematic diagram which shows the CMT process schematicly. It is a flowchart which shows the overlay welding method which concerns on at least one Embodiment of this invention for each process. It is a schematic diagram which shows the formation state of the 1st welding bead in step S10 of FIG. It is a schematic diagram which shows the formation state of the 2nd welding bead in step S20 of FIG. It is a figure which shows the locus IV of the welding torch drawn on the base metal in FIG. FIG. 6 (b) is an enlarged view showing a locus under stationary conditions in FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely explanatory examples. No.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
Further, for example, an expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also includes a concavo-convex portion or a concavo-convex portion within a range in which the same effect can be obtained. The shape including the chamfered portion and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.

FIG. 1 is an example of an apparatus configuration for carrying out the overlay welding method according to at least one embodiment of the present invention. In the present embodiment, a case where overlay welding is performed on the surface of the welding object 1 which is a structure having a substantially cylindrical shape will be described as an example.

The welding object 1 is, for example, a body of a cask for storing used fuel and storing it in water, and is made of carbon steel. By performing overlay welding by the welding machine 2 on the outer peripheral surface of the object 1 to be welded having a substantially cylindrical shape, a corrosion-resistant overlay layer is formed so as to cover the surface of the base metal with the welding metal. The weld metal is, for example, aluminum.
In the present embodiment, the body of the cask is illustrated as the object to be welded 1, but the object to be welded 1 may broadly include a structure to be welded by overlay welding.

Since the welding object 1 is a large structure, the welding object 1 can be rotated in the circumferential direction (arrow a) by a turning device (not shown). The welding machine 2 relatives the base 4 installed on the field 3, the welding torch 6 arranged so as to face the outer surface of the welding object 1, and the welding torch 6 with respect to the outer surface of the welding object 1. Includes an arm 8 for performing movement. In the welding operation, a welding bead is formed by moving the welding torch 6 along a predetermined trajectory with respect to the outer surface of the welding object 1 rotated by the turning device.

The welding machine 2 is a welding machine that can use the low heat input welding mode. As such a mode for low heat input welding, for example, a push-pull system capable of controlling the delivery of the welding wire to the molten pool can be used. As an example of the low heat input welding mode using the push-pull system, there is a CMT (Cold Metal Transfer) process which is a low temperature treatment as compared with the conventional MIG / MAG process. The CMT process alternately repeats hot treatment and cold treatment, and has been conventionally used for MIG / MAG robot welding and brazing mainly for ultra-lightweight thin plates. In the present embodiment, overlay welding is performed by using a CMT process for such an ultra-lightweight thin plate.

Here, FIG. 2 is a schematic diagram schematically showing the CMT process. When the welding wire 10 sent out from the welding machine 2 is separated from the base material 12 on the outer surface of the object to be welded 1, an arc 13 is generated between the welding wire 10 and the base material 12 (FIG. 2A). ). When the welding wire 10 is further sent out and comes into contact with (short-circuits) the molten pool of the base metal 12, the arc disappears and the welding current drops sharply (FIG. 2B). At this time, in the CMT process, the welding machine 2 pulls the welding wire 10 back from the welding pond to support the droplet cutting during the short circuit and suppress the short circuit current (FIG. 2 (c)). In the CMT process, the process of FIGS. 2 (a) to 2 (c) is automatically repeated, so that the heat input that the arc gives to the base metal 12 is momentarily stopped, and the amount of heat input can be reduced. ..

The welding machine 2 is configured to be selectively switchable between a CMT mode for carrying out the above-mentioned CMT process and a pulse mode for carrying out the conventional MIG / MAG process. The switching control between the CMT mode and the pulse mode is performed by the control unit 20 which is a control unit included in the welding machine 2. In addition to such mode switching control, the control unit 20 is configured to be able to set various welding parameters including the rod movement pattern of the welding torch 6 in each mode.

As such a welding machine 2, for example, a welding system compatible with the CMT process manufactured by Fronius can be used.

FIG. 3 is a flowchart showing the overlay welding method according to at least one embodiment of the present invention for each process.
First, the first weld bead 100, which is a pre-weld bead, is formed on the base metal 12 (step S10). Here, FIG. 4 is a schematic view showing a state of formation of the first welding bead 100 in step S10 of FIG.
As described above, since the welding object 1 has a substantially cylindrical shape, the outer surface is a curved surface. However, in FIG. 4, the outer surface along the circumferential direction of the welding object 1 is shown in order to make the illustration easier to understand. Is shown in a plane.

As shown in FIG. 4, by generating an arc 13 between the welding torch 6 and the base metal 12, a molten pool 14 having a predetermined size is formed in the base metal 12. While the welding wire 10 which is a welding metal is fed to the molten pool 14, the welding torch 6 is moved in the welding direction I while weaving at a predetermined cycle, so that a part of the welding wire 10 melts into the base metal 12. , The first weld bead 100 is formed.
In FIG. 4, reference numeral II indicates a locus of the welding torch 6, and reference numeral III indicates a feeding direction of the welding wire 10.

The setting conditions of the welding machine 2 when forming the first welding bead 100 may be arbitrary, but for example, the same settings as those of the second welding bead 200 described later may be applied.

Subsequently, the second weld bead 200 is formed in the region adjacent to the first weld bead 100 (step S20). That is, that is, the welding torch 6 is moved to the region adjacent to the first welding bead 100 formed in advance, and an arc is generated between the welding torch 6 and the base metal 12 to the molten pool 14. While feeding the weld metal, the welding torch 6 is moved in the welding direction while weaving to form the second welding bead 200. By repeatedly forming the weld bead in this way, the surface of the base metal 12 is covered with the weld metal over a wide area.

Here, FIG. 5 is a schematic view showing the formation state of the second welding bead 200 in step S20 of FIG. 3, and FIG. 6 is a diagram showing the locus IV of the welding torch 6 drawn on the base metal 12 in FIG. ..
As described above, since the welding object 1 has a substantially cylindrical shape, the outer surface is a curved surface, but in FIGS. 5 and 6, in order to make the illustration easier to understand, the welding object 1 is along the circumferential direction. The outer surface is shown in a plane.

The locus IV of the welding torch 6 on the base metal 12 continues from the start point S where the formation of the second welding bead 200 starts to the end point E where the formation of the second welding bead 200 ends. Since the second welding bead 200 is formed over the entire circumferential direction of the welding object 1, the start point S and the end point E indicate substantially the same point. That is, the second welding bead 200 is formed by moving the welding torch 6 over 360 degrees along the outer surface of the object 1 to be welded. Further, the formation of the second welding bead 200 is performed so that the second welding bead 200 following the first welding bead 100 overlaps one end 100a of the preceding first welding bead 100.

As shown in FIG. 6, the rod pattern of the welding torch 6 when forming the second welding bead 200 is as follows: (a) start condition, (b) steady condition, for each forming stage of the second welding bead 200. (C) Classified as end conditions.

(A) The start condition is a condition for starting the formation of the second welding bead 200, and a pulse mode having a larger amount of heat input than the CMT mode is selected. Further, (a) the rod movement pattern under the start condition is a zigzag pattern along the welding direction I, and is set to, for example, a forward angle of 10 degrees and a torch angle of 0 degrees. As described above, by selecting the pulse mode in which the amount of heat input is large under the start condition (a), the penetration into the base metal 12 can be deepened, and the occurrence of fusion failure in the vicinity of the start point S can be effectively suppressed.

(B) The stationary condition is a condition for forming the second weld bead 200, and is a main condition for forming the second weld bead 200. (B) Under stationary conditions, the CMT mode, in which the amount of heat input is smaller than that in the pulse mode, is selected. By selecting the CMT mode having a small amount of heat input in this way, it is possible to suppress the melting of the base metal 12 when forming the second weld bead 200 and reduce the dilution rate. Further, in the CMT mode, since the amount of heat input is smaller than that in the pulse mode, the height of the build-up formed becomes large, so that the build-up can be efficiently formed.

Here, FIG. 7 is an enlarged view showing the locus IV under the stationary condition (b) of FIG. (B) The rod of the welding torch 6 under steady conditions is implemented so that the locus IV includes the first rod pattern IV-1 heading in the direction opposite to the welding direction I. By performing such a rod movement, the molten pool 14 formed in the base metal 12 is less likely to precede the welding torch 6. As a result, even when the heat input amount of the welding torch 6 is low, the necessary heat input can be performed on the base metal 12, and the occurrence of fusion failure can be effectively suppressed.

Such a first rod pattern IV-1 is performed toward the first welding bead 100. That is, the rod of the welding torch 6 is moved so that the welding torch 6 rides on the first welding bead 100 formed earlier. As a result, the thickness of the built-up layer formed can be effectively increased while suppressing the occurrence of fusion failure with the first weld bead 100. As a result, the working time required for forming the second welding bead 200 can be effectively shortened.

Further, the rod of the welding torch 6 is implemented so that the locus IV includes the second rod pattern IV-2 that goes straight along the welding direction I. Such a rod is preferably carried out along the end 100a of the first weld bead 100. When the second welding bead 200 is overlaid on one end 100a of the first welding bead 100 and welded, the weld metal of the second welding bead 200 is not sufficiently melted in the base metal 12, and fusion failure is likely to occur. By performing the second rod pattern IV-2 on the end portion 100a of the first welding bead 100 in this way, it is possible to promote the penetration of the molten metal into the base metal 12 and effectively suppress the occurrence of fusion defects. ..
In the second rod pattern IV-2, the welding torch 6 is apparently shown to advance on the surface of the base metal 12, but as described above with reference to FIG. 1, the welding object 1 When weaving the welding torch while rotating it with a turning device, even if it is realized by temporarily stopping the weaving of the welding torch 6 (movement along the direction perpendicular to the rotation direction of the welding object 1). good.

(B) Stationary conditions are further classified into (b-1) first stationary conditions and (b-2) second stationary conditions. The first stationary condition (b-1) and the second stationary condition (b-2) have the same rod pattern, but in the first stationary condition (b-1), the second stationary condition (b-2). The amplitude is smaller than that of. This is because when the (a) start condition is directly shifted to the (b-2) second stationary condition, there is a high possibility that a melting defect will occur due to a sudden change in the bar pattern. Therefore, in the present embodiment, by interposing the (b-1) first stationary condition having a small amplitude between the (a) start condition and the (b-2) second stationary condition, such melting failure Is suppressed.

(C) The end condition is a condition when the formation of the second welding bead 200 is completed, and a pulse mode having a larger amount of heat input than the CMT mode is selected. The bar pattern in (c) end conditions is the same as in (b) stationary conditions. As described above, in the (c) end condition, by selecting the pulse mode in which the amount of heat input is large, the welding metal can be deeply melted into the base metal 12, and the occurrence of fusion failure at the end point E can be effectively performed. Can be suppressed.

Further, under the end condition (c), the formation of the second welding bead 200 ends on the side of the first welding bead 100. At the end point E, a bulge shape is not a little generated when the welding torch 6 is separated from the base metal 12, but such a bulge shape does not hinder the formation of a further welding bead following the second welding bead 200. can do. As a result, when the weld bead is repeatedly formed, the overlap with the next weld bead to be formed can be satisfactorily formed.

Further, in the present embodiment, from (a) start condition to (c) end condition, the weaving of the welding torch 6 has an amplitude in the first region A on the first welding bead 100 side from the end 100a of the first welding bead 100. T1 is carried out so as to be smaller than the amplitude T2 in the second region B opposite to the first region A. As a result, the inclination of the overlay formed in the second region B can be made gentler than that of the overlay formed in the first region A. As a result, when the weld bead is repeatedly formed, the overlap with the next weld bead to be formed can be satisfactorily formed.

As described above, according to at least one embodiment of the present invention, when forming a welding bead along the welding direction I by overlay welding, the locus IV of the welding torch 6 is directed in the direction opposite to the welding direction I. The rod of the welding torch 6 is operated so as to include the first rod pattern IV-1. By performing such a rod movement, the molten pool formed in the base metal 12 is less likely to precede the welding torch 6. As a result, even when the heat input amount of the welding torch 6 is low, the necessary heat input can be performed on the base metal 12, and the occurrence of fusion failure can be effectively suppressed.
In this way, it is possible to provide a build-up welding method capable of efficient build-up formation while suppressing the occurrence of defects due to poor fusion by using a low heat input welding torch.

At least one embodiment of the present invention can be used in an overlay welding method in which the surface of a base metal is covered with a weld metal.

1 Welding object 2 Welding machine 3 Field 4 Base 6 Welding torch 8 Arm 10 Welding wire 12 Base material 13 Arc 14 Molten pond 20 Control unit 100 1st welding bead 200 2nd welding bead A 1st area B 2nd area E end Point I Welding direction IV Trajectory IV-1 1st rod pattern IV-2 2nd rod pattern S Start point

Claims (17)

While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by carrying out the weaving is provided so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction .
The first Unbo pattern, the first Ru done toward the weld bead, overlay welding method. In the step of forming the second welding bead, the weaving is performed so that the locus of the welding torch with respect to the base metal includes a second rod pattern traveling straight along the welding direction. overlay welding method according to 1. The overlay welding method according to claim 2 , wherein the second rod pattern is performed on the end portion of the first welding bead. The overlay welding method according to any one of claims 1 to 3 , further comprising a step of starting the formation of the second weld bead with a heat input amount higher than that of the step of forming the second weld bead. The overlay welding method according to any one of claims 1 to 4 , further comprising a step of terminating the formation of the second weld bead with a heat input amount higher than that of the step of forming the second weld bead. The overlay welding method according to claim 4 or 5 , wherein in the step of starting the formation of the second welding bead or the step of ending the formation of the second welding bead, the weaving is performed along the welding direction. .. The step of forming the second welding bead is
The step of performing the weaving with the first amplitude and
The step of performing the weaving with a second amplitude larger than the first amplitude, and
The overlay welding method according to claim 6 , further comprising. The weaving is performed so that the amplitude in the first region on the side of the first weld bead from the center line of the second weld bead is smaller than the amplitude in the second region on the side opposite to the first region. The overlay welding method according to any one of claims 1 to 7. The overlay welding method according to any one of claims 1 to 8 , wherein the formation of the second weld bead ends on the first weld bead side from the center line of the second weld bead. The overlay welding method according to any one of claims 1 to 9 , wherein the overlay welding is clad welding in which the surface of the base metal is covered with the weld metal. The overlay welding method according to any one of claims 1 to 10 , wherein the overlay welding is performed using a welding machine capable of switching between a low heat input welding mode and a pulse mode. While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by carrying out the weaving is provided so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction.
In the step of forming the second welding bead, the weaving is performed so that the locus of the welding torch with respect to the base metal includes a second rod pattern traveling straight along the welding direction. Method. While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by performing the weaving so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction.
A step of starting the formation of the second welding bead with a higher amount of heat input than the step of forming the second welding bead, and a step of starting the formation of the second welding bead.
A overlay welding method. While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by performing the weaving so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction.
A step of terminating the formation of the second welding bead with a higher amount of heat input than the step of forming the second welding bead, and a step of completing the formation of the second welding bead.
A overlay welding method. While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by carrying out the weaving is provided so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction.
The weaving is performed so that the amplitude in the first region on the side of the first weld bead from the center line of the second weld bead is smaller than the amplitude in the second region on the side opposite to the first region. Overlay welding method. While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by carrying out the weaving is provided so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction.
A overlay welding method in which the formation of the second weld bead ends on the first weld bead side from the center line of the second weld bead. While the weld metal is fed to the molten pool generated by generating an arc between the welding torch and the base metal, the welding torch is moved in the welding direction while weaving to form the first welding bead, and the first welding bead is formed. 1 This is an overlay welding method in which overlay welding is performed by forming a second weld bead in the area adjacent to the weld bead.
A step of forming the second welding bead by carrying out the weaving is provided so that the locus of the welding torch with respect to the base metal includes a first rod pattern directed in the direction opposite to the welding direction.
The overlay welding is a overlay welding method performed by using a welding machine capable of switching between a low heat input welding mode and a pulse mode.

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