KR101482310B1 - Multilayer Electro Gas Arc Welding and Welded material thereof - Google Patents

Abstract

The present invention provides a multi-layer electrogas arc welding method capable of preventing the propagation of brittle cracks even when brittle cracks occur, comprising a torch for an electrode wire for supplying an electrode wire to be welded between workpieces to be welded, A first molten metal forming step of forming an arc molten metal formed by the electrode wire of the torch for the electrode wire using a welding apparatus including a welding body connected to a torch for an electrode wire; And a second molten metal forming step of forming a molten metal having an inlet heat amount smaller than that of the first molten metal forming step are alternately performed.

Description

TECHNICAL FIELD [0001] The present invention relates to a multilayer electrogas arc welding method and a multilayer electrogas arc welding and welding material,

The present invention relates to an electrogas arc welding method having a multi-layer welded portion, and a welded multi-layered welded wire.

Electro gas arc welding method has been developed and applied to improve welding productivity of heavy plates required in shipbuilding.

Particularly, there is a demand for development of a welding technique for welding extreme backing materials according to the demand for extreme backing materials of 60 mm or more. Thus, a tandem electrogas arc welding apparatus using two electrodes has been proposed. As shown in FIG. 1A, tandem electro-arc arc welding uses carbon dioxide 60 as a protective gas, a water-soluble copper deposit 40 on the front surface of the welded material 30 and a fixed backing material 50 on the back surface. . When the molten metal 32 is formed by melting the electrode wires W1 and W2 through the arc generated between the supplied electrode wires W1 and W2 and the welded material 30 and a certain amount of molten metal is formed The torches 10 and 20 to which the electrode wires W1 and W2 are supplied are raised and welded.

Generally, the above-mentioned electro-arc arc welding is applied to the steel construction of a superficial material. When brittle cracks C occur in the welds 30 as shown in FIG. 2, the brittle cracks generated in the welds follow the welds 30 There is a problem that there is a risk of brittle fracture.

The present invention has been made to solve the above problems and it is an object of the present invention to provide a multilayer electrogas arc welding method capable of preventing the propagation of brittle cracks even when brittle cracks occur, The purpose is to provide.

It is another object of the present invention to provide a multi-layer welding portion capable of preventing a brittle fracture due to brittle cracks by forming a discontinuity surface capable of preventing the propagation of brittle cracks, and a welding material capable of propagating a brittle crack along a weld line with a discontinuous welding line .

In order to achieve the above object, the present invention provides a welding method and a welding method as described below.

The present invention uses a welding apparatus including a torch for supplying an electrode wire for welding between workpieces to be welded and a welding body connected to the torch for the electrode wire, A first molten metal forming step of forming an arc molten metal; And a second molten metal forming step of forming a molten metal having an inlet heat amount smaller than that of the first molten metal forming step are alternately performed.

At this time, in the first molten metal forming step, the second molten metal forming step melts only the electrode wire to the arc, and the heat input amount is decreased as compared with the first molten metal forming step, (W3) can be melted.

The second molten metal forming step may be performed when the rising distance of the welding main body in the first molten metal forming step is a certain distance or more.

Alternatively, the second molten metal forming step may supply a higher voltage than the first molten metal forming step.

Alternatively, the first molten metal forming step and the second molten metal forming step are performed with an ascending step rising when a predetermined amount or a predetermined amount of molten metal is formed, and in the first molten metal forming step, The rising distance between the metal forming steps may be longer than the rising distance before the first molten metal forming step is performed again in the second molten metal forming step.

In addition, the non-conducting wire may be a material having higher toughness than the electrode wire.

Alternatively, the present invention is a welding object including a welded portion welded with a backing material, wherein the welded portion includes a first welding layer having a first welding line and a second welding line formed narrower in the width direction than the first welding line, Wherein the first weld layer and the second weld layer provide a weld having a multilayer formed by one-pass welding.

At this time, the first welding layer and the second welding layer may have the same thickness.

According to the present invention, it is possible to provide a multilayer electrogas arc welding method capable of preventing a brittle crack from propagating even when brittle cracks occur, and in particular, preventing a brittle crack from propagating in a tangent line have.

In addition, the present invention can provide a multi-layer welding portion capable of preventing brittle fracture due to brittle cracks by forming a discontinuity surface capable of preventing the propagation of brittle cracks, and a welding material capable of propagating a brittle crack along a weld line with a discontinuous welding line .

1 is a schematic view of a conventional electrogas arc welding apparatus.
FIG. 2 is a view showing a state in which a crack propagates when cracks are generated in a welded product welded by a conventional electro-gas arc welding apparatus.
Fig. 3 is a schematic view showing a state in which a first welding layer is formed as an electro-arc arc welding apparatus according to the present invention.
4 is a schematic view showing a state in which a second welding layer is formed as an electrogas arc welding apparatus according to the present invention.
FIG. 5 is a view showing, from another angle, the formation of the first welding layer in the electrogas arc welding apparatus according to the present invention. FIG.
6 is a view showing a state in which crack propagation is prevented when cracks are generated in a welded product welded by the present invention.
7 is a flowchart of the electrogas arc welding method of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The present invention relates to the welding of post-welded materials capable of electro-arc arc welding, and to electro-arc arc welding in which the weld is vertically erected and the weld is longitudinally filled.

3 to 5 show an electrogas arc welding apparatus according to the present invention. 3 shows an electrogas arc welding apparatus for forming a first welding layer, and FIG. 4 shows an electrogas arc welding apparatus for forming a second welding layer. In FIG. 5, A view of the welding portion in the gas immersion well 40 is shown in the gas arc welding apparatus.

3, the electro-arc arc welding apparatus of the present invention uses carbon dioxide 60 as a protective gas, and a water-soluble copper deposit 40 is attached to the front surface of the welded material B (see FIG. 5) And a torch 110 for an electrode wire and a torch 120 for a non-conducting wire are disposed between the backing material 50 and the copper deposit 40.

The torch 110 for the electrode wire is connected to the electrode wire feeder 151 and feeds the electrode wire W1 supplied from the electrode wire feeder 151. The torch 120 for the non- And supplies and supplies the non-polarized wire W3 supplied from the non-polarized wire supply unit 152. The non-

The electrode wire supplying part 151 and the non-conducting wire supplying part 152 include driving means for supplying and receiving wires, respectively, and an encoder (not shown) attached to the driving means and capable of measuring the wire feeding amount.

The torch 110 for the electrode wire and the torch 120 for the non-conducting wire are connected to the welding body 150. The welding main body 150 includes driving means (not shown), and the operation of the driving means (not shown) causes the welding main body 150 to rotate with the torch 110 for the electrode wire, the torch 120 for the non- Can rise together.

In the present invention, the welding main body 150, the electrode wire supplying part 151 and the non-conducting wire supplying part 152 are connected to the control part 155 and the control part 155 controls the wire feeding amount, Movement and the like can be controlled.

In order to form the first molten metal 132 in the present invention, the non-polarized wire W3 is not supplied to the arc A formed by the electrode wire W1 and only the electrode wire W1 is supplied to the first molten metal 132 are formed.

Meanwhile, FIG. 4 shows a state in which the second molten metal 142 is formed.

The second molten metal 142 is formed continuously after the first molten metal 132 is formed in a predetermined amount and the weld body 150 is raised. As shown in FIG. 4, the electrode wire W1 is fed from the torch 110 for the electrode wire. The torch 120 for the non-conducting wire is connected to the non-conducting wire W3 via the arc (W1) formed by the electrode wire W1, A to melt the non-polarized wire W3 together with the electrode wire W1. In the present invention, the non-polarized wire W3 having a higher toughness than the electrode wire W1 is used. However, the non-polarized wire W3 having a different composition from the electrode wire W1 may be used. The non-polarized wire W3 may be used.

After the second molten metal 142 is thus formed, the first molten metal 132 is again formed and the first weld layer 130 and the second weld layer 140 are formed alternately.

FIG. 5 illustrates the formation of the first weld layer 130 after the second weld layer 140 is formed.

The base material B is diluted in the first molten metal 132 by the heat input from the arc A of the electrode wire W1 in the electrogas arc welding so that the widths l1 and l2 of the welded bead (L < ll or l2). &Lt; / RTI &gt;

In the present invention, when forming the first welding layer 130, only the electrode wire W1 is charged into the arc A formed by the electrode wire W1 at the same voltage, but when the second welding layer 140 is formed Since the non-polarized wire W3 is further melted at the same voltage as when the first welding layer 130 is formed, when the second welding layer 140 is formed, The amount of heat is reduced. Therefore, the amount of dilution of the base material (B) decreases when the second welding layer (140) is formed more than the first welding layer (130). That is, the width 12 of the weld bead in the second weld layer 140 is narrower than the width 11 of the weld bead in the first weld layer 130.

By changing the widths of the beads of the first welding layer 130 and the second welding layer 140, the weld lines 131 and 141 can be discontinuously formed. That is, when the composition of the first welding layer 130 and the second welding layer 140 is different, not only the discontinuity surface 160 between the first welding layer 130 and the second welding layer 140 is formed, The first weld line 131 and the second weld line 141 are also broken by the discontinuity surface 160.

FIG. 6 shows a case where cracks are generated in a weld formed by alternately forming the first weld layer 130 and the second weld layer 140. In the case where the first and second weld layers 130 and 140 have different compositions, the brittle crack C1 propagates in the weld layer when brittle cracks C1 are generated inside the weld layer, Propagation of the brittle crack can be prevented by encountering the discontinuity surface 160 having a different composition.

The brittle cracks C2 generated in the heat affected zone around the weld line 131 may also cause the brittle cracks C2 to encounter other weld layers because the weld lines 131 and 141 are not continuous by the discontinuity 160. [ Even if brittle cracks C2 are generated around the second weld layer 140 as shown in FIG. 6, the second weld layer 130 and the discontinuous surface 160 are encountered, Whereby the brittle crack C2 is suppressed from propagation.

3 to 6, the composition of the electrode wire W1 is different from that of the nonpolar electrode wire W3. However, as described above, the electrode wire W1 and the non-electrode wire W3 may have the same composition. In this case, since the amount of heat input is smaller than that of forming the first molten metal 132 at the time of forming the second molten metal 142, the less the base material B is diluted, the first welding layer 130 and the second welding There may be some differences in the composition of the layer 140. Since the first weld line 131 and the second weld line 141 are connected by the discontinuous surface 160 even if the electrode wire W1 and the non-conducting wire W3 have the same composition, the brittle crack C2 of the heat- Is blocked by the discontinuous surface 160 is the same.

Fig. 7 shows a flowchart of the method of the present invention.

The first molten metal 132 in which the arc A is formed is formed by using the electrode wire W1 in the same manner as in the electrogas arc welding S110. At this time, the first molten metal 132 hardens to become the first welding layer 130. After a predetermined amount of the first molten metal 132 is formed, the welding main body 150 is raised (S120).

At this time, whether or not the first molten metal 132 is formed in a predetermined amount may be measured by measuring the actual feed amount of the electrode wire W1 through an encoder (not shown) provided in the electrode wire feeder 151, It is also possible to estimate the feed rate based on time in speed.

The first molten metal forming step (S110) and the first rising step (S120) may be performed only once, but may be repeated a plurality of times.

In addition, after the first rising step S120, the non-polarized wire W3 is supplied to the arc A together with the electrode wire W1 to form a second molten metal 142 (S130) When a predetermined amount of the second molten metal 142 is formed in the molten metal forming step S130, the welding main body 150 is raised (S140).

At this time, if the same voltage is used, since more metal is melted than the first molten metal formation (S110), heat input to the base material (B) is reduced. The dilution of the base material B into the molten metal in the second molten metal forming step S130 is reduced and the width l2 of the weld bead of the second weld layer 140 becomes smaller than the width of the first weld layer 130 And the first weld line 131 and the second weld line 141 are connected to the discontinuity surface 160. As shown in FIG.

Alternatively, a voltage higher than the voltage in the second molten metal forming step (S130) may be provided in the first molten metal forming step (S110), so that the width l1 of the bead of the first weld layer 130, It is also possible to make the width 12 of the beads of the beads 140 different.

After the predetermined amount of the second molten metal 142 is formed in the second molten metal forming step S130, the electrode wire torch 110 and the non-conducting wire torch 120 are welded to the welding main body 150, The first weld metal layer 130 and the second weld metal layer 140 are alternately arranged along the longitudinal direction of the welded portion S140 and then the first molten metal forming step S110 is performed again, do. At this time, a predetermined amount of measurement is measured through an encoder (not shown) provided in the electrode wire supplying unit 151, and is raised when a predetermined amount is exceeded, or is increased after a predetermined time by multiplying the set amount of supply by time .

At this time, the amount of the first molten metal 132 in the first molten metal forming step (S110) and the amount of the second molten metal 142 in the second molten metal forming step (S130) are the same, It is preferable that the thickness of the welding layer 130 and the thickness of the second welding layer 140 are substantially equal to each other. This is because when one layer is wide, the brittle crack propagation in the layer does not deteriorate the overall performance of the welded part.

In addition, in the present invention, the amount of heat input may be made different by increasing the rising distance in the lifting step (S120, S140) in which the welding main body 150 is lifted. That is, the rising distance of the welding main body 150 in the rising step S120 after the first molten metal forming step S110 is made larger than the amount of the molten metal being filled, It is possible to increase the welding resistance due to the length of the electrode wire W1 by lengthening the distance d between the forming position of the electrode wire W1 and the forming position A of the electrode wire W1, It is possible to reduce the amount of heat.

On the contrary, in the rising step S10 after the second molten metal forming step S130, the rising distance is made smaller than the rising step S120 after the first molten metal forming step S110 and the welding due to the electrode wire W1 It is possible to adjust the shape of the beads of the weld layers 130 and 140 in such a manner that the resistance is reduced and the heat input amount in the first molten metal forming step S110 is larger than the second molten metal forming step S130 .

The amount of feeding of the electrode wire W1 and the non-conducting wire W3 is measured by an encoder (not shown) of the electrode wire feeder 151 and the non-electrode wire feeder 152. However, May be disposed in a path through which the electrode or non-polarized wire (W1, W3) passes. For example, it may be disposed inside the electrode wire torch 110 and the non-electrode wire torch 120, instead of the electrode wire feeder 151 and the non-electrode wire feeder 152.

In the present invention, only two wires are targeted, but it is also possible to realize a discontinuity surface by using more wires than necessary.

In the above description, one electrode wire W1 and the non-electrode wire W3 are welded together. However, in the case where the thickness of the welded material exceeds 50 mm, the method in which the non- , I.e., a tandem electrogas arc welding method. In this case, a total of four torches, two electrode wire torches, and two non-conducting wire torches are included. When one layer is formed, two electrode wires are melted. When another layer is formed, two And the nonconductive wire is melted in the arc formed by the electrode wire and the electrode wire.

In the present invention, the torch for the electrode wire and the torch for the non-conducting wire may be integrated into one torch rather than a separate torch.

110: Torch for electrode wire 120: Torch for non-conducting wire
130: first welding layer 131: first welding line
132: first molten metal 140: second welding layer
141: second weld line 142: second molten metal
150: welding body 151: electrode wire supply part
152: Non-polarized wire supply unit 155:
W1: Electrode wire W3: Non-conducting wire

Claims (8)

delete A torch for supplying an electrode wire to be welded between the workpieces to be welded, and a welding body connected to the torch for the electrode wire,
A first molten metal forming step of forming an arc molten metal formed by the electrode wire of the torch for the electrode wire; And
And a second molten metal forming step of forming a molten metal with a smaller amount of heat input than the first molten metal forming step,
In the first molten metal forming step, only the electrode wire is melted in the arc,
Wherein the second molten metal forming step melts the non-conducting wire (W3) together with the electrode wire (W1) so that the heat input amount is reduced from the first molten metal forming step.
3. The method of claim 2,
Wherein the second molten metal forming step is performed when the rising distance of the welding body in the first molten metal forming step is equal to or greater than a predetermined distance.
delete A torch for supplying an electrode wire to be welded between the workpieces to be welded, and a welding body connected to the torch for the electrode wire,
A first molten metal forming step of forming an arc molten metal formed by the electrode wire of the torch for the electrode wire; And
And a second molten metal forming step of forming a molten metal with a smaller amount of heat input than the first molten metal forming step,
Wherein the first molten metal forming step and the second molten metal forming step are performed together with a rising step for a predetermined time or a predetermined amount of molten metal is formed,
Wherein the rising distance between the first molten metal forming step and the second molten metal forming step is shorter than the rising distance before the first molten metal forming step is performed again in the second molten metal forming step, welding method.
The method of claim 3,
Wherein the non-conducting wire is a material having higher toughness than the electrode wire.
A weld, comprising a welded joint of a backing material,
The welding portion is formed by alternately forming a first welding layer having a first welding line and a second welding layer having a second welding line formed to be wider than the first welding line in the longitudinal direction of the welding portion,
Wherein the first welding layer and the second welding layer have a multilayer formed by one-pass welding.
8. The method of claim 7,
Wherein the first weld layer and the second weld layer are of the same thickness.

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