KR101482309B1 - Multilayer Electro Gas Arc Welding and Welded material thereof - Google Patents

Abstract

The present invention provides a multilayered electrosurgical arc welding method capable of preventing the propagation of brittle cracks even when brittle cracks occur, and it is an object of the present invention to provide a multilayered electrosurgical arc welding method in which a first wire for a wire , A second wire torch to which a second wire is fed, and a welding body connected to the first and second wire torches, wherein the arc first wire formed by the first wire of the torch for electrode wire A first molten metal forming step of melting only the molten metal to form a first molten metal; A rising step of raising the welding body after a predetermined amount of the first wire is melted; And a second molten metal forming step of melting the second wire of the torch for the second wire together with the first wire to form a second molten metal; Layer electrogas arc welding method.

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.

It is an object of the present invention to provide a multilayered electrogas arc welding method capable of preventing the propagation of brittle cracks even when brittle cracks occur.

Another object of the present invention is to provide a welded article having a multi-layer welded portion in which a discontinuity surface capable of preventing the propagation of brittle cracks is formed to prevent brittle fracture due to brittle cracks.

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

The present invention relates to a torch for a first wire to which a first wire is fed so as to weld between workpieces to be welded, a torch for a second wire to which a second wire is fed, and a welding body connected to the torch for the first and second wires A first molten metal forming step of melting only the first wire of the arc formed by the first wire of the torch for electrode wire to form a first molten metal, A rising step of raising the welding body after a predetermined amount of the first wire is melted; And a second molten metal forming step of melting the second wire of the torch for the second wire together with the first wire to form a second molten metal; Layer electrogas arc welding method.

Whether or not a predetermined amount of the first wire is melted in the ascending step can be determined by measuring the feeding amount of the first wire.

And a second rising step of raising the welding body after the first wire and the second wire are melted in the second molten metal forming step, and after the second rising step, feeding of the second wire is stopped And the first molten metal forming step can be performed again.

Furthermore, the first rising step and the second rising step may be performed periodically so that the forming amounts of the first molten metal and the second molten metal are the same.

In addition, the second wire may have higher toughness than the first wire.

Also, the second wire is a non-conductive wire to which current is not supplied, and the second wire can be melted in an arc formed by the first wire.

Alternatively, the present invention is a welding object including a welded portion welded with a backing material, wherein the welded portion is arranged alternately along the longitudinal direction of the welded portion, the first welded portion and the second welded portion having a different composition from the first welded portion, Wherein the first welding layer and the second welding layer are formed by one-pass welding, and a portion where a composition of the first welding layer and the second welding layer is mixed is formed between the first welding layer and the second welding layer Thereby providing a multi-layered welded material.

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

The welding portion may be formed by the welding method described above.

The present invention can provide a multilayer electrogas arc welding method capable of preventing the propagation of brittle cracks even if brittle cracks occur through the above method.

The present invention is capable of preventing the propagation of brittle cracks to a discontinuous layer formed by alternately forming two different layers.

In addition, the present invention provides a welded material having a multi-layer welded portion in which a discontinuous layer capable of preventing the propagation of brittle cracks is formed to prevent brittle fracture due to brittle cracks.

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

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 is a view showing a welding portion in the side of the copper plating 40 in the electrogas arc welding apparatus of FIG. 3 And FIG. 5 shows an electrogas arc welding apparatus for forming a second welding layer.

3, the electro-arc arc welding apparatus according to the present invention uses carbon dioxide 60 as a protective gas, and a water-cooled copper deposit 40 is attached to the front surface of the welded material B (see FIG. 4) 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 electrode wire W1 is fed from the electrode wire torch 110. The electrode wire W1 is melted in the arc A formed by the electrode wire W1 and the first molten metal 132 is formed. At this time, the non-polarized wire supply part 152 of the non-polarized wire torch 120 does not operate, and therefore, the first molten metal 132 is formed only by the electrode wire W1.

Meanwhile, FIG. 5 shows a state in which the second molten metal 142 is formed.

The second molten metal 142 is continuously formed after the predetermined amount of the first molten metal 130 is formed and raised. As shown in FIG. 4, the non-polarized wire W3 is melted together with the electrode wire W1 .

At this time, the non-polarized wire W3 uses a material having a composition different from that of the electrode wire W1, and accordingly, the second molten metal 142 may have a composition different from that of the first molten metal 132. [

4, the torch 110 for the electrode wire feeds the electrode wire W1 to form an arc A. The torch 120 for the non-conducting wire is connected to the electrode wire W3 through the non- To the arc A formed by the wire W1 to melt the non-polarized wire W3 together with the electrode wire W1. In the present invention, the non-polarized wire W3 having higher toughness than the electrode wire W1 is used. However, the non-polarized wire W3 having a composition different from that of the electrode wire W1 may be used.

The second welding layer 140 formed of the second molten metal 142 is stacked on the first welding layer 130 formed of the first molten metal 132 and the first molten metal 132 is formed again , The first welding layer 130 and the second welding layer 140 are alternately stacked along the longitudinal direction of the welding portion.

The first weld layer 130 and the second weld layer 140 are alternately stacked to create a discontinuity surface between the first weld layer 130 and the second weld layer 140, It is possible to prevent such a brittle crack from propagating on the welded portion.

FIG. 6 shows a flowchart of the electrogas arc welding method of the present invention.

Initially, the first molten metal 132 is formed by using the electrode wire W1 in the same manner as in the conventional 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-conducting wire W3 is supplied together with the electrode wire W1 to form the second molten metal 142 (S130). Since the composition of the non-polarized wire W3 is different from that of the electrode wire W1, the second molten metal 142, in which both the electrode wire W1 and the non-polarized wire W3 are melted, Is different from the molten first molten metal 132 in composition.

At this time, the second molten metal forming step S130 melts not only the electrode wire W1 but also the non-conducting wire W3 in the same arc A as in the first molten metal forming step S110, The characteristics of the heat affected zone due to welding heat as well as the molten metal 142 are also deformed.

That is, in the case of the first welded layer 130 having the first molten metal 132 formed thereon, a general electrogas arc welding method is employed, and the heat is excessively heated, so that the structure is uneven and the characteristics of the welded portion may be deteriorated And the second molten metal 142 is solidified, the non-polarized wire W3 is melted together with the electrode wire W1. As a result, the heat is reduced, so the structure is fine and the characteristics of the welded portion are improved .

Particularly, in the present invention, the non-oriented structure (the HAZ portion around the first welding layer 130) and the microstructure (the HAZ portion around the second welding layer 140) are alternately generated, do.

On the other hand, in the second molten metal forming step S130, when the predetermined amount of the second molten metal 142 is formed, the welding main body 150 is raised. Particularly, in the second molten metal forming step (S130), the non-conducting wire W3 must be inserted into the arc A formed by the electrode wire W1, so that when the molten metal comes in, The non-polarized wire W3 may not melt so that the welding main body 150 should rise so that the non-polarized wire W3 does not deviate from the arc A of the electrode wire W1 (S140).

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 together with the welding main body 150 (S140), and thereafter the first molten metal forming step (S110) is performed again. At this time, the predetermined amount of measurement is measured through an encoder (not shown) provided in the electrode wire supplying unit 151 and the non-conducting wire supplying unit 152, and is raised when the predetermined amount is exceeded, And may be performed in such a manner as to rise after a lapse of 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.

Some of the features of the weld according to the invention are shown in Fig. 7, in the present invention, the first welding layer 130 and the second welding layer 140 are alternately arranged along the longitudinal direction of the welding portion, and the first welding layer 130 and the second welding layer 130 The weld layer 140 is welded in one pass. That is, the second welding layer 140 is formed continuously with the first welding layer 130, and a portion where the composition of the first welding layer 130 and the second welding layer 140 is mixed 160 < / RTI >

The composition of the first welding layer 130 and the second welding layer 140 is changed so that the mixed portion 160 serves as a discontinuity surface. That is, in the case of brittle cracks, the brittle crack propagates along the weld in the absence of the discontinuity. However, even if the brittle crack occurs in the weld in the present invention, since the discontinuity continuously exists along the longitudinal direction of the weld, ) Will stop.

Therefore, the welded portion according to the present invention does not propagate even when brittle cracks (C) are generated, so that it is possible to provide a welded material having resistance to brittle cracks.

In addition, not only the welded portion but also the heat affected portion around the welded portion are alternately formed with the coarse texture and the microstructure, so that the brittle crack C in the heat affected portion can also be stopped without propagating.

3 to 5, the electrogas arc welding apparatus using the electrode wire W1 as the first wire and the non-conducting wire W3 as the second wire has been described. However, as shown in FIG. 1, the tandem electro- It should be understood that the present invention can be implemented in such a manner that each is an electrode wire like a device.

It is also possible to form the first molten metal 132 and the second molten metal 142 in such a manner that the electrode wires are alternately melted. That is, when the first molten metal 132 is formed, only the electrode wire W1 is melted. When the second molten metal 142 is formed, the supply of the electrode wire W1 is stopped and the other electrode wire Of W2) can be melted to form molten metals having different compositions from each other.

3 to 6, the feeding amount of the electrode wire W1 and the non-conducting wire W3 is measured by the encoder (not shown) of the electrode wire supplying part 151 and the non-conducting wire supplying part 152, An encoder (not shown) may be disposed in the path through which the electrodes or non-polarized wires W1 and W3 pass. 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.

Further, although only two wires are used in the present invention, it is also possible to realize a discontinuous surface by using more wires than necessary.

3 to 6, one electrode wire W1 and the non-electrode wire W3 are welded. However, when the thickness of the welded material exceeds 50 mm, Or in a tandem electrogas arc welding manner. 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 supplied as separate torches, but it goes without saying that the two torches may be supplied together in an integrated torch.

110: Torch for electrode wire 120: Torch for non-conducting wire
130: first welding layer 132: first molten metal
140: second welding layer 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 (9)

A torch for a first wire to which a first wire is fed so as to weld between workpieces to be welded, a torch for a second wire to which the second wire is fed, and a welding body connected to the torch for the first and second wires Device,
A first molten metal forming step of melting only the arc first wire formed by the first wire of the torch for electrode wire to form a first molten metal;
A rising step of raising the welding body after a predetermined amount of the first wire is melted; And
A second molten metal forming step of melting a second wire different in composition from the first wire together with the first wire or melting only a second wire different in composition from the first wire to form a second molten metal; Wherein the multi-layer electrogas arc welding method comprises the steps of:
The method according to claim 1,
Wherein the step of determining whether the first wire is melted in a predetermined amount is determined by measuring a feeding amount of the first wire.
The method according to claim 1,
Forming a second molten metal in the second molten metal forming step, and then raising the weld body,
And after the second rising step, feeding of the second wire is stopped and a first molten metal forming step is performed again.
The method of claim 3,
Wherein the first elevating step and the second elevating step are performed periodically so that the forming amounts of the first molten metal and the second molten metal are the same.
5. The method according to any one of claims 1 to 4,
Wherein the second wire is a material having higher toughness than the first wire.
6. The method of claim 5,
Wherein the second wire is a non-conductive wire to which current is not supplied, and the second wire is melted in an arc formed by the first wire.
A weld, comprising a welded joint of a backing material,
Wherein the welding portion includes a first welding layer and a second welding layer which are different in composition from the first welding layer alternately along the longitudinal direction of the welding portion,
Wherein the first welding layer and the second welding layer are formed by one-pass welding,
And a multilayer in which a portion where the composition of the first welding layer and the second welding layer are mixed is formed between the first welding layer and the second welding layer.
8. The method of claim 7,
Wherein the first weld layer and the second weld layer are of the same thickness.
9. The method of claim 8,
Wherein the weld is formed by the method of any one of claims 1 to 4.

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