JP6522179B1 - Welding apparatus and welding method using the welding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decrease in toughness of a weld portion caused by an increase in welding heat input, which occurs in welding composed of at least two or more electrodes spaced apart in the welding progress direction, and to prevent the high temperature of the first layer bead Provided are a welding apparatus and a welding method using the welding apparatus, which can suppress cracking (welding defects). A welding apparatus includes a molten pool formed by at least one of at least two electrodes spaced apart in the welding direction and at least one of electrodes positioned behind a leading electrode. And a hot wire supplied to the The electrode is composed of a leading first electrode and a trailing second electrode spaced apart from the first electrode in the welding direction. The hot wire is supplied to the molten pool formed by the second electrode. [Selected figure] Figure 1

Description

  The present invention relates to a welding apparatus provided with at least two or more electrodes and a welding method using the welding apparatus.

  Conventionally, consumable electrode type arc welding using a filler wire is known as a welding method. In this welding method, an arc is generated between the consumable electrode and the base material, and welding is performed while feeding the filler wire to the arc generating portion. The filler wire is melted by the heat from the arc and transferred to the molten pool.

  For example, Patent Document 1 discloses a two-electrode hot wire MAG welding method as consumable electrode type arc welding. In this two-electrode hot wire MAG welding method, current is output from the welding power source to energize the leading welding wire, an arc is generated between the base material and the leading welding wire, and electricity from the filler wire power source is further generated. The welding proceeds while feeding the heated filler wire to the molten pool formed on the rear side of the arc.

JP, 2013-252523, A

  By the way, as a two-electrode welding method of the single-sided one-run welding method, it has a leading first electrode and a trailing second electrode disposed with a space between the first electrode and the welding progress direction, The configuration is known. In this two-electrode welding method, welding is performed such that the back wave bead and the first layer bead are formed while the key hole is opened by the first electrode, and the weld bead of the second electrode is superimposed on the bead of the first electrode to form a front bead. It is a technology.

  The two-electrode welding method is a two-pool welding method in which an interval is provided between a first electrode and a second electrode, and it is known that the amount of heat input for welding is high. When welding a steel plate having a predetermined thickness or more, it is necessary to increase the amount of weld metal. In order to increase the amount of weld metal by applying the welding method, it is necessary to adjust the current value and voltage value of the first electrode and the second electrode or to slow the welding speed, etc. Also, the toughness of the welded portion may be reduced. In addition, there is a possibility that the welded portion has a penetration shape in which there is a high possibility that high temperature cracking (welding defects) may occur due to butt solidification at the central portion of the weld metal of the primary layer bead formed by the first electrode.

  For example, in the two-electrode hot wire MAG welding method of Patent Document 1, one electrode of the hot wire is added to the one-electrode MAG welding to form two electrodes, and one electrode of the hot wire is added to the two-electrode MAG welding. It is not the configuration that That is, in the two-electrode hot wire MAG welding method of Patent Document 1, the back wave bead and the first layer bead are formed while the key hole is opened at the first electrode, and the weld bead of the second electrode is overlapped on the bead of the first electrode It is not a configuration that can realize the single-sided one-run welding method for forming the front bead.

  The present invention has been made to solve the problems as described above, and in a single-sided single-run welding application technique constituted by at least two or more electrodes spaced apart in the welding direction, welding heat input is achieved It is an object of the present invention to provide a welding apparatus and a welding method using the welding apparatus, which can suppress high temperature cracking (welding defects) of the first layer bead generated due to the increase of

  As means for solving the problems of the above-mentioned prior art, (1) the welding device according to the present invention has at least two electrodes spaced apart in the welding direction and a portion behind the leading electrode And a hot wire to be supplied to a molten pool formed by at least one of the positioned electrodes.

  (2) Further, in the welding device according to (1), the electrode includes a leading first electrode and a trailing second electrode disposed with a gap between the first electrode and the first electrode. , And the hot wire is supplied to the molten pool formed by the second electrode.

  (3) In the welding device of (1) or (2), the apparatus further includes a hot wire nozzle connected to the torch for supplying the hot wire inserted into the hollow structure to the molten pool. The hot wire nozzle is provided with a thick portion with a thick inner peripheral surface at a tip end portion so as to close the hollow interior at a predetermined length in the tube axis direction, and the hot wire is attached to the thick portion It is characterized in that an insertion hole of a small diameter is formed to such an extent that it can be passed, and a hot wire tip is provided at a predetermined distance from the thick portion.

  (4) Further, in the welding device according to (3), the hot wire tip is provided inside the hot wire nozzle such that a conduction distance of the hot wire is 25 mm or more and 100 mm or less.

  (5) The welding method according to the present invention is a welding method using the welding apparatus according to any one of (1) to (4), wherein at least at least one of the electrodes located behind the lead electrode Welding is advanced while supplying a heated hot wire to the molten pool formed on the rear side of the arc generated at one electrode.

  (6) In the welding method according to (5), the hot wire is provided at an interval of 5 mm or more and 20 mm or less between the electrode forming the molten pool to be supplied.

  (7) In the welding method according to (5) or (6), the electrode forming the molten pool to which the hot wire is supplied is provided so as to have a receding angle of 5 degrees or more and 45 degrees or less. Do.

  According to the present invention, since the hot wire is supplied to the molten pool formed in at least one electrode located rearward of the leading electrode, welding is performed by the hot wire which is melted without generating an arc. The amount of weld metal can be increased while suppressing the amount of heat, and the high temperature cracking (welding defect) of the first layer bead and the decrease in toughness of the welded portion can be suppressed.

It is an explanatory view showing a welding device concerning an embodiment of the invention. It is a sectional view showing a hot wire nozzle of a welding device concerning an embodiment of the invention. It is an explanatory view showing a welding method using a welding device concerning an embodiment of the invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals, and the description thereof will be appropriately omitted or simplified. Further, the configuration, size, arrangement and the like of the configuration described in each drawing can be appropriately changed within the scope of the present invention.

Embodiment.
FIG. 1 is an explanatory view showing a welding apparatus according to an embodiment of the present invention. Specifically, FIG. 1 shows a form in which a hot wire is supplied to the second electrode by a two-electrode welding method. Welding apparatus 100 in accordance with the present embodiment is to weld pool 7 formed by two electrodes 1 and 2 spaced apart in the welding direction and electrode 2 located behind head electrode 1. And a hot wire 3 to be supplied. Electrodes 1 and 2 in the embodiment shown in FIG. 1, a first electrode 1 preceding, row after example spaced apart L ₁ of about 300mm between the first electrode 1 in the welding direction And the second electrode 2 of

  The first electrode 1 is a welding wire of a consumable electrode protruding from the tip of the leading torch 10 by a predetermined length, and is automatically fed from the leading torch 10. The first electrode 1 is energized by a current output from a welding power supply (not shown) and generates an arc with the base material 5. The welding wire is, for example, a solid wire. The preceding torch 10 may be configured by a simple device, or may be configured to be automatically controlled as being attachable to a robot arm or the like.

  The second electrode 2 is a welding wire of a consumable electrode which protrudes a required length from the tip of the trailing torch 20 and is automatically fed from the trailing torch 20. The second electrode 2 is energized by a current output from a welding power supply (not shown) and generates an arc with the base material 5. The welding wire is, for example, a flux cored wire. The trailing torch 20 may also be configured by a simple device, or may be configured to be automatically controlled as being attachable to a robot arm or the like.

  Welding apparatus 100 shields a welding portion from air by shielding gas, and performs welding while melting (consuming) welding wire by arc plasma generated between the tip of welding wire and base material 5 . The shield gas is supplied at a controlled flow rate from a gas supply device (not shown). The shield gas is, for example, a carbon dioxide gas, an inert gas, or a mixture of an inert gas and a carbon dioxide gas.

The hot wire 3 is a filler wire heated to just below the melting point, and is inserted into the molten pool 7 in order to increase the amount of weld metal without generating an arc. As shown in FIG. 1, the hot wire 3 is provided in a state inserted into a hot wire torch 30 having a hot wire nozzle 4 with a hollow structure at its tip, and is inserted substantially perpendicularly to the molten pool 7 . Hot wire 3, in the rear side of the second electrode 2 are disposed with an interval L ₂ of 5mm or more 20mm or less between said second electrode 2. This is because it is the most desirable distance at which the arc of the second electrode 2 and the hot wire 3 are prevented from interfering with each other and the molten metal heat of the second electrode 2 can sufficiently melt the hot wire 3. The hot wire 3 is energized by a current output from a hot wire power supply (not shown) and supplied to the molten pool 7 formed on the rear side of the arc generated in the second electrode 2.

  FIG. 2 is a cross-sectional view showing a hot wire nozzle of a welding apparatus according to an embodiment of the present invention. As shown in FIG. 2, the hot wire nozzle 4 is composed of a proximal end 40a connected to the distal end of the hot wire torch 30, and a feeding unit 40b provided from the middle to the distal end. . The hot wire nozzle 4 is attached to and detached from the hot wire torch 30 by screwing the female screw portion 43 formed on the inner peripheral surface on the rear end side to the male screw portion 31 formed on the tip portion to the hot wire torch 30 It can be attached freely. Incidentally, the length of the hot wire nozzle 4 is about 10 cm as an example.

  At the tip of the hot wire nozzle 4, a thick portion 42 with a thick inner peripheral surface is provided with a predetermined length in the tube axis direction so as to close the hollow interior, and the hot wire 3 is passed through the thick portion 42 The insertion hole 42a of a small diameter is formed to such an extent that it can do. The insertion hole 42 a is formed to have a diameter that is slightly larger than the wire diameter of the hot wire 3. By having the thick portion 42, the hot wire nozzle 4 can suppress bending of the hot wire 3 and can determine a stable aim to the molten pool 7.

The hot wire tip 41 is provided at a predetermined distance from the thick portion 42. Specifically, hot wire tip 41, such that the conduction distance L ₃ of the hot wire 3 is 25mm or 100mm or less, provided inside the hot wire nozzle 4 from the thick portion 42 with a predetermined distance There is. When energized the distance L ₃ is too short, too late heating of the hot wire 3, because the hot wire 3 in the molten pool 7 may not be sufficiently melted. Therefore, energizing the distance L ₃ of the hot wire 3, it is necessary to secure a certain distance. On the other hand, when the energization distance L ₃ of the hot wire 3 is too long, vibration occurs in the hot wire 3, it may not be possible to perform stable welding. Therefore, energization distance L ₃ of the hot wire 3 can eliminate melt defects of the hot wire 3 in the melt pool 7, and so as not to cause variation due shake, as a condition of melt without generating an arc, 25 mm or more 100mm It is set to be as follows. As the welding conditions for the energization distance _{L 3} between 25mm or 100mm or less, for example, the diameter of the hot wire 3 is at 1.0mm or 1.6mm or less, feed rate of the hot wire 3 per minute 10 m or more and 30 m or less.

Incidentally, the scope of the current distance _{L 3} between 25mm or 100mm or less is a range in consideration of the various welding conditions. Depending on the welding conditions, in actual construction, it is preferable to set the energization distance _{L 3} to 60mm or more 80mm or less (preferably about 70 mm). The welding conditions in this case are, for example, the diameter of the hot wire 3 of about 1.2 m, and the feed amount of the hot wire 3 per minute is 14 to 18 m (preferably about 16 m).

  Inside the hot wire tip 41, a wire passage 41a is formed, through which the hot wire 3 is inserted and slidably supported. The hot wire 3 is inserted from the hot wire torch 30 into the wire passage 41 a, and a current supplied from a power supply (not shown) is conducted through the hot wire tip 41.

  Welding apparatus 100 is not limited to the illustrated configuration. For example, the electrodes are not limited to two of the first electrode 1 and the second electrode 2, and may be configured as three or more electrodes spaced apart in the welding direction. In this case, it is assumed that the hot wire 3 is supplied to the molten pool at a selected electrode or all the electrodes among the electrodes located behind the first electrode.

  Next, a welding method using welding apparatus 100 of the above-mentioned composition is explained based on Drawings 1-3. FIG. 3 is an explanatory view showing a welding method using the welding apparatus according to the embodiment of the present invention. Specifically, FIG. 3 shows a macro cross section of the weld when the hot wire is supplied to the second electrode by the two-electrode welding method.

The welding method in the present embodiment is a two-electrode type MAG welding method as an example. In addition, the welding method in this embodiment can be implemented in various joints, such as a butt joint, a lap joint, a T joint, and a butt joint. In the welding method in the present embodiment, welding is performed by arranging the first electrode 1 and the second electrode 2 at predetermined intervals L ₁ (for example, about 300 mm) in the front-rear direction with respect to the welding progress direction.

  In the welding method in the present embodiment, first, the leading torch 10 is held, current is supplied from the welding power source, an arc is generated between the first electrode 1 and the base material 5, and a molten pool 6 is generated. At this time, carbon dioxide gas is supplied from the leading torch 10 toward the base material 5 as a shield gas. It is for preventing the metal which became high temperature from reacting with oxygen and nitrogen. In the first electrode 1, as shown by the broken line A in FIG. 3, the back wave bead and the first layer bead are formed while the key hole is opened.

  Next, the trailing torch 20 is held, power is supplied from the welding power source, an arc is generated between the second electrode 2 and the base material 5, and a molten pool 7 is generated. At this time, carbon dioxide gas is supplied from the trailing torch 20 toward the base material 5 as a shield gas. In the second electrode 2, as shown by the broken line B in FIG. 3, a surface bead is formed by overlapping the bead formed by the first electrode 1.

  The second electrode 2 is provided to have a receding angle θ of 5 degrees or more and 45 degrees or less, as shown in FIG. When the second electrode 2 is arranged in the direction perpendicular to the base material 5, the molten metal to which the hot wire 3 is added also precedes the arc point of the second electrode 2, and welds the preceding molten metal. There is a possibility that As a result, the molten metal generated by the second electrode 2 may not be sufficiently dissolved in the first layer beat formed by the first electrode 1. The reason why the receding angle θ is 45 degrees or less is that the upper limit of the welding operation due to mechanical constraints is defined. In addition, when the second electrode 2 has a receding angle θ of 45 degrees or more, the shape of the front bead changes to cause a problem in quality. In actual construction, the receding angle θ of the second electrode 2 may be 5 degrees or more and 20 degrees or less in consideration of the workability of the welding operation while suppressing the precedence of the weld metal to which the hot wire 3 is also added. It can be said that it is the most appropriate angle.

  Then, in the welding method in the present embodiment, welding is performed while supplying the hot wire 3 heated by applying electricity from the welding power source to the molten pool 7 formed on the rear side of the arc generated in the second electrode 2. Let go. The hot wire 3 is supplied to the molten pool 7 using a hot wire torch 30 having a hot wire nozzle 4 of the above configuration at its tip. By using the hot wire nozzle 4, the runout of the hot wire 3 can be prevented, and the aim of the hot wire 3 can be stabilized and determined.

  The welding power source for energizing the hot wire 3 uses pulses to set the required feed amount according to the base current, peak current, frequency, ratio, and thickness of the base material 5. The execution current value is, for example, 180 to 220A.

  Incidentally, when the welding method in the present embodiment is carried out, it is also conceivable to insert the hot wire 3 into the molten pool 6 formed by the first electrode 1 to increase the amount of weld metal. However, when the hot wire 3 is inserted into the molten pool 6 formed by the first electrode 1, the molten metal to which the hot wire 3 is added also precedes the arc point of the first electrode 1 and the preceding melting occurs. It may weld metal. As a result, the root portion may be insufficiently melted and the back wave bead may not be stably obtained. In order to improve the welding quality, it is necessary to firmly form the back wave bead in the first electrode 1. Therefore, in the welding method in the present embodiment, the hot wire 3 is not inserted into the molten pool 6 formed by the first electrode 1 but is inserted into the molten pool 7 formed by the second electrode 2 To improve welding quality.

  In addition, in the welding method in this Embodiment, you may use the welding apparatus which has three or more electrodes arrange | positioned at intervals in the welding advancing direction. In this case, it is assumed that the hot wire 3 is supplied to the molten pool at a selected electrode or all the electrodes among the electrodes located behind the first electrode.

  Here, problems with the conventional two-electrode type MAG welding method will be described. Generally, in the two-electrode type MAG welding method, when performing single-sided one-run butt welding, it is necessary to perform welding by increasing the amount of weld metal as the base material becomes thicker. As a method of increasing the amount of weld metal, it is conceivable to reduce the welding speed, to increase the current and voltage of the first electrode 1 and the second electrode 2, or to increase the number of electrodes. However, in these methods, the heat input to the weld increases, so the toughness of the weld decreases, and high temperature cracking also occurs in the first layer beat. In addition, there is a high probability that a welding defect occurs, in which the bead previously welded by the first electrode is remelted by the arc of the second electrode. Therefore, in the two-electrode type MAG welding method, when performing single-sided one-run butt welding, the thickness of the steel plate is limited to, for example, about 22 mm.

  For example, in the case of shipbuilding, the revision of the classification rules has led to an increase in the thickness of steel applied to ships. In this case, in the conventional two-electrode type MAG welding method, it is difficult to perform single-sided one-run butt welding because the steel material is a thick plate (for example, about 25 mm), and welding can not but be performed by multi-run welding method . Therefore, in the conventional two-electrode type MAG welding method, the construction is time-consuming and there is a problem that the productivity is lowered. As described above, in the industry that welds thick plates such as shipbuilding, bridges, construction, and construction machines, a new construction technique of single-sided one-run butt welding is desired in the two-electrode welding method.

  Therefore, in welding apparatus 100 according to the present embodiment, as described above, at least two or more electrodes 1 and 2 arranged at intervals in the welding advancing direction and the electrode positioned behind head electrode 1 And a hot wire 3 supplied to the molten pool 7 formed by at least one of the electrodes 2. Specifically, the electrode is configured of a leading first electrode 1 and a trailing second electrode 2 disposed at an interval between the first electrode 1 and the first electrode 1 in the welding direction. The hot wire 3 is supplied to the molten pool 7 formed by the second electrode 2.

  Therefore, in the welding device 100, the amount of weld metal can be increased while suppressing the amount of heat input by the hot wire 3 which is melted without generating an arc, so that the decrease in toughness of the welded portion can be suppressed. High temperature cracking (welding defects) can also be suppressed. That is, while the limit of the plate thickness of the steel plate is, for example, about 22 mm in the conventional welding apparatus, using the welding apparatus 100 of the present embodiment, even single-sided 1-run abutment Welding becomes possible.

  In addition, welding apparatus 100 according to the present embodiment further includes hot wire nozzle 4 connected to torch 30 for the hot wire to supply hot wire 3 inserted into the hollow structure to molten pool 7. ing. The hot wire nozzle 4 is provided with a thick portion 42 having a thick inner peripheral surface at a tip end portion so as to close the hollow interior at a predetermined length in the tube axis direction, and the hot wire 3 is passed through the thick portion 42 The insertion hole 42a of a small diameter is formed to such an extent that it can do. Then, the hot wire tip 41 is provided in the hot wire nozzle 4 at a predetermined distance from the thick portion 42. Therefore, in this welding apparatus 100, the hot wire 3 can be stably held by the thick portion 42, and the bending of the hot wire 3 can be suppressed, and a stable aim to the molten pool 7 can be determined. it can.

In particular, the welding device 100 of this embodiment, as current distance L ₃ of the hot wire 3 is in the range of 25mm or 100mm or less, by providing the hot wire tip 41 within the hot wire nozzle 4, the molten Melting failure of the hot wire 3 in the pond 7 can be eliminated, and fluctuation due to runout can also be prevented, and stable welding can be performed.

  Further, in the welding method of the present embodiment, since the hot wire 3 is disposed at an interval of 5 mm or more and 20 mm or less between the electrode forming the molten pool 7 to be supplied, the arc of the second electrode 2 is And the interference of the hot wire 3 can be prevented, and the hot wire 3 can be sufficiently melted by the molten pool heat of the second electrode 2.

  Further, in the welding method of the present embodiment, since the second electrode 2 is provided to have a receding angle θ of 5 degrees or more and 45 degrees or less, the leading of the weld metal to which the hot wire 3 is added is suppressed. The workability of the welding operation can be enhanced without being subject to mechanical constraints.

  Although the present invention has been described above based on the embodiment, the present invention is not limited to the configuration of the embodiment described above. For example, the hot wire nozzle 4 is not limited to the illustrated shape, and may have another shape. In addition, welding apparatus 100 of the present embodiment can be applied to an apparatus used for two-electrode mug single-sided welding, such as a two-electrode mug single-run welding apparatus or a bent outer plate single-sided welding apparatus conventionally used. In addition, the welding method in the present embodiment is not limited to the two-electrode type MAG welding method, and can also be implemented by, for example, MIG welding shielded with an inert gas. In short, the scope of the various modifications, applications, and uses that the so-called person skilled in the art makes as needed is mentioned in the scope of the present invention (the technical scope).

  DESCRIPTION OF SYMBOLS 1 1st electrode, 2 2nd electrode, 3 hot wire, 4 hot wire nozzle, 5 base materials, 6, 7 molten pool, 10 leading torch, 20 trailing torch, 30 hot wire torch, 31 internal thread, 40a base End portion, 40b feeding portion, 41 hot wire tip, 41a wire passage, 42 thick portion, 42a insertion hole, 43 internal thread portion, 100 welding device.

Claims (7)

At least two or more electrodes spaced apart in the welding direction;
What is claimed is: 1. A welding apparatus comprising: a hot wire supplied to a molten pool formed by at least one of electrodes positioned behind a leading electrode. The electrode is
A leading first electrode,
And a second electrode of a rear row spaced apart from the first electrode in the welding direction;
The welding device according to claim 1, wherein the hot wire is supplied to a molten pool formed by the second electrode. And a hot wire nozzle connected to the torch for feeding the hot wire inserted into the hollow structure into the molten pool.
The hot wire nozzle is provided with a thick portion having a thick inner peripheral surface at a tip end portion so as to close the hollow interior at a predetermined length in a tube axis direction, and the hot wire is passed through the thick portion A small diameter insertion hole is formed to the extent that
The welding device according to claim 1, wherein a hot wire tip is provided at a predetermined distance from the thick portion.   The welding device according to claim 3, wherein the hot wire tip is provided inside the hot wire nozzle such that a conduction distance of the hot wire is 25 mm or more and 100 mm or less. A welding method using the welding apparatus according to any one of claims 1 to 4,
Welding is advanced while supplying a heated hot wire to the molten pool formed on the rear side of the arc generated at at least one of the electrodes positioned behind the front electrode. , Welding method.   The welding method according to claim 5, wherein the hot wire is provided at an interval of 5 mm or more and 20 mm or less between the electrode forming the molten pool to be supplied.   The welding method according to claim 5 or 6, wherein the electrode forming the molten pool to which the hot wire is supplied is provided to have a receding angle of 5 degrees or more and 45 degrees or less.

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