JP7030371B2 - Variable polarity three-wire gas protection indirect arc welding method, equipment and its use - Google Patents

Description

The present invention belongs to the field of material processing, and relates to a variable polarity indirect arc welding method, specifically, a variable polarity three-wire gas protection indirect arc welding method, an apparatus, and its use.

With the development of modern industry, the application of large parts is becoming more and more widespread in the fields of construction, ship manufacturing, bridges, machinery, pressure vessels, tracks, piping and so on. The application of thick plates occupies a large proportion in the manufacture of these large members (Non-Patent Documents 1 to 3). It is very important to improve the welding efficiency of planks.

The plate narrow gap welding technique can reduce the welding area by 30% or more, significantly reduce the filling material, and significantly improve the welding efficiency. However, in traditional gas metal arc welding, the welding gun is connected to one pole of the power supply, the workpiece is connected to the other pole of the power supply, and a conductive path is provided between the plate and the workpiece. In narrow gap welding, the welding wire of gas metal arc welding tends to cause an arc strike with the side wall of the plate material, which causes a defect that the root of the weld seam does not fuse, which limits the reduction of the butt seam gap of the plate material.

Unlike traditional welding methods, indirect arc welding workpieces are not connected to the power supply and arcs occur only between the electrodes. Therefore, it is possible to effectively avoid the occurrence of arc strikes on the side wall in narrow gap welding. Currently, research on indirect arcs is mainly concentrated on two-wire indirect arc welding (Non-Patent Documents 4 to 5), and two-wire indirect arcs have a clear drawback of insufficient heat input.

Patent Document 1 (Application No .: 201510145041.4) discloses a three-wire gas-protected indirect arc welding method for the problem of insufficient heat input of the two-wire indirect arc. FIG. 1 is a diagram illustrating the principle of three-wire indirect arc welding. As shown in FIG. 1, the main wire is connected to the cathodes of two DC power supplies, and the two side wires are connected to the anodes of two DC power supplies, respectively. With the introduction of the third welding wire, the distribution of the magnetic field around the indirect arc was improved, the variable range of the indirect arc welding parameters was expanded, and the defect of insufficient heat input of the indirect arc was improved. However, the method is still flawed, that is, in the structure, the two side wires are centrally symmetric with respect to the main wire, so that the magnetic field between the main wire and the side wires is relative to the main wire. It becomes centrally symmetric, and the two indirect arcs are independent of each other and the deflection at the tail occurs, which weakens the heating action of the arc on the center position of the weld seam, and the protrusion of the center of the weld seam is likely to occur between the layers. Welding defects are likely to occur.

For the problem of morphological divergence of the three-wire indirect arc, Patent Document 2 (Application No .: 201811075326.5) discloses a new type three-wire gas protection indirect arc welding method, apparatus and use thereof. FIG. 2 is a diagram illustrating the principle of the new three-wire indirect arc welding. As shown in FIG. 2, the main wire is connected to the anodes of two DC power supplies, and the side wires are connected to the cathodes of the two DC power supplies. By adjusting the distribution of the magnetic field and electric field around the welding wire with such a power supply connection method and combining the two indirect arcs, the arc form is concentrated and the melting depth of the three-wire indirect arc welding is further improved. Let me. However, although the method is also deficient, since the arc morphology is concentrated, the indirect arc does not heat the weld seam side wall, and a fusion defect of the weld seam side wall is likely to occur.

It is necessary to provide a new type of three-wire gas protection indirect arc welding method for solving the above-mentioned problems based on the above-mentioned defects in the three-wire indirect arc welding and the causes thereof.

Chinese Patent Application Publication No. 104772552 Chinese Patent Application Publication No. 109079287

Ohata M. , Toyoda M. et al. .. Damage concept for evaluating ductile clucking of steel structure structured to load-scale cyclic tracing [J]. Science & Technology of Advanced Materials, 2016, 5 (5): 241-249. Fan Z, Wang Z, Tang J. et al. Analysis on temperature field and temperature of temperature up on healing of range-span steel structure of the National Stadium [J]. Journal of Building Structure, 2007, 28 (2): 32-40. Jia GE, Wang S, Liang H, et al. Design and research of the luggage-span steel structure of thebadminton gymnasium for 2008 Olympic Games [J]. Journal of Building Structures, 2007, 28 (6): 10-17. Cao Mei Qing, Zou Zou, Wang Chun Shigeru, etc. Effect of welding current on arc characteristics of two-wire indirect arc welding [J]. Journal of Welding, 2005, 26 (12): 47-50. Effect of Zou Junzen, Zou Yong, Zou Increasing Magnetic Field on Two-Line Indirect Arc Welding Drop Transfer [J]. Journal of Welding, 2011, 32 (6): 69-72.

The present invention has been made in view of the problems of the three-wire indirect arc welding method described in the prior art, and provides a variable polarity three-wire gas-protected indirect arc welding method, an apparatus, and its use. The present invention mainly realizes periodic control of the magnetic field distribution around the welding wire by using two variable polarity welding power supplies, and further realizes control of the heating position of the indirect arc. When the main wire is an anode, the arc morphology is concentrated and good welding between the weld seam layers can be guaranteed, and when the main wire is a cathode, the arc is deflected to both sides and good welding of the weld seam sidewall can be guaranteed. .. The variable-polarity three-wire gas-protected indirect arc welding of the present invention solves the problems of side wall inwelding and weld seam indirect welding in narrow gap welding.

The technical means of the present invention are as follows.

One aspect of the present invention is a variable polarity three-wire gas protection indirect arc welding method in which a welding process is carried out using three welding wires and two variable polarity welding power sources.
Prior to welding, the main wire is connected to one pole of the two variable polarity welding power supplies, the other two side wires are connected to the other poles of the two variable polarity welding power supplies, respectively, and the welding workpiece is the two above. Variable polarity welding Steps to configure so that they are not connected to the power supply,
At the time of welding, the two variable polarity welding power supplies are turned on at the same time, the two variable polarity welding power supplies operate synchronously and are always the same as the polarity to which the main wire is connected, and the period of the variable polarity welding power supply polarity. It includes a welding step in which the magnetic field distribution around the welding wire is periodically controlled by the conversion of the positive and cathode, and the periodic runout of the coupled indirect arc is realized.

Further, the two side wires are arranged on both sides of the main wire so as to be symmetrically distributed with respect to the main wire, so that the two side wires form an angle of 20 ° to 120 ° with the main wire, respectively. The two side wires each intersect the extension of the main wire and the two intersections are located on the same horizontal line, and the two side wires are mirror-symmetrical with respect to the main wire.

Further, when the main wire is connected to the cathodes of the two variable polarity welding power supplies, the two indirect arcs are deflected to the two side wires, the coupled arcs are dispersed and the energy density of the arcs is reduced. When the main wire is connected to the anodes of the two variable polarity welding power supplies, the two indirect arcs are deflected to the main wire, the arcs are concentrated, the energy density of the coupled arc is increased, and the energy density is increased. By processing the base metal using the flexiblely adjustable coupling indirect arc and changing the control parameters of the two variable polarity welding power supplies, the heat input to the weld wire and the base metal is accurate. Achieve a flexible control process. The control parameters include, but are not limited to, parameters such as power frequency, duty cycle, current and voltage.

Further, the frequency of the two variable polarity welding power supply polarities is 10 Hz to 500 Hz, the output current direction is the same, the phase is the same, and the current of the main wire is always the current of the two side wires. It is a sum.

Further, the total welding current is maintained in the range of 240 A to 600 A, the wire feeding speed of the main wire is 3.5 m / min to 15 m / min, and the welding speed is 0.1 m / min to 4.0 m / min. Is controlled by.

Further, the protective gas used in the welding process by the welding method may be any one of CO ₂ and Ar or a mixed gas of CO ₂ and Ar, and the protective airflow is 0.1 to 50 L / min in each case. Is.

The present invention further provides an apparatus for carrying out the variable polarity three-wire gas protection indirect arc welding method. The device consists of three welding wires and two variable polarity welding power supplies.
Among them, the main wire is connected to one pole of the two variable polarity welding power supplies, while the two side wires are connected to the other poles of the two variable polarity welding power supplies, respectively, and the two side wires are connected to each other. The two side wires are arranged on both sides of the main wire and have a symmetrical distribution with respect to the main wire, and the angle between the two side wires and the main wire is maintained at 20 ° to 120 °. It intersects with the extension of the main wire, and the two intersections are located on the same horizontal line.
At the time of welding, the two variable polarity welding power supplies operate synchronously and the polarities connected to the main wire are always the same, the variable polarity frequency is 10 Hz to 500 Hz, and the output current direction is the same. The phases are the same and the current of the main wire is always the sum of the currents of the two side wires.

The present invention further provides a thin plate high speed welding method using a variable polarity three-wire gas protection indirect arc. By this method and in the process of high-speed welding, the direction parallel to the vertical surface of the welding wire is the welding direction, and the three welding wires are used as the filling metal, and the heat quantity and droplet transfer of the arc column of the indirect arc are used. Welding of filled metal and welding workpiece is realized by the amount of heat.

The present invention further provides a thick plate narrow gap welding method using a variable polarity three-wire gas protection indirect arc. By this method and in the process of welding, narrow gap multilayer multi-pass welding is realized under the condition that the welding wire is parallel to the vertical plane and the welding direction is no groove and the butt seam gap is less than 10 mm.

The present invention has the following advantages over the prior art.
1) The workpiece of the three-wire gas protection indirect arc provided by the present invention is not connected to the power supply, the arc forms an indirect arc only at the end of the weld wire, which causes the side wall arc strike phenomenon in narrow gap welding. Does not occur.
2) The present invention realizes periodic control of the magnetic field distribution between indirect arcs by using two variable polarity welding power supplies, and due to the characteristics of arc runout and welding wire arrangement, the arc is formed in the process of converting the power supply polarity. Periodic conversion between morphological concentration and arc morphological dispersion is realized, which enables accurate control of the arc heating position and the heat input to the base metal.

Therefore, according to the technical means of the present invention, controllable adjustment of the arc morphology can be realized. When the main wire is a cathode, the arc is deflected to both sides to sufficiently heat the side wall of the plate, which can improve the problem of side wall inwelding, while when the main wire is an anode, the arc is concentrated and welded. It is possible to suppress the unevenness between the seam layers and the non-welding between the layers. In the present invention, by controlling the deflection of the arc, accurate distribution of the heat source energy of the welding arc can be realized, the occurrence of melt-off defects in thin plate high-speed welding, side wall non-welding in thick plate narrow gap welding, and side wall arc strike. You can solve the problem effectively.

For the reasons described above, the present invention can be widely used in the fields of narrow gap welding and thin plate high speed welding.

In order to more clearly explain the technical means in the embodiment or the prior art of the present invention, the drawings for explaining the embodiment or the prior art will be briefly described below. The drawings in the following description are examples of a part of the present invention, and it is clear to those skilled in the art that other drawings can be obtained based on these drawings without performing creative labor.

It is a schematic diagram which shows the principle of three-wire indirect arc welding when a main wire is connected to a cathode in the prior art. It is a schematic diagram which shows the principle of three-wire indirect arc welding when a main wire is connected to an anode in the prior art. It is a schematic diagram which shows the principle of variable polarity three-wire indirect arc welding which concerns on this invention. It is a schematic diagram which shows the distribution system of the welding wire of three-wire indirect arc welding which concerns on this invention, in which (I) is a schematic diagram seen from the direction perpendicular to a welding direction, (II) is a schematic diagram which is seen in the welding direction. It is a schematic diagram seen from a parallel direction. It is a figure which shows the waveform of the current output of two variable polarity welding power sources, in which (a) is the waveform of the current of variable polarity welding power source 1, and (b) is the waveform of the current of variable polarity welding power source 2. Is. It is a figure which shows the arc form of the variable polarity three-wire indirect arc welding which concerns on this invention, in which (a) is the arc form when the main wire is an anode, (b) is the case where the main wire is a cathode. It is in the form of an arc. It is a schematic diagram of the Example which concerns on the thin plate high-speed welding by the variable polarity three-wire indirect arc welding in this invention. It is a schematic diagram of the example of the thick plate narrow gap welding based on the variable polarity three-wire gas protection indirect arc welding in this invention.

In the absence of conflicts, the embodiments of the present invention and the features of the embodiments can be combined with each other. Hereinafter, the present invention will be described in detail in relation to Examples with reference to the drawings.

In order to further clarify the purpose, technical means and advantages of the examples according to the present invention, the technical means in the examples of the present invention are clearly and completely described below in connection with the drawings in the examples of the present invention. To explain to. It is clear that the examples described are not all the examples, but only some of the examples according to the present invention. Hereinafter, the description for at least one exemplary embodiment is practically descriptive and does not imply any limitation on the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained without performing creative labor by those skilled in the art should fall within the claims of the present invention.

The terminology used herein is solely for the purpose of describing specific embodiments and is not intended to be a limitation of exemplary embodiments according to the present invention. It should be understood that the singular form used here also includes the plural, unless explicitly pointed out by the context. It should be noted that the use of the terms "connotation" and / and "preparation" herein means that there are features, steps, operations, parts, components and / or combinations thereof. Should be.

Unless specifically described separately, the scope of the present invention is not limited by the relative arrangement of the parts and the steps described in these examples, the expression formulas of numbers, and the numerical values. At the same time, for convenience of explanation, it is clear that the dimensions of each part shown in the drawings were not drawn in actual proportions. For those skilled in the art, known techniques, methods and equipment may not be described in detail, but in appropriate circumstances the techniques, methods and equipment should be considered as part of the permitted specification. Any specific values in the examples shown and described here should be construed as exemplary only and are not limiting. Therefore, different values may be used in other examples of the exemplary embodiment. Since similar codes and alphabets indicate similar ones in the drawings described below, once one is defined in one drawing, it does not need to be further described in the other drawings.

In the description of the present invention, the orientation or positional relationship indicated by "front, rear, top, bottom, left, right", "horizontal, vertical, vertical, horizontal", "top, bottom", etc. is usually shown in the drawings. It is based on orientation or positional relationship, for convenience and brief explanation of the present invention, and in the absence of conflicting explanations, those orientation terms always refer to the orientation of the device or element. Or, it does not imply or imply that it has a structure and operation in a defined orientation and should therefore not be understood to limit the scope of the claims of the invention. The directional terms "inside" and "outside" refer to the inside and outside of the outline of each part.

For convenience of explanation, one as shown in the drawing, using relative spatial terms such as "... above", "... above", "... above", "above ...", etc. One part or feature may explain the spatial relationship with another part or feature. It should be understood that the relative spatial term includes different orientations during use or operation other than the orientations in the drawing of the part. For example, when a part shown in a drawing is inverted, it is described as a part "above another part or structure" or "on top of another part or structure" and then "on another part or structure". Localized "down" or "under other parts or structures". Therefore, the exemplary term "... upward" includes two directions, "... upward" and "... downward". The component may be localized by another method (rotation 90 degrees or position in another orientation), with appropriate interpretation of the relative spatial description used herein.

In addition, the reason why the parts are limited by using the terms such as "first" and "second" is only for the convenience of distinguishing the corresponding parts, and unless otherwise explained, the above terms are used. It has no particular meaning and should therefore not be understood as limiting the claims of the invention.

As shown in FIG. 3, the present invention provides a method of variable polarity three-wire gas protection indirect arc welding, wherein the welding process is carried out using three welding wires and two variable polarity welding power sources. Specifically, it includes the following steps.

Before welding: First, one of the three welding wires is connected to the two variable-polarity welding power supplies (that is, one pole of the variable-polarity welding power supply 1 and the variable-polarity welding power supply 2), and the other two are connected. Welding wires are connected to the other poles of the variable polarity welding power supply 1 and the variable polarity welding power supply 2, respectively, and the welding workpiece is not connected to the two variable polarity welding power supplies.

Next, a welding wire connected to the anodes of the two variable polarity welding power supplies described above is arranged in the middle, and the welding wire is referred to as a main wire 3. On the other hand, the other two welding wires are arranged on both sides of the main wire 3, and the two welding wires are called side wires, that is, the first side wire 4 and the second side wire 5.

Within the spatial range, the space between the first side wire 4 and the main wire 3 and the space between the second side wire 5 and the main wire 3 are configured to form an angle of 20 ° to 120 °, and the two said sides. The wire intersects the extension line of the main wire 3, and the two intersections are located on the same horizontal line. As shown in FIG. 4, the orthogonal projection of the side wire and the main wire 3 in a plane perpendicular to the welding direction satisfies the following conditions. That is, the angle between the first side wire 4 and the main wire 3 and between the second side wire 5 and the main wire 3 is 20 ° to 120 °, and the two side wires are in the welding direction. It is mirror-symmetrical with respect to the main wire 3 along a direction parallel to.

During welding: The two variable polarity welding power supplies 1 and 2 are turned on at the same time. As shown in FIG. 5, the waveforms of the currents output from the two variable polarity welding power supplies are the same in the current direction of the outputs from the two variable polarity welding power supplies, the same amount of current, and the same variable polarity frequency. be. As shown in FIG. 6A, when the main wire 3 is an anode, the arc morphology is concentrated and the center of the weld seam can be sufficiently heated. As shown in FIG. 6B, when the main wire 3 is a cathode, the arc is deflected to both sides and the side wall of the weld seam can be sufficiently heated. By adjusting the variable polarity frequency, duty cycle, welding current, welding voltage, etc. of the two variable polarity welding power supplies according to the welding process provided in advance, the arc energy can be controlled and the base metal 6 can be welded. Realize.

The total welding current is maintained in the range of 240A to 600A, the variable polarity frequency is 50Hz to 500Hz, the wire feeding speed of the main wire 3 is 3.5m / min to 15m / min, and the welding speed is 0. It is controlled to .1 m / min to 4.0 m / min. The main wire has an angle range of 20 ° to 120 ° with the side wire. In the process of welding by the welding method, the protective gas used is any one of CO ₂ and Ar, or a mixed gas of CO ₂ and Ar, and the protective airflow is 0.1 to 50 L / min. be.

As shown in FIG. 7, the present invention further provides a thin plate high speed welding method based on a variable polarity three-wire gas protection indirect arc. In the process of adopting the method and performing high-speed welding by the method, the direction parallel to the vertical surface of the welding wire is set as the welding direction, and the three welding wires are used as the filling metal to form the arc column of the indirect arc. Welding between the filled metal and the welding workpiece is realized by the amount of heat and the amount of heat due to droplet transfer.

As shown in FIG. 8, the present invention further provides a thick plate narrow gap welding method based on a variable polarity three-wire gas protection indirect arc. In the process of adopting the method and performing welding by the method, the welding direction is parallel to the vertical surface of the welding wire, and there are many layers of 20 mm or more under the condition that there is no groove and the butt seam gap is less than 10 mm. Achieve path welding.

The specific operating principle of the present invention is as follows.

The present invention realizes control of arc form concentration and arc form divergence in indirect arc welding by using two variable polarity welding power supplies and adjusting the variable polarity frequency, duty cycle, welding current and welding voltage. This made it possible to accurately control the heating position and heat input of the three-wire indirect arc. When the main wire is an anode, the indirect arcs formed between the main wire 3 and the two side wires are simultaneously deflected to the main wire, and the two indirect arcs are directly coupled to one current density. It becomes a single arc with a large current, which concentrates the arc morphology and guarantees the fusion between the layers of the weld seam. When the main wire is a cathode, the indirect arcs formed between the main wire 3 and the two side wires are simultaneously deflected to the two side wires, which diverges the arc morphology and melts the side walls of the weld seam. We can guarantee the match. In addition, by adjusting the frequency of variable polarity under the condition that the welding current is kept constant, it is possible to control the concentration and divergence of the arc form, and the proper distribution of energy between the side wall of the weld seam and the layers. Achieve. The present invention can meet the demands of efficient welding such as thin plate high speed welding and thick plate narrow gap welding by utilizing the controllability of the variable polarity three-wire indirect arc form.

(Example 1)
Variable polarity three-wire gas protection indirect arc thin plate high-speed welding As shown in FIG. 7, the welding wire distribution method shown in FIG. 4 is used, in which the angle between the main wire 3 and the horizontal direction is 50 ° and the first side. The angle between the wire 4 and the second side wire 5 formed between the wire 4 and the main wire 3 is 30 °, respectively, and the two side wires are mirror-symmetrical to the main wire on both sides of the main wire 3, respectively. Arranged, the two side wires each contact the main wire 3 and both contacts are located on the same horizon. Among them, the model number of the three steel welded wires is ER50-6, the diameter of the main wire 3 is 1.6 mm, the diameters of the two side wires are both 1.2 mm, and the power supply is two ACs. Using a power source, the corresponding protective gas is a mixed gas of CO ₂ and Ar in a ratio of 80%: 20%. The model number of the plate is Q235, the dimensions of the plate are 300 mm x 150 mm x 2 mm, the butt seam gap of the plate is 1 mm, the height of the welding gun is 6 mm, the total welding current is 320 A, and the variable polarity. The frequency is 200 Hz and the welding speed is 2800 mm / min. As described above, a weld seam having a smooth and uniform surface, good fusion of the back surface of the weld seam, and no defects was obtained.

(Example 2)
Variable polarity gas protection 3-wire indirect arc thick plate narrow gap welding As shown in FIG. 8, the welding wire distribution method shown in FIG. 4 is used, in which the angle between the main wire 3 and the horizontal direction is 50 °. The angle between the main wire 3 and the side wire is 30 °, the diameter of the main wire is 1.6 mm, the two side wires are welded wires with a diameter of 1.2 mm, and the power supply is two AC power supplies. The corresponding protective gas is a mixed gas of CO ₂ and Ar in a ratio of 80%: 20%. The model number of the welding wire is ER50-6, the welding base material is Q235 low carbon steel, the dimensions of the plate material are 300 mm × 150 mm × 20 mm, the groove is not opened, and the base material bat seam gap is 8 mm. A ceramic spacer 7 is used on the back surface, the total welding current is 320 A, the variable polarity frequency is 150 Hz, and the welding speed is 550 mm / min. In this way, a welded seam with good multi-layered multi-pass molding was obtained.

Each of the above examples is merely for explaining the technical means of the present invention, and does not limit the scope of the present invention. Although the present invention has been described in detail with reference to each of the above-described examples, modifications to the technical means described in each of the above-mentioned examples and equivalent substitution for some or all of the technical features. It will be appreciated by those skilled in the art that these modifications and substitutions do not deviate from the scope of the technical means in the embodiments of the present invention in the nature of the corresponding technical means.

(Additional note)
(Appendix 1)
It is a variable polarity three-wire gas protection indirect arc welding method that carries out the welding process using three welding wires and two variable polarity welding power supplies.
Prior to welding, the main wire is connected to one pole of the two variable polarity welding power supplies, the other two side wires are connected to the other poles of the two variable polarity welding power supplies, respectively, and the welding workpiece is the two above. Variable polarity welding Steps to configure so that they are not connected to the power supply,
At the time of welding, the two variable polarity welding power supplies are turned on at the same time, the two variable polarity welding power supplies operate synchronously and are always the same as the polarity connected to the main wire, and the period of the variable polarity welding power supply polarity. Includes a welding step that periodically controls the magnetic field distribution around the weld wire by transforming the positive and cathode to achieve the periodic runout of the coupled indirect arc.
A variable polarity three-wire gas protection indirect arc welding method.

(Appendix 2)
The two side wires are arranged on both sides of the main wire so as to be symmetrically distributed with respect to the main wire, and the two side wires are configured to form an angle of 20 ° to 120 ° with the main wire, respectively. The two side wires intersect the extension of the main wire, respectively, and the two intersections are located on the same horizontal line.
The variable polarity three-wire gas protection indirect arc welding method according to Appendix 1, wherein the method is characterized by the above.

(Appendix 3)
When the main wire is connected to the cathodes of the two variable polarity welding power supplies, the two indirect arcs are deflected to the two side wires, the coupled arcs are dispersed, the energy density of the arcs is reduced, and the main wires When connected to the anodes of the two variable polarity welding power supplies, the two indirect arcs are deflected to the main wire, the arcs are concentrated, the energy density of the coupled arc is increased, and the energy density can be flexibly adjusted. A process of accurately and flexibly adjusting the heat input to the welding wire and the base metal by processing the base metal using the coupling indirect arc and changing the control parameters of the two variable polarity welding power supplies. To realize,
The variable polarity three-wire gas protection indirect arc welding method according to Appendix 1, wherein the method is characterized by the above.

(Appendix 4)
The variable polarity frequencies of the two variable polarity welding power supplies are 10 Hz to 500 Hz, the output current directions are the same, the phases are the same, and the current of the main wire is always the sum of the currents of the two side wires. Is,
The variable polarity three-wire gas protection indirect arc welding method according to Appendix 1, wherein the method is characterized by the above.

(Appendix 5)
The total welding current is maintained in the range of 240A to 600A, the wire feeding speed of the main wire is controlled to 3.5m / min to 15m / min, and the welding speed is controlled to 0.1m / min to 4.0m / min. Will be
The variable polarity three-wire gas protection indirect arc welding method according to Appendix 4, wherein the method is characterized by the above.

(Appendix 6)
The protective gas used in the welding process by the welding method is any one of CO ₂ and Ar or a mixed gas of CO ₂ and Ar, and the protective airflow is 0.1 to 50 L / min.
The variable polarity three-wire gas protection indirect arc welding method according to Appendix 4, wherein the method is characterized by the above.

(Appendix 7)
An apparatus for carrying out the variable polarity three-wire gas protection indirect arc welding method according to any one of Supplementary note 1 to 6.
The device consists of three welding wires and two variable polarity welding power supplies.
Among them, the main wire is connected to one pole of the two variable polarity welding power supplies, while the two side wires are connected to the other poles of the two variable polarity welding power supplies, respectively, and the two side wires are connected to each other. The two side wires are arranged on both sides of the main wire so as to be symmetrically distributed with respect to the main wire, the angle between the two side wires and the main wire is maintained at 20 ° to 120 °, and the two side wires are provided with each other. It intersects with the extension of the main wire and the two intersections are located on the same horizontal line.
At the time of welding, the two variable polarity welding power supplies operate synchronously and are always the same as the polarity connected to the main wire, the variable polarity frequency is 10 Hz to 500 Hz, the output current direction is the same, and the phase is A device for carrying out a variable polarity three-wire gas protection indirect arc welding method characterized by being the same.

(Appendix 8)
A thin plate high-speed welding method using a variable-polarity three-wire gas-protected indirect arc, which includes the method described in any one of Supplementary Notes 1 to 6, and in the process of performing high-speed welding, the direction in which the welding wire is parallel to the vertical surface. Welding of the filled metal and the welding workpiece is realized by utilizing the heat quantity of the arc column of the indirect arc and the heat quantity due to droplet transfer, with the three welding wires as the filling metal in the welding direction.
A thin plate high-speed welding method using a variable polarity three-wire gas protection indirect arc.

(Appendix 9)
A thick plate narrow gap welding method using a variable polarity three-wire gas protection indirect arc, which includes the method according to any one of Appendix 1 to 6, in which the welding wire is parallel to the vertical surface in the welding process. Is the welding direction, and narrow gap multi-layer multi-pass welding is realized under the condition that there is no groove and the butt seam gap is less than 10 mm.
A thick plate narrow gap welding method using a variable polarity three-wire gas protection indirect arc.

1 1st variable polarity welding power supply 2 2nd variable polarity welding power supply 3 Main wire 4 1st side wire 5 2nd side wire 6 Welding spare base material 7 Ceramic spacer

Claims (9)

It is a variable polarity three-wire gas protection indirect arc welding method that carries out the welding process using three welding wires and two variable polarity welding power supplies.
Prior to welding, the main wire is connected to one pole of the two variable polarity welding power supplies, the other two side wires are connected to the other poles of the two variable polarity welding power supplies, respectively, and the welding workpiece is the two above. Variable polarity welding Steps to configure so that they are not connected to the power supply,
At the time of welding, the two variable polarity welding power supplies are turned on at the same time, the two variable polarity welding power supplies operate synchronously and are always the same as the polarity connected to the main wire, and the period of the variable polarity welding power supply polarity. Includes a welding step that periodically controls the magnetic field distribution around the weld wire by transforming the positive and cathode to achieve the periodic runout of the coupled indirect arc.
A variable polarity three-wire gas protection indirect arc welding method. The two side wires are arranged on both sides of the main wire so as to be symmetrically distributed with respect to the main wire, and the two side wires are configured to form an angle of 20 ° to 120 ° with the main wire, respectively. The two side wires intersect the extension of the main wire, respectively, and the two intersections are located on the same horizontal line.
The variable polarity three-wire gas protection indirect arc welding method according to claim 1. When the main wire is connected to the cathodes of the two variable polarity welding power supplies, the two indirect arcs are deflected to the two side wires, the coupled arcs are dispersed, the energy density of the arcs is reduced, and the main wires When connected to the anodes of the two variable polarity welding power supplies, the two indirect arcs are deflected to the main wire, the arcs are concentrated, the energy density of the coupled arc is increased, and the energy density can be flexibly adjusted. A process of accurately and flexibly adjusting the heat input to the welding wire and the base metal by processing the base metal using the coupling indirect arc and changing the control parameters of the two variable polarity welding power supplies. To realize,
The variable polarity three-wire gas protection indirect arc welding method according to claim 1. The variable polarity frequencies of the two variable polarity welding power supplies are 10 Hz to 500 Hz, the output current directions are the same, the phases are the same, and the current of the main wire is always the sum of the currents of the two side wires. Is,
The variable polarity three-wire gas protection indirect arc welding method according to claim 1. The total welding current is maintained in the range of 240A to 600A, the wire feeding speed of the main wire is controlled to 3.5m / min to 15m / min, and the welding speed is controlled to 0.1m / min to 4.0m / min. Will be
The variable polarity three-wire gas protection indirect arc welding method according to claim 4. The protective gas used in the welding process by the welding method is any one of CO ₂ and Ar or a mixed gas of CO ₂ and Ar, and the protective airflow is 0.1 to 50 L / min.
The variable polarity three-wire gas protection indirect arc welding method according to claim 4. An apparatus for carrying out the variable polarity three-wire gas protection indirect arc welding method according to any one of claims 1 to 6.
The device consists of three welding wires and two variable polarity welding power supplies.
Among them, the main wire is connected to one pole of the two variable polarity welding power supplies, while the two side wires are connected to the other poles of the two variable polarity welding power supplies, respectively, and the two side wires are connected to each other. The two side wires are arranged on both sides of the main wire so as to be symmetrically distributed with respect to the main wire, the angle between the two side wires and the main wire is maintained at 20 ° to 120 °, and the two side wires are provided with each other. It intersects with the extension of the main wire and the two intersections are located on the same horizontal line.
At the time of welding, the two variable polarity welding power supplies operate synchronously and are always the same as the polarity connected to the main wire, the variable polarity frequency is 10 Hz to 500 Hz, the output current direction is the same, and the phase is A device for carrying out a variable polarity three-wire gas protection indirect arc welding method characterized by being the same. A thin plate high-speed welding method using a variable-polarity three-wire gas-protected indirect arc, including the method according to any one of claims 1 to 6, in which the welding wire is in a direction parallel to a vertical surface in the process of performing high-speed welding. Is the welding direction, and the three welding wires are used as the filling metal, and the filling metal and the welding workpiece are welded by utilizing the heat quantity of the arc column of the indirect arc and the heat quantity due to the droplet transfer.
A thin plate high-speed welding method using a variable polarity three-wire gas protection indirect arc. A thick plate narrow gap welding method using a variable polarity three-wire gas protection indirect arc, comprising the method according to any one of claims 1 to 6, in which the weld wire is parallel to a vertical surface in the welding process. The direction is the welding direction, and narrow gap multi-layer multi-pass welding is realized under the condition that there is no groove and the butt seam gap is less than 10 mm.
A thick plate narrow gap welding method using a variable polarity three-wire gas protection indirect arc.

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