CN113399853A

CN113399853A - Welding method and welding gun

Info

Publication number: CN113399853A
Application number: CN202110702544.2A
Authority: CN
Inventors: 单际华; 杨政; 徐兵; 裴晓俊; 张海舰; 邝安飞
Original assignee: Hangxiao Steel Structure Co Ltd
Current assignee: Hangxiao Steel Structure Co Ltd
Priority date: 2021-06-24
Filing date: 2021-06-24
Publication date: 2021-09-17
Anticipated expiration: 2041-06-24
Also published as: CN113399853B

Abstract

The invention relates to the technical field of building construction, in particular to a welding method and a welding gun for a steel structural member. The method comprises the following steps: firstly, splicing a wing plate, a lining plate, a clapboard and a web plate to form a welding bead, and carrying out gas shielded welding on the bottom position of the welding bead for preset time; then, performing mixed welding of gas shielded welding and electroslag welding on the welding bead from the bottom of the welding bead to the top until a stable slag bath is formed; and finally, carrying out electroslag welding on the welding bead only from the position where the stable slag pool is formed to the top of the welding bead. The welding process has the advantages that the overall better quality of the welding seam is ensured, the welding process is easy to carry out automatic production, the operation amount of manually installing the arc striking cap is reduced, the labor and material cost is saved, the processing flow of electroslag welding is optimized, the time consumed by the processing technology is shortened, and the equipment cost is saved; the welding seam at the starting end of electroslag welding is not required to be cut off, so that the filling amount of the welding seam is reduced. The invention also provides a welding gun, so that the welding gun for gas shielded welding and electroslag welding is combined, and the welding gun has the advantages of simple structure and low cost.

Description

Welding method and welding gun

Technical Field

The invention relates to the technical field of building construction, in particular to a welding method and a welding gun for a steel structural member.

Background

The box-shaped member is mainly applied to the field of buildings and has higher structural strength requirement. The box-type member is composed of wing plates, web plates, partition plates, lining strips and the like, and is manufactured through the working procedures of blanking, hole making, assembling, welding and the like.

In the prior art, welding beads formed by a wing plate, a lining plate, a partition plate and a web plate are usually welded by electroslag welding, and the quality of the bottom of a welding seam in the welding bead is usually poor due to the fact that the cooling speed of welding heat is high in the electroslag welding performed at the bottom of the welding bead.

In order to solve the above problems, it is desirable to provide a welding method and a welding gun, which can solve the problem that the quality of the bottom of the welding bead is not good in general.

Disclosure of Invention

One object of the present invention is to propose a welding method to improve the bottom quality of the weld.

Another object of the present invention is to provide a welding gun that combines the use of two welding methods, thereby improving the welding quality, improving the welding efficiency and reducing the welding cost.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method of welding comprising the steps of:

step 1: splicing the wing plate, the lining plate, the clapboard and the web plate to form a welding bead;

step 2: carrying out gas shielded welding on the bottom position of the welding bead for preset time;

and step 3: performing mixed welding of gas shielded welding and electroslag welding on the welding bead from the bottom of the welding bead to the top until a stable slag bath is formed;

and 4, step 4: and carrying out electroslag welding on the welding bead only from the position where the stable slag pool is formed to the top of the welding bead.

Preferably, the shielding gas of the gas shielded welding is carbon dioxide, argon or a carbon dioxide nitrogen argon mixed gas.

Preferably, the preset time is 1.5 to 3 minutes.

Preferably, the current and voltage used for the hybrid welding are gradually increased.

Preferably, the peak value of the current is 380A-400A, and the peak value of the voltage is 40V-45V.

Preferably, the electroslag welding in the step 4 adopts constant current and voltage.

Preferably, the current of the electroslag welding in the step 4 is 380 to 400A, and the voltage of the electroslag welding in the step 4 is 42 to 50V.

A welding torch for use in the welding method as described above, the welding torch comprising:

the welding gun body is provided with a first channel;

the conductive nozzle is arranged on the welding gun body, a second channel and an air outlet channel are formed in the conductive nozzle, and the first channel and the air outlet channel are respectively communicated with the second channel;

the gas supply assembly is arranged on the welding gun body and comprises a gas inlet and a gas outlet which are communicated, and the gas outlet is communicated with the first channel.

As a preferred aspect, the air supply assembly includes:

the mounting piece is sleeved on the welding gun body; and

the communicating piece is connected with the mounting piece, the communicating piece and the mounting piece are provided with through holes penetrating through the mounting piece and the communicating piece, one end of each through hole is formed with an air inlet, and the other end of each through hole is formed with an air outlet.

As a preferred aspect, the air supply assembly further includes:

and the gas protective sleeve is arranged around the periphery of the gas outlet channel.

The invention has the beneficial effects that:

the invention provides a welding method, which comprises the following steps: the method comprises the following steps of firstly splicing a wing plate, a lining plate, a partition plate and a web plate to form a weld bead, adopting gas shielded welding at the bottom end of the weld bead, adopting mixed welding of gas shielded welding and electroslag welding after preset time till a stable slag bath is formed, and then upwards moving the position where the stable slag bath is formed to the top of the weld bead to only carry out electroslag welding on the weld bead. On one hand, the method directly adopts gas shield welding to weld first to reach a certain depth and preheating quantity, and then carries out traditional electroslag welding to continue welding from bottom to top, so that the quality of a bottom welding seam is better, and the better quality of the whole welding seam is ensured. On the other hand, the welding method does not use auxiliary devices such as a jack, an arc striking cap and the like, omits the welding hole processing process of the electroslag welding starting end, is easy for automatic production, reduces the operation amount of manually installing the arc striking cap, saves the labor and material cost, optimizes the processing flow of the electroslag welding and shortens the time consumption of the processing technology; auxiliary devices such as a jack, an arc striking cap and the like are not used, so that the equipment cost is saved; the welding seam at the starting end of electroslag welding is not required to be cut off, so that the filling amount of the welding seam is reduced.

The invention also provides a welding gun which comprises a welding gun body, the conductive nozzle and the gas supply assembly, wherein the welding gun body is provided with a first channel, the conductive nozzle and the gas supply assembly are arranged on the welding gun body, the conductive nozzle is provided with a second channel, the first channel is communicated with the second channel, the gas supply assembly comprises a gas inlet and a gas outlet which are communicated, and the gas outlet is communicated with the first channel. Through setting up the subassembly of supplying gas, this welder both can be simultaneously or the electroslag welding process and the gas shielded arc welding process alone, avoids the operator to carry out welding process to the welding bead and changes welder, improves welding efficiency. Because two sets of welding guns are not required, the processing cost of the box-type component can be effectively reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a schematic diagram of a welding structure according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a wing plate, a web plate, a spacer plate and a lining strip according to an embodiment of the present invention;

FIG. 3 is a flow chart of a welding method according to an embodiment of the present invention;

FIG. 4 is a first schematic view of step 2 welding according to a first embodiment of the present invention;

FIG. 5 is a second schematic view of step 2 welding according to the first embodiment of the present invention;

FIG. 6 is a third schematic view of the welding process of step 2 according to the first embodiment of the present invention;

FIG. 7 is a schematic diagram of the welding process of step 3 according to one embodiment of the present invention;

FIG. 8 is a first schematic view of step 4 welding according to a first embodiment of the present invention;

FIG. 9 is a second schematic view of step 4 welding according to the first embodiment of the present invention;

fig. 10 is a schematic structural diagram of a welding gun according to a second embodiment of the present invention.

The figures are labeled as follows:

1-a wing plate; 2-a web; 31-a separator; 32-a liner; 4-welding a welding bead; 5-a welding gun; 51-a wire feed assembly; 52-torch body; 521-a first channel; 522-a communication port; 53-a contact tip; 531-second channel; 532-air outlet channel; 54-a gas delivery assembly; 541-a mounting piece; 542-a communication member; 543-through holes; 5431-air intake; 5432-air outlet; 544-a gas protective sheath; 6-welding seams; 7-welding flux; 8-a molten pool; 9-protective gas; 10-a welding wire; 11-a slag bath.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for convenience of description, only the structures related to the present invention are shown in the drawings, not the full structure.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be structurally related or interoperable between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

Example one

Compared with the traditional concrete building, the box-type member building has the advantages that steel plates or section steel replaces reinforced concrete, the strength is higher, and the shock resistance is better. The box-type member can be manufactured in a factory and installed on site, and the construction period of the industrial and architectural engineering can be greatly reduced. Meanwhile, the box-type member has the advantage of being capable of being repeatedly used, so that the construction waste can be greatly reduced, and the environment is protected. Accordingly, box-type members are widely used in industrial and civil buildings. At present, the application of box type member buildings in industrial buildings, high-rise buildings (houses) and space structures (stadiums and museums) is mature and gradually becomes the mainstream building technology, and the box type member buildings are the development direction of buildings in the future.

As the application of box-type members becomes wider, the process flow and quality requirements of builders and manufacturers for the production of box-type members are gradually increased. As shown in fig. 1 and 2, the box-shaped member is composed of a wing plate 1, a web 2, a partition plate 31, a lining strip 32 and the like, and is manufactured through blanking, hole making, assembling and welding processes, wherein a welding method of electroslag welding is generally used for a welding bead 4 formed among the partition plate 31, the wing plate 1, the web 2 and the lining strip 32, and the quality of a bottom portion of a welding bead 4 is generally poor because of a problem of a high cooling rate of welding heat in the electroslag welding performed at the bottom portion of the welding bead 4.

In order to solve the above problems, another welding process is available: firstly, processing a bottom hole on a web 2, wherein the hole diameter of the bottom hole is determined according to the thickness of a partition plate 31 and a slotted hole of a lining strip 32; then, hoisting the box-type component to an electroslag welder rack, and adjusting the position of the box-type component to ensure that the box-type component is horizontally arranged, so that the subsequent welding operation of the box-type component is facilitated; secondly, in order to ensure the quality of a bottom welding seam, adding a proper amount of arc striking agent into a copper arc striking cap, installing the arc striking cap at the lower end of a bottom hole, fixing the arc striking cap by using a jack and the like, adjusting the position and welding parameters of a welding gun and carrying out electroslag welding; and finally, cutting off the arc striking cap after welding.

However, in the method, a bottom hole needs to be formed in the web 2, auxiliary devices such as copper arc striking caps and jacks need to be used, the welding process is complicated, the welding speed is reduced, the material cost, the labor cost and the equipment cost are increased, and the automatic production is not easy to realize. In addition, the welding seam at the starting end of electroslag welding needs to be cut, and the cost of welding seam filling amount is increased.

In order to solve the above problem, as shown in fig. 2, the present embodiment provides a welding method including:

step 1: splicing the wing plate 1, the lining plate 31, the clapboard 32 and the web plate 2 to form a welding bead 4;

step 2: performing gas shielded welding on the bottom position of the welding bead 4 for a preset time;

and step 3: performing mixed welding of gas shielded welding and electroslag welding on the welding bead 4 from the bottom of the welding bead 4 to the top until a stable slag bath 11 is formed;

and 4, step 4: from the position where the stable slag bath is formed up to the top of the weld bead 4, only the electroslag welding is performed on the weld bead 4.

On one hand, the method adopts gas shield welding to weld the welding bead 4 at a certain depth to ensure that the welding bead 4 reaches preheating quantity, and then utilizes the traditional electroslag welding to weld the welding bead 4 from bottom to top, so that the quality of a bottom welding seam is better, and the integral better quality of the welding seam is ensured. On the other hand, the welding method does not use auxiliary devices such as a jack, an arc striking cap and the like, omits the welding hole processing process of the electroslag welding starting end, is easy for automatic production, reduces the operation amount of manually installing the arc striking cap, saves the labor and material cost, optimizes the processing flow of the electroslag welding and shortens the time consumption of the processing technology; auxiliary devices such as a jack, an arc striking cap and the like are not used, so that the equipment cost is saved; the welding seam at the starting end of electroslag welding is not required to be cut off, so that the filling amount of the welding seam is reduced.

To explain step 1 in detail, as shown in fig. 1, the spacers 31 are provided with linings 32 on both left and right sides, the linings 32 extend forward from the spacers 31 in the front-rear direction, the wing plates 1 are provided on the front end surfaces of the linings 32, the webs 2 are provided on the lower end surfaces of the linings 32 and the spacers 31, and the welding beads 4 are formed by the wing plates 1, the lining plates 31, the spacers 32, and the webs 2.

In order to realize the primary pre-fixing between the lining strip 32 and the separator 31, between the lining strip 32 and the web 2, between the separator 31 and the web 2, between the lining strip 32 and the wing plate 1 and between the web 2 and the wing plate 1, the welding and fixing between the lining strip 32 and the separator 31, between the lining strip 32 and the web 2, between the separator 31 and the web 2, between the lining strip 32 and the wing plate 1 and between the web 2 and the wing plate 1 are realized by arc welding, the primary fixing of the shape formed by the separator 31, the lining strip 32, the web 2 and the wing plate 1 is realized, and the subsequent electroslag welding process is convenient to carry out.

To describe step 2 in detail, as shown in fig. 3, first, the structure obtained in step 1 is placed on a table, the welding torch 5 with the welding wire 10 inserted therein is fed to the bottom of the weld bead 4, and the shielding gas 9 is introduced into the bottom of the weld bead 4 to form a shielding atmosphere at the bottom of the weld bead 4. Then, the welding wire 10 is subjected to an arc striking action to ignite the welding wire 10. The welding operation is performed on the welding wire 10 at the same time as the arc striking operation, and the welding wire 10 is fed, thereby realizing the welding of the bottom of the weld bead 4. The bottom of the welding channel 4 is preheated through gas shielded welding, so that the temperature of the bottom of the welding channel 4 is gradually increased, welding conditions are provided for subsequent electroslag welding, and the better quality of the welding line 6 at the bottom is ensured. The protective gas 9 can form a protective atmosphere in the weld bead 4, and can prevent the weld 6 from reacting with air after being heated and melted, thereby preventing the weld 6 from being oxidized or generating pores.

Preferably, the arc striking action and the wire feeding action can be delayed for a certain time, the delay time of the wire feeding action after the arc striking action can be 10-40 s, the welding of the welding bead 4 can be carried out after the shielding gas 9 completely exhausts the air at the bottom of the welding bead 4, the oxidation of the welding seam 6 can be avoided to the maximum extent, the better strength and hardness of the welding seam 6 are ensured, and the stable connection of the partition plate 31, the lining strip 32, the web plate 2 and the wing plate 1 is realized.

Illustratively, the shielding gas 9 adopted in this embodiment may be carbon dioxide, argon or carbon dioxide-argon mixed gas, both of which can realize the blocking of oxygen, and the carbon dioxide, argon or carbon dioxide-argon mixed gas is low in cost.

As a preferable scheme, the preset time for performing the gas shielded welding may be 1.5 minutes to 3 minutes, so that the bottom of the weld bead 4 is preheated to make the temperature of the bottom of the weld bead 4 reach the desired temperature required for the electroslag welding. In addition, the preset time is not too long, so that the energy waste caused by the overlong preheating time can be avoided. Specifically, as shown in fig. 4 and 5, the welding torch 5 moves from bottom to top, the weld bead 6 is formed from bottom to top in the weld bead 4, the weld bead 6 is formed with the molten pool 8 on the side close to the welding torch 5, the operator can observe the condition of the wing plate 1 from the outside of the box-shaped member, and when the root of the wing plate 1 gradually turns red, the operator can judge that the preheating is almost completed, and the preset time is 1.5 to 3 minutes.

For example, the material of the welding wire of the embodiment can be selected from ER50-6 or ER55-G, and the diameter of the welding wire can be 1 mm-3 mm, preferably 1.6 mm.

As described with respect to step 3, as shown in fig. 6, the hybrid welding process is beneficial to smooth transition from gas shielded welding in step 2 to electroslag welding in step 4, so as to avoid sudden temperature rise around the weld bead 4 caused by direct conversion to electroslag welding, so that metal around the weld bead 4 is melted at high temperature, and ensure good welding quality of the weld bead 4.

In the hybrid welding process, the conversion process of gas shielded welding and electroslag welding is particularly important, and in the conversion process, an operator mainly controls the melting state of the slag bath 11 by controlling factors such as current parameters, voltage parameters, the additive amount of a welding flux and the like, so that the stable transition from the gas shielded welding in the step 2 to the electroslag welding in the step 4 is realized.

Specifically, as shown in fig. 6, the current and voltage during the hybrid welding are gradually increased, and it is possible to avoid a sudden increase in temperature in the weld bead 4 due to direct excessive adjustment of the current and voltage, and to prevent excessive melting of the metal around the weld bead 4 and obtaining a poor crystal structure. Therefore, the gradual increase of the current and the voltage is beneficial to protecting the metal quality around the welding bead 4, thereby ensuring the welding quality of the welding bead 4. Specifically, in hybrid welding, the peak value of the current is 380A to 400A, and the peak value of the voltage is 40V to 45V.

Specifically, the flux 7 may be HF600 in mist or powder form, and the mist or powder flux 7 may prevent formation of welding slag or blowholes in the weld bead 6. Further, in the step 3, 5g to 10g of the welding flux 7 is gradually added into the welding bead 4 for a plurality of times, so that the slag bath 11 is prevented from being only coated by the welding flux 7, the slag bath 11 can be subjected to a welding process under the simultaneous protection of the protective gas 9 and the welding flux 7, a welding flux slag protective film above the slag bath 11 is preliminarily formed, and defects such as welding slag inclusion, air holes and the like caused by cooling of the slag bath 11 are avoided.

As described with reference to step 4, as shown in fig. 7 and 8, the welding bead 4 is only electroslag welded from the position where the stable slag bath 11 is formed up to the top of the welding bead 4, and the welding efficiency of the box member can be improved while the quality of the weld 6 of the box member is ensured.

Furthermore, the current of electroslag welding in the step 4 is 380-400A, the voltage is 42-50V, the heat of the slag bath 11 is increased, and the welding efficiency of the step 4 is improved.

As shown in fig. 7, in step 4, an operator uniformly adds 40g of flux 7 into the weld bead 4 in multiple times, so that the slag bath 11 can be stably protected by the flux 7 for electroslag welding, the slag bath 11 is prevented from being covered by the flux 7 only, the slag bath 11 can be protected by the shielding gas 9 and the flux 7 for welding, and defects such as welding slag inclusion and pores formed by cooling the slag bath 11 are avoided.

After step 4, when the weld bead 6 is completed by more than half the length of the weld bead 4, an arc-quenching cap is attached to the top end of the weld bead 4, and the gap between the arc-quenching cap and the upper surface of the box-shaped member is adjusted. After welding, slag and splashes in a welding area of a welding bead 4 are cleaned, a welding seam 6 of the web plate 2 is polished, defects such as undercut and crater are welded and ground flat, and after the box-shaped component is cooled to room temperature and reaches the time of the inspection requirement, nondestructive inspection is carried out according to the inspection requirement.

Example two

Because the box-type component electroslag welding process is performed by two welding methods of gas shielded welding and electroslag welding in the welding bead 4, if two welding guns 5 are used, the welding cost is high, and the welding process is complicated.

In order to solve the above problem, as shown in fig. 9, the present embodiment further provides a welding torch 5, and the welding torch 5 includes a torch body 52, a contact tip 53, and a gas supply unit 54. The welding gun body 52 is provided with a first channel 521, the contact tip 53 is arranged on the welding gun body 52, the contact tip 53 is provided with a second channel 531 and an air outlet channel 532, the air outlet channel 532 and the first channel 521 are respectively communicated with the second channel 531, the air supply assembly 54 is arranged on the welding gun body 52, the air supply assembly 54 comprises an air inlet 5431 and an air outlet 5432 which are communicated, and the air outlet 5432 is communicated with the first channel 521. The protective gas 9 introduced from the gas inlet 5431 can enter the welding position of the welding gun 5 through the first channel 521, the second channel 531 and the first channel 532, the welding wire 10 sequentially passes through the first channel 521 and the second channel 531, the welding gun 5 can simultaneously perform gas shielded welding and electroslag welding, the replacement of the welding gun 5 by an operator can be avoided, the welding efficiency of the box-shaped component is effectively improved, and the processing cost of the box-shaped component is effectively reduced.

Specifically, as shown in fig. 9, the air supply unit 54 includes a mounting member 541 and a communicating member 542 connected to each other, the mounting member 541 is sleeved on the welding gun body 52, the communicating member 542 and the mounting member 541 are provided with a through hole 543 penetrating through the mounting member 541 and the communicating member 542, one end of the through hole 543 is formed with an air inlet 5431, and the other end of the through hole 543 is formed with an air outlet 5432.

As shown in fig. 9, the mounting member 541 and the communicating member 542 may be an integral structure, which is beneficial to prevent gas from overflowing from the connection between the mounting member 541 and the communicating member 542, thereby being beneficial to ensure effective utilization of the gas 9.

Preferably, as shown in fig. 9, the gas supply assembly 54 further includes a gas protection sleeve 544, and the gas protection sleeve 544 surrounds the outer periphery of the gas outlet channel 532, so as to improve the utilization rate of the protection gas 9. Specifically, the gas sheath 544 may be a high temperature resistant plastic sheath that has the advantages of high temperature resistance and low cost. In addition, the gas protection sleeve 544 is detachable from the contact tip 53, which facilitates maintenance and replacement of the contact tip 53.

It is noted that the foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the present invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined by the appended claims and their equivalents.

Claims

1. A welding method, comprising the steps of:

step 1: splicing the wing plate (1), the lining plate (31), the clapboard (32) and the web plate (2) to form a welding bead (4);

step 2: carrying out gas shielded welding on the bottom position of the welding bead (4) for preset time;

and step 3: performing mixed welding of gas shielded welding and electroslag welding on the welding bead (4) from the bottom of the welding bead (4) to the top at the same time until a stable slag bath is formed;

and 4, step 4: the welding bead (4) is only electroslag welded from the position where a stable slag bath is formed up to the top of the welding bead (4).

2. Welding method according to claim 1, characterized in that the shielding gas (9) of the gas shielded welding is carbon dioxide, argon or a carbon dioxide argon mixture.

3. The welding method according to claim 1, characterized in that said preset time is comprised between 1.5 and 3 minutes.

4. The welding method of claim 1, wherein the hybrid welding employs a gradual increase in current and voltage.

5. The welding method according to claim 4, wherein the current has a peak value of 380 to 400A and the voltage has a peak value of 40 to 45V.

6. Welding method according to claim 1, characterized in that said electroslag welding in step 4 uses a constant current and voltage.

7. The welding method according to claim 1, wherein the current of the electroslag welding in the step 4 is 380A-400A, and the voltage of the electroslag welding in the step 4 is 42V-50V.

8. A welding torch for use in the welding method according to any one of claims 1 to 7, said welding torch comprising:

the welding gun body (52) is provided with a first channel (521);

the contact tube (53) is arranged on the welding gun body (52), a second channel (531) and an air outlet channel (532) are formed in the contact tube (53), and the first channel (521) and the air outlet channel (532) are respectively communicated with the second channel (531);

the gas supply assembly (54) is arranged on the welding gun body (52), the gas supply assembly (54) comprises a gas inlet (5431) and a gas outlet (5432) which are communicated, and the gas outlet (5432) is communicated with the first channel (521).

9. The welding gun according to claim 8, wherein the gas feed assembly (54) comprises:

the mounting piece (541) is sleeved on the welding gun body (52); and

the connecting piece (542) is connected with the mounting piece (541), a through hole (543) penetrating through the mounting piece (541) and the connecting piece (542) is formed in the connecting piece (542) and the mounting piece (541), an air inlet (5431) is formed at one end of the through hole (543), and an air outlet (5432) is formed at the other end of the through hole (543).

10. The welding gun according to claim 8, wherein the gas feed assembly (54) further comprises:

and the gas protection sleeve (544) is arranged around the periphery of the gas outlet channel (532).