A welding atmosphere protection device and method of use

Abstract

The application provides a welding atmosphere protection device and a use method. The welding atmosphere protection device comprises an atmosphere protection box, an atmosphere protection cover and a trailing cover. The atmosphere protection box comprises a box body and a box cover. The box body defines a containing space for placing a to-be-welded test plate. The box cover is arranged above the box body. A through slot is arranged in the middle of the box cover and extends along the length direction of the weld of the to-be-welded test plate. The atmosphere protection cover and the trailing cover are buckled above the through slot and can move back and forth above the through slot. The atmosphere protection cover is connected with a welding gun and a gas pipe. The welding gun is arranged between the atmosphere protection cover and the trailing cover. The gas pipe is used for feeding protective gas into the atmosphere protection box. The to-be-welded test plate is arranged in the space formed by the atmosphere protection box, the atmosphere protection cover and the trailing cover, so that the to-be-welded test plate is protected in all directions, the effective protection of the to-be-welded test plate during welding is realized, the to-be-welded test plate is prevented from being oxidized, and the occurrence of welding defects is reduced. The gas pipe is used for feeding protective gas and forming a protective gas wall at the through slot to prevent the gas in the external environment from flowing into the through slot from the edge of the through slot. The trailing cover is used for covering the place of the through slot which is not covered by the atmosphere protection cover. The trailing cover not only prevents the gas in the external environment from entering, but also effectively prevents the protective gas from leaking out.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a welding atmosphere protection device and its usage method. Background Technology

[0002] Titanium alloys are widely used in aerospace, automotive manufacturing, and medical device industries due to their excellent properties such as light weight, high strength, and corrosion resistance. Studies have found that welding titanium alloys after high-temperature preheating (300-700℃) can significantly improve the material's toughness. However, during the welding process after high-temperature preheating, especially in the high-temperature preheating stage, titanium alloys exhibit high chemical reactivity and readily react with oxygen and nitrogen in the air, leading to oxidation of the weld and surrounding areas. This reduces the plasticity and toughness of the weld joint, affecting the weld quality.

[0003] CN115156715A discloses a device and method for vector gas supply protection in laser welding, comprising a welding machine body, a hollow rotary motor at the lower part of the welding machine body, and a double-layer protective gas pipe connected below the hollow rotary motor. Two protective gas paths are provided in the welding machine body and the double-layer protective gas pipe, namely a first protective gas path and a second protective gas path. A first gas port and a second gas port are provided on the welding machine body, respectively connected to the first and second protective gas paths, with the first gas port located above the second gas port. This device addresses the problem of easy oxidation during traditional laser welding of titanium alloys, aluminum alloys, and high-temperature alloys by designing and manufacturing a rotatable vector-tracking welding protective cover. The hollow rotary motor drives the welding protective cover to rotate and position, ensuring that the welding protective cover remains parallel to the weld path direction, thus providing effective protection. However, this patent application only allows the welding protective cover 7 to be placed behind the welding trajectory during the welding process; it cannot effectively isolate the influence of external air on the welded workpiece during the high-temperature preheating stage. Summary of the Invention

[0004] In view of this, the present invention aims to provide a welding atmosphere protection device and a method of use, which can effectively prevent titanium alloy test plates from being oxidized during the high-temperature preheating stage and the welding stage.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A welding atmosphere protection device includes an atmosphere protection box, an atmosphere protection hood, and a drag hood. The atmosphere protection box includes a body and a lid. The body defines a space for placing a test plate to be welded. The lid covers the body, and a through groove is formed in the center of the lid, extending along the length of the weld seam of the test plate. The atmosphere protection hood and the drag hood are engaged above the through groove and can move back and forth above it. The atmosphere protection hood is connected to a welding torch and a gas guide pipe. The welding torch is positioned between the atmosphere protection hood and the drag hood. The gas guide pipe is used to introduce shielding gas into the atmosphere protection box. The test plate to be welded is located within the space formed by the atmosphere protection box, the atmosphere protection hood, and the drag hood, thus providing all-around protection for the test plate during welding, effectively preventing oxidation and reducing welding defects. The gas guide pipe introduces shielding gas and forms a shielding gas wall at the through groove, preventing gases from the external environment from flowing into the atmosphere protection box from the edge of the through groove and affecting the welding quality. The shroud is used to cover the area of ​​the channel not covered by the atmosphere protection cover, which not only prevents gas from entering from the external environment, but also effectively prevents the leakage of protective gas.

[0007] Furthermore, the atmosphere protection hood includes a first gas guide pipe, a second gas guide pipe, and a hood body. Both the first and second gas guide pipes are connected to the hood body, and the second gas guide pipe is movable in the vertical direction. The hood body is fastened to the top of the through groove. The non-fixed second gas guide pipe can be adjusted vertically according to the weld thickness to ensure sufficient protective gas is always present around the weld at each location, thereby expelling other gases around the weld and preventing oxidation.

[0008] Furthermore, the first gas guide pipe passes through the enclosure, with its inlet end connected to the protective gas source and its outlet end located at the through slot. The second gas guide pipe also passes through the enclosure, with its inlet end connected to the protective gas source and its outlet end extending into the atmosphere protection chamber. The outlet end of the first gas guide pipe is located at the through slot, utilizing the protective gas to form a barrier at the through slot, preventing gases from the external environment from entering the atmosphere protection chamber from the vicinity of the through slot. The combination of the fixed first gas guide pipe and the non-fixed second gas guide pipe better prevents oxidation of the test plate to be welded.

[0009] Furthermore, the atmosphere protection chamber consists of an insulation layer and a cooling layer from the inside out. A heating device is installed between the bottom of the test plate to be welded and the insulation layer located at the bottom. The heating device provides the heat required for high-temperature preheating, and placing it at the bottom of the test plate facilitates uniform heating. The insulation layer reduces heat loss and improves preheating efficiency. The cooling layer rapidly cools the outer side of the test plate after welding to prevent burns to personnel.

[0010] Furthermore, the atmosphere protection chamber also includes a temperature measuring device. This device monitors the temperature inside the atmosphere protection chamber in real time and regulates the temperature through a cooling layer to ensure that the temperature remains within a suitable range throughout the welding process.

[0011] Furthermore, the box cover includes a first box cover and a second box cover, both of which are movable horizontally above the box body. When the first box cover and the second box cover move in opposite directions, the atmosphere protection box is opened, facilitating the placement or removal of the test plate to be welded. When the first box cover and the second box cover move towards each other, the atmosphere protection box is closed, and a through groove is provided between the first box cover and the second box cover.

[0012] Furthermore, a first transparent cover plate and a second transparent cover plate are provided above the box cover, and the through groove is located between the two transparent cover plates. A guide groove is provided on the right side of the first transparent cover plate and a guide groove is provided on the left side of the second transparent cover plate. The atmosphere protection cover can move along the guide groove.

[0013] Compared with existing technologies, the welding atmosphere protection device of the present invention has the following advantages:

[0014] (1) By setting up an atmosphere protection box and using a drag hood in conjunction with the atmosphere protection hood, the test plate to be welded is in a closed space when the protective gas is introduced, which prevents oxidation from affecting the welding quality and improves the plasticity and toughness of the welded joint.

[0015] (2) In addition to setting a fixed first gas guide pipe to introduce protective gas into the through groove to prevent air from the outside environment from entering the atmosphere protection box, a movable second gas guide pipe is also set up to move up and down in the thickness direction to ensure that the distance between the gas outlet end of the second gas guide pipe and the weld is always kept at 12-20mm. Thus, when welding each layer of weld, protective gas is introduced into the weld to displace the air at the weld and effectively prevent oxidation. It is suitable for welding thick test plates with bevels.

[0016] (3) The welding atmosphere protection device of the present invention can be adjusted according to the test plates of different sizes and shapes, and has strong adaptability.

[0017] Another aspect of the present invention provides a method for using a welding atmosphere protection device, wherein the method employs the aforementioned welding atmosphere protection device, and the method includes the following steps:

[0018] Preparation phase:

[0019] Place the test plate to be welded into the atmosphere protection chamber. Move the first and second box covers in opposite directions. Place the first and second transparent cover plates on top of the box covers. The gap between the first and second box covers forms a through groove. The gap between the first and second transparent cover plates forms a through groove. Cover the first and second transparent cover plates with the atmosphere protection cover and the drag cover to ensure that the atmosphere protection cover and the drag cover cover the through groove.

[0020] Start the heating device, set the preheating temperature and time according to the type and thickness of the test plate to be welded, and fill the atmosphere protection box with protective gas through the first gas pipe and the second gas pipe.

[0021] Preheating phase:

[0022] When the preheating temperature reaches the set value, the heating device is turned off;

[0023] Welding stage:

[0024] Start the welding torch, adjust the welding current, welding speed and shielding gas flow rate according to the welding parameters. The welding torch moves back and forth in the front and back direction according to the set weld path to achieve welding of all welds. The movement of the welding torch drives the atmosphere shield and the drag shield to move synchronously to ensure that the atmosphere shield and the drag shield cover the through groove when the welding torch moves in the through groove. At the same time, the first gas guide pipe and the second gas guide pipe also move synchronously in the front and back direction, and keep the gas outlet end of the first gas guide pipe at the through groove, and the gas outlet end of the second gas guide pipe extends into the atmosphere shield box and is located 12-20mm above the weld.

[0025] Cooling phase:

[0026] After welding is completed, turn off the welding torch, increase the cooling water flow to quickly cool down the test plate to be welded, and determine whether the internal temperature of the atmosphere protection chamber is lower than 150℃. If so, close the first gas pipe and the second gas pipe.

[0027] Cleanup phase:

[0028] After the test plate to be welded has cooled to room temperature, remove the atmosphere protection cover and the drag cover, open the box cover, take out the test plate to be welded for cleaning and inspection, and clean the atmosphere protection box.

[0029] Furthermore, during the welding stage, when the temperature inside the atmosphere protection chamber is detected to be higher than 280°C, the flow rate of cooling water in the cooling layer is increased to lower the temperature.

[0030] The method of using the welding atmosphere protection device is the same as the advantages of the welding atmosphere protection device over the prior art, and will not be repeated here. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0032] Figure 1 This is a schematic diagram of the welding atmosphere protection device described in this invention;

[0033] Figure 2 A schematic diagram of the welding atmosphere protection device of the present invention with the second transparent cover plate and part of the box body removed;

[0034] Figure 3 a is a partial schematic diagram of the welding atmosphere protection device described in this invention;

[0035] Figure 3 b is Figure 3 A sectional view of a;

[0036] Figure 3 c is Figure 3 A schematic diagram showing the welding torch and atmosphere shield moving forward in state a;

[0037] Figure 3 d is Figure 3 A schematic diagram showing the second air duct moving upwards in state c.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Atmosphere protection chamber; 11. Heating device; 12. Insulation layer; 13. Cooling layer; 14. Temperature measuring device; 15. Cover; 16. Water pipe; 2. Atmosphere protection hood; 21. First gas guide pipe; 22. Second gas guide pipe; 23. Cover body; 3. Trailer cover; 4. Test plate to be welded; 5. Welding torch; 6. First transparent cover plate; 7. Second transparent cover plate. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The embodiments described herein are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] It should be noted that the terms "upper," "lower," "left," "right," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0042] like Figures 1-2 As shown, a welding atmosphere protection device includes an atmosphere protection box 1, an atmosphere protection hood 2, and a drag hood 3. The atmosphere protection box 1 includes a box body and a box cover 15. The box body defines an accommodating space for placing a test plate 4 to be welded. The box cover 15 covers the box body. A through groove is formed in the middle of the box cover 15. The through groove extends along the length of the weld seam of the test plate 4 to be welded. The atmosphere protection hood 2 and the drag hood 3 are fastened to the through groove and can move back and forth above the through groove. The atmosphere protection hood 2 is connected to a welding torch 5 and a gas guide pipe, respectively. The welding torch 5 is disposed between the atmosphere protection hood 2 and the drag hood 3. The gas guide pipe is used to introduce protective gas into the atmosphere protection box 1.

[0043] The test plate 4, which is to be welded, has high chemical reactivity during high-temperature preheating and the subsequent welding process, and is prone to reacting with oxygen, nitrogen, and other gases in the air. The test plate 4 is located within the space formed by the atmosphere protection chamber 1, the atmosphere protection hood 2, and the drag hood 3, thus providing comprehensive protection for the test plate 4 during the welding process. This effectively protects the test plate 4 from oxidation, thereby improving the plasticity and toughness of the weld joint and reducing welding defects. The gas guide pipe is used to introduce protective gas and forms a protective gas wall at the through-slot, preventing gases from the external environment from flowing into the atmosphere protection chamber 1 from the edge of the through-slot and affecting the welding quality. The drag hood 3 is used to cover the areas of the through-slot not covered by the atmosphere protection hood 2, preventing not only the entry of gases from the external environment but also effective prevention of protective gas leakage.

[0044] Furthermore, the test plate 4 to be welded is made of titanium alloy. The welding torch 5 uses tungsten inert gas welding, which has the advantages of fast welding speed, good weld quality, and small heat-affected zone, and is suitable for welding difficult-to-weld materials such as titanium alloy.

[0045] The welding torch 5 has a drag shield 3 in front and an atmosphere shield 2 behind it. When the welding torch 5 moves back and forth in the welding direction, the atmosphere shield 2 and the drag shield 3 also move synchronously in the welding direction.

[0046] As a preferred example of the present invention, the atmosphere protection cover 2 includes a first air guide pipe 21, a second air guide pipe 22 and a cover body 23. The first air guide pipe 21 and the second air guide pipe 22 are both connected to the cover body 23, and the second air guide pipe 22 can move in the vertical direction. The cover body 23 is fastened to the top of the through groove.

[0047] The cover 23 not only covers part of the through-slot but also provides mounting points for the first gas guide pipe 21 and the second gas guide pipe 22. For a thick test plate 4 with a bevel, if only a fixed gas guide pipe is used, the distance between the gas guide pipe and the bottom weld seam may be too large in the initial stage of welding, which may result in the shielding gas not reaching the bottom weld seam or residual air at the bottom weld seam, which is detrimental to welding quality and stability. The non-fixed second gas guide pipe 22 can be adjusted up and down according to the welding thickness to ensure that there is always sufficient shielding gas around the weld seam at each position to expel other gases around the weld seam and avoid oxidation. Furthermore, the position of the second gas guide pipe 22 is adjusted according to the welding thickness. In the thickness direction, the distance between the second gas guide pipe 22 and the weld seam is 12-20 mm.

[0048] Furthermore, the first air guide pipe 21 passes through the cover 23, and the air inlet end of the first air guide pipe 21 is connected to the protective gas source, and the air outlet end is set at the through slot. The second air guide pipe 22 passes through the cover 23, and the air inlet end of the second air guide pipe 22 is connected to the protective gas source, and the air outlet end extends into the atmosphere protection box 1.

[0049] The protective gas source provides the protective gas, which is an inert gas, argon, and / or helium. The outlet of the first gas guide pipe 21 is positioned at the through-slot, forming a barrier with the protective gas to prevent gases from the external environment from entering the atmosphere protection chamber 1 from the vicinity of the through-slot. The outlet of the second gas guide pipe 22 is adjusted to be 12-20 mm away from the weld. The combination of the fixed first gas guide pipe 21 and the non-fixed second gas guide pipe 22 better prevents oxidation of the test plate 4 to be welded. Using an inert gas as the protective gas avoids the emission of harmful substances.

[0050] Furthermore, the atmosphere protection chamber 1 consists of a heat insulation layer 12 and a cooling layer 13 from the inside out, and a heating device 11 is provided between the bottom of the test plate 4 to be welded and the heat insulation layer 12 located at the bottom.

[0051] The heating device 11 provides the heat required for high-temperature preheating. Placing the heating device 11 at the bottom of the test plate 4 to be welded promotes uniform heating. The heat insulation layer 12 reduces heat loss and improves preheating efficiency. The cooling layer 13 rapidly cools the outer side of the test plate 4 after welding to prevent burns. Specifically, the cooling layer 13 is a water-cooling device connected to a water pipe 16, through which cold water flows to enable the cooling layer 13 to operate and lower the temperature.

[0052] The atmosphere protection chamber 1 also includes a temperature measuring device 14, used to monitor the internal temperature of the atmosphere protection chamber 1 in real time and to regulate the temperature through the cooling layer 13, ensuring that the temperature remains within a suitable range during the welding process. As welding progresses, the weld space gradually decreases, the heat of the test plate 4 to be welded continuously increases, and the temperature in the atmosphere protection chamber 1 also continuously increases. When the temperature reaches 280℃, the cooling water flow rate of the inlet water pipe 16 is adjusted to cool down the chamber.

[0053] To facilitate the removal of the test plate 4 to be welded from the atmosphere protection chamber 1, the cover 15 includes a first cover and a second cover, both of which are movable horizontally above the chamber. When the first cover and the second cover move in opposite directions, the atmosphere protection chamber 1 is opened, facilitating the placement or removal of the test plate 4. When the first cover and the second cover move towards each other, the atmosphere protection chamber 1 is closed, and a through groove exists between the first cover and the second cover.

[0054] A first transparent cover plate 6 and a second transparent cover plate 7 are disposed above the box cover 15. The through groove is located between the two transparent cover plates. A guide groove is provided on the right side of the first transparent cover plate 6 and a guide groove is provided on the left side of the second transparent cover plate 7. The atmosphere protection cover 2 can move along the guide grooves to prevent positional displacement. The transparent cover plates are used to observe the working status in the atmosphere protection box 1 and the welding status of the test plate 4 to be welded. Both transparent cover plates can move left and right above the box body. Considering the high temperature during welding, the first transparent cover plate 6 and the second transparent cover plate 7 are made of transparent quartz glass to avoid the adverse effects of high welding temperatures.

[0055] The welding atmosphere protection device of the present invention, by setting up an atmosphere protection box 1 and using a drag hood 3 in conjunction with an atmosphere protection cover 2, keeps the test plate 4 to be welded in a sealed space when shielding gas is introduced, preventing oxidation from affecting the welding quality and improving the plasticity and toughness of the welded joint. In addition to setting up a fixed first gas guide pipe 21 to introduce shielding gas into the through groove to prevent air from the external environment from entering the atmosphere protection box 1, a movable second gas guide pipe 22 is also provided, which moves up and down in the thickness direction to ensure that the distance between the gas outlet end of the second gas guide pipe 22 and the weld is always maintained at 12-20mm. This ensures that shielding gas is introduced into the weld during each layer of welding, displacing air at the weld and effectively preventing oxidation. This device is suitable for welding thick test plates 4 with bevels. Furthermore, the welding atmosphere protection device of the present invention can be adjusted according to different sizes and shapes of test plates 4, making it highly adaptable.

[0056] In this invention, the welding torch 5, atmosphere protection cover 2, drag cover 3, and second gas guide tube 22 can be moved manually or driven by an automatic translation device.

[0057] The method of using a welding atmosphere protection device according to the present invention includes the following steps:

[0058] Preparation phase:

[0059] Place the test plate 4 to be welded into the atmosphere protection chamber 1. Move the first and second lids in opposite directions. Place the first transparent cover plate 6 and the second transparent cover plate 7 above the lid 15. The gap between the first and second lids forms a through groove. The gap between the first transparent cover plate 6 and the second transparent cover plate 7 forms a through groove. Cover the first transparent cover plate 6 and the second transparent cover plate 7 with the atmosphere protection cover 2 and the drag cover 3 to ensure that the atmosphere protection cover 2 and the drag cover 3 cover the through groove.

[0060] Start the heating device 11, set the preheating temperature and time according to the type and thickness of the test plate 4 to be welded, and fill the atmosphere protection box 1 with protective gas through the first gas pipe 21 and the second gas pipe 22.

[0061] Preheating phase:

[0062] When the preheating temperature reaches the set value, the heating device 11 is turned off;

[0063] Welding stage:

[0064] Start the welding torch 5, adjust the welding current, welding speed and shielding gas flow rate according to the welding parameters, and the welding torch 5 moves back and forth in the front and back direction according to the set weld path to achieve welding of all welds. The movement of the welding torch 5 drives the atmosphere shield 2 and the drag shield 3 to move synchronously to ensure that the atmosphere shield 2 and the drag shield 3 cover the through groove when the welding torch 5 moves in the through groove. At the same time, the first gas guide pipe 21 and the second gas guide pipe 22 also move synchronously in the front and back direction, and keep the gas outlet end of the first gas guide pipe 21 at the through groove, and the gas outlet end of the second gas guide pipe 22 extends into the atmosphere shield box 1 and is located 12 to 20 mm above the weld.

[0065] Cooling phase:

[0066] After welding is completed, turn off the welding torch 5, increase the cooling water flow to quickly cool down the test plate 4 to be welded, and determine whether the internal temperature of the atmosphere protection box 1 is lower than 150℃. If so, close the first gas pipe 21 and the second gas pipe 22.

[0067] Cleanup phase:

[0068] After the test plate 4 to be welded has cooled to room temperature, remove the atmosphere protection cover 2 and the drag cover 3, open the box cover 15, take out the test plate 4 to be welded for cleaning and inspection, and clean the atmosphere protection box 1.

[0069] Specifically, during the preheating stage, the temperature inside the atmosphere protection chamber 1 is monitored in real time by the temperature measuring device 14, and the stability and accuracy of the preheating temperature are maintained by adjusting the power of the heating device 11.

[0070] Specifically, during the welding stage, when welding any layer of weld, such as Figure 3 As shown in a to 3c, the welding torch 5 moves forward, and the atmosphere shield 2 and the drag shield 3 move synchronously. Correspondingly, the first gas guide pipe 21 moves synchronously within the through groove, and the second gas guide pipe 22 descends and moves to a distance of 12-20 mm from the weld seam of that layer before moving forward synchronously. When welding the next layer of weld seam, as... Figure 3 As shown in diagram d, the welding torch 5 moves forward, and the atmosphere shield 2 and the drag shield 3 move synchronously. Correspondingly, the first gas guide pipe 21 also moves within the channel. The second gas guide pipe 22 moves upward until its outlet end is 12-20 mm away from the weld seam, then moves forward synchronously. The upward speed of the second gas guide pipe 22 depends on the welding speed. The faster the welding speed, the faster the second gas guide pipe 22 moves upward.

[0071] During welding, as each weld layer is welded, the space continuously decreases, which can reduce the gas flow rate of the first gas guide pipe 21 and the second gas guide pipe 22. This ensures the formation of a protective gas wall to improve airtightness while reducing the consumption of protective gas.

[0072] During the welding stage, the temperature inside the atmosphere protection chamber 1 is monitored in real time by the temperature measuring device 14, and the working state of the cooling layer 13 is adjusted as needed. Specifically, when the temperature inside the atmosphere protection chamber 1 is detected to be higher than 280°C, the flow rate of cooling water in the cooling layer 13 is increased to lower the temperature.

[0073] Specifically, during the cooling stage, when the internal temperature of the atmosphere protection box 1 is below 150°C, the first gas guide pipe 21 and the second gas guide pipe 22 are closed to ensure that the weld has low residual welding stress and to prevent the welding material from reacting with oxygen, nitrogen and other gases in the air.

[0074] It should be noted that the length direction mentioned in this invention refers to the front-to-back direction in the figure, and the thickness direction mentioned in this invention refers to the top-to-bottom direction in the figure.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A welding atmosphere protection device, characterized in that, The system includes an atmosphere protection box (1), an atmosphere protection cover (2), and a drag cover (3). The atmosphere protection box (1) includes a box body and a box cover (15). The box body defines a space for placing a test plate (4) to be welded. The box cover (15) covers the box body. A through groove is opened in the middle of the box cover (15). The through groove extends along the length of the weld of the test plate (4) to be welded. The atmosphere protection cover (2) and the drag cover (3) are fastened to the through groove and can move back and forth above the through groove. The atmosphere protection cover (2) is connected to the welding torch (5) and the gas guide pipe respectively. The welding torch (5) is set between the atmosphere protection cover (2) and the drag cover (3). The gas guide pipe is used to introduce protective gas into the atmosphere protection box (1). The atmosphere protection cover (2) includes a first gas guide pipe (21), a second gas guide pipe (22) and a cover body (23). The first gas guide pipe (21) and the second gas guide pipe (22) are both connected to the cover body (23), and the second gas guide pipe (22) can move in the vertical direction. The cover body (23) is fastened to the top of the through groove. The first gas guide pipe (21) passes through the cover body (23), and the inlet end of the first gas guide pipe (21) is connected to the protective gas source, and the outlet end is set at the through groove. The second gas guide pipe (22) passes through the cover body (23), and the inlet end of the second gas guide pipe (22) is connected to the protective gas source, and the outlet end extends into the atmosphere protection box (1) and is located 12~20mm above the weld. The atmosphere protection box (1) consists of a heat insulation layer (12) and a cooling layer (13) from the inside out. A heating device (11) is provided between the bottom of the test plate (4) to be welded and the heat insulation layer (12) at the bottom. The box cover (15) includes a first box cover and a second box cover. Both the first box cover and the second box cover can move along the left and right direction above the box body. A first transparent cover plate (6) and a second transparent cover plate (7) are provided above the box cover (15). The through groove is located between the two transparent cover plates. A guide groove is provided on the right side of the first transparent cover plate (6) and a guide groove is provided on the left side of the second transparent cover plate (7). The atmosphere protection cover (2) can move along the guide groove.

2. The welding atmosphere protection device according to claim 1, characterized in that, The atmosphere protection chamber (1) also includes a temperature measuring device (14).

3. A method of using the welding atmosphere protection device as described in any one of claims 1 to 2, characterized in that, Includes the following steps: Preparation phase: Place the test plate (4) to be welded into the atmosphere protection box (1), move the first box cover and the second box cover in opposite directions, place the first transparent cover plate (6) and the second transparent cover plate (7) above the box cover (15), the gap between the first box cover and the second box cover forms a through groove, the gap between the first transparent cover plate (6) and the second transparent cover plate (7) forms a through groove, cover the atmosphere protection cover (2) and the drag cover (3) above the first transparent cover plate (6) and the second transparent cover plate (7), and ensure that the atmosphere protection cover (2) and the drag cover (3) cover the through groove; Start the heating device (11), set the preheating temperature and time according to the type and thickness of the test plate (4) to be welded, and fill the atmosphere protection box (1) with protective gas through the first gas pipe (21) and the second gas pipe (22); Preheating phase: When the preheating temperature reaches the set value, turn off the heating device (11). Welding stage: Start the welding torch (5), adjust the welding current, welding speed and shielding gas flow rate according to the welding parameters, the welding torch (5) moves back and forth in the front and back direction according to the set weld path to achieve welding of all welds, the movement of the welding torch (5) drives the atmosphere shield (2) and the drag shield (3) to move synchronously, ensuring that when the welding torch (5) moves in the through groove, the atmosphere shield (2) and the drag shield (3) cover the through groove; at the same time, the first gas guide pipe (21) and the second gas guide pipe (22) also move synchronously in the front and back direction, and keep the gas outlet end of the first gas guide pipe (21) set at the through groove, and the gas outlet end of the second gas guide pipe (22) extends into the atmosphere shield box (1) and is located 12~20mm above the weld; Cooling phase: After welding is completed, turn off the welding gun (5), increase the cooling water flow to cool down the test plate (4) quickly, and determine whether the internal temperature of the atmosphere protection box (1) is lower than 150℃. If so, turn off the first gas pipe (21) and the second gas pipe (22). Cleanup phase: After the test plate (4) to be welded has cooled to room temperature, remove the atmosphere protection cover (2) and the drag cover (3), open the box cover (15), take out the test plate (4) to be welded for cleaning and inspection, and clean the atmosphere protection box (1).

4. The method of using the welding atmosphere protection device according to claim 3, characterized in that, During the welding stage, when the temperature inside the atmosphere protection box (1) is monitored to be higher than 280°C, the flow rate of cooling water in the cooling layer (13) is increased to cool it down.

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