Welding method

Abstract

The invention discloses a welding method which comprises the following steps that a first plate body and a second plate body are arranged on a ceramic gasket and form a V-shaped groove, the V-shaped groove is provided with a first inclined face and a second inclined face, and the width of the V-shaped groove is gradually increased in the direction away from the ceramic gasket; the welding device is started, so that a welding gun of the welding device moves along the extending path of the V-shaped groove, and meanwhile, the welding device sprays welding protection gas; when arc quenching is needed, step attenuation arc suppression is adopted, so that the width of a welding seam is gradually reduced, and finally, an electric arc is led to the first inclined surface of the V-shaped groove to complete arc quenching; when arc striking is conducted again, the welding gun conducts arc striking again on the second inclined face of the V-shaped groove and moves to the starting point of the welding seam width step attenuation, and then the welding gun rotates a circle at the starting point of the welding seam width step attenuation; and finally, the welding gun reciprocates between the first inclined surface and the second inclined surface along the crescent track while moving along the extending path of the V-shaped groove. The welding quality can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of hull welding, and in particular to a welding method. Background Art

[0002] In the field of shipbuilding, the quality of welding technology is directly related to the overall structural strength and safety performance of the ship. At present, gas shielded welding has been widely used in various welding positions in shipbuilding due to its many advantages such as high welding efficiency, beautiful weld formation, and strong rust resistance. Among them, for V-shaped groove butt welds, the welding method of single-sided welding and double-sided forming with ceramic pads has become a conventional and important technical means. This method uses a ceramic pad on the back of the weld to achieve good double-sided weld formation under single-sided welding, which not only simplifies the welding operation process, but also significantly improves welding efficiency and reduces production costs.

[0003] However, in the actual welding process, it is often affected by a variety of complex factors, resulting in the inability to carry out the welding process continuously, requiring arc stopping or passive arc extinction. For example, sudden failure of welding equipment, interruption of welding material supply, short pauses caused by operators due to operating specifications or fatigue, etc. When arc stopping or passive arc extinction occurs, not only shrinkage defects are easily generated at the location of arc extinction, but also cracks may be generated. These shrinkage holes and cracks will seriously damage the continuity and density of the weld, greatly reduce the mechanical properties of the welded joint, and then pose a potential threat to the overall structural strength and safety of the ship, seriously affecting the welding quality, and becoming one of the key issues that need to be urgently solved in the shipbuilding process. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a welding method which can solve the above-mentioned problems existing in the prior art.

[0005] To achieve the above objectives, this application adopts the following technical solutions: In one aspect, a welding method is provided, comprising: S10, placing a first plate body and a second plate body on a ceramic liner, wherein a V-shaped groove is formed between the first plate body and the second plate body, wherein the V-shaped groove has a first inclined surface and a second inclined surface, and a width of the V-shaped groove gradually increases in a direction away from the ceramic liner; S20, starting the welding device so that the welding gun of the welding device moves along the extension path of the V-shaped groove while the welding device sprays welding shielding gas; S30, when the arc needs to be extinguished, step-attenuation arc extinguishing is adopted to gradually reduce the width of the weld; finally, the arc is guided to the first inclined surface of the V-shaped groove to complete the arc extinguishing; S40. When re-striking an arc, the welding torch strikes an arc again on the second inclined surface of the V-shaped groove and moves to the starting point of the stepped attenuation of the weld width. Immediately afterwards, the welding torch makes a full circle at the starting point of the stepped attenuation of the weld width. Finally, while moving along the extending path of the V-shaped groove, the welding torch reciprocally swings between the first inclined surface and the second inclined surface along a crescent-shaped trajectory.

[0006] Preferably, in the step S30, the length of the weld with a gradually decreasing width is 20 mm to 30 mm.

[0007] Preferably, in the step S30, after the welding torch moves 20 mm to 25 mm along the extending path of the V-shaped groove on the first inclined surface, the arc is extinguished.

[0008] Preferably, in the step S30, when the arc is led to the first inclined surface of the V-shaped groove, the included angle between the welding torch and the first inclined surface is 75 degrees to 85 degrees in the projection along the extending direction of the V-shaped groove.

[0009] Preferably, in the step S40, when the welding torch strikes an arc again on the second inclined surface of the V-shaped groove, the included angle between the welding torch and the extending path of the V-shaped groove is 70 degrees to 80 degrees, and the included angle between the welding torch and the second inclined surface is 75 degrees to 85 degrees in the projection along the extending direction of the V-shaped groove.

[0010] Preferably, in the step S10, a connecting piece is installed. The connecting piece is in an n shape and has an avoidance groove. One end of the connecting piece is connected to the first plate body, and the other end of the connecting piece is connected to the second plate body. The avoidance groove communicates with the V-shaped groove. S50. When the welding torch moves along the extending path of the V-shaped groove and approaches the connecting piece, swing the welding torch so that the included angle between the welding torch and the weld is a first angle. Before the welding torch touches the connecting piece, the welding torch tilts in a direction away from the connecting piece so that the included angle between the welding torch and the weld is a second angle, and the welding nozzle of the welding torch is located in the avoidance groove of the connecting piece. After the welding torch welds the V-shaped groove located in the avoidance groove, the arc is extinguished. The welding torch bypasses the connecting piece, the welding torch tilts in a direction away from the connecting piece so that the included angle between the welding torch and the weld is a third angle, and the welding nozzle of the welding torch is located in the avoidance groove of the connecting piece. The welding torch strikes an arc again at the arc extinguishing point in the V-shaped groove and continues to move along the extending path of the V-shaped groove. After the welding nozzle of the welding torch completely leaves the avoidance groove, the included angle between the welding torch and the weld resumes to the first angle for continuous welding.

[0011] Preferably, the second angle is 70 degrees to 80 degrees.

[0012] Preferably, the third angle is 30 degrees to 50 degrees.

[0013] Preferably, the duration for the welding torch to bypass the connecting member is 0.2 seconds to 0.8 seconds.

[0014] Preferably, the welding method further includes S60: After welding is completed, fill welding and capping welding are carried out according to normal welding processes.

[0015] The beneficial effects of the present application are as follows: By adopting stepped decay arc extinguishing and transferring the position of the arc extinguishing point, the cooling rate of the weld during arc extinguishing is reduced in the welding method of the present application. This is not only beneficial for the discharge of impurities and reduction of segregation, but also makes the weld metal at the arc extinguishing center full, thereby avoiding shrinkage cavity defects and cracks caused by arc stopping or passive arc extinguishing. When restarting the arc, it makes a circle at the starting point of the stepped decay of the weld width. While the welding torch moves along the extension path of the V-shaped groove, it reciprocates between the first inclined surface and the second inclined surface along a crescent-shaped trajectory, ensuring joint fusion and reducing the generation of welding defects, guaranteeing the continuity and compactness of the weld and the mechanical properties of the welded joint, improving the welding quality, and further enhancing the overall structural strength and safety of the ship. Description of the Drawings

[0016] The following further elaborates on the present application in detail with reference to the drawings and embodiments.

[0017] Figure 1 is a flowchart of the welding method of the present application; Figure 2 and Figure 3 is a schematic diagram of step S30 in the welding method of the present application; Figure 4 is Figure 2 a top view; Figure 5 is Figure 3 a schematic diagram of the projection along the X direction; Figure 6 and Figure 7 is a schematic diagram of step S40 in the welding method of the present application; Figure 8 is Figure 6 a top view; Figure 9 is Figure 7 a schematic diagram of the projection along the X direction; Figures 10 to 12 is a schematic diagram of step S50 in the welding method of the present application.

[0018] Explanation of the reference numerals in the drawings: In the figure: 11. First plate body; 12. Second plate body; 13. Ceramic gasket; 14. Welding torch; 15. V-shaped groove; 16. Connecting piece; 151. First inclined surface; 152. Second inclined surface; 161. Avoidance groove. Specific implementation mode

[0019] To make the technical problems solved by this application, the technical solutions adopted, and the achieved technical effects clearer, the technical solutions of the embodiments of this application will be further described in detail below. Obviously, the described embodiments are only part of the embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.

[0020] In the description of the present invention, unless otherwise clearly specified and limited, terms such as "connected", "fixed", "connected", "communicated", "abutted", "clamped", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In this application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature is at a lower horizontal height than the second feature.

[0022] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts depict the operations (or steps) as sequential processes, many of the operations can be performed in parallel, concurrently, or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operations are completed, but it can also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0023] Unless specifically stated or defined otherwise, the term "and / or" used in the present invention includes any and all combinations of one or more of the associated listed items.

[0024] In the shipbuilding of the prior art, CO2 and other gas shielded welding are widely used in various welding positions, and the V-shaped groove butt weld usually adopts the welding method of single-sided welding and double-sided forming with ceramic liner. When the ceramic liner is attached to the back of the groove for root base welding, the arc needs to be stopped or passively extinguished due to various factors, and shrinkage holes will occur at the position of arc extinguishing, accompanied by cracks. The arc crater shrinkage holes and cracks of this kind of arc extinguishing are generally in the form of an irregular oblong with a thin line of varying lengths, and the overall shape is similar to a "tadpole". Arc crater shrinkage hole cracks may occur in CO2 gas shielded welding with ceramic liner of different materials, different plate thicknesses, different welding positions, and different welding wire types. Arc crater shrinkage hole cracks are easy to occur in shipyards but difficult to prevent completely.

[0025] The root base welding of the single-sided and double-sided formation of the ceramic backing by CO2 gas shielded welding, after the arc is extinguished, the welding wire cannot continue to melt to form metal, resulting in insufficient metal filling at the end, and the ceramic backing base welding cannot form new weld metal after melting like the parent material or the previous weld metal, and the weld molten by the ceramic backing base welding protrudes from the back to form excess height. After the arc is extinguished, the two sides of the arc pit cool and shrink, causing the weld metal in the center of the arc pit to be seriously insufficient to form the arc pit. At the same time, because the arc heat disappears after the arc is extinguished, the cooling speed will inevitably accelerate, causing the shrinkage strain rate to accelerate, the component segregation to intensify, and the impurities and low-melting-point components in the center of the weld to gather, leading to the factors of thermal cracking. In addition, the stress state of the arc pit is complex and different from the continuous weld, and is in a complex three-dimensional tensile stress state. At the same time, the shrinkage cavity is different from the pores. Its shape is irregular and some have sharp corners, which not only weakens the ability of the weld to resist application, but also provides conditions for the generation and expansion of cracks. Therefore, shrinkage cavities and cracks often appear at the same time in the negative film of X-ray detection. Its crack is the most harmful defect among welding defects.

[0026] After the arc is stopped or the arc is passively extinguished at the root of the ceramic liner, shrinkage cavities accompanied by tiny cracks can be observed from the front end of the weld, some of which are hidden inside the end weld, and some are hidden on the back of the end weld. There are usually two existing process technologies: one is to grind the arc pit position to remove defects after the arc is extinguished, and the end of the base weld forms an inclined transition and then re-attaches the ceramic liner to start arc welding. The second is to remove the back ceramic liner after the entire weld is welded, and use carbon arc air gouging to remove shrinkage cavities and cracks on all the back stop and extinguish joints, and then weld and repair them.

[0027] The above process technology has the following problems: 1. In order to deal with arc-extinguishing joint defects at any time, on-site construction personnel need to be equipped with a large number of auxiliary tools such as grinding, the process is cumbersome and the construction efficiency is low.

[0028] 2. For the arc stop and arc extinction joints on the back of the weld seam, the shrinkage cavity and crack defects are removed by carbon arc air gouging in a reverse buckle manner. It is highly demanding for the welding repair technology to make the back of the flat butt joint in a reverse buckle become the overhead welding. If the welding repair is not properly handled, welding defects such as slag inclusion are likely to occur again.

[0029] 3. The treatment of the arc extinction joint adds multiple processes such as grinding and air gouging, and the construction efficiency needs to be improved.

[0030] This application provides a welding method, which avoids the generation of shrinkage cavities and cracks, reduces the complexity of welding, and improves the welding efficiency and quality.

[0031] For the convenience of description, the up and down directions described below are Figure 2 the same as the up and down directions of itself, the left and right directions described below are Figure 2 the same as the left and right directions of itself, and the front and back directions, the welding direction X, and the extending direction of the V-groove described below are all Figure 3 the same as the left and right directions of itself.

[0032] As Figures 1 to 12 shown, this embodiment provides a welding method, which is a solution for controlling the shrinkage cavity and crack of the arc pit at the end of the backing weld with a ceramic backing 13. The welding method includes the following steps: S10. Place the first plate body 11 and the second plate body 12 on the ceramic backing 13. A V-groove is formed between the first plate body 11 and the second plate body 12. The V-groove has a first inclined surface 151 and a second inclined surface 152. The first inclined surface 151 and the second inclined surface 152 are mirror-symmetrical. The width of the V-groove gradually increases along the direction away from the ceramic backing 13. The first inclined surface 151 is located on the side surface of the first plate body 11, and the second inclined surface 152 is located on the side surface of the second plate body 12. Both the first plate body 11 and the second plate body 12 are steel plates.

[0033] Taking the example that the first plate body 11 and the second plate body 12 are horizontally spaced apart, the ceramic backing 13 is located below the first plate body 11 and the second plate body 12. The width direction of the V-groove is the arrangement direction of the first plate body 11 and the second plate body 12. The width of the V-groove gradually decreases from top to bottom. During welding, the welding torch 14 of the welding device extends into the V-groove from top to bottom to achieve welding.

[0034] S20. Start the welding device, and while the welding torch 14 of the welding device moves along the extending path of the V-groove, the welding device sprays welding protective gas. In this application, the welding torch 14 moves along the X direction.

[0035] S30. When arc extinction is required, stepwise attenuation arc extinguishing is adopted to make the width of the weld seam gradually decrease. Finally, the arc is led to the first inclined surface 151 of the V-groove to complete arc extinction.

[0036] In step S30, the bead width is gradually reduced by adopting stepped decay for arc extinguishing, and then the arc extinguishing point position is transferred to the first inclined surface 151. When adopting stepped decay for arc extinguishing, the arc extinguishing current, arc extinguishing voltage, and decay time are adjusted by using the arc extinguishing function and decay parameter function of the welding device. The decay causes the bead width to gradually decrease. Compared with ordinary arc starting and extinguishing, the decay arc extinguishing prolongs the residence time of arc starting and extinguishing, reduces the cooling rate of the weld seam when the ceramic backing 13 is arc extinguished, which is beneficial to the discharge of impurities and reduction of segregation.

[0037] S40, when restarting the arc, the welding torch 14 restarts the arc on the second inclined surface 152 of the V-groove and moves to the starting point of the stepped decay of the weld width, that is Figure 8 the D in. Immediately afterwards, the welding torch 14 makes a circle at the starting point of the stepped decay of the weld width to increase the heat of the arc starting joint, make the fusion with the arc extinguishing joint better and the back formation more beautiful. Finally, while the welding torch 14 moves along the extension path of the V-groove, it reciprocates between the first inclined surface 151 and the second inclined surface 152 along the crescent-shaped trajectory P, increasing the weld formation coefficient. The weld formation coefficient is the fusion width B / depth of fusion h, thereby reducing the generation of low-melting-point inclusions in the ceramic backing.

[0038] When restarting the arc at the starting point of the stepped decay after the decay type of arc starting and extinguishing, the present application adopts a method of starting the arc by making a circle. The welding torch 14 starts the arc at a position 5 mm away from the V-groove on the upper inclined surface opposite to the first inclined surface 151 and quickly retreats. The end of the welding torch 14 makes a vertical circle at the starting point of the stepped decay of the weld seam in the horizontal direction of the welding torch 14, and finally swings horizontally along the crescent-shaped trajectory P, increasing the weld formation coefficient and reducing the generation of low-melting-point inclusions in the ceramic backing, solving the problem of ensuring joint fusion and reducing the generation of welding defects.

[0039] Such as Figure 4 , further, in step S30, the length E of the weld seam with gradually decreasing width is 20 mm to 30 mm. Since the thermal conductivity of the ceramic backing is small, the temperature difference in the Z-axis direction of the weld seam center is small, and low-melting-point inclusions are easily displaced to the weld seam center during the cooling and crystallization of the weld seam. The present application uses a stepped decay arc welding method with instantaneous frequent arc breaking within 0.2 seconds. The decay step length E is about 20 mm to 30 mm, and its crystallization direction is from both sides and the backing to the weld surface. The low-melting-point inclusions in the molten pool are displaced to the surface; then the arc is led to the first inclined surface 151 of the V-groove.

[0040] Optionally, the welding torch 14 extinguishes the arc after moving 20 mm to 25 mm along the extension path of the V-groove on the first inclined surface 151, displacing the low-melting-point inclusions in the molten pool to the surface, avoiding the internal factors for crack generation, that is Figure 4 the F in is 20 mm to 25 mm.

[0041] In one embodiment, in step S30, when the arc is directed to the first bevel 151 of the V-shaped groove, the angle between the welding gun 14 and the first bevel 151 along the projection of the extension direction of the V-shaped groove is 75 degrees to 85 degrees, so that the weld formed by the arc is smoothly transitioned, which is conducive to the operation of the next welding. Figure 5 The G in the range is 75 to 85 degrees.

[0042] When the electric arc is directed to the first bevel 151 of the V-shaped groove, the transverse angle G of the welding gun 14 is changed so that G is approximately 75 to 85 degrees, and the entire arc is directed to the first bevel 151 of the V-shaped groove. The attenuation parameter function of the welding gun 14 is then used to weld a weld of 20 mm to 25 mm in length and then the arc is extinguished. This can reduce the cooling rate of the weld during arc closure welding of the ceramic liner 13, facilitate impurity discharge and reduce segregation, and at the same time make the weld metal in the arc extinguishing center full to avoid the formation of arc pits, thereby controlling the generation of arc closure shrinkage cavities and thermal cracks.

[0043] Further, in step S40, when the welding gun 14 re-starts the arc on the second bevel 152 of the V-shaped groove, the angle between the welding gun 14 and the extension path of the V-shaped groove is 70 degrees to 80 degrees, so that the weld seam of the second bevel 152 of the V-shaped groove is thin and smoothly transitioned. Figure 7 H in the figure is 70 to 80 degrees. At the same time, in the projection along the extension direction of the V-shaped groove, the angle between the welding gun 14 and the second inclined surface 152 is 75 to 85 degrees, so that the weld seam of the second inclined surface 152 of the V-shaped groove is smoothly transitioned, and does not affect the normal welding of the arc-extinguishing joint after the arc is started. Figure 9 The I in is 75 to 85 degrees.

[0044] During welding, especially when the welding length is long, the connector 16 will be installed to avoid displacement between the first plate 11 and the second plate 12 that affects the welding quality. Therefore, in some embodiments, the connector 16 will be installed in step S10. The connector 16 is n-shaped and has an avoidance groove 161. One end of the connector 16 is connected to the first plate 11, and the other end of the connector 16 is connected to the second plate 12. The first plate 11 and the second plate 12 are both welded to the connector 16. The avoidance groove 161 is connected to the V-shaped groove. The connector 16 is a Π-type card code or a support row, and the avoidance groove 161 is the R hole of the Π-type card code or the support row. The connector 16 will hinder the movement of the welding gun 14. At this time, the present application adopts the obstacle forced arc extinguishing and its arc starting method for sensing. The specific steps are as follows: Step S50, which is used when the obstacle forces the arc to be extinguished. That is, when the welding torch 14 moves along the extension path of the V-groove and approaches the connecting member 16, the welding torch 14 is swung so that the angle between the welding torch 14 and the weld seam is a first angle, and the first angle is the angle when the welding torch 14 normally welds along the V-groove. Before the welding torch 14 touches the connecting member 16, that is, when the welding torch 14 is about to touch the connecting member 16, the distance between the welding torch 14 and the connecting member 16 is 1 mm to 5 mm. The welding torch 14 is tilted in the direction away from the connecting member 16 so that the angle between the welding torch 14 and the weld seam is a second angle, that is, the welding torch 14 is tilted in the direction of X, and the second angle is Figure 12 K in. At this time, the nozzle of the welding torch 14 will be located in the avoidance groove 161 of the connecting member 16, and the welding torch 14 welds the V-groove located in the avoidance groove 161 and then extinguishes the arc.

[0045] After the obstacle forces the arc to be extinguished, the arc starting method is as follows: The welding torch 14 quickly bypasses the connecting member 16, and the welding torch 14 is tilted in the direction away from the connecting member 16 so that the angle between the welding torch 14 and the weld seam is a third angle, that is Figure 12 The third angle in is L, so that the nozzle of the welding torch 14 is located in the avoidance groove 161 of the connecting member 16. The welding torch 14 arcs again at the arc extinguishing point in the V-groove and continues to move along the extension path of the V-groove. After the nozzle of the welding torch 14 completely leaves the avoidance groove 161, the included angle between the welding torch 14 and the weld seam returns to the first angle for continuous welding.

[0046] Specifically, in the above process, within about 0.5 seconds after the obstacle forces the arc to be extinguished, the weld seam is in a red-hot high-temperature state. Then, the arc starting method is adopted. At this time, an arc is immediately started and welded at the arc extinguishing point to eliminate the insufficient filling of the molten metal at the end of the arc, thereby avoiding the generation of arc crater shrinkage cracks at the end of the backing weld.

[0047] Optionally, the second angle is 70 degrees to 80 degrees, so that the backing weld is welded to the middle of 161, that is, tilted in the reverse direction of the X direction, so that the backing weld is welded to the central area of the V-shaped groove 15 in the avoidance groove 161, and then the arc is extinguished.

[0048] Optionally, the third angle is 30 degrees to 50 degrees. At this angle, the welding torch 14 can better pass through the R hole of 161 to connect the arc extinguishing point. The welding torch 14 immediately jumps over the connecting member 16 and then tilts in the X direction at an angle of about 30 degrees to 50 degrees. The welding torch 14 arcs again at the arc extinguishing point in the avoidance groove 161, so that the welding torch 14 can continue to weld according to the normal angle and welding method of the welding torch 14 after jumping over the connecting member 16.

[0049] Furthermore, the duration M for the welding torch 14 to bypass the connecting member 16 is 0.2 seconds to 0.8 seconds, so that the welding torch 14 quickly bypasses the connecting member 16, avoiding excessive temperature drop at the V-groove and improving the welding quality.

[0050] In one embodiment, the welding method further includes S60: after welding is completed, welding is performed by filling welding and cap welding according to a normal welding process. After welding is completed, welding is performed by filling welding and cap welding according to a normal welding process. After welding is completed, X-ray inspection is performed according to the weld requirements. X-ray inspection is performed on the positions of the joints using the attenuated arc-exiting method, the arc-starting and arc-turning method, and the obstacle forced arc-exiting and arc-starting method during welding. The flaw detection results are qualified when there is no shrinkage cavity or crack.

[0051] Steps S30 to S50 of the present application merely represent corresponding steps and do not represent a sequential order.

[0052] Through the above steps, the present application reduces welding defects, helps reduce the material and time costs of rework and repair, thereby improving construction production efficiency and reducing the overall rework time. In addition, through the above steps, the present application reduces the air gouging back-tightening welding process, saves the material costs of welding wire, carbon rod, gas, etc. generated by rework, and avoids material waste.

[0053] Optionally, the welding shielding gas is carbon dioxide. Carbon dioxide can prevent metal oxidation and optimize the welding process. In other embodiments, inert gases such as argon, helium, and nitrogen can also be used.

[0054] The technical principles of the present application are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation methods of the present application without creative work, and these methods will fall within the scope of protection of the present application.

Claims

1. A welding method, characterized in that, It includes the following steps: S10. Set the first plate body (11) and the second plate body (12) on the ceramic gasket (13). A V-shaped groove is formed between the first plate body (11) and the second plate body (12). The V-shaped groove has a first inclined surface (151) and a second inclined surface (152). The width of the V-shaped groove gradually increases along the direction away from the ceramic gasket (13). S20. Start the welding device, so that while the welding torch (14) of the welding device moves along the extension path of the V-shaped groove, the welding device sprays welding protective gas. S30. When arc extinguishing is required, adopt stepped attenuation arc extinguishing, so that the width of the weld gradually decreases; finally, lead the arc to the first inclined surface (151) of the V-shaped groove to complete arc extinguishing. S40. When re-igniting the arc, the welding torch (14) re-ignites on the second inclined surface (152) of the V-shaped groove and moves to the starting point of the stepped attenuation of the weld width. Immediately afterwards, the welding torch (14) makes a circle at the starting point of the stepped attenuation of the weld width. Finally, while the welding torch (14) moves along the extension path of the V-shaped groove, it reciprocates between the first inclined surface (151) and the second inclined surface (152) along a crescent-shaped trajectory.

2. The welding method according to claim 1, wherein, In the step S30, the length of the weld with a gradually decreasing width is 20 mm to 30 mm.

3. The welding method according to claim 1, characterized in that In the step S30, the welding torch (14) completes arc extinguishing after moving 20 mm to 25 mm along the first inclined surface (151) of the V-shaped groove.

4. The welding method according to claim 1, characterized in that In the step S30, when leading the arc to the first inclined surface (151) of the V-shaped groove, along the projection in the extension direction of the V-shaped groove, the included angle between the welding torch (14) and the first inclined surface (151) is 75 degrees to 85 degrees.

5. The welding method according to claim 1, characterized in that, In the step S40, when the welding torch (14) re-ignites on the second inclined surface (152) of the V-shaped groove, the included angle between the welding torch (14) and the extension path of the V-shaped groove is 70 degrees to 80 degrees. Along the projection in the extension direction of the V-shaped groove, the included angle between the welding torch (14) and the second inclined surface (152) is 75 degrees to 85 degrees.

6. The welding method according to any one of claims 1 to 5, characterized in that, In the step S10, install the connecting piece (16). The connecting piece (16) is in an n shape and has an avoidance groove (161). One end of the connecting piece (16) is connected to the first plate body (11), and the other end of the connecting piece (16) is connected to the second plate body (12). The avoidance groove (161) is communicated with the V-shaped groove. S50. When the welding torch (14) moves along the extension path of the V-groove and approaches the connecting member (16), swing the welding torch (14) so that the welding torch (14) forms a first angle with the weld seam. Before the welding torch (14) touches the connecting member (16), the welding torch (14) tilts away from the connecting member (16) so that the welding torch (14) forms a second angle with the weld seam, and the nozzle of the welding torch (14) is located in the avoidance groove (161) of the connecting member (16). After the welding torch (14) welds the V-groove located in the avoidance groove (161), the arc is extinguished; The welding torch (14) bypasses the connecting member (16). The welding torch (14) tilts away from the connecting member (16) so that the welding torch (14) forms a third angle with the weld seam, and the nozzle of the welding torch (14) is located in the avoidance groove (161) of the connecting member (16). The welding torch (14) reignites at the arc extinguishing point in the V-groove and continues to move along the extension path of the V-groove. After the nozzle of the welding torch (14) completely leaves the avoidance groove (161), the included angle between the welding torch (14) and the weld seam resumes to the first angle for continuous welding.

7. The welding method according to claim 6, characterized in that, The second angle is 70 degrees to 80 degrees.

8. The welding method according to claim 6, characterized in that, The third angle is 30 degrees to 50 degrees.

9. The welding method according to claim 6, characterized in that, The time for the welding torch (14) to bypass the connecting member (16) is 0.2 seconds to 0.8 seconds.

10. The welding method according to any one of claims 1 to 5, characterized in that, It further includes S60: After welding is completed, welding is carried out according to the method of filler welding and capping welding in the welding process.

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