A special-shaped multi-stage oxygen-free welding process

Abstract

The present invention relates to the technical field of oxygen-free welding, and in particular to a special-shaped multi-stage oxygen-free welding process, comprising the following steps: S1. Pretreatment, measuring and cutting the material to be processed; S2. Grooving, deoxidizing, brushing and drying the welded parts of the cut material to be processed; S3. Pre-welding, splicing the grooved material to be processed, and then pre-welding, cleaning after pre-welding, forming multiple parts; S4. Welding, connecting the multiple parts after pre-welding, welding under the protection of a protective structure after connection, and obtaining a formed product; S5. Post-treatment, cleaning and polishing the welding position in the product. The purpose is to reduce the difficulty and complexity of welding through multi-stage oxygen-free welding and protect the molten metal during the welding process, so as to make the performance of the welding part more uniform, so as to improve the welding efficiency and welding quality.

Description

Technical Field

[0001] The invention relates to the technical field of oxygen-free welding, and in particular to a special-shaped multi-stage oxygen-free welding process. Background Art

[0002] At present, most cups on the market are cylindrical in shape, while the cup body with special-shaped structure is small in size, and the eccentric design mold mechanism cannot be made or the mold strength is not enough, so it is difficult to achieve mass production. In addition, the length, width and flatness ratio of the cup body is too large, and the conventional bulging process cannot meet the size and appearance requirements. The expansion ratio is too large, and the shoulder and mouth shapes are different, one is round and the other is oval and flat, and the rolling rib cannot be smoothly realized. Therefore, in the processing of the special-shaped cup body, the welding process is adopted to realize the connection between the cup body and other components, and through welding, metal connections of different materials can be realized, making the special-shaped cup body more beautiful and practical.

[0003] When welding metals of different materials, the mechanical properties of the welding position are different due to the differences in organization and chemical composition. At different welding positions, the hardness, toughness, plasticity, strength, durability, and high-temperature impact resistance are different. Due to this difference, high-temperature welding will reduce the service life of the metal and the durability of the surface crystal liquid film.

[0004] Oxygen-free welding is a welding method that uses high-temperature heating to weld metal materials together under protective gas. This method mainly controls the oxygen content so that the oxygen concentration in the welding area reaches an extremely low level, reduces the generation of pollutants, and avoids the occurrence of oxidation, thereby ensuring welding quality and reliability. In the processing of special-shaped thermos cups, more precise matching and positioning are required to ensure the close connection and sealing between the various components. However, due to the changes in angles and distances in the welding parts, the welding points of the welding equipment cannot be correctly aligned with the cup body to be welded, which increases the difficulty and complexity of welding. In addition, welding of different materials may also face the problem of differences in welding performance. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a special-shaped multi-stage oxygen-free welding process, which reduces the difficulty and complexity of welding through multi-stage oxygen-free welding and protects the molten metal during the welding process, making the performance of the welding part more uniform, so as to improve the welding efficiency and welding quality.

[0006] The present invention solves the above technical problems by the following technical means: A special-shaped multi-stage oxygen-free welding process comprises the following steps: S1. Pre-processing: measuring and cutting the materials to be processed; S2. Slotting, deoxidizing, brushing and drying the welded parts of the cut materials to be processed; S3. Pre-welding, splicing the slotted materials to be processed, and then pre-welding, cleaning after pre-welding, to form multiple parts; S4. Welding, connecting the pre-welded parts, and then welding them under the protection of the protective structure to obtain a formed product; S5. Post-processing: cleaning and polishing the welding positions in the product.

[0007] According to the above technical means, the thin steel plate to be processed is first measured and cut to facilitate material selection according to different product types, and then deoxidized, brushed and dried during grooving to remove impurities, dust, etc. that affect welding, so as to facilitate subsequent welding; the thin steel plates are welded into separate parts by pre-welding and then connected to form a special shape, and oxygen-free welding is performed under the protection of a protective structure, so that with the cooperation of pre-welding, welding and a protective structure, the difficulty and complexity of welding can be reduced, and the performance of the welding parts can be made more uniform, so as to improve welding efficiency and welding quality; finally, the welding position is cleaned and polished to obtain a special-shaped cup body that is convenient for subsequent processing.

[0008] Preferably, in the step S2, during deoxidation, at least one of mechanical grinding, pickling, electrolytic pickling, laser cleaning and polishing is used.

[0009] More preferably, deoxidation is performed by pickling, and during pickling, dilute acid is used with stirring to perform deoxidation.

[0010] More preferably, the dilute acid is at least one of dilute hydrochloric acid, hydrofluoric acid, dilute sulfuric acid and dilute nitric acid, and the concentration is 0.2-0.8 mol / L.

[0011] Immersing and cleaning with dilute acid can effectively remove the oxide layer and dust on the steel plate. Stirring can reduce the pickling time and improve the cleaning efficiency.

[0012] Further preferably, in step S2, a wire brush or a nylon brush is used for brushing with clean water, so that the oxide layer remaining on the surface of the steel plate can be removed, and then the moisture can be removed by drying to facilitate subsequent processing.

[0013] Preferably, in the step S3, during the splicing, the cut materials to be processed are bent into at least one of special-shaped components with different diameters, ovals, squares, and diamonds.

[0014] Preferably, in the step S3, during pre-welding, the bent material to be processed is welded into shape by laser welding.

[0015] Further preferably, inert gas protection is performed during laser welding.

[0016] Further preferably, the inert gas is at least one of nitrogen, argon, helium and carbon dioxide, and the flow rate of the inert gas is 5-20 L / min and the pressure is 0.1-0.5 MPa.

[0017] Further preferably, when cleaning is performed after pre-welding, the cleaning is performed by at least one of mechanical grinding and polishing.

[0018] By first splicing, parts of different shapes are formed, which is convenient for customization according to different product types. Then laser welding is carried out, and inert gas protection is used during laser welding to form a welding area with more uniform performance. Finally, the welding area is cleaned to make it smooth and flat, which is conducive to subsequent processing.

[0019] Preferably, in the step S4, a connecting column is used for connection, and the connecting column has a plurality of annular parts with different diameters, and two adjacent annular parts are smoothly connected.

[0020] By using a connecting column and an annular part to coaxially connect parts of different diameters, on the one hand, the welding parts can be aligned more accurately, which is beneficial for subsequent welding; on the other hand, compared with the method of robot clamping or motor telescopic clamping, it can reduce the oxygen in the welding part, thereby reducing oxidation and improving the welding quality.

[0021] Preferably, in the step S4, when welding is performed under the protection of the protective structure, the welding end of the laser welding part is extended into the protective structure for welding, and air blowing protection is performed.

[0022] Further preferably, the protective structure may be at least one of an arc-shaped part and an opening and closing part, and the protective structure fits the gap between the welding parts.

[0023] Preferably, when performing air blowing protection, air is blown outside the protection structure, and the gas flow rate is 12-32 L / min and the pressure is 0.2-0.8 MPa.

[0024] By using a protective structure to protect the welding part and extending the welding end into the protective structure, on the one hand, it can isolate part of the oxygen during laser welding to reduce the occurrence of oxidation, and it can also block the arc generated during welding to reduce the impact on the workers; and by fitting the gap between the protective structure and the welding part, it is conducive to air blowing protection to further improve the welding quality.

[0025] By blowing inert gas from the outside of the protective structure to the inside of the welding part, on the one hand, gas protection can be carried out to expel oxygen from the welding part, further reducing the oxygen content in the welding part to improve the welding quality; on the other hand, since the welding parts rotate during welding, the slag produced by the molten pool during welding covers the surface of the molten pool to resist wind, oxygen and nitrogen, so that the molten pool exists longer, the metallurgical reaction is more complete, the composition of the welding part is more stable, and the mechanical properties are better.

[0026] Preferably, in the step S4, during welding, a filler material is also used for welding.

[0027] Further preferably, the filling material is a stainless steel coated core in a filamentous shape.

[0028] Further preferably, the core comprises the following raw materials in parts by weight: 1.2-6 parts of iron powder, 0.1-0.5 parts of cobalt powder, 0.02-0.1 parts of aluminum oxide, 0.1-0.3 parts of aluminum iron, 0.5-1.2 parts of nickel powder, 1.5-3 parts of ice crystal powder, 1-3 parts of quartz sand, and 0.05-0.15 parts of molybdenum powder.

[0029] By adding cobalt powder to the flux core, the wear resistance and corrosion resistance of the welded joint can be significantly improved, thereby extending the service life of the welded structure. It can also enhance the close bonding between the metal particles in the welded part, improve the strength, toughness and adhesion of the cemented carbide, and promote alloying; By adding ice crystal powder to the flux core, arc stability can be promoted and welding slag performance can be adjusted, while quartz sand can adjust the fluidity and crack resistance of welding materials, improve burning resistance, absorb gases generated by metals such as aluminum, and form slag. It is also beneficial to maintain dimensional stability after welding. Combined with cobalt powder, the mechanical properties of the welding part can be made more uniform. By adding a small amount of molybdenum powder to the flux core, the hardness, wear resistance, corrosion resistance, and thermal shock resistance can be improved, and alloying can be promoted. In combination with ice crystal powder, quartz sand, and cobalt powder, the welding quality can be improved. In combination with air blowing protection, gas-slag combined protection can be formed to further improve the welding quality.

[0030] More preferably, the weight of the drug core is 20-28% of the weight of the filling material.

[0031] Preferably, in the step S4, the energy density of welding is 1*10 5 w / cm²~4*10 6 w / cm², the pulse waveform is one of the flat-top square pulse waveform and the pre-spike pulse waveform.

[0032] Further preferably, the energy density of welding is 5*10 5 w / cm²~9*105 w / cm².

[0033] Further preferably, the pulse waveform is a flat-top square pulse waveform.

[0034] The welding quality can be further improved by controlling the energy density during laser welding and selecting the pulse waveform.

[0035] The present application adopting the above scheme has the following beneficial effects: 1. In the present application, the thin steel plate to be processed is first measured and cut so as to be selected according to different product types, and then deoxidized, brushed and dried during slotting to remove impurities, dust and the like that affect welding, so as to facilitate subsequent welding; the thin steel plates are welded into separate parts by pre-welding and then connected to form a special shape, and oxygen-free welding is performed under the protection of a protective structure, so that the difficulty and complexity of welding can be reduced with the cooperation of pre-welding, welding and a protective structure, and the performance of the welding part can be made more uniform, so as to improve welding efficiency and welding quality; finally, the welding position is cleaned and polished to obtain a special-shaped cup body that is convenient for subsequent processing; 2. By using a protective structure to protect the welding part and extending the welding end into the protective structure, on the one hand, it can isolate part of the oxygen during laser welding to reduce the occurrence of oxidation, and can also shield the arc generated during welding to reduce the impact on the workers; and by fitting the gap between the protective structure and the welding part, and blowing inert gas from the outside of the protective structure to the welding part inside, on the one hand, gas protection can be performed to discharge the oxygen in the welding part, further reducing the oxygen content in the welding part to improve the welding quality; on the other hand, because the welding parts rotate during welding, the slag generated by the molten pool during welding covers the surface of the molten pool to resist wind, oxygen and nitrogen, so that the molten pool exists longer, the metallurgical reaction is more complete, the composition of the welding part is more stable, and the mechanical properties are better; 3. In the present application, during welding, by using welding wire and adding cobalt powder, ice crystal powder, quartz sand and molybdenum powder to the flux core of the welding wire, the hardness, wear resistance, corrosion resistance and thermal shock resistance can be improved, and the alloying and other properties can be promoted, thereby making the mechanical properties of the welding part more uniform, improving the welding quality, and cooperating with air blowing protection to form gas-slag combined protection, thereby further improving the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present application may be further illustrated by non-limiting examples given in the accompanying drawings; Figure 1 This is a flow chart of a special-shaped multi-stage oxygen-free welding process in an embodiment of the present application; Figure 2 This is a diagram of the clamped state of the special-shaped structure in the embodiment of the present application during welding; Figure 3 This is one of the assembly drawings of the special-shaped structure on the connecting column in the embodiment of the present application; Figure 4 This is the second assembly diagram of the special-shaped structure on the connecting column in the embodiment of the present application; Figure 5 This is the third assembly diagram of the special-shaped structure on the connecting column in the embodiment of the present application; Figure 6 This is the fourth assembly drawing of the special-shaped structure on the connecting column in the embodiment of the present application; Among them, 100, screw rod; 110, first clamping block; 120, second clamping block; 200, connecting column; 300, protection structure; 400, first special-shaped component; 500, second special-shaped component; 600, annular portion. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention: Example 1

[0038] Preparation of filling materials Step 1: Evenly mix the following parts by weight: 3.5 parts of iron powder, 0.15 parts of cobalt powder, 0.05 parts of aluminum oxide, 0.25 parts of aluminum iron, 0.78 parts of nickel powder, 1.8 parts of ice crystal powder, 2.2 parts of quartz sand and 0.1 parts of molybdenum powder, and stir and dry at 210±5°C for 45-90 minutes to obtain a spare core; Step 2: Wrap the spare core in a stainless steel belt, and then draw the wire to obtain a filamentary material that meets the specifications; Step 3: annealing the filamentary material and cleaning the surface to obtain a filling material.

[0039] like Figure 1 As shown, a special-shaped multi-stage oxygen-free welding process The following steps are involved: S1. Pre-treatment: 304 stainless steel sheets with a thickness of 0.3 to 0.5 mm are measured and cut to lengths of 80 mm and 120 mm respectively; S2. Slotting, soak the 304 stainless steel sheets to be welded, which were cut to 80 mm and 120 mm, in 0.6 mol / L dilute hydrochloric acid for 1-2 hours, and slowly stir during the soaking process. After stirring, brush with a wire brush while washing with clean water. After brushing, dry in an oven at 110±5°C to obtain 80 mm and 120 mm 304 stainless steel sheets; S3. Pre-welding, the slotted 80 mm 304 stainless steel sheet is bent into a first special-shaped component 400, the 120 mm 304 stainless steel sheet is bent into a second special-shaped component 500, and then bent into an arc at the splicing position, and then pre-welding is performed. During the pre-welding, the bent first special-shaped component 400 and the second special-shaped component 500 are welded into shape by laser welding. During the laser welding process, argon gas is blown, the flow rate of argon gas is 8 L / min, and the pressure is 0.35 MPa. After the welding is completed, it is cleaned by mechanical grinding to form the first special-shaped component 400 and the second special-shaped component 500 respectively; S4. Welding, connecting the pre-welded first special-shaped member 400 and the second special-shaped member 500, using a connecting column 200 for connection, the connecting column 200 has a plurality of annular portions 600 of different diameters, and two adjacent annular portions 600 are smoothly connected, and the first special-shaped member 400 and the second special-shaped member 500 are sleeved on the connecting column 200 for connection; S41. After the connection, the arc-shaped protective structure 300 is placed at the connection between the first special-shaped member 400 and the second special-shaped member 500 (eg Figure 2-3 As shown), the welding end of the laser welding part is extended into the arc-shaped protective structure 300 for welding. During welding, a filler is placed at the joint part through a wire feeding device, and air is blown outside the arc-shaped protective structure 300. The gas flow rate is 20 L / min and the pressure is 0.6 MPa to obtain a formed product; S5. Post-processing: mechanically grinding and polishing the welding position in the product to obtain the product.

[0040] In this embodiment, the first special-shaped component 400 and the second special-shaped component 500 are both hollow cylindrical. Example 2

[0041] Preparation of filling materials II In this embodiment, the preparation of the filling material is the same as in Example 1, except that the amounts of the core composition are different, as follows: 4.2 parts of iron powder, 0.33 parts of cobalt powder, 0.02 parts of aluminum oxide, 0.18 parts of aluminum iron, 1.1 parts of nickel powder, 2.45 parts of ice crystal powder, 2.05 parts of quartz sand and 0.08 parts of molybdenum powder.

[0042] A special-shaped multi-stage oxygen-free welding process The following steps are involved: S1. Pretreatment: 304 stainless steel sheets with a thickness of 0.3-0.5 mm were measured and cut to lengths of 80 mm and 12 mm respectively; S2. Slotting, soak the 304 stainless steel sheets to be welded, which were cut to 80 mm and 120 mm, in 0.6 mol / L dilute hydrochloric acid for 1-2 hours, and slowly stir during the soaking process. After stirring, brush with a wire brush while washing with clean water. After brushing, dry in an oven at 110±5°C to obtain 80 mm and 120 mm 304 stainless steel sheets; S3. Pre-welding, the slotted 80 mm 304 stainless steel sheet is bent into a first special-shaped component 400, the 12 mm 304 stainless steel sheet is bent into a second special-shaped component 500, and then bent into an arc at the splicing position, and then pre-welding is performed. During the pre-welding, the bent first special-shaped component 400 and the second special-shaped component 500 are welded into shape by laser welding. During the laser welding process, argon gas is blown, the flow rate of argon gas is 8 L / min, and the pressure is 0.35 MPa. After the welding is completed, it is cleaned by mechanical grinding to form the first special-shaped component 400 and the second special-shaped component 500 respectively; S4. Welding, the pre-welded first shaped member 400 and the second shaped member 500 are connected, when connecting, the connecting column 200 is used for connection (such as Figure 4-5 As shown in FIG. 2 ), the connecting column 200 has a plurality of annular portions 600 of different diameters, and two adjacent annular portions 600 are smoothly connected, and the first special-shaped component 400 and the second special-shaped component 500 are sleeved on the connecting column 200 for connection; S41. After the connection, the arc-shaped protective structure 300 is placed at the connection between the first special-shaped member 400 and the second special-shaped member 500, (such as Figure 5 As shown in the figure, the welding end of the laser welding part is extended into the arc-shaped protective structure 300 for welding. During welding, a filler is placed at the joint part through a wire feeding device, and air is blown outside the arc-shaped protective structure 300. The gas flow rate is 20 L / min and the pressure is 0.6 MPa to obtain a formed product. S5. Post-processing: mechanically grinding and polishing the welding position in the product to obtain the product.

[0043] In this embodiment, the first special-shaped component 400 and the second special-shaped component 500 are both elliptical.

[0044] Example 3, Preparation of Filling Material III In this embodiment, the preparation of the filling material is the same as that of Example 1, except that the amounts of the core composition are different, as follows: 6.0 parts of iron powder, 0.5 parts of cobalt powder, 0.1 parts of aluminum oxide, 0.3 parts of aluminum iron, 1.2 parts of nickel powder, 3.0 parts of ice crystal powder, 3.0 parts of quartz sand and 0.15 parts of molybdenum powder.

[0045] The following steps are involved: S1. Pretreatment: 304 stainless steel sheets with a thickness of 0.3-0.5 mm were measured and cut to lengths of 80 mm and 10 mm respectively; S2. Slotting, soak the 304 stainless steel sheets to be welded, which were cut to 80 mm and 10 mm, in 0.6 mol / L dilute hydrochloric acid for 1-2 hours, and slowly stir during the soaking process. After stirring, brush with a wire brush while washing with clean water. After brushing, dry in an oven at 110±5°C to obtain 80 mm and 120 mm 304 stainless steel sheets; S3. Pre-welding, the slotted 80 mm 304 stainless steel sheet is bent into a first special-shaped component 400, the 10 mm 304 stainless steel sheet is bent into a second special-shaped component 500, and then bent into an arc at the splicing position, and then pre-welding is performed. During the pre-welding, the bent first special-shaped component 400 and the second special-shaped component 500 are welded into shape by laser welding. During the laser welding process, argon gas is blown, the flow rate of argon gas is 8 L / min, and the pressure is 0.35 MPa. After the welding is completed, it is cleaned by mechanical grinding to form the first special-shaped component 400 and the second special-shaped component 500 respectively; S4. Welding, the pre-welded first shaped member 400 and the second shaped member 500 are connected, when connecting, the connecting column 200 is used for connection (such as Figure 6 As shown in FIG. 2 ), the connecting column 200 has a plurality of annular portions 600 of different diameters, and two adjacent annular portions 600 are smoothly connected, and the first special-shaped component 400 and the second special-shaped component 500 are sleeved on the connecting column 200 for connection; S41. After the connection, the arc-shaped protective structure 300 is placed at the connection of the first special-shaped component 400 and the second special-shaped component 500, and the welding end of the laser welding part is extended into the arc-shaped protective structure 300 for welding. During welding, a filler is placed at the connection part through a wire feeding device, and air is blown on the outside of the arc-shaped protective structure 300. The gas flow rate is 20 L / min and the pressure is 0.6MPa to obtain a formed product; S5. Post-processing: mechanically grinding and polishing the welding position in the product to obtain the product.

[0046] In this embodiment, the first special-shaped component 400 and the second special-shaped component 500 are both square-shaped.

[0047] The welded products of Examples 1-3 were tested by visual inspection, leakage detection, thermal insulation performance test, tensile test, impact test, X-ray detection, and welding process assessment. During the leakage detection, high-pressure gas was introduced and soapy water was applied to the welding part; during the thermal insulation performance test, 80°C hot water was added to the product, and then it was sealed and finally placed in a refrigerator at 0°C for 24 hours for testing; during the tensile test, the test was carried out in accordance with the national standard GB / T 2651-2008 "Welded Joint Tensile Test Method", and the tensile strength Rm was used as the expression; during the impact test, the EN ISO 148-1 standard was followed and KU8 was used. During the welding process assessment, the AWS D1.1 standard was followed; According to the above results, in Examples 1 and 3 of the present application, the welding parts have good welding quality and relatively uniform mechanical properties. In Example 2, although the tensile strength of the welding parts is low, the welding process and testing methods used are the same, which may be due to the ratio of the flux core in the welding wire and the special-shaped structure of the welding parts, but the overall situation meets the quality requirements of the thermos cup. Therefore, in this application, by using pre-welding, welding and the cooperation of the protective structure 300 in the process of processing the thin steel plate into a special-shaped thermal insulation container, the difficulty and complexity of welding can be reduced, and the performance of the welding parts can be made more uniform, so as to improve the welding efficiency and welding quality; finally, by cleaning and polishing the welding position, a special-shaped cup body that is convenient for subsequent processing is obtained. Example 4

[0048] In this embodiment, the first special-shaped component 400 and the second special-shaped component 500 are both hollow cylindrical, and the filling material is the filling material in Embodiment 1, such as Figure 1 As shown, the welding process is as follows: The following steps are involved: S1. Pretreatment: 304 stainless steel sheets with a thickness of 0.3-0.5 mm are measured and cut into lengths of 80 mm and 120 mm respectively; S2. Slotting, soak the 304 stainless steel sheets to be welded, which were cut to 80 mm and 120 mm, in 0.6 mol / L dilute hydrochloric acid for 1-2 hours, and slowly stir during the soaking process. After stirring, brush with a wire brush while washing with clean water. After brushing, dry in an oven at 110±5°C to obtain 80 mm and 120 mm 304 stainless steel sheets; S3. Pre-welding, the slotted 80 mm 304 stainless steel sheet is bent into a first special-shaped component 400, the 120 mm 304 stainless steel sheet is bent into a second special-shaped component 500, and then bent into an arc at the splicing position, and then pre-welding is performed. During the pre-welding, the bent first special-shaped component 400 and the second special-shaped component 500 are welded into shape by laser welding. During the laser welding process, argon gas is blown, the flow rate of argon gas is 8 L / min, and the pressure is 0.35 MPa. After the welding is completed, it is cleaned by mechanical grinding to form the first special-shaped component 400 and the second special-shaped component 500 respectively; S4. Welding, the pre-welded first special-shaped component 400 and the second special-shaped component 500 are connected. When connecting, a connecting column 200 is used for connection. The connecting column 200 has a plurality of annular portions 600 of different diameters. Two adjacent annular portions 600 are smoothly connected. The first special-shaped component 400 and the second special-shaped component 500 are sleeved on the annular portions 600 on the connecting column 200 for connection, and the first clamping block 110 and the second clamping block 120 are used to press the first special-shaped component 400 and the second special-shaped component 500 against each other under the rotation of the screw rod 100, so as to facilitate welding of components of different sizes (such as Figure 2-3 shown); S41. After the connection, the arc-shaped protective structure 300 is placed at the connection of the first special-shaped component 400 and the second special-shaped component 500, and the welding end of the laser welding part is extended into the arc-shaped protective structure 300 for welding. During welding, a filler is placed at the connection part through a wire feeding device, and air is blown on the outside of the arc-shaped protective structure 300. The gas flow rate is 20 L / min and the pressure is 0.6MPa to obtain a formed product; S5. Post-processing: mechanically grinding and polishing the welding position in the product to obtain the product. Example 5

[0049] In this embodiment, the first special-shaped component 400 and the second special-shaped component 500 are both hollow cylindrical and do not use filling materials. Figure 1 As shown, the welding process is as follows: S1. Pretreatment: 304 stainless steel sheets with a thickness of 0.3-0.5 mm are measured and cut into lengths of 80 mm and 120 mm respectively; S2. Slotting, soak the 304 stainless steel sheets to be welded, which were cut to 80 mm and 120 mm, in 0.6 mol / L dilute hydrochloric acid for 1-2 hours, and slowly stir during the soaking process. After stirring, brush with a wire brush while washing with clean water. After brushing, dry in an oven at 110±5°C to obtain 80 mm and 120 mm 304 stainless steel sheets; S3. Pre-welding, the slotted 80 mm 304 stainless steel sheet is bent into a first special-shaped component 400, the 120 mm 304 stainless steel sheet is bent into a second special-shaped component 500, and then bent into an arc at the splicing position, and then pre-welding is performed. During the pre-welding, the bent first special-shaped component 400 and the second special-shaped component 500 are welded into shape by laser welding. During the laser welding process, argon gas is blown, the flow rate of argon gas is 8 L / min, and the pressure is 0.35 MPa. After the welding is completed, it is cleaned by mechanical grinding to form the first special-shaped component 400 and the second special-shaped component 500 respectively; S4. Welding, the pre-welded first special-shaped component 400 and the second special-shaped component 500 are connected. When connecting, a connecting column 200 is used for connection. The connecting column 200 has a plurality of annular portions 600 of different diameters. Two adjacent annular portions 600 are smoothly connected. The first special-shaped component 400 and the second special-shaped component 500 are sleeved on the annular portions 600 on the connecting column 200 for connection, and the first clamping block 110 and the second clamping block 120 are used to press the first special-shaped component 400 and the second special-shaped component 500 against each other under the rotation of the screw rod 100, so as to facilitate welding of components of different sizes (such as Figure 2-3 shown); S41. After the connection, the arc-shaped protective structure 300 is placed at the connection between the first special-shaped member 400 and the second special-shaped member 500, and the welding end of the laser welding part is extended into the arc-shaped protective structure 300 for welding, and the outer side of the arc-shaped protective structure 300 is blown, the gas flow rate is 20 L / min, the pressure is 0.6MPa, and a formed product is obtained; S5. Post-processing: mechanically grinding and polishing the welding position in the product to obtain the product.

[0050] The same test method as in Example 1-3 was used for testing. According to the above results, by using filler materials and in cooperation with the clamping block, the alignment accuracy of the two special-shaped components can be improved, and the welding quality can be improved by cooperating with the annular portion. Under the same conditions, by welding without using filler materials, although there is no difference in appearance performance, leakage performance and thermal insulation performance, the tensile strength is significantly reduced, and the deposition efficiency is also reduced. That is, by using filler materials, the tensile performance of the welding part can be enhanced, and it helps to make the welding process smoother, improve the deposition efficiency, and help to improve the uniformity of the performance of the welding part.

[0051] The above is a detailed introduction to a special-shaped multi-stage oxygen-free welding process provided by the present invention. The description of the specific embodiment is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0052] It should be noted that if no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be purchased commercially.

[0053] The above examples are intended to provide a better understanding of the present invention, and are not intended to be limiting of the best implementation mode described herein, nor are they intended to limit the content and protection scope of the present invention. Any product identical or similar to the present invention that is derived by anyone under the inspiration of the present invention or by combining the present invention with features of other prior arts shall fall within the protection scope of the present invention.

Claims

1. A special-shaped multi-stage oxygen-free welding process, characterized in that: The following steps are involved: S1. Pre-processing: measuring and cutting the materials to be processed; S2. Slotting, deoxidizing, brushing and drying the welded parts of the cut materials to be processed; S3. Pre-welding, splicing the slotted materials to be processed, and then pre-welding, cleaning after pre-welding, to form multiple parts; S4. Welding, connecting the pre-welded components, and welding them under the protection of the protective structure (300) to obtain a formed product; S5. Post-processing: cleaning and polishing the welding positions in the product.

2. The special-shaped multi-stage oxygen-free welding process according to claim 1 is characterized in that: In the step S2, during deoxidation, at least one of mechanical grinding, pickling, electrolytic pickling, laser cleaning, and polishing is used.

3. The special-shaped multi-stage oxygen-free welding process according to claim 1 is characterized in that: In the step S3, during the splicing, the cut materials to be processed are bent into at least one of special-shaped components with different diameters, ovals, squares, and diamonds.

4. The special-shaped multi-stage oxygen-free welding process according to claim 1 or 3, characterized in that: In the step S3, during pre-welding, the bent material to be processed is welded into shape by laser welding.

5. The special-shaped multi-stage oxygen-free welding process according to claim 1 is characterized in that: In the step S4, when the connection is performed, a connection column (200) is used for connection, and the connection column (200) has a plurality of annular portions (600) with different diameters, and two adjacent annular portions (600) are smoothly connected.

6. The special-shaped multi-stage oxygen-free welding process according to claim 1 or 5, characterized in that: In the step S4, when welding is performed under the protection of the protective structure (300), the welding end of the laser welding part is extended into the protective structure (300) for welding, and air blowing protection is performed.

7. The special-shaped multi-stage oxygen-free welding process according to claim 6 is characterized in that: When performing the air blowing protection, air is blown outside the protection structure (300), with a gas flow rate of 12-32 L / min and a pressure of 0.2-0.8 MPa.

8. The special-shaped multi-stage oxygen-free welding process according to claim 1 is characterized in that: In the step S4, during welding, a filler material is also used for welding, and the filler material is a stainless steel coated flux core in a filamentous shape.

9. The special-shaped multi-stage oxygen-free welding process according to claim 8, characterized in that: The core comprises the following raw materials in parts by weight: 1.2-6 parts of iron powder, 0.1-0.5 parts of cobalt powder, 0.02-0.1 parts of aluminum oxide, 0.1-0.3 parts of aluminum iron, 0.5-1.2 parts of nickel powder, 1.5-3 parts of ice crystal powder, 1-3 parts of quartz sand, and 0.05-0.15 parts of molybdenum powder.

10. The special-shaped multi-stage oxygen-free welding process according to claim 1, characterized in that: In the S4 step, the energy density of welding is 1*10 5 w / cm²~4*10 6 w / cm², the pulse waveform is one of the flat-top square pulse waveform and the pre-spike pulse waveform.

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