Welding method of thin aluminum plate

Abstract

The invention discloses a welding method for a thin aluminum plate. The welding method comprises the steps of preparation before welding, spot welding treatment, welding treatment and post-welding treatment. By the adoption of the welding method, an argon arc welding method is adopted, technological parameters are optimized, different welding currents, voltages, welding wire diameters, protective gas types and gas flow are selected according to structural parts of different welding seams, spot welding correction is carried out, then welding treatment is carried out, and the welding requirements of 5052 aluminum alloy sheets with the thickness being 2 mm and 1.5 mm are met; by means of the welding method, the welding steps are simplified, the welding process and the selection standard of all materials are standardized, and the welding method is suitable for application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy thin plate welding, and in particular to a welding method for thin aluminum plates. Background Art

[0002] Aluminum alloys have high specific strength, high fatigue strength, good fracture toughness and low crack growth rate. They also have excellent forming processability and good corrosion resistance. They have been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industries. The wide application of aluminum alloys has promoted the development of aluminum alloy welding technology. At the same time, the development of welding technology has expanded the application field of aluminum alloys. 5 series aluminum alloy is an aluminum alloy with Mg as the main added element. Due to its good corrosion resistance, it is also called rust-proof aluminum alloy. It is also a widely used alloy in AI-Mg alloys. It has lower density than pure aluminum, strong resistance to seawater corrosion, good weldability and polishability, and higher strength than pure aluminum and AI-Mn series alloys.

[0003] 5052-H32 material is aluminum-magnesium alloy. 5052 aluminum alloy belongs to Al-Mg alloy and has a wide range of applications. 5052 aluminum alloy has good forming performance, corrosion resistance and weldability, medium strength and other advantages. It is widely used in aerospace and is often used to manufacture aircraft fuel tanks and oil pipes. Especially for 5052 aluminum alloy sheets with a thickness of 2mm and 1.5mm, the existing welding method is prone to thermal cracks and pores, which affects the welding effect and leads to poor welding strength. Summary of the invention

[0004] The technical problem to be solved by the present invention is to standardize the welding method, which is conducive to the efficient and safe welding of thin aluminum plates, thereby providing a welding method suitable for thin aluminum plates, which can improve the quality of the weld and ensure that no defects such as pores and cracks are generated. In order to meet the welding requirements of 5052 aluminum alloy thin plates with a thickness of 2 mm and 1.5 mm, specifically, a welding method for thin aluminum plates.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a welding method for thin aluminum plates, the welding method includes pre-welding preparation, spot welding treatment, welding treatment and post-welding treatment, and specifically includes the following steps: S1. Preparation before welding: Check in advance whether the surface of the structural parts and welding wire to be welded is dry. If the surface is wet, it needs to be dried, and then use fine sandpaper to clean the surface oil, oxide film, and impurities. After cleaning, welding is required within 8 hours; S2. Spot welding: After the cleaning of the structural parts in step S1 is completed, the spot welding positions and number are determined according to the position and size of the structural parts to be welded. The number of spot welding is required to be at least 3, and the distance between two adjacent spot welding positions is 50 to 150 mm. Then, tungsten inert gas arc welding is used for spot welding. During the spot welding process, the length, width and excess height of the spot welding weld are required not to exceed the required values ​​of the design drawings. S3. Welding process: for the structural parts after spot welding in step S2, tungsten inert gas welding is adopted for full welding, the welding current is 90 to 105A, the welding voltage is 19 to 22V, the flow rate of the shielding gas is 8 to 10L / min, and the welding speed is controlled between 300 and 400mm / min; S4. Post-weld treatment: the structural parts after the welding treatment in step S3 are naturally cooled at room temperature.

[0006] Furthermore, a thin aluminum plate welding method according to the present invention is adopted, wherein the thin aluminum plate is a 5052-H32 rust-proof aluminum alloy plate, and the thickness of the rust-proof aluminum alloy plate is 1.5 to 2 mm.

[0007] Furthermore, a thin aluminum plate welding method described in the present invention is adopted. In the step S1, 240-grit sandpaper is used to clean the surface oil stains, and during the cleaning process, the original protective film of the structural parts needs to be retained and cannot be removed. The original protective film is removed after the welding is completed.

[0008] Furthermore, a thin aluminum plate welding method described in the present invention is adopted. In the step S2, during spot welding, anti-deformation preventive measures should be taken to prevent deformation according to the overall shape structure of the welded structural part; during the spot welding process, if the weld length, width and excess height of the spot welding exceed the required values ​​of the design drawing, filing and trimming should be performed; if there are welding defects such as cracks, pores, slag inclusions and tungsten inclusions, the weld nodules at the spot welding position should be removed and cleaned again before welding.

[0009] Furthermore, a thin aluminum plate welding method described in the present invention is adopted. In the welding step S3, for the structural parts adopting butt-type I welds, a 1.2 mm welding wire is selected, a welding current of 95 to 105 A, a welding voltage of 19 to 21 V, a gas flow rate of the shielding gas of 8 to 9 L / min, and a welding speed of 300 to 350 mm / min are used.

[0010] Furthermore, a thin aluminum plate welding method described in the present invention is adopted. In the step S3, for the structural parts adopting overlapping T-shaped welds, a 1.2 mm welding wire is selected, a welding current of 90 to 100 A, a welding voltage of 20 to 22 V, a gas flow rate of 9 to 10 L / min for the shielding gas, a welding speed of 350 to 400 mm / min, and during the welding process, wavy deformation is prevented.

[0011] Furthermore, in the welding method of a thin aluminum plate described in the present invention, the protective gas is high-purity argon gas, and the high-purity argon gas refers to argon gas with a purity of 99.99%.

[0012] Furthermore, in the welding method of a thin aluminum plate described in the present invention, the welding wire is 5 series ER5356 aluminum welding wire.

[0013] Furthermore, using the thin aluminum plate welding method described in the present invention, in the step S4, the structural parts after welding are first naturally cooled at a temperature of 26°C, and then the welds are mechanically trimmed with a gas grinder to remove spatter, and finally a small wooden hammer or a leather hammer is used to correct the welded structural parts and release the welding stress.

[0014] Compared with the prior art, the method for welding thin aluminum plates described in the present invention has the following beneficial effects: an argon arc welding method is adopted to optimize process parameters; different welding currents, voltages, welding wire diameters, shielding gas types and gas flow rates are selected according to structural parts of different welds; spot welding correction is performed before welding, so as to meet the welding requirements of 5052 aluminum alloy thin plates with a thickness of 2 mm and 1.5 mm, and ensure that no defects such as pores and cracks are generated, thereby significantly improving the welding efficiency of welded joints, weld quality and product qualification rate; the welding method described in the present invention simplifies the welding steps, standardizes the welding process, and standardizes the selection criteria of various materials, so as to be suitable for promotion and application. DETAILED DESCRIPTION

[0015] The following will be combined with 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

[0016] This embodiment provides a welding method for a thin aluminum plate, wherein the thin aluminum plate is a 5052-H32 rust-proof aluminum alloy plate, and the thickness of the rust-proof aluminum alloy plate is 1.5 mm. The welding method includes pre-welding preparation, spot welding treatment, welding treatment and post-welding treatment, and specifically includes the following steps: S1. Preparation before welding: Check in advance whether the surface of the structural parts to be welded and the welding wire are dry, and prepare the corresponding welding equipment, including the following aspects: First, check whether the surface of the workpiece to be welded and the welding wire is dry. If the surface is wet, it needs to be dried; Second, use 240-grit sandpaper to clean the surface oil, oxide film, and other impurities, and weld within 8 hours; Third, the welding method is argon arc welding (AC), the welding wire is ER5356 (5 series) welding wire, and the gas is high-purity argon gas (99.99%); Fourth, the original protective film of the aluminum plate cannot be removed and should be removed after welding is completed; Fifth, welder operators need to wear protective equipment, such as masks and protective clothing; Sixth, the welding environment requires ventilation, constant temperature, sufficient light, and no flammable or explosive items stored.

[0017] S2. Spot welding: After the cleaning of the structural parts, determine the spot welding position and quantity according to the position and size of the structural parts to be welded, which specifically includes the following aspects: First, determine the spot welding position and quantity according to the position and size of the welded structural parts. The number of spot welding is required to be at least three, and the distance between two adjacent spot welding positions is required to be 50-150mm; Second, during spot welding, preventive measures such as anti-deformation should be taken according to the welded structural parts to prevent deformation; Third, the length, width and excess height of the spot welding seam cannot exceed the required values ​​in the drawings. If they exceed, they should be filed and trimmed. If there are welding defects such as cracks, pores, slag inclusions, tungsten inclusions, etc., the weld nodules at the spot welding position should be removed and cleaned again before welding.

[0018] S3. Welding treatment: For the structural parts after spot welding, tungsten inert gas arc welding is used for full welding. The specific welding method should be carried out according to different butt welds, including the following two types of welds: One is to butt-weld Type I weld, using 1.2mm welding wire, welding current 95A, welding voltage 19V, gas flow 8L / min, and welding speed of about 300mm / min.

[0019] The second is to overlap the T-shaped weld, using 1.2mm welding wire, welding current 90A, welding voltage 20V, gas flow 9L / min, welding speed about 350mm / min. Pay attention to the wavy deformation during the welding process.

[0020] S4. Post-weld treatment: For structural parts after welding, post-weld treatment is required, which specifically includes the following aspects: One is to cool naturally at room temperature (26°C); The second is to use a gas grinder to mechanically trim the weld to remove spatter; The third is to use a small wooden hammer or leather hammer to correct the welded structural parts and release welding stress. Example 2

[0021] The welding method of a thin aluminum plate provided in this embodiment is different from that in Embodiment 1 in that, first, the thickness of the rust-proof aluminum alloy plate is a 2 mm thin plate; second, the process conditions used in the welding process are different, which are specifically reflected as follows: Welding treatment: For the structural parts after spot welding, tungsten inert gas arc welding is used for full welding. The specific welding method should be carried out according to different butt welds, including the following two types of welds: One is to butt-weld Type I weld, using 1.2mm welding wire, welding current 105A, welding voltage 21V, gas flow 9L / min, and welding speed about 350mm / min.

[0022] The second is to overlap the T-shaped weld, using 1.2mm welding wire, welding current 100A, welding voltage 22V, gas flow 10L / min, and welding speed of about 400mm / min; pay attention to wavy deformation during the welding process.

[0023] It can be seen that by adopting the welding method described in the present invention, the argon arc welding method is adopted, the process parameters are optimized, and different welding currents, voltages, welding wire diameters, shielding gas types and gas flow rates are selected according to the structural parts of different welds. After spot welding correction, welding processing is performed to meet the welding requirements of 5052 aluminum alloy sheets with a thickness of 2 mm and 1.5 mm, ensuring that defects such as pores and cracks are not generated. This can significantly improve the welding efficiency of the welded joint, the weld quality and the product qualification rate.

[0024] Other details of the present invention are conventional technologies known to those skilled in the art and are therefore not described in detail.

[0025] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. The above description is only a preferred implementation method of the present invention and does not limit the present invention. Any minor modifications, equivalent substitutions and improvements made according to the technical solutions of the present invention should be included in the protection scope of the technical solutions of the present invention.

Claims

1. A method for welding a thin aluminum plate, characterized in that: The welding method includes pre-welding preparation, spot welding process, welding process and post-welding process, and specifically includes the following steps: S1. Preparation before welding: Check in advance whether the surface of the structural parts and welding wire to be welded is dry. If the surface is wet, it needs to be dried, and then use fine sandpaper to clean the surface oil, oxide film, and impurities. After cleaning, welding is required within 8 hours; S2. Spot welding: After the cleaning of the structural parts in step S1 is completed, the spot welding positions and number are determined according to the position and size of the structural parts to be welded. The number of spot welding is required to be at least 3, and the distance between two adjacent spot welding positions is 50 to 150 mm. Then, tungsten inert gas arc welding is used for spot welding. During the spot welding process, the length, width and excess height of the spot welding weld are required not to exceed the required values ​​of the design drawings. S3. Welding process: for the structural parts after spot welding in step S2, tungsten inert gas welding is adopted for full welding, the welding current is 90 to 105A, the welding voltage is 19 to 22V, the flow rate of the shielding gas is 8 to 10L / min, and the welding speed is controlled between 300 and 400mm / min; S4. Post-weld treatment: the structural parts after the welding treatment in step S3 are naturally cooled at room temperature.

2. A method for welding a thin aluminum plate according to claim 1, characterized in that: The thin aluminum plate is a 5052-H32 rust-proof aluminum alloy plate, and the thickness of the rust-proof aluminum alloy plate is 1.5 to 2 mm.

3. A method for welding a thin aluminum plate according to claim 1, characterized in that: In step S1, 240-grit sandpaper is used to clean the surface oil stains, and during the cleaning process, the original protective film of the structural parts needs to be retained and cannot be removed. The original protective film will be removed after the welding is completed.

4. A method for welding a thin aluminum plate according to claim 1, characterized in that: In step S2, during spot welding, anti-deformation preventive measures should be taken according to the overall shape and structure of the welded structural parts to prevent deformation; during spot welding, if the length, width and excess height of the spot weld exceed the required values ​​of the design drawings, filing and trimming should be performed; if there are welding defects such as cracks, pores, slag inclusions and tungsten inclusions, the weld nodules at the spot welding positions should be removed and cleaned again before welding.

5. The method for welding a thin aluminum plate according to claim 1, characterized in that: In step S3, for the structural parts adopting butt-type I welds, a 1.2 mm welding wire is selected, a welding current of 95-105 A, a welding voltage of 19-21 V, a gas flow rate of 8-9 L / min of shielding gas, and a welding speed of 300-350 mm / min are used.

6. A method for welding a thin aluminum plate according to claim 1, characterized in that: In step S3, for the structural parts adopting overlapping T-shaped welds, a 1.2 mm welding wire is selected, a welding current of 90-100 A, a welding voltage of 20-22 V, a gas flow rate of 9-10 L / min for the shielding gas, a welding speed of 350-400 mm / min, and during the welding process, wavy deformation is prevented.

7. A method for welding a thin aluminum plate according to claim 1, characterized in that: The protective gas is high-purity argon gas, and the high-purity argon gas refers to argon gas with a purity of 99.99%.

8. The method for welding a thin aluminum plate according to claim 1, characterized in that: The welding wire is 5 series ER5356 aluminum welding wire.

9. A method for welding a thin aluminum plate according to claim 1, characterized in that: In step S4, the welded structural parts are first naturally cooled at a temperature of 26°C, and then the welds are mechanically trimmed with a gas grinder to remove spatters. Finally, a small wooden hammer or leather hammer is used to calibrate the welded structural parts and release welding stress.