Argon arc welding method for storage tank in high-humidity environment

Abstract

The invention provides an argon arc welding method for a storage tank in a high-humidity environment, which comprises the following steps of: during welding preparation, using a flame spray gun to extend a certain distance towards two sides by taking a to-be-welded wet welding seam as a center to serve as a preheating area for preheating treatment; during welding, back argon filling protection is adopted, a worker holds an argon filling tool on the inner side of a tank in a matched mode to move along with a welding seam, the back of a welding part is covered with an argon filling protection part, and a relative sealed space filled with argon is formed in the welding part; in the welding process, the circulating cooling component is controlled to circularly cool the peripheral side of the welding gun; and after welding is completed, a welding seam is checked and cleaned. According to the method, the to-be-welded storage tank part is subjected to heat treatment, the welding environment is converted into the dry environment, and the influence of the high-humidity welding environment on welding is avoided; the welding seam quality and the mechanical property are improved through back argon filling protection; welding cooling ensures proper temperature of the welding gun, prolongs the service life of the welding gun and improves the stability of welding parameters; the circulating cooling component is mounted on the welding gun, so that high-temperature components of the welding gun are efficiently cooled, and efficient and sustainable use of the welding gun is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a argon arc welding method for a storage tank in a high humidity environment. Background Art

[0002] With the rapid development of industries such as petrochemicals, the production capacity of the hydrogen peroxide industry has been rapidly expanded. Hydrogen peroxide, as a strong oxidant, has special requirements for the material and welding technology of the storage container. Stainless steel is selected as the main material for hydrogen peroxide storage due to its excellent corrosion resistance. When welding stainless steel, the back of the weld must be protected to prevent oxidation, because oxidation on the back of the weld will produce a variety of defects. For example, when the back of the stainless steel weld is exposed to air, oxidation, slag, porosity or honeycomb defects will occur near the surface of the back weld, which will greatly affect the welding quality of the joint root, and then affect the strength and toughness of the weld, greatly reduce the intergranular corrosion performance, and shorten the service life of the weld. Therefore, it is very necessary to effectively protect the back of the weld during the welding process.

[0003] In the welding process of storage tanks or various pipe fittings, in order to ensure the welding quality, it is often necessary to fill argon gas on the back of the welding part for protection. Argon arc welding is a commonly used welding method. However, during the welding process, if the protective gas cannot be effectively provided on the back of the welding, it may cause defects such as oxidation and porosity in the weld, thereby affecting the strength and sealing of the welded structure; and many areas are in a high humidity environment, which will bring many challenges to the argon arc welding of storage tanks. High humidity may cause defects such as porosity and cracks in the welding process, affecting the quality of the weld and the structural strength of the storage tank.

[0004] Therefore, we propose a tank argon arc welding method in a high humidity environment to solve the problems raised in the background technology. Summary of the invention

[0005] The purpose of the present invention is to provide a argon arc welding method for a storage tank in a high humidity environment, so as to solve the problem that the high humidity environment may cause defects such as pores and cracks in the welding process, affecting the weld quality and the structural strength of the storage tank.

[0006] To achieve the above object, the technical solution adopted by the present invention is: A method for argon arc welding of a storage tank in a high humidity environment comprises the following steps: Step 1: Welding preparation; Install circulating cooling components at the parts of the welding gun that are prone to heat; use a flame spray gun to take the wet weld to be welded as the center and extend a distance to both sides as the preheating area for preheating treatment; Step 2: welding; During welding, argon arc welding is used for base welding, the welding current is set between 80A and 100A, the welding voltage is adjusted to 16-18V, the argon gas flow rate is controlled at 10-15L / min, the welding speed is controlled at 6-10cm / min, and the swing welding is adopted; When welding, argon filling protection is used at the back. Workers hold the argon filling tool inside the tank and move along the weld to cover the argon filling protection component on the back of the welding part, forming a relatively sealed space filled with argon gas at the welding part. During welding, the circulating cooling component is controlled to circulate and cool the surrounding area of ​​the welding gun; Step 3: Post-welding processing: inspect and clean the weld.

[0007] Further, in step one, the preheating area is centered on the wet weld and extends 90mm-110mm on both sides.

[0008] Furthermore, in step one, the preheating temperature is 120°C-180°C.

[0009] Furthermore, in step one, chalk powder is applied within a range of 200 mm on both sides of the weld of the storage tank to be welded.

[0010] Furthermore, the circulating cooling component in step 2 includes a sealing sleeve installed on the side of the welding gun, a heat conducting plate is arranged on the fitting surface between the sealing sleeve and the welding gun, and both ends of the sealing sleeve are respectively connected to a water inlet pipe and a drain pipe, and the water inlet pipe and the drain pipe are both connected to a water tank.

[0011] Furthermore, a tee is connected to one side wall of the sealing sleeve, the tee is connected to a drain pipe, the tee is also connected to a branch pipe, an atomizing nozzle is installed at one end of the branch pipe, and the atomizing nozzle faces the metal gun barrel of the welding gun.

[0012] Furthermore, the heat conducting plate is a copper plate.

[0013] Furthermore, the sealing sleeve and the welding gun are wrapped by an insulating waterproof tape.

[0014] Furthermore, the argon filling protection component described in step 2 includes a sealing cover, a hand-held rod is fixed to the outer wall of the sealing cover, a partition is provided in the middle of the sealing cover, a plurality of through holes are opened on the partition, and a connecting pipe connected to the argon storage tank is connected to the back of the sealing cover.

[0015] Furthermore, the back of the sealing cover is configured as a transparent cover, and a flexible endoscope is mounted on the transparent cover.

[0016] The present invention converts the welding environment into a dry environment by heat treating the storage tank parts to be welded, thereby avoiding the influence of high-humidity welding environment on welding; the weld quality and mechanical properties are improved by back argon filling protection; welding cooling ensures that the temperature of the welding gun is appropriate, prolongs its life and welding parameter stability; and by installing a circulating cooling component on the welding gun, the high-temperature components of the welding gun are efficiently cooled, ensuring efficient and sustainable use of the welding gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings herein are used to provide further explanation of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0018] Figure 1 An overall process flow chart of a welding method provided by an embodiment of the present invention; Figure 2 A schematic diagram of a circulating cooling component and its installation structure provided in an embodiment of the present invention; Figure 3 for Figure 2 A partial enlarged view of the middle part; Figure 4 A schematic diagram of the structure of the argon-filled protection component provided in this illustrated embodiment.

[0019] In the figure, 1- welding gun; 2- sealing sleeve; 201- heat conduction plate; 202- control button; 3- water inlet pipe; 4- three-way pipe; 401- drain pipe; 402- branch pipe; 403- atomizing nozzle; 404- control valve; 5- water tank; 6- self-priming pump; 7- hand-held rod; 8- sealing cover; 9- partition; 10- transparent cover; 11- connecting pipe. DETAILED DESCRIPTION

[0020] In order to make those skilled in the art better understand the present invention, the present invention is further clearly and completely described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the absence of conflict, the features in the embodiments and examples of this application can be combined with each other.

[0021] A typical embodiment of the present invention provides a tank argon arc welding method in a high humidity environment, such as Figure 1 As shown, the construction steps include welding preparation, welding and post-welding processing.

[0022] 1. Welding preparation, such as Figure 1 As shown, the process includes the following steps S101-S104.

[0023] S101. Material preparation, welding wire and sufficient argon gas. Sufficient welding wire can ensure that the welding process will not be interrupted due to welding wire shortage, thus ensuring the continuity of welding. Sufficient supply of argon gas can form an effective protective atmosphere, prevent the welding area from oxidation and absorption of harmful gases, and improve the purity and quality of the weld.

[0024] S102. Inspection and modification of welding equipment. Check the argon arc welding machine, including power connection, current and voltage adjustment. Carefully check the power connection of the argon arc welding machine to avoid welding interruptions or welding defects caused by power failure. Accurately adjust the current and voltage to ensure that the heat input during the welding process is just right, which not only ensures that the weld is fully fused, but also prevents changes in metal structure and performance degradation caused by overheating.

[0025] Install a circulating cooling component on the heating-prone part of the welding torch 1, and check the sealing between the circulating cooling component and the welding torch 1. Installing a circulating cooling component on the heating-prone part of the welding torch can significantly reduce the temperature of the welding torch during long-term operation, avoid damage to the welding torch and unstable welding parameters caused by overheating, and check the sealing between the circulating cooling component and the welding torch to prevent water leakage from affecting the cooling effect.

[0026] S103, weldment treatment: apply chalk powder within 200mm on both sides of the weld to prevent welding spatter from contaminating the weldment surface.

[0027] S104, local preheating treatment, using a flame spray gun to take the wet weld as the center, extend 90mm-110mm on both sides as the preheating area, preferably 100mm as the preheating area, and the preheating temperature reaches 120℃-180℃, preferably 150℃. Preheating the tank part to be welded changes the humidity of the welding environment, converts the welding environment into a dry environment, and avoids the influence of high humidity welding environment on welding.

[0028] During the welding preparation stage, sufficient material preparation ensures welding continuity and weld quality; equipment inspection and modification avoid power failure and unstable welding parameters; the installation of circulating cooling components and sealing inspection ensure the normal operation of the welding gun and the cooling effect.

[0029] In this step, the tank parts to be welded can be pickled to provide a clean, flat and corrosion-resistant welding surface. The preheating treatment reduces welding stress and deformation and avoids deterioration of weldment structure.

[0030] 2. Welding S201, argon arc welding primer, accurately set welding parameters, set the welding current between 80A-100A, accurately adjust the welding voltage to 16-18V, control the argon gas flow rate at 10-15L / min, select 2.5mm tungsten electrode diameter to ensure arc concentration and high energy density, control the welding speed at 6-10cm / min, and use a small swing method to weld, which helps to evenly distribute heat, make the weld beautiful, and reduce defects such as unfusion and slag inclusions.

[0031] S202, back argon filling protection, the worker uses the hand-held rod 7, cooperates with the hand-held argon filling tool inside the tank to move along the weld, and covers the argon filling protection component on the back of the welding part, forming a relatively sealed space filled with argon gas at the welding part, effectively preventing air from entering the welding area, avoiding oxidation and pores on the back of the weld, and improving the quality and mechanical properties of the weld.

[0032] S203, welding cooling, during the welding process, the circulating cooling component is controlled to circulate the water in the water tank to the side around the welding gun.

[0033] Welding cooling: During the welding process, the circulating cooling component is controlled to circulate the water in the water tank 5 into the side of the welding gun 1. The circulating cooling component is controlled to circulate the water in the water tank 5 into the sealing sleeve 2, which can quickly take away the large amount of heat generated by the welding gun and keep the temperature of the welding gun within a suitable range, which helps to extend the service life of the welding gun 1, ensure the stability of welding parameters, and avoid welding defects caused by overheating of the welding gun 1.

[0034] During the welding process, precise welding parameter settings make the weld firm, beautifully shaped, and reduce defects; back argon filling protection improves weld quality and mechanical properties; welding cooling ensures that the welding gun temperature is appropriate, extending its life and welding parameter stability.

[0035] In this embodiment, the circulating cooling component includes a sealing sleeve 2, a water inlet pipe 3, a drain pipe 401, a water tank 5 and a self-priming pump 6.

[0036] The sealing sleeve 2 is installed on the side of the welding gun 1, and a heat conducting plate 201 is installed at the contact surface between the sealing sleeve 2 and the welding gun 1. One side wall of the sealing sleeve 2 is connected to the water inlet pipe 3, and the other side wall of the sealing sleeve 2 is connected to the drain pipe 401. A self-priming pump 6 is installed on the water inlet pipe 3. The water inlet pipe 3 and the drain pipe 401 are both connected to the water tank 5. The heat conducting plate 201 is a copper plate.

[0037] A tee pipe 4 is connected to one side wall of the sealing sleeve 2, and the tee pipe 4 is connected to the drain pipe 401. The tee pipe 4 is also connected to a branch pipe 402, and an atomizing nozzle 403 is installed at one end of the branch pipe 402. A control valve 404 is installed on the branch pipe 402. The atomizing nozzle 403 faces the metal gun rod of the welding gun 1. The sealing sleeve 2 is provided with a control button 202, and the sealing sleeve 2 and the welding gun 1 are wrapped with an insulating waterproof tape. The water in the water tank 5 can be continuously pumped into the sealing sleeve 2 through the self-priming pump 6, and the heat conducting plate 201 attached to the outside of the high-temperature part of the welding gun 1 can be quickly cooled through the sealing sleeve 2.

[0038] During operation, the control valve 404 can be opened through the control button 202, and a small amount of water flows through the branch pipe 402 and the atomizing nozzle 403, and is splashed to the metal rod of the welding gun 1 after being atomized. The water mist is used to quickly cool the metal rod, and since the metal rod is in a high temperature state, the water mist is quickly evaporated, effectively avoiding the formation of water droplets on the metal rod, thereby ensuring the stability of welding; the operation of cooling the metal rod can be performed during the process of stopping welding.

[0039] According to this embodiment, the circulating cooling component can efficiently dissipate heat for the high-temperature components of the welding gun 1. The synergistic effect of the water inlet pipe 3, the drain pipe 401 and the self-priming pump 6 ensures the continuous circulation of water, making the cooling effect stable and lasting. The setting of the three-way pipe 4 realizes the reasonable distribution of water flow. While ensuring that most of the water is normally discharged through the drain pipe to maintain the overall cooling effect, a small part of the water is controlled by the control valve 404 to flow through the branch pipe 402 and the atomizing nozzle 403 to form a fine water mist to perform targeted cooling on the metal rod of the welding gun 1. Not only can the temperature of the metal rod be quickly reduced, but also the high temperature of the metal rod can quickly evaporate the water mist to avoid the formation of water droplets, thereby ensuring the stability of welding; the setting of the control button 202 facilitates the operation of the control valve 404, and can flexibly cool the metal rod, further optimizing the flexibility and controllability of cooling.

[0040] In this embodiment, the argon filling protection component includes a sealing cover 8, a hand-held rod 7 fixed to the outer wall of the sealing cover 8, a partition 9 is provided on the inner wall of the middle part of the sealing cover 8, and the partition 9 is provided with a plurality of through holes. A connecting pipe 11 is connected to the back plate of the sealing cover 8, and the connecting pipe 11 is connected to the argon storage tank. The back plate of the sealing cover 8 is set as a transparent cover 10. A flexible endoscope is installed on the inner wall of the transparent cover 10.

[0041] During operation, the argon gas tank can be opened to introduce the argon gas into the sealing cover 8. Since the sealing cover 8 covers the back of the welding part, a relatively sealed space is formed at the back of the welding part, and the argon gas is introduced into the sealed space. The partition 9 quickly blocks the argon gas, cooperates with the through hole to disperse it, and then guides it out through the through hole. When the argon gas passes through the through hole, the flow rate of the argon gas will be reduced due to the restriction and diversion effect of the through hole, thereby avoiding the situation where the local argon concentration in the welding area is too high or too low, and providing more uniform and effective protection for the welding area.

[0042] The transparent cover 10 can be used to observe in real time the flow of argon gas inside the sealing cover 8, the condition of the welding part, and whether there are any abnormal conditions, such as sparks flying, weld color changes, etc., which helps operators to detect problems in time and make corresponding adjustments to ensure the quality of welding.

[0043] By adding a flexible endoscope, the welder can observe the argon filling condition in the sealing cover 8 from different directions.

[0044] 3. Post-welding treatment S301. Weld inspection: After welding is completed, check whether the weld has surface defects. Surface defects include pores, cracks, slag inclusions, lack of fusion, and undercut.

[0045] S302. Clean the weld seam, clean the welding slag and spatter around the weld seam, pickle the welded tank weld seam, and neutralize the welded parts with clean water after pickling.

[0046] Post-welding treatment can detect defects in time through weld inspection, and weld cleaning can avoid corrosion and stress concentration; this method comprehensively improves the quality and reliability of tank argon arc welding, and ensures the safety and performance of the tank after welding.

[0047] The scope of protection claimed by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention may have various deformations and changes. Any modifications, improvements and equivalent substitutions made within the concept and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for argon arc welding of storage tanks in a high humidity environment, characterized in that: Includes steps: Step 1: Welding preparation; Install circulating cooling components at the parts of the welding gun that are prone to heat; use a flame spray gun to take the wet weld to be welded as the center and extend a distance to both sides as the preheating area for preheating treatment; Step 2: welding; During welding, argon arc welding is used for base welding, the welding current is set between 80A and 100A, the welding voltage is adjusted to 16-18V, the argon gas flow rate is controlled at 10-15L / min, the welding speed is controlled at 6-10cm / min, and the swing welding is adopted; When welding, argon filling protection is used at the back. Workers hold the argon filling tool inside the tank and move along the weld to cover the argon filling protection component on the back of the welding part, forming a relatively sealed space filled with argon gas at the welding part. During welding, the circulating cooling component is controlled to circulate and cool the surrounding area of ​​the welding gun; Step 3: Post-welding processing: inspect and clean the weld.

2. The method for argon arc welding of storage tanks in a high humidity environment according to claim 1, characterized in that: Step 1: The preheating area is centered on the wet weld and extends 90mm-110mm on both sides.

3. The method for argon arc welding of storage tanks in a high humidity environment according to claim 2, characterized in that: In step 1, the preheating temperature is 120°C-180°C.

4. The method for argon arc welding of storage tanks in a high humidity environment according to claim 1, 2 or 3, characterized in that: In step 1, chalk powder is applied within 200mm on both sides of the weld of the tank to be welded.

5. The method for argon arc welding of storage tanks in a high humidity environment according to claim 4, characterized in that: The circulating cooling component in step 2 includes a sealing sleeve installed around the welding gun, a heat conducting plate is arranged on the fitting surface between the sealing sleeve and the welding gun, and the two ends of the sealing sleeve are respectively connected to a water inlet pipe and a drain pipe, and the water inlet pipe and the drain pipe are both connected to the water tank.

6. The method for argon arc welding of storage tanks in a high humidity environment according to claim 5, characterized in that: A tee pipe is connected to one side wall of the sealing sleeve, and the tee pipe is connected to a drain pipe. The tee pipe is also connected to a branch pipe, and an atomizing nozzle is installed at one end of the branch pipe, and the atomizing nozzle faces the metal gun rod of the welding gun.

7. The method for argon arc welding of storage tanks in a high humidity environment according to claim 5 or 6, characterized in that: The heat conducting plate is a copper plate.

8. The method for argon arc welding of storage tanks in a high humidity environment according to claim 7, characterized in that: The sealing sleeve and the welding gun are wrapped by an insulating waterproof tape.

9. The method for argon arc welding of storage tanks in a high humidity environment according to claim 1 or 8, characterized in that: The argon filling protection component described in step 2 includes a sealing cover, a hand-held rod is fixed to the outer wall of the sealing cover, a partition is provided in the middle of the sealing cover, a plurality of through holes are opened on the partition, and a connecting pipe connected to the argon storage tank is connected to the back of the sealing cover.

10. The method for argon arc welding of storage tanks in a high humidity environment according to claim 9, characterized in that: The back of the sealing cover is arranged as a transparent cover, and a flexible endoscope is mounted on the transparent cover.

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