A double clad related assembly single rod high pressure seal TIG welding method

Abstract

The application belongs to the technical field of automatic high-pressure sealed TIG welding, and particularly relates to a double-cladding related assembly single-rod high-pressure sealed TIG welding method. The method comprises the following steps: sending and positioning and clamping of a double-cladding related assembly single rod, tail sealing, cavity high-pressure sealing, high-frequency high-pressure arc striking welding, and cavity gas releasing. The application has the beneficial effect that through the design of automation and cavity airflow, the high-pressure stability effect of the sealed cavity is achieved, the welding airflow direction is effectively controlled, and the oxidation problem of the weld and the heat-affected zone is solved.

Description

Technical Field

[0001] This invention belongs to the field of automated high-pressure sealing TIG welding technology, specifically relating to a single-rod high-pressure sealing TIG welding method for double-shell related components. Background Technology

[0002] The AP1000 double-clad related component single-rod circumferential weld employs a high-pressure sealed TIG welding method. TIG welding is a common welding method, but the weld penetration and formation are affected by fluctuations in chamber pressure. The single-rod of the double-clad related component is used for reactor power regulation, placing high demands on the weld. Existing double-clad related component single-rods involve high-pressure welding of thin-walled tubes and thin-walled end plugs. Due to the influence of chamber pressure and sealing conditions, defects such as insufficient weld penetration, unstable weld formation, and weld burn-through occur. During the welding process, high-pressure rotation of the single-rod, increased chamber pressure, and welding fume emissions contribute to internal welding defects. Summary of the Invention

[0003] The purpose of this invention is to provide a high-pressure sealing TIG welding method for a single rod of a double-clad related component, which solves the stability problem of circumferential welding of a single rod of a double-clad related component under high pressure.

[0004] The technical solution of the present invention is as follows: a high-pressure sealing TIG welding method for a single rod of a double-shell related component, including feeding, positioning and clamping of the single rod of the double-shell related component, tail sealing, high-pressure sealing of the chamber, high-frequency high-pressure arc welding, and gas release from the chamber.

[0005] The single rod of the double-layer shell related component is fed, positioned, and clamped by manually feeding it through the rotating chuck and the single rod sealing component into the welding chamber, stopping at the positioning block, and the rotating chuck clamping the single rod of the double-layer shell related component.

[0006] The tail seal is achieved by fitting the lower end sealing component into the lower end plug and the outer shell, with the weld between the lower end plug and the outer shell tightly fitting the sealing element.

[0007] The high-pressure sealing of the chamber is achieved by introducing high-pressure helium gas into the welding chamber through the welding torch component. Due to the high pressure, the U-shaped openings of the seals in the welding chamber and the seals at the lower end plug expand and tightly adhere to the single rod of the related component of the double-layer shell, thus achieving a high-pressure seal. At the same time, the pneumatic valve of the exhaust pipe opens and the exhaust is closed. By adjusting the exhaust branch with a flow meter, the pressure in the chamber is kept stable and balanced within the required range.

[0008] The high-frequency high-voltage arc ignition welding is performed after the voltage stabilization is completed. The rotating chuck drives the single rod of the double-layer shell related component to rotate. The high-frequency high-voltage arc igniter discharges to the single rod of the double-layer shell related component through the electrode in the welding gun component. When the arc is successfully ignited, the welding machine power supply outputs DC pulse current to complete the high-voltage TIG welding of the single rod of the double-layer shell related component.

[0009] The chamber gas release is achieved by opening the exhaust valve after the high-pressure TIG welding is completed and the weld has been cooled for a certain period of time. At the same time, the high-pressure gas in the welding chamber is released by switching to low-flow gas purging to ensure the welding chamber environment.

[0010] The exhaust pipe is connected to the bottom of the welding chamber by a through hole. The positioning block is mechanically connected to the chamber and serves to position the single rod of the relevant components. The welding torch component includes the welding torch and its connecting parts, which are mechanically connected to the welding chamber. The welding shielding gas enters the welding chamber from the welding torch component. The single rod sealing part is mechanically connected to the welding chamber. The sealing element in the single rod sealing part is made of soft rubber. When subjected to pressure, it expands and isolates the outer shell entering the welding chamber from the outside, forming a sealed chamber. The lower end sealing part is inserted into the lower end plug of the single rod. The lower end sealing part is fixed by a mechanical locking device. The pressure of the inner shell connected to the sealing part chamber forms a seal on the single rod. The lower end sealing part rotates together with the outer shell clamped by the rotating chuck.

[0011] The beneficial effects of this invention are as follows: 1. By employing automated and chamber airflow design methods, a high-pressure stability effect is achieved in the sealed chamber, effectively controlling the welding airflow direction and solving the oxidation problem of the weld and heat-affected zone. 2. Through the design of the single-rod sealing mechanism for non-standard double-shell related components, the problem of air leakage during the rotation of single rods in double-shell related components during the welding process is effectively solved. 3. Through the design of high-frequency, high-pressure arc initiation, the problem of arc initiation stability in TIG welding under high-pressure helium protection is effectively solved. 4. Through the design of welding pulses, welding heat is reduced and molten pool stirring is accelerated, effectively solving the problems of weld protrusion and porosity defects. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a single-rod high-pressure sealing TIG welding method for a double-shell related component provided by the present invention.

[0013] In the diagram, 1. Lower end plug; 2. Outer shell; 3. Inner shell; 4. Upper end plug; 5. Single rod sealing component; 6. Lower end sealing component; 7. Sealing element; 8. Rotary chuck; 9. Welding chamber; 10. Welding torch component; 11. Positioning block; 12. Exhaust pipe. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] A TIG welding method for high-pressure sealing of a single rod of a double-clad related component includes feeding, positioning and clamping of the single rod of the double-clad related component, tail sealing, high-pressure sealing of the chamber, high-frequency high-pressure arc welding, and gas release from the chamber.

[0016] The single rod of the double-shell related component is fed, positioned and clamped by manually passing the single rod through the rotating chuck 8 and the single rod sealing component 5 into the welding chamber 9, and stopped at the positioning block 11. The rotating chuck 8 completes the clamping of the single rod of the double-shell related component.

[0017] The tail seal of the single rod of the double-shell related component is achieved by fitting the lower end sealing component 6 into the lower end plug 1 and the outer shell 2, and the weld between the lower end plug 1 and the outer shell 2 is tightly fitted with the sealing component 7.

[0018] The high-pressure sealing of the chamber of the single rod of the double-clad related component is achieved by introducing high-pressure helium gas into the welding chamber 9 through the welding torch component 10. Due to the high pressure, the U-shaped opening of the sealing element 7 inside the welding chamber 9 and the sealing element 7 at the lower end plug 1 expands and tightly adheres to the single rod of the double-clad related component, thus achieving a high-pressure seal. Simultaneously, the pneumatic valve of the exhaust pipe 12 opens, and the exhaust is closed. By adjusting the exhaust branch equipped with a flow meter, the pressure within the chamber is maintained within a stable balance within the required range.

[0019] The high-frequency, high-voltage arc ignition welding of the single rod of the double-clad related component is performed after voltage stabilization. The rotating chuck 8 drives the single rod of the double-clad related component to rotate, and the high-frequency, high-voltage arc igniter, controlled by a program, discharges onto the single rod of the double-clad related component through the electrodes in the welding torch component 10. Once the arc is successfully ignited, the welding machine power supply outputs a DC pulse current to complete the high-voltage TIG welding of the single rod of the double-clad related component.

[0020] The chamber gas release of the single rod of the double-shell related component is carried out after the high-pressure TIG welding is completed and the weld is cooled for a certain period of time. The high-pressure gas in the welding chamber 9 is released by opening the exhaust valve, and at the same time, the gas flow rate is switched to low flow to purge and ensure the welding chamber environment.

[0021] The exhaust pipe 12 has a through hole at the bottom of the welding chamber 9 connected to the exhaust pipe. The positioning block 11 is mechanically connected to the chamber 9, serving to position the single rod of the relevant components. The welding torch component 10, including the welding torch and its connecting parts, is mechanically connected to the welding chamber 9. Welding shielding gas enters the welding chamber 9 from the welding torch component 10. The single rod sealing component 5 is mechanically connected to the welding chamber 9. The key component of the single rod sealing component 5 is the sealing element 7, made of soft rubber. When subjected to pressure, it expands, isolating the outer shell 2 entering the welding chamber 9 from the outside, forming a sealed chamber. The lower end sealing component 6 is inserted into the lower end plug of the single rod. The lower end sealing component 6 is fixed to the sealing element 7 by a mechanical locking device. The pressure of the inner shell 3 connected to the sealing element 7 chamber forms a seal on the single rod. The lower end sealing component 6 rotates together with the outer shell 2 clamped by the rotating chuck 8.

[0022] The features of this invention are as follows:

[0023] 1. The gas circulation design of the welding chamber is adopted to achieve continuous and stable welding of the single-bar chamber pressure of the double-shell related components.

[0024] 2. The non-standard double-layer shell sealing component design effectively ensures the sealing effect between the chamber and the workpiece during welding.

[0025] 3. High-frequency high-voltage combined with DC pulse high-voltage rotary circumferential welding is carried out in a high-purity helium environment, and the welding quality of the double-layer thin-walled tube is guaranteed through process control.

[0026] 4. Using a sealing component connected to the chamber and a sealing component tooling at the lower end of the single rod, a seal is formed between the entire single rod and the chamber under the action of gas pressure.

Claims

1. A method of double containment related assembly single rod high pressure seal TIG welding, characterized by: The process includes feeding, positioning, and clamping of a single rod of a double-shell related component, tail sealing, high-pressure sealing of the chamber, high-frequency and high-pressure arc welding, and gas release from the chamber. The high-pressure sealing of the chamber involves introducing high-pressure helium gas into the welding chamber through the welding torch component. Due to the high pressure, the U-shaped openings of the seals in the welding chamber and the seals at the lower plug expand and tightly adhere to the single rod of the double-shell component, achieving a high-pressure seal. Simultaneously, the pneumatic valve in the exhaust pipe opens and the exhaust is closed. By adjusting the exhaust branch equipped with a flow meter, the pressure inside the chamber is kept stable and balanced within the required range. The single rod of the double-layer shell related component is fed, positioned and clamped by manually feeding the single rod of the double-layer shell related component into the welding chamber through the rotating chuck and the single rod sealing component, stopping at the positioning block, and the rotating chuck completes the clamping of the single rod of the double-layer shell related component. The tail seal is achieved by fitting the lower end sealing component into the lower end plug and the outer shell, with the weld between the lower end plug and the outer shell tightly fitting the sealing element. The high-frequency high-voltage arc ignition welding is performed after the voltage stabilization is completed. The rotating chuck drives the single rod of the double-layer shell related component to rotate. The high-frequency high-voltage arc igniter discharges to the single rod of the double-layer shell related component through the electrode in the welding gun component. When the arc is successfully ignited, the welding machine power supply outputs DC pulse current to complete the high-voltage TIG welding of the single rod of the double-layer shell related component.

2. The single-rod high-pressure sealing TIG welding method for a double-shell related component as described in claim 1, characterized in that: The chamber gas release is achieved by opening the exhaust valve after the high-pressure TIG welding is completed and the weld has been cooled for a certain period of time. At the same time, the high-pressure gas in the welding chamber is released by switching to low-flow gas purging to ensure the welding chamber environment.

3. The single-rod high-pressure sealing TIG welding method for a double-shell related component as described in claim 1, characterized in that: The exhaust pipe is connected to the bottom of the welding chamber by a through hole. The positioning block is mechanically connected to the chamber and serves to position the individual rods of the relevant components. The welding torch component includes the welding torch and its connecting parts, which are mechanically connected to the welding chamber. The welding shielding gas enters the welding chamber from the welding torch component.

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