A method for welding thick plates of hollow tungsten extremely deep penetration tig welding

Abstract

The invention relates to a method for welding thick plates of hollow tungsten extremely deep penetration TIG welding, which comprises the following steps: step 1: fixing the workpiece to be welded on the welding fixture; -1000A, starting arc current is 350-1100A, slightly higher than welding current, cut-off current is 200-300A, starting time is 0.4-0.6s, transition time is 0.5-0.8s, falling time is 2-3s, ionized gas The flow rate is 4‑6L / min, the shielding gas flow rate is 15‑20L / min, the gas supply time is 3‑5s in advance, the inner hole of the hollow tungsten electrode is filled with argon gas, the gas flow rate is 3‑5L / min, and the shielding gas on the weld Both the shielding gas and the lower shielding gas are argon, the gas flow rate is 18-20L / min, the gas delay after welding is 15-40s, the workpiece gap is 0.2-0.5mm, and the welding speed is 200-500mm / min; Step 3: Pass Press the welding preparation and welding start buttons on the welding machine to start welding thick plates. The invention realizes the one-time penetration of the thick plate, and ensures the high quality of the welding seam while realizing the high-speed welding of the thick plate.

Description

technical field [0001] The invention relates to a welding method, in particular to a method for welding thick plates of hollow tungsten extremely deep penetration TIG welding. Background technique [0002] For a long time, argon tungsten arc welding has a stable welding process and good welding quality, and has been widely used in actual welding production. However, this method has obvious defects: the single-pass welding seam has shallow penetration, low deposition rate and no It is suitable for thick plate welding. The STIG welding system achieves the effect of plasma arc through the high-efficiency electromagnetic compression of the arc. The arc energy is concentrated during welding. During the welding process, the arc pressure and the surface tension of the liquid metal in the molten pool are balanced to form a stable The small hole effect, with super penetrating ability, can penetrate steel plates below 12mm at one time, but due to the limited current carrying capacity ...

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Problems solved by technology

[0002] For a long time, argon tungsten arc welding has a stable welding process and good welding quality, and has been widely used in actual welding production. However, this method has obvious defects: the single-pass welding seam has shallow penetration, low deposition rate and no It is suitable for thick plate welding. The STIG welding system achieves the effect of plasma arc through the high-efficiency electromagnetic compression of the arc. The arc energy is concentrated during welding. During the welding process, the arc pressure and the surface tension of the liquid metal in the molten pool are balanced to form a stable The small hole effect, with super penetrating ability, can penetrate steel plates below 12mm at one time, but due to the limited current carrying capacity of TIG welding tungsten electrodes, the maximum welding current that can be used during welding is small, if a large current is used When welding, the tungsten electrode required is very thick

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