Techniques and Operating Procedures for Tungsten Inert Gas Welding Process

Understanding of Tungsten Inert Gas Welding Process

Tungsten Inert Gas Welding Process, also known as non-melting electrode gas shielded welding, uses pure tungsten or activated tungsten (thorium tungsten, cerium tungsten, zirconium tungsten, lanthanum tungsten) as the non-melting electrode and inert gas protection arc welding, with high quality but slow speed. Tungsten inert gas welding process refers to non-melting electrode gas shielded welding, a kind of arc welding method which uses added gas as protective medium. Its advantages are good visibility of arc and molten pool, easy operation, no or little slag, and no need to clean slag after welding. However, special windproof measures need to be taken when working outdoors.

Techniques of Tungsten Inert Gas Welding Process

• Technique 1: Tungsten inert gas welding process itself belongs to visible arc operation, and the shape and flow of molten pool can be well observed, which is much superior to stick arc welding.

• Technique 2: Controlling the stability of hand during welding is the key, avoiding trembling and burning the tungsten electrode and causing tungsten inclusion in the molten pool. The control method can be to support the index finger of the welding gun on the welded pipe or plate. The length of tungsten electrode extension can be selected according to the depth of the groove, generally 3 to 5 mm.

Regarding the wire feeding method, it can be selected according to the size of the groove. When the groove angle is small, the welding wire can be placed in the middle of the molten pool and sent in continuously. When the groove is larger, two-sided wire feeding (being quite skilled to avoid touching the tungsten electrode) can be used, and the welding gun moves left and right to ensure good fusion at the edge. Regarding the full fish scale on the surface, according to the standard, the weld bead reinforcement of the tungsten inert gas welding process is generally 0 to 2 mm, and the surface should be smooth without undercut, porosity or cracks.

Operating Procedures of Tungsten Inert Gas Welding Process

The argon arc welding must be operated by a specialist to turn on the switch. Before work, check whether the equipment and tools are in good condition. Check the welding power supply and control system for grounding wires, and add lubricating oil to the transmission parts. The rotation must be normal, and argon gas and water sources must be unobstructed. If there is leakage, repair should be notified immediately. Check whether the welding gun is normal and whether the grounding wire is reliable.

Check whether the high-frequency ignition system and welding system are normal, and whether the wire and cable joints are reliable. For automatic wire feeder argon arc welding, it is also necessary to check whether the adjustment mechanism and wire feeder mechanism are intact. According to the material of the workpiece, choose the polarity, and connect the welding circuit. Generally, the material is connected to DC positive, and aluminum and aluminum alloy use reverse connection method or AC power supply. Check whether the welding groove is qualified, and there should be no oil stains or rust on the groove surface. Oil and rust should be removed within 200 mm on both sides of the weld.