What is
TIG welding?
TIG welding: clean seams, stable connections
Tungsten inert gas welding (TIG welding) is a gas shielded welding process and is one of the fusion welding processes. It is used wherever optimum quality and spatter-free weld seams are required. TIG welding is suitable, among other things, for stainless steels, aluminum and nickel alloys as well for thin sheet metal made of aluminum and stainless steel. It is used in pipeline and container construction, in portal construction and in aerospace applications.
TIG welding: This is how it works
In TIG welding, the required current is supplied via a tungsten electrode, which is temperature-resistant and does not melt. This electrode emits an arc that heats up and liquefies the material. There is a nozzle for shielding gas around the electrode. This protects the heated material from chemical reactions with the ambient air. The noble gases argon, helium or mixtures thereof are used for this purpose. The inert, i.e. non-reactive, gases prevent chemical reactions with the liquid weld pool and the heated material. This ensures high-quality weld seams.
As the tungsten electrode does not melt, in TIG welding the filler material is fed in by hand or in mechanized form by an external wirefeeder.
The tungsten electrode
The tungsten electrode is the heart of TIG welding. At 3380 degrees Celsius, tungsten has the highest melting point of all pure metals in the periodic system. This means that the electrode does not melt when it emits an arc that heats and liquefies the material. The electrodes are produced using a sintering process. In order to improve their properties, they can be alloyed with oxidic additives. The electrodes are color-coded according to the alloy:
This is how a TIG welding system is structured:
(1) Mains connection
(2) Power source
(3) Hosepack
(4) Grounding cable
(5) Welding torch
(6) Ground terminal
(7) Workpiece
(8) Filler metal
(9) Shielding gas
Process variants of TIG welding
Cold-Wire TIG welding
A cold-wire feed increases productivity: The welding speed increases and the filler metal is fed precisely and evenly to the weld pool. This allows even less-experienced welders to achieve outstanding results.
TIG Hot-Wire welding
TIG hot-wire welding was developed from cold wire TIG welding. In TIG hot-wire welding, the filler metal is heated. This has various advantages: The deposition amount and rate increase, the welding speed rises and the fusion is reduced.
Orbital welding
The basic setup of orbital welding equipment includes a fixed pipe and a moveable TIG welding torch/welding head that moves around the pipe. The moveable orbital welding head is also referred to as a spot welding gun. The orbital welding technique is useful wherever consistent seam qualities must be attained under controlled conditions. Consequently, the main usage areas for this welding technology are pipeline construction, the food industry, and the chemical industry. With the orbital technique, it is not only possible to produce pipe-to-pipe connections, but also to weld pipes into pipe baseplates.
Cladding
Cladding is a process in which the components are coated with special alloys in order to extend their service life significantly. This coating is carried out through mechanized electro-surfacing. Fronius Speed Cladding makes the coating process up to three times faster and more efficient.
ArcTig
The ArcTig welding process is a TIG process variant for mechanized joint welding. It allows for an excellent weld seam appearance, reliable full penetration welding of the root pass and very high weld quality. Due to the increased welding speed and reduced work to prepare the seam, ArcTig also makes the whole welding process more cost-effective.
Which materials are suitable for TIG welding?
The most widely used materials in TIG welding include stainless steels, aluminum and nickel alloys and thin sheets of aluminum and stainless steel. With a mechanized wirefeeder, cost-effective welding speeds can be achieved for sheet thicknesses of less than 4 mm. For thicker sheets the cost-effectiveness decreases, and the TIG process is recommended for welding the root pass only. More powerful processes such as MIG/MAG or submerged arc welding are suitable for welding the filler beads.
Professional welding systems for TIG welding
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