TPi September 2019

Products & developments

ArcTig welding with enhanced cooling When welding, it is not only seam quality that matters: speed also plays a significant role. Both of these help the welder to work more efficiently. With the modified TIG process ArcTig, Fronius has developed an innovation for mechanised joint welding that addresses these requirements.

© Fronius International GmbH

A special welding torch allows the TIG arc to be focused in a targeted manner and its energy density is increased. Users can weld up to 10mm-thick high- alloy sheets and pipes without extensive seam preparation, to a high quality standard, and faster. The ArcTig welding process from Fronius is based on the principle of tungsten inert gas (TIG) welding. In this process, an arc burns between a non-melting tungsten electrode and the metallic workpiece in an oxygen-free, reactionless gas atmosphere. The current flow heats the electrode, resulting in an electron flow. This reduces the combined resistance, producing a soft, wide arc. The inert protective gas shield means there are no chemical reactions with the liquid weld pool. This enables users to produce a perfect weld-seam appearance without tempering colours and spatter, as well as the best weave pattern. TIG welding is suited to a variety of different materials and applications, including titanium. The ArcTig welding process is designed for applications in container and pipe construction, in the manufacture of turbines and the construction of special machines, cranes and tanks. The key

The ArcTig welding process from Fronius achieves high welding speeds and weld seam quality

to 10mm. In conventional TIG welding, several layers are often needed. As there is no gap during seam preparation, no weld pool support is required for the ArcTig process. This cuts down on rework to a large extent, since the weld seam is raised to a minimal degree and there is very little distortion due to the reduced heat input. This enables users to accelerate processing times considerably, while the welding process also permits higher welding speeds. Because it is similar to TIG welding, users do not have to adjust to a new process and can weld immediately. This minimises the need for training and prevents incorrect operation by the welder, as only a few parameters need to be set. Users can make use of standard TIG electrodes that are quick to change and can easily be re-ground as necessary. The new electrode clamping system clamps the electrode over a large area. To make the weld seam more accessible and to enable the arc to be manipulated better, the free end of the electrode can be adjusted depending on the requirements. Fronius International GmbH – Austria contact@fronius.com www.fronius.com

innovation is the optimised welding torch with an electrode clamping system, which enables the electrode to be cooled right to the tip. This increases the combined resistance and creates a high arc voltage. Electron emission takes place over a small area but at a high density. This makes the arc narrower and more targeted, allowing the user to achieve improved weld seam quality. Another advantage of the cooling is that it prevents overheating of the electrode during welding, providing increased arc stability and ensuring a longer service life and improved ignition. Users can easily upgrade all TIG power sources from Fronius above an output of 220 amperes to the ArcTig process. The only equipment required is the new welding torch and an additional heat exchanger to provide the cooling capacity and the required temperature stability. ArcTig is also available as a complete system.

© Fronius International GmbH

The focused and high- pressure arc allows the ArcTig to be used to weld components in one layer to a material thickness of up

The ArcTig welding process is suitable for the efficient continuous production of pipes

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September 2019 TUBE PRODUCTS INTERNATIONAL