TPT January 2014

Technology News

The TIGer hot wire welding technology By Jean-Pierre Barthoux – technical director and European welding engineer

the layers to within a range of normally between 1.5 and 3.5mm. This flexibility enables the quantity of weld metal to be adjusted to strict requirements and allows significant savings to be made taking into account the costs of filler products (generally the noble alloys). The optimised welding speeds are of the order of 70 to 90cm/min with deposition rates of between 2.5 and 6kg/h – about three times more than with the TIG hot wire technology. In all cases and whatever the pass thickness chosen, complete control over dilution is provided with a rate of the order of 12 per cent on the first layer and of the order of 1.5 to 2 per cent from the second layer deposited. In the case of surfacing with nickel- based grades, this level of performance enables the difficulties associated with requirements relating to limitations of 5 per cent ferrite in the deposits to be easily surmounted. Old generation hot wire TIG surfacing machines can be converted to integrate the TIGer technology providing a ten- fold increase in the productivity of existing installations cheaply. Once the investment has been made, a machine fitted with the TIGer technology will prove to be profitable and economical allowing a 20 to 50 per cent drop in operating costs per kilogram of weld metal.

and controlled so as to combine into a single arc with the calorific value of the combination of both powers, but with characteristics which are unusual for such intensities. Indeed, depending on the position of the two electrodes, it is possible to considerably reduce fusion of the base metal to arrive at dilution rates, which predestine the TIGer for use in surfacing applications. The addition of the wire preheated using the Joule effect via the control of a third current source enables the special profile of the weld pool to be

THE TIGer technology first resulted from a Polysoude technological development, a variant of the hot wire TIG welding principle. A significant amount of investigation enabled the company to define the combination of optimum operating conditions and torch design required to obtain the best levels of performance. The basic principle involves the juxtaposition of two TIG arcs, organised

used and to considerably improve the efficiency of the procedure. The control of the deposition rate remains, as for all the variants of the TIG technology, independent of the setting of the arc parameters and the quality of the deposition is similar to that which can be obtained with conventional TIG. It is remarkable to observe that the level of compactness is of the same order as that expected for the welding of high-strength assemblies, which also enables preliminary buttering carried out before heterogeneous welding operations to be envisaged without restriction along with surfacing applications. Depending on require- ments, it is possible to optimise the thickness of

TIGer welding technology

Polysoude – France Fax: +33 240 681 188

Email: info@polysoude.com Website: www.polysoude.com

HALL 6/Stand n°6H42 7-11 April 2014 Tube Düsseldorf 2014

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J anuary 2014