At the Stainless Steel World Conference & Exhibition in November 2015 in Maastricht, The Netherlands, Polysoude’s latest TIG-based weld overlay cladding technology was on show.
The Stainless Steel World Conference & Exhibition presents the newest and most relevant innovations in the field of corrosion resistant alloys (CRAs), together with sharing knowledge and good practice. Polysoude, invited by Netherlands-based publishing company KCI, took part in the event as an exhibitor and delivered a technical presentation by Kees Meurs on the company’s new TIGer process – TIG electrically reinforced – a process designed particularly for tubing with corrosion resistant alloys.
The principles and numerous technical and economic advantages of the TIGer welding solution were emphasised during the conference. From quality perspective, the quality of the deposit, the low dilution rate and the tight control of the cladding thickness are all crucial requirements for companies striving towards zero-defect weld cladding.
When calculating the profitability of a project, productivity gains are achieved due to high deposition rate; the absence of the need for post cladding machining; and the repeatability of operations derived from successful automation. These are all acutely advantageous economic aspects.
TIGer technology is a variant of hot-wire TIG welding. The basic principle involves the juxtaposition of two TIG arcs, organised, controlled and combined to act as one single arc with a calorific value equal to the sum of two power sources, but with characteristics that are unusual for such intensities.
The addition of a preheated wire, which uses a third power source for Joule heating, enables special profiles of the weld pool to be achieved. This also significantly improves the efficiency of the process.
Depending on the requirements, it is possible to optimise the thickness of the layers to within a range of 1.5 and 3.5 mm. This flexibility enables the quantity of
weld metal to be adjusted to strict requirements and thus allows significant savings with respect to the costs of filler materials, which are generally noble alloys.
Optimised welding speeds in the order of 70 to 90 cm/min can be achieved with deposition rates of between 2.5 and 6.0 kg/h, about three times faster than that from hot-wire TIG technology.
Control over dilution in the order of 12% for the first layer and 1.5 to 2.0% for subsequent layers is achievable. TIGer technology is calculated to reduce operating costs per kilogram of weld metal deposited by between 20 to 50%.
Following recent industrial successes, Polysoude has reaffirmed its ambition to advance the welding and cladding fields by designing innovative, competitive solutions that draw on in-depth studies of its customers’ specific needs and technological expertise.