Eliminating oxidation and discolouration when welding stainless and duplex steels as well as titanium, zirconium and nickel alloys is crucial in many industries today, because of improving quality control procedures. Welds have to be free from metallurgical defects otherwise they can potentially be rejected, often leading to a significant loss in time and resources.
The quality of welds on tubes, pipes and flat sheet metal can be dramatically improved with the addition of a low cost Weld Trailing Shield®.
Huntingdon Fusion Techniques HFT® have designed and developed Argweld® flat and radiused Trailing Shields® which simply attach onto any TIG/GTAW, PAW/Plasma and MIG/GMAW welding torch, providing an additional inert gas coverage during welding of reactive metals where discolouration or oxidation needs to be eliminated.
Luke Keane, Technical Sales Manager for HFT® said: “The addition of a low cost Trailing Shields® ensures that the weld stays under a protective argon gas coverage, while the hot weld metal is cooling, preventing it from oxidising on contact with air. The materials mentioned above are chosen for their corrosion resistant properties in particular and if they are then allowed to oxidise during the weld cycle, expensive post welding cleaning techniques become necessary.”
“These lightweight, easy to use Trailing Shields® pay for themselves in just one weld! They are perfect for manual welders, as well as well as automatic machines by helping to cover the weld with an inert gas coverage during and after welding, producing bright, shiny, oxide free welds every time.”
The Trailing Shield® is connected to the argon gas supply, diffusing gas evenly without turbulence through the multi layers of stainless steel mesh built into the body of the shield. At each side, replaceable silicone rubber side shields provide a barrier to prevent the argon escaping sideways and remaining over the weld metal. As the welding torch is moved forward, the weld remains under an argon gas shield until the welded metal has cooled below its oxidation temperature.
Trailing Shields® are reusable, with a temperature resistance of up to 230ºC. They prevent re-work, eliminate the need for an expensive purge chamber and allow for faster welding.
For manual welding, the welder finds that with this lightweight and low cost tool, there is no difficulty in dragging it along the surface being welded. One further benefit is that it carries the welding torch at 90º to the weld.
Radiused Shields are designed to suit the exact diameter of the pipe or vessels being welded. Flat models are available for sheet and plate welding.