Huntingdon Fusion Techniques HFT® has designed and developed the Argweld® flat and radiused Trailing Shields®, made to attach onto any tungsten inert gas (TIG)/gas tungsten arc welding (GTAW), plasma arc welding (PAW) and metal inert gas (MIG)/gas metal arc welding (GMAW) welding torch, providing an additional inert gas coverage during welding of reactive metals where discolouration or oxidation needs to be eliminated.
The Trailing Shield® connects 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 from 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.
The addition of a low-cost Trailing Shield® ensures that the weld stays under a protective argon gas coverage, while the hot weld metal is cooling, preventing it from oxidizing on contact with air, said Luke Keane, technical sales manager for HFT®. Materials such as stainless and duplex steels, as well as titanium, zirconium and nickel alloys are chosen for their corrosion-resistant properties in particular, and if they are then allowed to oxidize during the weld cycle, expensive post-welding cleaning techniques become necessary.
Trailing Shields® are reusable, with a temperature resistance of up to 230°C, and prevent re-work, eliminate the need for an expensive purge chamber, and allow for faster welding.
Image courtesy of Huntingdon Fusion Techniques®