For most stainless steel and titanium welding applications, preventing any oxidation or discoloration from forming on or adjacent to the weld is paramount.
To give additional argon gas shield coverage during welding, a trailing shield can be fitted to the welding torch. This ensures that the hot weld zone is shielded with argon for a longer period than if it were shielded with the torch nozzle gas only.
The extra inert gas shielding gives time for the metal to cool below the temperature at which it would oxidize. The improved shielding produces a brighter, shinier weld without discoloration.
Range of Models Available
A wide range of trailing shields to fit any make of TIG (GTAW), MIG, or Plasma (PAW) welding torch for manual or automatic welding can be obtained; one source is welding ancillaries manufacturer Huntingdon Fusion Techniques Ltd, distributed in the U.S. by COB Industries Inc. Flat trailing shields are available for welding sheet metalwork or plate work. Radiused trailing shields are manufactured for every diameter of tube pipe or vessel from 1 in. upwards. As well as those radiused for outside welding, HFT manufactures a version for inside welding.
Trailing shield models are also available for robotic welding, where wider and longer shields are required for greater welding speeds than are possible with manual welding.
Additional benefits of the trailing shield are that gas consumption is reduced, faster welding times are obtained, and the need to use a purge enclosure is eliminated.