Tungsten arc welding

A gas—tungsten arc-welding system is more complex. In addition to the components of the shielded-metal arc system, provisions must be made for the inert gas supply and water or air cooling of the welding torch. GTAW systems may range from manual to automatic. 

Weldments subjected to corrosive attack over a period of time may crack adjacent to the weld seams if the residual stresses are not removed. Gas—tungsten arc welding and gas—metal arc welding ate recommended for joining magnesium, the former for thinner materials and the latter for thicker materials. Maintaining a protective atmosphere is a critical issue in welding these alloys. 

Table 6.2 Airborne emissions associated with welding 304 stainless steel comparing gas tungsten arc welding to friction stir welding...

Ino] Gas tungsten arc welding, SEM, EPMA Phase transformations on weld alloy Cr9Fe2iNi6o... 

The delta ferrite content of each lot and/or heat of weld filler metal used for welding of austenitic stainless steel code components shall be determined for each process to be used in production. Delta ferrite determinations for consumable inserts, electrodes, rod or wire filler metal used with the gas tungsten arc welding process, and deposits made with the plasma arc welding process may be determined by either of the alternative methods of magnetic measurement or chemical analysis described in Section III of the ASME Code. 

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