GMAW shielding gas flow optimisation by refinement of nozzle geometry

With an ongoing demand to improve the efficiency of the gas metal arc welding process, steps are being taken to reduce the shielding gas consumption. However, sufficient shielding gas coverage of the weld region is essential for the generation of high quality welds, and drafts can be detrimental to its efficiency. In industry, the general practise to ensure coverage is to increase the shielding gas flow rate, however, too high a flow rate can induce undesirable turbulence in the shielding gas column, whilst adding unnecessary cost to the process. A simplified computational fluid dynamics model has been generated, and validated through extensive experimental trials, to accurately model the shielding gas flow when subjected to the adverse effects of cross drafts. Several nozzle geometry changes have been investigated with the aim of improving the shielding gas column’s resistance to drafts, eliminating the requirement to increase the shielding gas flow rate