Quality of weld joint in the form of its mechanical and metallurgical properties produced using gas metal arc welding process is governed by combination of parameters employed. These parameters also affect arc stability, bead appearance and thermal and metal transfer behaviour. For a given shielding gas, diameter and composition of filler wire, different modes of metal transfer that can be achieved are short circuit, globular, spray and pulsed spray. The spray metal transfer provides better

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... of operation due to controlled mode of it but at relatively higher welding current above transition level. This may give rise to increase in heat input and temperature of weld pool along with wider weld isotherm which may adversely affect quality weld joint. This problem to some extent can be minimized by pulsing of welding current resulting in application of comparatively lower heat input and temperature of weld pool. But application of pulse current gas metal arc welding involves additional pulse parameters of pulse current Ip, base current, Ib, pulse on time, tp and pulse off time tb simultaneously interacting in nature. Together, there can be infinite combination of possible parameters at a given heat input. Therefore, the major challenges in application of pulse current gas metal arc welding process are to select an appropriate combination of pulse parameters that will be able to produce a weld joint with superior quality. Considering all these, detail study of methods of selection of pulse parameters in pulsed current gas metal arc welding has been discussed.