Uma Contribui?§?￡o na Determina?§?￡o das Vari??veis da Corrente Cont?-nua Pulsada para o Arame Tubular E71T-1M

摘要

This work has as main objective to implement the FCAW welding process with pulsed current. For this purpose, the influence of nozzle distance (DBCP) on two levels (19 and 24 mm) and droplet diameter (Dg) size were analyzed according to the following criteria: Droplet diameter equal to the diameter of the electrode wire (Dg = De), droplet diameter less than the diameter of the electrode wire (Dg De) and, finally, droplet diameter larger than the diameter of the electrode wire (Dg De), without changind the deposition rate. The analysis of the results showed that the experimental methodology used is effective to determine the pulsed current variables for the E71T-1M rutile tubular wire. Thus, it was possible to produce weld beads with good surface and morphological appearance, as well as good arc stability (without weld spatter) when using a 24 mm of distance from the nozzle to the workpiece (DBCP) and smaller droplet diameter (Dg) than the diameter of the electrode-wire (De). Moreover, when using DBCP of 24 mm, a significant variation in the welding energy was observed when different droplet diameters were used. About that, with DgDe was obtained 9,0 kJ/cm and for DgDe 12.6 kJ/cm. This represents an increase of about 40% when droplet diameters smaller than the electrode diameter (Dg De) are used.