Efeitos do comprimento de revers？o e do angulo de ataque sobre a estrutura de solidifica？？o do cord？o em soldagem MIG/MAG com "Switch Back"

the welding technique denominated switch-back technique consists in a torch oscillation in the welding direction rather than transversally. however, there is not much information in literature about the solidification structure of the bead when this technique is applied. therefore, in this work is presented a study on the effect of the torch leading angle and of the reversion course length over the bead solidification structure. welds were carried out with pulsed mig/mag process on plain carbon steel plates. the results showed that the parameters under analysis modify the solidification mode of the bead. in general, when the angle of torch leads to pushing-pulling movement, equiaxial grains near the fusion line is favored. in relation to the course length, its increase leads to finer solidification structure.