Modelling of globular transfer considering momentum flux in GMAW

The static force balance model (SFBM) has been widely used to analyse metal transfer in gas metal arc welding (GMAW). Although the SFBM is capable of predicting the detaching drop size in the globular mode with reasonable accuracy, discrepancy between the calculated and experimental results increases with current. In order to reduce discrepancy, the SFBM is modified in this work by introducing the momentum flux. The momentum flux is generated by the axial fluid flow within the drop, which is induced by the pinch pressure. While the momentum flux has negligible effects on metal transfer in the low current range, it increases with current and becomes compatible with the electromagnetic force in the high current range. The modified force balance model predicts the experimental results more accurately than the SFBM and extends its application to the projected mode of the spray mode.