Keyhole Formation During Spot Laser Welding: Heat and Fluid Flow Modeling in a 2D Axisymmetric ConfigurationM. Courtois, M. Carin, P. LeMasson, S. Gaied 
ArcelorMittal, Global R&D, Montataire, France
LIMATB Laboratory, Université de Bretagne Sud, Lorient, France
For a better understanding of phenomena associated to the appearance of defects in laser welding, a heat and fluid flow model is developed. This study is focused on the modeling of a static laser shot on a sample of steel. This 2D axialsymmetric configuration is used to study phenomena related to the creation of the keyhole. This model takes into account the three phases of the matter: the vaporized metal, the liquid phase and the solid base. To track the evolution of these three phases, coupled equations of energy and momentum are solved. The liquid / vapor interface is tracked using the Level-Set method. The free surface deformation is analyzed and melt pool shapes are compared to experimental macrographs.