Melting efficiency calculation of “finite-element-modeled” weld-bead and “experimental” weld-bead for laser-irradiated Hastelloy C-276 sheet

The cross-sectional geometry of the weld bead, which is associated with the maximum utilization of input energy, has been determined in the present work. In this respect, finite element analysis (FEA) has been implemented to generate five different weld bead shapes at around a similar peak temperature of 1700 °C to simulate laser beam welding of Hastelloy C-276 sheet through the bead-on-plate (BOP) method. Variations in the volumetric heat-source model, process parameters, and bead geometries led to varying melting efficiency. Three methods were implemented for the calculation of the melting efficiency associated with different bead geometries. The melting efficiency of bead geometries was found to be in the order: cylindrical shape > dowel pin shape > conical shape > tack nail shape > semi-circular shape. The melting efficiency was found to drop with the increment in the linear heat input. The analysis of the heat flux (HFL) vector showed that the inclination of the maximum heat flux vector with the welding direction is an important factor in determining the melting efficiency. Graphical Abstract