Effect of enhanced heat and mass transport and flow reversal during cool down on weld pool shapes in laser spot welding of steel

Numerical Model for Predicting Bead Geometry and Microstructure in Laser Beam Welding of Inconel 718 Sheets

“…In order to avoid numerical instabilities due to a zero in the denominator at the solid region, the coefficient e 0 must have a small value (10 −3 in the present model). Moreover, the coefficient C must have a high value in order to make zero the velocity of the fluid flow in the solid region C = 10 6 kg·m −3 ·s −1 [31].…”

“…The cooling stage has direct influence on the final shape of the melt pool [31], as well as the developed microstructure [35]. Therefore, a cooling period is simulated, whose duration is twice the time required by the laser beam to pass over the modeled cross section.…”

Effects of interfaces on heat transfer in laser welding of electrical steel laminations

“…The enhanced thermal conductivity of the liquid metal with the value of 6.0 in X and Z direction was set to simulate the heat transfer caused by the flow of the liquid [8,14,15]. The specific heat capacity was thought to be constant at both the solid region and the liquid region.…”

“…Temperature distribution in laser welding of traditional structures has been extensively researched [7][8][9][10][11][12][13][14][15]. In these researches, the heat applied by the laser beam was simulated by the surface or body heat source model, the convection and radiation boundaries were defined to simulate the heat exchange between the coupons and the environment.…”

“…In these researches, the heat applied by the laser beam was simulated by the surface or body heat source model, the convection and radiation boundaries were defined to simulate the heat exchange between the coupons and the environment. The enhanced thermal conductivity of the fused metal was set to simulate the heat transfer caused by the flow of the liquid [8,14,15]. However, most of these work was based on the butt coupons or the lapped coupons [7,12].…”