Laser pulsed welding in thin sheets of Zircaloy-4

A simulation technique for the welding process design to obtain the high reliability of nuclear fuel spacer grids is presented. A finite element model of pulsed laser welding for Zircaloy-4 plate is developed, which incorporates the phase transitions and the dynamic material properties with transient temperature. The effects of pulsed laser parameters on the pool shape and welding-induced distortion are analyzed by simulations and verified by experiments. The parametric study presents that the welding induced distortions are highly dependent on the geometry of the molten zone and the heat affected zone.