Articles techniques et présentations

The application of an oscillating magnetic field on the high-power full-penetration laser beam welding process of a 20 mm thick stainless steel plate was numerically and experimentally investigated. In the simulations, three-dimensional heat transfer and fluid dynamics as well as electromagnetics were solved taking into account the most important physical effects of the process, namely the thermo-capillary (Marangoni) convection at the weld pool boundaries, natural convection due to gravity in the melt volume and latent heat of the solid-liquid phase transition at the phase boundaries.

It was shown, that the application of an oscillating magnetic field that induces eddy currents in the melt results in a Lorentz force that is capable of compensating for the hydrostatic pressure due to gravity.