Effects of two superimposed laser beams on spatter formation during laser welding of high alloyed steel

This paper presents an experimental approach for the reduction of the spatter formation during deep penetration laser welding using the spatial superposition of two laser spots. Experimental testing was performed on high alloyed austenitic steel sheets using both a high power disk laser and a diode laser. The spatter formation was reduced significantly through this approach in comparison to a conventional process using a standard top hat power density. High-speed images show the differences in the weld pool behavior in terms of the capillary length and the fluctuation of the metal vapor caused by the additional laser spot.