In this paper, the microstructure of laser beam welded Sc-modified AA2519-F has been taken under investigation. The welded joint has been produced using Fanuc 710i industrial robot equipped with YLS-6000 6 kW laser beam source. The welding speed and laser power were equal to 0.75 m/min and 3.2 kW, respectively. The investigation involved microstructure observations with the use of both light microscope and scanning electron microscope with energy dispersive spectroscopy (EDS) analysis of chemical composition and microhardness distribution measurements. It has been stated that laser beam welding allows to obtain Sc-modified AA2519-F weld of good quality, characterized by the presence of an equiaxed grain zone containing scandium-rich precipitates adjacent to the fusion boundary.

The work is focused on welding of fine-grained ultra-high-strength steel S960MC by laser beam welding and electron beam welding technologies. For a given type of steel, when the heat input is exceeded, the mechanical properties of welded joints will deteriorate. As a result, using beam welding technologies to limit the amount of heat input is recommended. Several butt welds were made, and mechanical tests and macroscopic analyses were performed to determine the impact of welding parameters on mechanical properties. Using beam welding technologies, the value of heat input was reduced by up to 73% compared to gas metal arc welding. When compared to a gas metal arc welded joint, the width of the soft zone was reduced by 69 to 79%. This resulted in a considerable reduction in the width of the soft zone, which was reflected in a 24% increase in yield strength and a 23% increase in tensile strength compared to gas metal arc welding.