Investigations on the Specifics of Laser Power Modulation in Laser Beam Welding of Round Bars

Abstract Welding round bars of large diameters in a rotational laser beam welding process corresponds with weld pool bulging and the risk defects. Power modulation is promising approach for bulge reduction keyhole stabilisation to achieve superior quality. The following investigations are about specific effects power diameter 30 mm. speed 0.95 m/min argon used as shielding gas. Triangle shaped at 8 kW average power, 0/2/4/6 amplitude 2/10/50 Hz frequency bar 1.4301 steel alloy. welds evaluated by visual inspection, metallographic cross sections scanning acoustic microscopy. amount defects increases medium high modulation, but already reduced low modulation. Weld can be impeded normalised 0.05 depth 0.86. modulation’s advantages mixing degassing do not apply because linear speed’s gradient from specimen surface centre.