Investigation of oscillation parameters on molten pool dynamic behavior and microstructural evolution in laser welding of steel plates

This study examines the effects of oscillation amplitude, frequency, and welding speed on energy distribution, molten pool flow, temperature evolution, and weld morphology in oscillating laser welding of 304 stainless steel. A MATLAB-based energy model and CFD simulations, validated by high-speed imaging and infrared thermography, show that smaller amplitudes concentrate energy and increase penetration but may cause instability and spatter, while larger amplitudes improve energy uniformity and molten pool stability. Higher welding speeds reduce heat input and penetration, whereas higher frequencies enhance flow uniformity, promote grain refinement, and suppress defects, improving weld quality.