This study evaluates the influence of selected welding parameters on temperature distribution during the production of butt welds in DSS 2304 (EN 1.4362) using a dual IPG YLS 5000 fiber laser with a wavelength of 1.06 μm and a maximum output power of 5 kW. Numerical simulations were performed using ANSYS 2022 R2 software to analyze temperature fields in the weld area. The thermophysical properties of DSS were calculated using JMatPro v6.1 software based on its chemical composition. The geometric model was designed considering test samples with a thickness of 5 mm. A progressive finite element mesh was generated, employing 3D SOLID70 elements with a length of 0.1 mm in the welding zone along the weld trajectory. A conical volumetric heat source model was utilized. Third-kind boundary conditions were applied to define the cooling of welded sheets by convection and radiation through argon and ambient air. Numerical simulations were employed to analyze and optimize performance parameters, including laser power, and the power beam ratio of tandem dual beams for welding DSS 2304. The resulting temperature fields were verified using their comparison with the macrostructures of the produced welds. The mechanical properties of the welded joints were tested through tensile testing and microhardness measurements.

Dual beam laser welding of UNS S32750 superduplex stainless steel was performed to investigate the effect of beam-power distribution on microstructure and mechanical properties. Plates with a thickness of 3 mm were welded at a constant total power and travel speed using leading and lagging power splits of 50:50, 80:20, and 65:35. The heat affected zone width was metallographically estimated at approximately 100 µm for all conditions, consistent with comparable gross thermal exposure under constant nominal linear energy input (P_total/v). A slight modification to the power distribution altered the solidification texture and austenite morphology. The 50:50 configuration produced a refined ferritic matrix with a continuous network of grain boundaries, Widmanstätten, and intragranular acicular austenite. The 80:20 condition increased ferrite path continuity, while the 65:35 split produced an intermediate morphology. Vickers hardness reached a maximum for the 80:20 split (HAZ: 345 HV; weld metal: 349 HV). Ultimate tensile strength remained statistically constant between 908 MPa and 914 MPa, whereas elongation decreased from 28% at 50:50 to 24% at 80:20 and 23% at 65:35. All welds exhibited ductile fracture with microvoid coalescence, and electrochemical performance was comparable, with critical pitting temperature values between 78 °C and 91 °C. Beam power distribution primarily affects solidification morphology and enables control of the hardness-to-ductility balance, with a 50:50 split providing the most favorable combination of properties.