Influence of Wire Arc Additive Manufacturing Parameters on the Morphology, Microstructure, and Hardness of DSS2209 Single-Bead Deposited Layers

This study systematically investigates the effects of key process parameters in wire arc additive manufacturing (WAAM) on the surface morphology, geometric dimensions, microstructure, and microhardness of single-bead single-layer deposits fabricated from 2209 duplex stainless steel. Using a controlled variable approach, the influences of wire feed speed, travel speed, oscillation pattern, oscillation frequency, and oscillation amplitude on the deposition quality were examined. Experimental results indicate that wire feed speed and travel speed significantly affect the bead width, height, and fusion zone morphology, with optimal ranges identified as 4.5-6.5 m/min and 5-6 mm/s, respectively. Among the oscillation patterns, sinusoidal and figure-eight trajectories resulted in uniform deposition distribution and a refined microstructure, whereas the circular pattern led to fish-scale surface features and coarse grains. The optimal oscillation frequency and amplitude were determined to be 4 Hz and 4 mm, respectively, under which the deposits exhibited high surface quality, no defects other than the depression in the arc extinction zone, and the microhardness remains stable in the range of 280-290 HV. Comprehensive analysis indicates that investigating the influence of these process parameters on the morphology, microstructure, and hardness of DSS2209 single-bead deposits can effectively enhance the overall performance of WAAM-fabricated 2209 duplex stainless steel components, thereby providing a reliable foundation for subsequent multi-layer and multi-bead deposition.