Trailing rotating-extrusion-assisted wire arc additive manufacturing of duplex stainless steel

A trailing rotating-extrusion-assisted wire arc additive manufacturing method was proposed and investigated. Conventional method can fabricate large components with complex structures. Here, we demonstrate that the performance of components can be improved. The deposited layer was deformed under trailing rotating-extrusion treatment. The surface morphology of the deposited layers changed from scaly bulges to a flat surface with flashes on both sides. Materials after the rotating-extrusion treatment had obvious grain refinement regions, in which the original coarse columnar crystals were refined. The proportion of austenite increased significantly. The average hardness of the rotating-extrusion region was 317.7 HV0.5 which was 19% higher than that of the original region. The tensile strength of the sample fabricated by the new method was improved.