A novel strategy to fabricate thin 316L stainless steel rods by continuous directed energy deposition in Z direction

Thin 316L stainless steel rods were fabricated by continuous directed energy deposition in Z direction. The process parameters (laser power, scan velocity, and powder feeding rate) were carefully selected to obtain a stable deposition process and the effects of powder feeding rate and scan velocity were studied. A preliminary study on microstructure and tensile properties of the specimens was carried out. Results indicated that the specimen showed superior austenite/ferrite (gamma/delta) dual phase microstructure, high strength (608.24 MPa), and good plastic deformation capacity (65.08% shrinkage rate) when setting the laser power at 45.2 W, powder feeding rate at 2.81 g/min, and scan velocity at 0.5 mm/s. The technique reported in this paper is expected to lay the foundation for the deposition of wire or frame structures more efficiently than traditional layer-by-layer directed energy deposition.