Direct Metal Laser Deposition of Austenitic Stainless Steel Structures: Processing and Characterization

摘要

Direct metal laser deposition (DMLD) offers many advantages, namely lower time-to-market, near-net-shape production, high energy efficiency, high material utilization rate, and flexibility of producing components with complex geometries. Here, DMLD was used to create near-net-shape austenitic stainless steel (SS) structures to study the influence of the scanning parameters and scanning strategy on physical, mechanical and corrosion properties. The mechanical properties were evaluated in terms of hardness and reduced elastic modulus using Vickers hardness testing and a depth-sensing indentation technique. The corrosion properties were investigated in a NaCl solution using electrochemical techniques of open circuit potential and cyclic potentiodynamic polarization. DMLD structures exhibited a hardness of 397 HV, which is quite high, compared to 223 HV in commercial AISI 316SS plate. DMLD austenitic SS structure demonstrated a reduced modulus of 126 GPa and a hardness of 4.95 GPa in depth-sensing nanoindentation testing. The analysis of cyclic polarization data revealed that the pit growth resistance of both the samples was similar.