On the Microstructure and Electrochemical Properties of Additively Manufactured Duplex Stainless Steels Produced Using Laser-Powder Bed Fusion

The microstructure and electrochemical properties of additively manufactured 22Cr duplex stainless steel (DSS) and 25Cr super duplex stainless steel (SDSS) produced by laser-powder bed fusion (L-PBF) are reported herein. The as-built microstructure is fully ferritic, while a 50/50 ferrite-austenite phase ratio was achieved by post heat treatment. The electrochemical response of DSS and SDSS prepared by L-PBF was investigated using cyclic potentiodynamic polarization (CPP) tests in 0.6 M NaCl solution and compared with the wrought counterparts. Both 22Cr DSS and 25Cr SDSS prepared by L-PBF showed comparable electrochemical response to their corresponding wrought alloys at room temperature. The findings herein demonstrate the feasibility of additive manufacturing as applied to DSS.