Corrosion Properties of Powder Bed Fusion Additively Manufactured 17-4 PH Stainless Steel

The corrosion susceptibility of a laser powder bed fusion (LPBF) additively manufactured alloy, UNS S17400 (17-4 PH), was explored compared to conventional wrought material. Microstructural characteristics were characterized and related to corrosion behavior in quiescent, aqueous 0.6 M NaCl solutions. Electrochemical measurements demonstrated that the LPBF 17-4 PH alloy exhibited a reduced passivity range and active corrosion compared to its conventional wrought counterpart. A microelectrochemical cell was used to further understand the effects of the local scale and attributed the reduced corrosion resistance of the LPBF material to pores with diameters >= 50 mu m.