The effects of heat treatment on microstructure evolution of 17-4 PH single tracks deposited by AM-DED

Direct Energy Deposition (DED) is an additive manufacturing technique that has received increasing attention from several industrial fields to produce near-net-shape parts, for repairing components or applying hard-facing coatings. In this context, the 17-4 PH stainless steel is an attractive material because it combines good corrosion resistance with high toughness and strength. In the present work, the effects of post-building heat treatment routes applied to 17-4 PH single tracks deposited by DED on an AISI 316L plate were investigated and preliminary results are shown. Optical microscopy was used to study the effects of solubilization and different aging times on the microstructure, focusing on the amount of δ ferrite inside the tracks. Moreover, Vickers microhardness tests were performed to analyze the evolution of hardness across the substrate/track interface.