Raffeis, I.I.RaffeisVroomen, U.U.VroomenAdjei-Kyeremeh, F.F.Adjei-KyeremehGroßmann, D.D.GroßmannHammelrath, H.H.HammelrathWesthoff, E.E.WesthoffBremen, S.S.BremenBoscolo Bozza, D.D.Boscolo BozzaBührig-Polaczek, A.A.Bührig-Polaczek2022-03-062022-03-062020https://publica.fraunhofer.de/handle/publica/26365310.1002/mawe.201900136A methodology is presented that compares the microstructural and mechanical properties of as-cast and additive-made ferritic-austenitic duplex steel 1.4517. Microstructure of approximately equal amounts of ferrite and austenite measured in as-cast material could not be replicated in post heat-treated laser powder bed fusion samples after 30-min and 60-min of post heat treatment. This is attributed to nitrogen loss during powder atomization which left fewer austenite formers. Post-heat treated laser powder bed fusion samples of duplex structure had its austenite content repeatedly adjusted between 38 % and 40 %. As-built laser powder bed fusion tensile specimens which had a ferritic microstructure recorded high tensile and yield strength but had very poor elongation. Post heat-treated duplex laser powder bed fusion tensile specimen built in both horizontal and vertical orientations had good tensile and yield strength comparable to conventional casting processes; Tensile strength - 739-MPa (horizontal), 759-MPa (vertical); Yield strength (Rp0.2) - 489-MPa (horizontal), 525-MPa (vertical). The horizontally built duplex specimen had a very high elongation of 32 % than the vertical (11 %) or conventionally reported (22 %). This work establishes the 1.4517 duplex steel as a good candidate with good mechanical properties when processed by additive manufacturing.en621669journal article