Comparison of Material Properties of Duplex Stainless Steel 1.4462 Processed by DED-LB/M and PBF-LB/M

Maier A, Rühr M, Stephan M, Roth S, Schmidt M (2023)

Publication Language: English

Publication Type: Book chapter / Article in edited volumes

Publication year: 2023

Publisher: Springer

Edited Volumes: Additive Manufacturing in Multidisciplinary Cooperation and Production

Series: Springer Tracts in Additive Manufacturing (STAM)

City/Town: Cham

Pages Range: 105 - 114

ISBN: 978-3-031-37671-9

URI: https://link.springer.com/chapter/10.1007/978-3-031-37671-9_9

DOI: 10.1007/978-3-031-37671-9_9

Abstract

Duplex stainless steels (DSS) combine high strength and ductility with excellent corrosion resistance due to a synergistic effect between ferritic and austenitic phases in a balanced ratio. In Additive Manufacturing (AM) processes such as Laser-based Directed Energy Deposition (DED-LB/M) and Laser Powder Bed Fusion (PBF-LB/M), it is a great challenge to achieve high build quality and the desired duplex microstructure at the same time. In this work, the as-built (AB) and subsequent heat-treated (HT) conditions of DSS 1.4462 were compared in terms of microstructural and mechanical properties after being processed by both DED-LB/M and PBF-LB/M. DED-LB/M resulted in a heterogeneous microstructure with an almost balanced ferrite–austenite phase ratio. Strength and ductility of the DED-LB/M AB condition correspond to the specification of conventionally manufactured DSS 1.4462 by reaching 468 ± 1 MPa in yield strength (YS) and 31 ± 1% elongation at break (A). A standard post-process heat treatment consisting of solution annealing (1,050 °C; 2 h) and quenching in water homogenized the DED-LB/M microstructure but had only a minor effect on the mechanical properties. In contrast to DED-LB/M, PBF-LB/M leads to a finer-grained and mainly ferritic microstructure (14 - 17% austenite). Ductility (A = 15 ± 1%) and impact toughness (KV = 48 ± 12 J) of the PBF-LB/M AB condition are very low due to the lack of austenite formation. Consequently, post-process heat treatment was required to achieve the desired ferrite–austenite phase balance. The subsequent equalization of the phase ratio reduced the overall hardness and strength (YS = 720 ± 1%), but significantly increased ductility (A = 39 ± 1%) and impact toughness (KV = 125 ± 15 J), resulting in mechanical properties that were in good agreement with the specification of DSS 1.4462.

Authors with CRIS profile

Andreas Maier
Michael Schmidt Lehrstuhl für Photonische Technologien

Involved external institutions

Bayerisches Laserzentrum gemeinnützige Forschungsgesellschaft mbH (BLZ) DE Germany (DE) KSB SE & Co. KGaA DE Germany (DE)

How to cite

APA:

Maier, A., Rühr, M., Stephan, M., Roth, S., & Schmidt, M. (2023). Comparison of Material Properties of Duplex Stainless Steel 1.4462 Processed by DED-LB/M and PBF-LB/M. In Igor Drstvensek, Snehashis Pal, Nataša Ihan Hren (Eds.), Additive Manufacturing in Multidisciplinary Cooperation and Production. (pp. 105 - 114). Cham: Springer.

MLA:

Maier, Andreas, et al. "Comparison of Material Properties of Duplex Stainless Steel 1.4462 Processed by DED-LB/M and PBF-LB/M." Additive Manufacturing in Multidisciplinary Cooperation and Production. Ed. Igor Drstvensek, Snehashis Pal, Nataša Ihan Hren, Cham: Springer, 2023. 105 - 114.

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