PBF-LB/M of Low-Alloyed Steels: Bainite-like Microstructures despite High Cooling Rates

Bartels D, Novotny T, Mohr A, van Soest F, Hentschel O, Merklein C, Schmidt M (2022)

Publication Language: English

Publication Type: Journal article

Publication year: 2022

Journal

Materials MDPI

Book Volume: 15

Pages Range: 6171

Issue: 17

DOI: 10.3390/ma15176171

Abstract

Laser-based powder bed fusion of metals (PBF-LB/M) is an emerging technology with enormous potential for the fabrication of highly complex products due to the layer-wise fabrication process. Low-alloyed steels have recently gained interest due to their wide potential range of applications. However, the correlation between the processing strategy and the material properties remains mostly unclear. The process-inherent high cooling rates support the assumption that a very fine martensitic microstructure is formed. Therefore, the microstructure formation was studied by means of scanning electron microscopy, hardness measurements, and an analysis of the tempering stability. It could be shown that additively manufactured Bainidur AM samples possess a bainitic microstructure despite the high process-specific cooling rates in PBF-LB/M. This bainitic microstructure is characterized by an excellent tempering stability up to temperatures as high as 600 °C. In contrast to this, additively manufactured and martensitic-hardened specimens are characterized by a higher initial hardness but a significantly reduced tempering stability. This shows the potential of manufacturing products from Bainidur AM for high-temperature applications without the necessity of a post-process heat treatment for achieving the desired bainitic microstructure.

Authors with CRIS profile

Dominic Bartels Lehrstuhl für Photonische Technologien Oliver Hentschel Lehrstuhl für Photonische Technologien Michael Schmidt Lehrstuhl für Photonische Technologien

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies

Related research project(s)

Selective laser beam melting of composite material for lightweight structures (A5) (SFB 814 (A5)) CRC 814 - Additive Manufacturing (SFB 814) July 1, 2011 - June 30, 2023

Involved external institutions

Deutsche Edelstahlwerke Specialty Steel GmbH & Co. KG DE Germany (DE) Schaeffler Technologies AG & Co. KG DE Germany (DE)

How to cite

APA:

Bartels, D., Novotny, T., Mohr, A., van Soest, F., Hentschel, O., Merklein, C., & Schmidt, M. (2022). PBF-LB/M of Low-Alloyed Steels: Bainite-like Microstructures despite High Cooling Rates. Materials, 15, 6171. https://dx.doi.org/10.3390/ma15176171

MLA:

Bartels, Dominic, et al. "PBF-LB/M of Low-Alloyed Steels: Bainite-like Microstructures despite High Cooling Rates." Materials 15 (2022): 6171.

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