A Comparative Investigation of Duplex and Super Duplex Stainless Steels Processed through Laser Powder Bed Fusion
Author:
Gargalis Leonidas1, Karavias Leonidas1, Graff Joachim S.2ORCID, Diplas Spyros2, Koumoulos Elias P.3ORCID, Karaxi Evangelia K.1ORCID
Affiliation:
1. Conify, Lavrion Ave.1, Lavrion Technological and Cultural Park (LTCP), 19500 Lavrion, Greece 2. SINTEF Industry, Forskningsveien 1, 0373 Oslo, Norway 3. IRES—Innovation in Research & Engineering Solutions, Rue Koningin Astritlaan 59B, 1780 Wemmel, Belgium
Abstract
The aim of this paper was to compare duplex (DSS) and super duplex stainless steel processed by laser powder bed fusion (LPBF) based on the process parameters and microstructure–nanomechanical property relationships. Each alloy was investigated with respect to its feedstock powder characteristics. Optimum process parameters including scanning speed, laser power, beam diameter, laser energy density, and layer thickness were defined for each alloy, and near-fully dense parts (>99.9%) were produced. Microstructural analysis was performed via optical (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The samples were subjected to stress relief and high-temperature annealing. EBSD revealed the crystallographic orientation and quantified the phases in the as-built and annealed sample conditions. The as-built samples revealed a fully ferritic microstructure with a small amount of grain boundary austenite in the SDSS microstructure. High-temperature solution annealing resulted in the desired duplex microstructure for both alloys. There were no secondary phases present in the microstructure after both heat treatments. Nanoindentation generated nanomechanical (modulus) mapping grids and quantified the nanomechanical (both hardness and modulus) response; plasticity and stress relief were also assessed in all three conditions (as-built, stress-relieved, and annealed) in both DSS and SDSS. Austenite formation in the annealed condition contributed to lower hardness levels (~4.3–4.8 Gpa) and higher plastic deformation compared to the as-built (~5.7–6.3 Gpa) and stress-relieved conditions (~4.8–5.8 Gpa) for both alloys. SDSS featured a ~60% austenite volume fraction in its annealed and quenched microstructure, attributed to its higher nickel and nitrogen contents compared to DSS, which exhibited a ~30% austenite volume fraction.
Funder
European Commission
Subject
General Materials Science,Metals and Alloys
Reference71 articles.
1. Francis, R., and Byrne, G. (2021). Duplex Stainless Steels—Alloys for the 21st Century. Metals, 11. 2. Sharma, L., and Sharma, K. (2022). Dissimilar welding of super duplex stainless steel (SDSS) and pipeline steel—A brief overview. Mater. Today Proc. 3. Effect of filler metal on solidification, microstructure and mechanical properties of dissimilar super duplex/pipeline steel GTA weld;Khan;Mater. Sci. Eng. A,2021 4. Gatto, M.L., Cerqueni, G., Groppo, R., Tognoli, E., Santoni, A., Cabibbo, M., Mattioli-Belmonte, M., and Mengucci, P. (2023). On the Biomechanical Performances of Duplex Stainless Steel Graded Scaffolds Produced by Laser Powder Bed Fusion for Tissue Engineering Applications. J. Funct. Biomater., 14. 5. Gatto, M.L., Santoni, A., Santecchia, E., Spigarelli, S., Fiori, F., Mengucci, P., and Cabibbo, M. (2023). The Potential of Duplex Stainless Steel Processed by Laser Powder Bed Fusion for Biomedical Applications: A Review. Metals, 13.
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