Insights into Engineering Super-Duplex Stainless-Steel Microstructures: Composition Alterations and Processing Strategies in LPBF.
Saved in:
| Title: | Insights into Engineering Super-Duplex Stainless-Steel Microstructures: Composition Alterations and Processing Strategies in LPBF. |
|---|---|
| Authors: | Karavias, Leonidas1 (AUTHOR), Gargalis, Leonidas1,2 (AUTHOR), Karaxi, Evangelia K.1 (AUTHOR), Koumoulos, Elias P.2 (AUTHOR) |
| Source: | Materials (1996-1944). Jun2026, Vol. 19 Issue 11, p2344. 24p. |
| Subjects: | Duplex stainless steel, Powder bed fusion, Austenite, Chemical structure, Nanoindentation, Heat treatment, Mechanical behavior of materials, Microstructure |
| Abstract: | This study investigates in situ methodologies for enhancing austenite formation in Laser Powder Bed Fusion (LPBF)-processed Super Duplex Stainless Steel (SDSS), aiming to eliminate the requirement for post-process heat treatments. The evaluated approaches included layer remelting, increased layer thickness (from 40 μm to 80 μm), and chemical modification by blending SDSS with Stainless Steel SS316L at a 50/50 weight ratio. Microstructural characterization and macro-hardness testing were conducted, complemented by nanoindentation analyses to assess the local mechanical response of the austenite and ferrite phases in samples exhibiting the highest austenite content. The findings indicate that neither layer remelting nor increased layer thickness alone substantially elevated austenite content; the as-built microstructure remained predominantly ferritic under these conditions. In contrast, compositional adjustment through SS316L powder blending yielded a significant increase in austenite, resulting in a duplex microstructure. These compositional changes and the resulting phase balance were associated with a reduction in macro-hardness relative to the ferritic microstructures. Nanoindentation results showed comparable nanomechanical properties in both phases, suggesting that the decreased macro-hardness in the duplex microstructure is primarily attributable to changes in chemical composition and diminished solid-solution strengthening, rather than the increased austenite fraction itself. These results highlight the limitations of thermal strategies alone in achieving phase balance in LPBF-processed SDSS and demonstrate the effectiveness of compositional tuning in promoting favorable duplex microstructures. [ABSTRACT FROM AUTHOR] |
| Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | This study investigates in situ methodologies for enhancing austenite formation in Laser Powder Bed Fusion (LPBF)-processed Super Duplex Stainless Steel (SDSS), aiming to eliminate the requirement for post-process heat treatments. The evaluated approaches included layer remelting, increased layer thickness (from 40 μm to 80 μm), and chemical modification by blending SDSS with Stainless Steel SS316L at a 50/50 weight ratio. Microstructural characterization and macro-hardness testing were conducted, complemented by nanoindentation analyses to assess the local mechanical response of the austenite and ferrite phases in samples exhibiting the highest austenite content. The findings indicate that neither layer remelting nor increased layer thickness alone substantially elevated austenite content; the as-built microstructure remained predominantly ferritic under these conditions. In contrast, compositional adjustment through SS316L powder blending yielded a significant increase in austenite, resulting in a duplex microstructure. These compositional changes and the resulting phase balance were associated with a reduction in macro-hardness relative to the ferritic microstructures. Nanoindentation results showed comparable nanomechanical properties in both phases, suggesting that the decreased macro-hardness in the duplex microstructure is primarily attributable to changes in chemical composition and diminished solid-solution strengthening, rather than the increased austenite fraction itself. These results highlight the limitations of thermal strategies alone in achieving phase balance in LPBF-processed SDSS and demonstrate the effectiveness of compositional tuning in promoting favorable duplex microstructures. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 19961944 |
| DOI: | 10.3390/ma19112344 |
