Abstract
A key feature when using martensitic steels is the proportion of retained austenite present in the final component. Martensitic steels manufactured by laser powder-bed fusion (LPBF) have been shown to have more retained austenite than when conventionally manufactured. The LPBF microstructure is characterised by small grains containing ultrafine solidification cells (<1 μm). This study shows that the solidification cells can fully suppress thermal martensite. The retained austenite is highly metastable, and will readily transform to deformation martensite either in-build from thermal strain or post-build from deformation. This raises concerns around sample preparation methods causing incorrect phase quantification in LPBF-built martensitic steels.
Original language | English |
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Article number | 100917 |
Number of pages | 7 |
Journal | Additive Manufacturing |
Volume | 30 |
Early online date | 24 Oct 2019 |
DOIs | |
Publication status | Published - 1 Dec 2019 |
Externally published | Yes |