Abstract
In the present work, the tensile properties of 15–5 PH steel fabricated by selective laser melting (SLM) were examined with respect to the transient austenite phase. Compared with the 8%-transient-phase sample, the 18%-transient-phase one shows higher ultimate tensile strength and relatively low yield strength, as well as hardening behavior. We conducted in-situ neutron-diffraction study to examine the microstructure evolution for mechanistic understanding. After applying the external load, most non-equilibrium, retained austenite in the 8%-transient-phase sample transforms before the yield strength, whereas in the 18%-transient-phase sample only 50% of the austenite transforms. Accompanying with the phase transformation, a decrease in the dislocation density and the dislocation strain energy-assisted phase transformation of the ferrite phase are found in the 8%-transient-phase sample even before yielding, which, however, is not the case in the 18%-transient-phase sample. The study demonstrates the SLM enables tuning the amount of transient-phase ratio and coherency between phases to realize a mechanical property control for additive manufactured steel.
Original language | English |
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Pages (from-to) | 60-67 |
Number of pages | 8 |
Journal | Intermetallics |
Volume | 109 |
DOIs | |
State | Published - Jun 2019 |
Keywords
- Neutron diffraction
- Additive manufacturing
- Selective laser melting
- Stainless steel
- Anisotropy
- SITU NEUTRON-DIFFRACTION
- MECHANICAL-PROPERTIES
- DISLOCATION-STRUCTURE
- AUSTENITE
- DEFORMATION
- MARTENSITE
- PROFILE
- TRANSFORMATION
- ALLOY