Abstract
The microstructural development of 316L stainless steel (SS) was investigated over a wide range of systematically varied laser powder bed fusion (LPBF) parameters, such as laser power, scan speed, hatch spacing and volumetric energy density. Relative density, melt pool width and depth, and the size of sub-grain cellular structure were quantified and related to the temperature field estimated by Rosenthal solution. Use of volumetric energy density between 46 and 127 J/mm3 produced nearly fully dense (≥99.8%) samples, and this included the best parameter set: power = 200 W; scan speed = 800 mm/s; hatch spacing = 0.12 mm; slice thickness = 0.03; energy density = 69 J/mm3). Cooling rate of 105 to 107 K/s was estimated base on the size of cellular structure within melt pools. Using the optimized LPBF parameters, the as-built 316L SS had, on average, yield strength of 563 MPa, Young’s modulus of 179 GPa, tensile strength of 710 MPa, and 48% strain at failure.
| Original language | English |
|---|---|
| Article number | 832 |
| Journal | Metals |
| Volume | 11 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2021 |
Funding
This research was sponsored by the DEVCOM U.S. Army Research Laboratory under a cooperation agreement contract, W911NF1720172. The views, opinions and conclusions made in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the DEVCOM U.S. Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein. Nathalia Diaz Vallejo expresses her gratitude to the Fulbright Program and the Colombian Institute of Educational Credit and Technical Studies (ICETEX) for providing partial stipend for her doctoral studies under the “Fulbright-Pasaporte a la Ciencia” fellowship program. Funding: This research was sponsored by the DEVCOM U.S. Army Research Laboratory under a cooperation agreement contract, W911NF1720172. The views, opinions and conclusions made in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the DEVCOM U.S. Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein. Nathalia Diaz Vallejo expresses her gratitude to the Fulbright Program and the Colombian Institute of Educational Credit and Technical Studies (ICETEX) for providing partial stipend for her doctoral studies under the “Fulbright-Pasaporte a la Ciencia” fellowship program.
Keywords
- 316L stainless steel
- Laser powder bed fusion
- Melt pool dimension
- Microstructure