Abstract
Additive manufacturing as a new processing technique can produce unique microstructure that is difficult to achieve using conventional techniques. In this study, we have investigated the creep behavior of 316 L stainless steel produced by a laser powder bed fusion process at temperatures of 550, 600 and 650 °C and stresses between 175 and 300 MPa. We found that additively-manufactured 316 L stainless steel had a higher stress dependence of the minimum creep rate than conventionally-made Type 316 SS, which could be attributed to the dislocation cell structure resulting from the printing process. The dislocation cell structure was unstable under creep, evolving into a uniform dislocation structure under the test conditions. While internal porosity in AM 316 L SS may serve as nucleation sites of creep voids and may be responsible for a relatively lower creep life, additively-manufactured 316 SS did not show inferior creep ductility when compared with conventionally-made 316 SS. The creep life of AM 316 L SS could be improved by stabilizing dislocation cell structure and/or reducing internal porosity through an optimized additive manufacturing process.
| Original language | English |
|---|---|
| Article number | 152847 |
| Journal | Journal of Nuclear Materials |
| Volume | 548 |
| DOIs | |
| State | Published - May 2021 |
Funding
Work was supported by the Transformational Challenge Reactor Program supported by the U.S. Department of Energy, Office of Nuclear Energy under Contract DE-AC02-06CH11357. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. We would like acknowledge Chase Joslin and Ryan Duncan for specimen preparation at ORNL and Ed Listwan and David Rink for assistance with the creep test, and Peter Kenesei for assistance in X-ray tomography reconstruction at ANL. Kurt Terrani at ORNL and Florent Heidet at ANL provided useful direction and discussions during this effort. Work was supported by the Transformational Challenge Reactor Program supported by the U.S. Department of Energy, Office of Nuclear Energy under Contract DE-AC02-06CH11357 . Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences , under Contract No. DE-AC02-06CH11357 . This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357 . We would like acknowledge Chase Joslin and Ryan Duncan for specimen preparation at ORNL and Ed Listwan and David Rink for assistance with the creep test, and Peter Kenesei for assistance in X-ray tomography reconstruction at ANL. Kurt Terrani at ORNL and Florent Heidet at ANL provided useful direction and discussions during this effort.
Keywords
- 316 L stainless steel
- Additive manufacturing
- Creep
- Dislocation substructure
- Porosity
