About this Abstract |
Meeting |
Superalloys 2021
|
Symposium
|
Superalloys 2021
|
Presentation Title |
3 Ton Melting with CaO Desulfurization of Ni-base Single Crystal Superalloy TMS-1700, Simulating a Recycling of Used Turbine Blades |
Author(s) |
Tadaharu Yokokawa, Hiroshi Harada, Kyoko Kawagishi, Makoto Osawa, Michinari Yumaya, Toshiharu Kobayashi, Takuya Sugiyama, Shinsuke Suzuki, Masao Sakamoto |
On-Site Speaker (Planned) |
Tadaharu Yokokawa |
Abstract Scope |
In order to investigate the applicability of a direct and complete recycling method to commercial-scale ingot production, 3 tons of a Ni-base single crystal (SC) superalloy, TMS-1700(MGA1700) was melted and desulfurized by CaO during the melting. Sulfur content in the molten alloy was reduced from about 23 ppm to about 2 ppm 60 min after adding granular CaO to the molten alloy. Microstructural observations using SEM and EPMA showed no presence of inclusions caused by CaO addition. Creep rupture lives of the recycle-simulated TMS-1700 were equivalent to that of the standard TMS-1700 under the conditions from 800 °C/735 MPa to 1100 °C/137 MPa. The recycle-simulated TMS-1700 exhibits even better oxidation resistance compared with the standard TMS-1700, which has better oxidation resistance than CMSX-4TM. Thus, it became clear that the CaO desulfurization improves the oxidation resistance of Ni-base superalloys. High cycle fatigue (HCF) properties of the standard and the recycle-simulated TMS-1700 were equivalent. From the results described above, it has been suggested that the application of direct and complete recycling method to commercial-scale ingot production is feasible. |
Proceedings Inclusion? |
Undecided |