About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
C-2: Effects of Trace Impurities in Ni-base Single Crystal Superalloys on High-temperature Properties and Disablement of Impurities by CaO for Recycle of Superalloys |
Author(s) |
Kyoko Hashi Kawagishi, Chihiro Tabata, Tadaharu Yokokawa, Yuji Takata, Michinari Yuyama, Takahide Horie, Hirotoshi Maezawa, Shinsuke Suzuki, Hiroshi Harada |
On-Site Speaker (Planned) |
Kyoko Hashi Kawagishi |
Abstract Scope |
In determining the specifications for the production or recycling process of Ni-base single crystal superalloys, it is important to clarify the allowable trace impurity concentration. In this study, the effects of Pb and Sb on high-temperature strength and oxidation resistance of 6th generation superalloy TMS-238 were summarized. It was found that both Sb and Pb do not have a large effect on creep rupture life, but they degrade oxidation resistance. The removal of impurities by melting in a CaO crucible was tested and its mechanism was examined. It was found that Ca forms a compound with impurities within the alloy and prevents the segregation of impurities at the oxide film/substrate interface. The effect of CaO was also confirmed in an experiment in which impurity S was removed from 1st generation Ni-base superalloy TMS-1700 by adding CaO particles in a 3-ton commercial melting furnace. Similar results were obtained for this alloy, where it was also found that CaS had formed inside the alloy, thus improving the oxidation resistance of TMS-1700. |
Proceedings Inclusion? |
Definite: At-meeting proceedings |