| About this Abstract |
| Meeting |
10th International Symposium on Superalloy 718 and Derivatives (2023)
|
| Symposium
|
Superalloy 718 and Derivatives
|
| Presentation Title |
Alloy Design and Development of a Novel Ni-Co Based Superalloy GH4251 |
| Author(s) |
Hongyao Yu, Hailong Qin, Xizhen Chen, Guangbao Sun, Bin Gan, Yu Gu, Teng An, Jinglong Qu, Jinhui Du, Zhongnan Bi |
| On-Site Speaker (Planned) |
Hongyao Yu |
| Abstract Scope |
The need of developing new high temperature materials has increased significantly in the last decade owing to the demand of higher engine operating temperature. This demand has motivated the development of a new Ni-Co based superalloy GH4251 with service temperature up to 700°C~800°C. Based on disk used alloy U720Li, the GH4251 alloy is designed by adjusting the content of Co, Cr, Ti, Nb and other elements. On the one hand, by increasing the Co content to 25 wt.%, the stacking fault energy is effectively reduced, which makes it easy to form nano-twins and other substructures that strengthening the alloy together with γ′ precipitates. The yield strengths of the alloy can achieve 1100MPa at 750℃ and the creep-rupture life is more than 500h at 750℃ under 530MPa with fine grain size (ASTM 8), which is superior than U720Li. On the other hand, a certain Nb element is added to replace Ti element, which can reduce the γ′ solvus temperature and its precipitating dynamic, along with a changed thermal deformation behavior caused by lower stacking fault energy, leading to a significant better hot work ability and weld ability compared with U720Li. Beside being used as disk or ring forgings, this novel GH4251 alloy can also be well processed by additive manufacturing due to its low cracking tendency.
Keywords: Ni-Co based superalloy, alloy design, disk forging, additive manufacturing |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |