| About this Abstract |
| Meeting |
Superalloys 2024
|
| Symposium
|
Superalloys 2024
|
| Presentation Title |
B-8: The Effect of Direct Current Heating on the Creep Behaviour of Polycrystalline Ni-based Superalloys |
| Author(s) |
Ryo Sasaki, Satoshi Utada, Yuanbo T. Tang, Carlos A. Nunes, Roger C. Reed |
| On-Site Speaker (Planned) |
Ryo Sasaki |
| Abstract Scope |
This study discusses the effect of the direct current heating (DCH) on the creep behaviour of Ni-based superalloys, in an attempt to converge on best practice and also reliability. Particular features are the use of an electro-thermal mechanical testing (ETMT) system which has allowed for direct comparison of the DCH heating method with the more conventional resistance furnace heating (FH) approach. In addition, particular attention is paid to a testing protocol to confirm the accuracy of temperature measurement during DCH. Waspaloy, Alloy713C and Alloy246 are used in different geometrical configurations, thus enabling us to establish the difference in creep behaviours caused by altering the sample sizes and the heating methods. The creep rupture lives of the materials tested by the DCH method were consistently shorter than that tested by the FH method. Microstructural investigation revealed that there is no influence of heating method on the coarsening rate of the fine γ′ precipitates and on the thickness of the oxide layer in Waspaloy during creep test at 732 °C. Moreover, the presence of an axial temperature gradient did not influence the creep life unduly. The radial temperature gradient as estimated by an analytical model has affected to some extent. It is hypothesised that the diffusivity is increased by the direct current, and the dislocation climb is facilitated in the DCH testing for Waspaloy. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |