About this Abstract |
| Meeting |
Superalloys 2021
|
| Symposium
|
Superalloys 2021
|
| Presentation Title |
Is the Carbon Content Really an Issue for the LCF Durability of Forged γ/γ' Ni-based Disk Alloys? |
| Author(s) |
Adele Govaere, Anne-Laure Rouffié, Jean-Michel Franchet, Daniel Galy, Alexandre Devaux, Coraline Crozet, Paraskevas Kontis, Patrick Villechaise, Jonathan Cormier |
| On-Site Speaker (Planned) |
Adele Govaere |
| Abstract Scope |
The Non Metallic Inclusions (NMIs) population of two versions of AD730™ (the standard one and a high carbon doped one) alloy were studied in terms of oxidation and low-cycle fatigue behavior at 450°C and 700°C. Cracking of NMIs was observed in the early stages of oxidation without any applied load, even at intermediate temperature. It is assisted by volume expansion and thermal mismatch between the NMIs and the surrounding g/g′ matrix. It was observed that the cracking took place in the Nb-rich part of the inclusions. However, the presence of pre-cracked inclusions does not have a detrimental effect on the fatigue lifetimes. The mechanical behaviors and mechanisms were investigated. Moreover, addition of carbon may lead to a debit in LCF life depending on the loading direction with respect to the NMIs cluster alignments. The observation of the fracture surfaces showed that no cracks initiated within inclusions in the high carbon content material despite a much higher density of NMIs. The inclusions and grain size distributions, the particles alignment orientations as well as the environment strongly contribute to the crack initiation mechanisms. |
| Proceedings Inclusion? |
Undecided |