| About this Abstract |
| Meeting |
Superalloys 2024
|
| Symposium
|
Superalloys 2024
|
| Presentation Title |
Precipitation of γ′ in Two γ-γ′ Ni-based Superalloys During the Solvus Transition Stage of Ingot to Billet Conversion; Effects on γ Grain Structure and Implications for Open Die Forging |
| Author(s) |
Angus Coyne-Grell, Marcos Pérez, Ioannis Violatos, Jérôme Blaizot , Christian Dumont, Sebastien Nouveau |
| On-Site Speaker (Planned) |
Angus Coyne-Grell |
| Abstract Scope |
Udimet®720Li and AD730®UDIMET is a registered trademark of Special Metals Corporation. AD730 is a registered trademark of Aubert & Duval are γ-γ' Ni-based superalloys manufactured through casting and wrought processing, i.e. using ingot-to-billet conversion. These alloys are intended for use in safety critical aeroengine components, and there are strict requirements on the microstructural characteristics they must achieve at the end of the conversion process. Conventional ingot-to-billet conversion is an expensive and complex process, requiring multiple open-die forging operations and reheating steps to achieve a homogeneous microstructure. A main goal of this conversion process is to refine the as-cast grain structure, which comprises grains centimetres in size, down to a grain size of approximately 20 ìm. The present work studies the microstructural evolution of Udimet 720Li and AD730 billet material at the “solvus transition” stage of the conversion process, i.e. the controlled cooling through the solvus temperature. The formation of γ' prime precipitates during controlled cooling from supersolvus temperatures, and their interaction with the grain structure is the focus of this work. It is shown that the size and morphology of the grains in both alloys are significantly affected by discontinuous precipitation during cooling through the solvus temperature, and a method to exploit this during industrial ingot-to-billet conversion is suggested. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |