About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
C-4: Exploring Microstructural Characteristics, Mechanical Behavior, Hydrogen Embrittlement and Long-term Stability of Polycrystalline CoNiCr-based Superalloys |
Author(s) |
Svetoslava Tsankova, Oliver Nagel, Andreas Bezold, Bianca Grandjean, Andreas Kirchmayer, Mathias Göken, Steffen Neumeier |
On-Site Speaker (Planned) |
Oliver Nagel |
Abstract Scope |
Polycrystalline γ/γ' CoNiCr-based superalloys have a promising combination of properties for aerospace and stationary gas turbine applications. In this study, four alloys, CoWAlloy1, 2, 3 and 6, were selected for further investigation. Microstructures of fully heat-treated materials were characterized by scanning and transmission electron microscopy and long-term stability at 750 °C was examined for various durations up to 1000 h. Tensile tests were performed between 25 °C and 700 °C, revealing dynamic strain aging in CoWAlloy2, 3 and 6 at intermediate temperatures of 400-650 °C. Hydrogen charging induced a decrease in tensile ductility at 25°C in the µ phase containing CoWAlloy3. Creep experiments were performed on CoWAlloy1, an alloy with increased Ti and Ta content, at 750 °C and 800 MPa, with variations of the secondary γ' precipitate size and grain size to identify optimal microstructural parameters. It was found that smaller grain sizes lead to a significantly higher creep resistance at these testing conditions. |
Proceedings Inclusion? |
Definite: At-meeting proceedings |