About this Abstract |
| Meeting |
11th International Symposium on Superalloy 718 and Derivatives 2026: Legacy, Innovations, and Future Directions
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| Symposium
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Superalloy 718 and Derivatives 2026: Legacy, Innovations, and Future Directions
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| Presentation Title |
In situ monitoring of η phase evolution kinetics in the Inconel 706 superalloy by electrical resistivity |
| Author(s) |
Laurane Finet, Raphaël Persée, Ronan Mainguy, Moukrane Dehmas |
| On-Site Speaker (Planned) |
Laurane Finet |
| Abstract Scope |
Inconel 706 is a superalloy mainly used for very large gas turbine components. Its microstructure is composed of γ’ and γ’’ as hardening phases and η phase for some applications to control grain size and to improve creep rupture life. Studying the η phase precipitation kinetics in such alloy can be challenging using classical methodologies. Electrical resistivity, an in situ phase transformation analysis technique, seems promising in tracking microstructural evolution in γ/γ’ superalloys. However, its effectiveness still needs to be assessed in more complex precipitation sequence such as γ/γ’-γ’’-η/δ like in Inconel 706 superalloy. Various heat treatments were tested using an in-house resistivimeter to study the precipitation and dissolution kinetics, covering solution treatment, cooling rate and stabilization treatment. The variations in electrical resistivity during the heating stage of solution treatment were attributed to the successive dissolution of the three types of precipitates: γ’, γ’’ and η phases. The complete dissolution of η phase occurred after 40 minutes at 990°C while at least 2h30 are needed at 965°C. η phase precipitation occurs during slow cooling before reaching the temperature of stabilization, which is not the case for fast cooling. Various isothermal treatments were then tested and showed different electrical resistivity evolution reflecting different precipitation sequences depending on the temperature. Electrical resistivity proved to be efficient in monitoring the precipitation and dissolution kinetics in INCONEL 706 during various heat treatments and could be useful to determine time-temperature-transformation diagrams in γ/γ’-γ’’-η/δ superalloys. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |