About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Materials Genome, CALPHAD, and a Career over the Span of 20, 50, and 60 Years: An FMD/SMD Symposium in Honor of Zi-Kui Liu
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Presentation Title |
High Temperature Creep Induced Phase Transformation in Austenitic Stainless Steels |
Author(s) |
Guocai Chai, Joakim Odqvist |
On-Site Speaker (Planned) |
Guocai Chai |
Abstract Scope |
Microstructures of two heat resistant austenitic stainless steels after long term ageing and creep testing have been studied using thermodynamic calculations and electron microscopy techniques. Martensitic phases have been observed in both steels. 17Cr10Ni austenitic steel was creep-tested at 800°C. Formation of martensite is mainly due to the precipitation of Cr2N. The consumption of Cr content in the matrix leads to an increase in Ms temperature and consequently formation of martensite. 18Cr8Ni austenitic steel was creep-tested at 600°C. Formation of martensite in this steel is mainly due to local depletion of Cr and Ni near the grain boundary due to different types of intermetallic precipitates, which causes an increase of Ms temperature. The influence of stress or strain on the precipitation is studied by an extra energy added to the Gibbs energy of the austenite phase to predict the precipitation behaviours by comparing with the aged materials. |
Proceedings Inclusion? |
Planned: |
Keywords |
Phase Transformations, Iron and Steel, High-Temperature Materials |