Grain Size Depending Dwell-Fatigue Crack Growth in Inconel 718
| Autor: | Jonas Saarimäki, Johan Moverare, Mattias Lundberg |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Gas turbines
nickel base superalloys Materials science electron microscopy 02 engineering and technology Materials Engineering Paris' law 021001 nanoscience & nanotechnology Condensed Matter Physics Turbine Grain size Superalloy 020303 mechanical engineering & transports 0203 mechanical engineering mechanical characterzation fracture Materialteknik Fracture (geology) General Materials Science Constant load fatigue Composite material 0210 nano-technology Inconel human activities |
| Popis: | Inconel 718 is a commonly used superalloy for turbine discs in the gas turbine industry. Turbine discs are normally subjected to dwell-fatigue as a result of long constant load cycles. Dwell-times have been shown to give rise to increased crack propagation rates in superalloys at elevated temperatures. Dwell-time crack propagation behavior in Inconel 718 has been tested at 550 °C using Kb test samples with 2160 s dwell-times at maximum load and “pure fatigue” tests. The dwell-time effect has been studied for differently processed Inconel 718, that is, fine grained bar, grain enlarged bar, and cast material. This has been done in order to investigate the effect of grain size on crack propagation. Microstructure characterization is conducted using scanning electron microscopy techniques such as electron channeling contrast imaging and electron backscatter diffraction. Time dependent crack propagation rates are strongly affected by grain size. Propagation rates increase with decreasing grain size, whereas crack tip blunting increased with increasing grain size. Funded by Swedish Energy Agency Siemens Industrial Turbomachinery ABGKN Aerospace Engine Systems Royal Institute of Technology through the Swedish research program TURBO POWER |
| Databáze: | OpenAIRE |
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