About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
The Influence of Ex-service Steel Turbine Blade Microstructural Variability on Fatigue Behaviour and Lifetime Extension Approaches |
Author(s) |
Ara Masis Masis Khodavirdi, Philippa Reed, Andrew Hamilton |
On-Site Speaker (Planned) |
Ara Masis Masis Khodavirdi |
Abstract Scope |
Ex-service stainless steel (SS) turbine blades from the low-pressure stage of steam turbines are shot peened as a means of fatigue lifetime extension to allow redeployment. The variability of the microstructure within and between blades of a given SS alloy may influence the lifetime prediction models. The study aims to quantify the microstructural variability, in terms of grain size, distribution and orientation in relation to the fatigue crack initiation/propagation processes to incorporate into fatigue lifetime predictive models. EBSD mapping was used to quantify microstructural variability and mechanical testing used to correlate macro-mechanical properties to microstructural changes. Short and long crack fatigue samples were analysed by sectioning and EBSD scanning to study the microstructural variation and subsequent shot peening effect on crack initiation and propagation. A mechanistic understanding of the influence of microstructural variability on the predictive models of life extension of shot peened blades is thereby developed. |
Proceedings Inclusion? |
Planned: |
Keywords |
Iron and Steel, Mechanical Properties, Surface Modification and Coatings |