Influence of heat treatment on microstructure and hot crack susceptibility of laser-drilled turbine blades made from Rene 80
- Siemens AG Energy Section, PGBE21, 45473 Muelheim/Ruhr (Germany)
- Federal Institute for Materials Research and Testing (BAM), 12200 Berlin (Germany)
- Siemens Power Generation, PE 3472, 10548 Berlin (Germany)
Turbine components from conventionally cast nickel-base alloy Rene 80 show different hot cracking susceptibilities depending on their heat treatment conditions leading to slightly different microstructures. Electron probe micro-analysis, focused ion beam technique and analytical transmission electron microscopy were applied to reveal and identify grain boundary precipitates and the {gamma}-{gamma}'-microstructure. The distribution of borides along grain boundaries was evaluated statistically by quantitative metallography. The following features could be correlated with an increase of cracking susceptibility: i) Increasing grain size, ii) increasing fraction of grain boundaries with densely spaced borides, iii) lack of secondary {gamma}'-particles in matrix channels between the coarse cuboidal {gamma}'-precipitates. The latter feature seems to be responsible for linking-up of cracked grain boundary precipitates which occurred as an additional cracking mechanism after one heat treatment, whereas decohesion at the boride-matrix-interface in the heat affected zone of laser-drilled holes was observed for both heat treatments.
- OSTI ID:
- 21137476
- Journal Information:
- Materials Characterization, Vol. 59, Issue 11; Other Information: DOI: 10.1016/j.matchar.2008.01.021; PII: S1044-5803(08)00062-4; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
- Country of Publication:
- United States
- Language:
- English
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