Abstract
In order to develop an Fe/Ni dissimilar-weld rotor structure for an Advanced Ultra Super Critical turbine, fundamental studies on the metallurgical properties of Fe/Ni welds are needed. In the work reported in this paper, we studied the microstructure evolution and creep rupture properties of Fe/Ni weld joints with different compositions. Investigation of thermally aged Fe/Ni diffusion couples revealed that Fe-based ferritic steel and Alloy 617 weld joints with a large difference in Cr content showed strong C diffusion at the weld interface. This decreased the creep rupture life of the weld joint, caused by coarsening of a martensitic structure near the interface. Analysis using Fe/Ni diffusion couples and thermodynamic calculations suggested that the driving force of C diffusion is the chemical potential gradient at the interface, and the difference in Cr content between Fe and Ni accelerates the C diffusion.
| Original language | English |
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| Pages | 1341-1351 |
| Number of pages | 11 |
| Publication status | Published - 2014 Jan 1 |
| Externally published | Yes |
| Event | 7th International Conference on Advances in Materials Technology for Fossil Power Plants - Waikoloa, HI, United States Duration: 2013 Oct 22 → 2013 Oct 25 |
Other
| Other | 7th International Conference on Advances in Materials Technology for Fossil Power Plants |
|---|---|
| Country | United States |
| City | Waikoloa, HI |
| Period | 13/10/22 → 13/10/25 |
ASJC Scopus subject areas
- Fuel Technology
- Renewable Energy, Sustainability and the Environment