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Vol.47, No.7, 440 ~ 447, 2009
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| Title |
| Solidification and Segregation Behaviors with Solidification Rate in Co base superalloy, FSX-414 |
| 이현정 Hyun Jung Lee , 이재현 Je Hyun Lee , 서성문 Seong Moon Seo , 조창용 Chang Young Jo , 권석환 Seok Hwan Gwon , 장병문 Byeong Moon Chang |
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| Abstract |
| Co base superalloys have been widely used for the parts of gas turbine due to their excellent strength, thermal fatigue, oxidation resistance and weldability at high temperature. In this study, directional solidifications were carried out at various solidification rates, including 0.5~300 μm/s in the Co base superalloy FSX-414. The cellular interface were formed at a low solidification rate, 1 μm/s, and the dendritic interface was found at higher solidification rates, 5~300 μm/s. As the spacing of dendrite structure decreased, the size and spacing of eutectics decreased. Dendrite arm spacing decreased with increasing solidification rates and temperature gradient. It was interesting to find the M23C6 eutectic microstructure formed between γ dendrites. Composition analysis showed that Cr and W were segregated severely between the dendrites, which resulted in the formation of Cr-rich M23C6 and W-rich MC carbides. |
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| Key Words |
| directional solidification, thermal gradient, solidification rate, Co-base superalloy, segregation |
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