Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
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Solidification and Segregation Behaviors with Solidification Rate in Co base superalloy, FSX-414

일방향 응고된 Co기 초내열합금 FSX-414의 응고속도에 따른 응고조직 및 편석 거동

  • Lee, Hyun-Jung (Department of Materials Science and Engineering, Changwon National University) ;
  • Lee, Je-Hyun (Department of Materials Science and Engineering, Changwon National University) ;
  • Seo, Seong-Moon (High Temperature Materials Lab., Korea Institute of Machinery and Materials) ;
  • Jo, Chang-Young (High Temperature Materials Lab., Korea Institute of Machinery and Materials) ;
  • Gwon, Seok-Hwan (R&D Center, Korea Lost Wax Co.) ;
  • Chang, Byeong-Moon (R&D Center, Korea Lost Wax Co.)
  • 이현정 (창원대학교 재료공학과) ;
  • 이재현 (창원대학교 재료공학과) ;
  • 서성문 (한국기계연구원 환경재료연구센터) ;
  • 조창용 (한국기계연구원 환경재료연구센터) ;
  • 권석환 (한국로스트왁스 기술연구소) ;
  • 장병문 (한국로스트왁스 기술연구소)
  • Received : 2009.01.15
  • Published : 2009.07.25
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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 $0.5{\sim}300{\mu}m/s$ in the Co base superalloy FSX-414. The cellular interface were formed at a low solidification rate, $1{\mu}m/s$, and the dendritic interface was found at higher solidification rates, $5{\sim}300{\mu}m/s$. 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 $M_{23}C_{6}$ eutectic microstructure formed between $\gamma$ dendrites. Composition analysis showed that Cr and W were segregated severely between the dendrites, which resulted in the formation of Cr-rich $M_{23}C_{6}$ and W-rich MC carbides.

Keywords

References

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