Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
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Effect of Mo addition on the Creep Properties of 9Cr-3W Steel

9Cr-3W 강의 크리프 특성에 미치는 Mo 첨가의 영향

  • Kim, Yong-Rai (Nuclear Materials Division, Korea Atomic Energy Research Institute) ;
  • Jang, Jinsung (Nuclear Materials Division, Korea Atomic Energy Research Institute) ;
  • Kim, Tae-Kyu (Nuclear Materials Division, Korea Atomic Energy Research Institute)
  • 김용래 (한국원자력연구원 원자력재료개발부) ;
  • 장진성 (한국원자력연구원 원자력재료개발부) ;
  • 김태규 (한국원자력연구원 원자력재료개발부)
  • Received : 2012.11.05
  • Accepted : 2013.02.04
  • Published : 2013.02.28
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Abstract

The effect of the Mo addition on the high temperature creep properties of the 9Cr-3W steel was also evaluated. Two experimental steels, (9Cr-3W and 9Cr-3W-0.5Mo), were prepared using a vacuum induction melting process, followed by hot rolling and heat treatment processes. Three types of precipitates, ($M_{23}C_6$, Nb-rich MX and V-rich MX) were observed in a typical tempered martensitic matrix. Significant effects of the Mo addition on the tensile properties were not observed. However, the creep properties at $650^{\circ}C$ under applied stresses of 140 and 150 MPa were considerably enhanced by the Mo addition. The microstructural observation after the creep test indicated that the addition of Mo could function to retain the recovery of the martensitic matrix, thus resulting in the enhanced creep properties of the 9Cr-3W-0.5Mo steel. Furthermore coarsening of the $M_{23}C_6$ carbides and formation of Laves phases were observed in both samples after the creep tests.

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References

  1. Corwin WR, Nucl. Eng. & Tech., "U. S. Generation IV reactor intergrated materials technology program", 38 (2006) 591.
  2. Kim TK, Baek JH, Han CH, Kim SH and Lee CB, J. Nucl. Mater., "Effects of the fabrication process parameters on the precipitates and mechanical properties of a 9Cr-2W-V-Nb steel", 389 (2009) 359-364. https://doi.org/10.1016/j.jnucmat.2009.01.302
  3. Crawford DC, Porterm DL and Hayes SL, J. Nucl. Mater., "Fuels for sodium-cooled fast reactors : US perspective", 371 (2007) 202-231. https://doi.org/10.1016/j.jnucmat.2007.05.010
  4. Kim TK and Kim SH, J. Nucl. Mater., "Study on the cold working process for FM steel cladding tubes", 411 (2011) 208- 212. https://doi.org/10.1016/j.jnucmat.2011.02.017
  5. Fujita T, Sato T and Takahashi N, Trans. ISIJ, "Effect of molybdenum and tungsten on the long term creep rupture strength of 12% chromium heat resisting steel containing vanadium, niobium and boron", 18 (1978) 115-124.
  6. Hosoi Y, Wada N, Kunimitsu S and Urita T, J. Nucl. Mater., "Precipitation behavior of laves phase and its effect on toughness of 9Cr-2Mo Ferritic-Martensitic steel", 141(3) (1986) 461-467.
  7. Tsuda Y, Ishii R, Yamada M, Azuma T, Tanaka Y and Ikeda Y, JSME, "Development of high strength 12%Cr ferritic steel for turbine rotor", 2 (1997) 131.
  8. Mohyla P and Foldyna V, Mater. Sci. Eng., "Improvement of reliability and creep resistance in advanced low-alloy steels", 510(1) (2009) 234-237.
  9. Hald J, Int. J. Pres. Ves. Pip., "Microstructure and long-term creep properties of 9-12% Cr steels", 85 (2008) 30-37. https://doi.org/10.1016/j.ijpvp.2007.06.010
  10. Maruyama K, Sawada K and Koike JI, ISIJ Int., "Strengthening mechanisms of creep resistant tempered martensitic steel", 41 (2001) 641-653. https://doi.org/10.2355/isijinternational.41.641
  11. Foldyna V, Lecomte-Beckers J, Proceedings of the 7-th Liege Conference Materials for Advanced Power Engineering, Forschungszentrum Julich, Germany, (2002) 1477.
  12. Baek JH, Han CH, Kim SH, Lee CB and Hahn DH, J. Kor. Inst. Met. & Mater., "Microstructural and mechanical properties of Ta-bearing 9%Cr Ferritic/Martensitic steels", 47 (2009) 209- 216.
  13. Abe F, Curr. Opin. Solid St. M., "Bainitic and martensitic creepresistant steels", 8 (2004) 305-311. https://doi.org/10.1016/j.cossms.2004.12.001
  14. Kushima H, Kimura K and Abe F, Tetsu to Hagane, "Degradation of Mod. 9Cr-1Mo steel during long-term creep deformation", 85 (1999) 841-847. https://doi.org/10.2355/tetsutohagane1955.85.11_841