Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
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Effects of Ni and Cr Contents on the Fracture Toughness of Ni-Mo-Cr Low Alloy Steels in the Transition Temperature Region

Ni-Mo-Cr계 저합금강의 천이온도영역에서의 파괴인성에 미치는 Ni 및 Cr 함량의 영향

  • 이기형 (한국과학기술원 신소재공학과) ;
  • 박상규 (한국과학기술원 신소재공학과) ;
  • 김민철 (한국원자력연구원 원자력재료연구부) ;
  • 이봉상 (한국원자력연구원 원자력재료연구부) ;
  • 위당문 (한국과학기술원 신소재공학과)
  • Received : 2009.05.19
  • Published : 2009.09.25
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Abstract

Materials used for a reactor pressure vessel(RPV) are required high strength and toughness, which determine the safety margin and life of a reactor. Ni-Mo-Cr low alloy steel shows better mechanical properties than existing RPV steels due to higher Ni and Cr contents compared to the existing RPV steels. The present study focuses on effects of Ni, Cr contents on the cleavage fracture toughness of Ni-Mo-Cr low alloy steels in the transition temperature region. The fracture toughness was characterized by a 3-point bend test of precracked Charpy V-notch(PCVN) specimens based on ASTM E1921-08. The test results indicated that the fracture toughness was considerably improved with an increase of Ni and Cr contents. Especially, control of Cr content was more effective in improving fracture toughness than manipulating Ni content, though Charpy impact toughness was changed more extensively by adjusting Ni content. These differences between changes in the fracture toughness and that in the impact toughness were derived from microstructural features, such as martensite lath size and carbide precipitation behavior.

Keywords

References

  1. S. G. Druce and B. C. Edwards, Nucl. Energy 9, 347 (1980)
  2. K. Suzuki, J. Nucl. Mater. 108&109, 443 (1982) https://doi.org/10.1016/0022-3115(82)90515-3
  3. Y. S. Ahn, H. D. Kim, T. S. Byun, Y. J. Oh, G. M. Kim, and J. H. Hong, Nucl. Eng. Design 194, 161 (1999) https://doi.org/10.1016/S0029-5493(99)00196-X
  4. Y. R. Im, Y. J. Oh, B. J. Lee, J. H. Hong, and H. C. Lee, J. Nucl. Mater. 297, 138 (2001) https://doi.org/10.1016/S0022-3115(01)00610-9
  5. P. Bowen, S. G. Druce, and J. F. Knott, Acta Metall. 34, 1121 (1986) https://doi.org/10.1016/0001-6160(86)90222-1
  6. D. A. Curry and J. F. Knott, Met. Sci. 12, 511 (1978) https://doi.org/10.1016/0036-9748(78)90198-9
  7. R. O. Ritchie, W. L. Server, and R. A. Wullaert, Metall. Trans. 10A, 15 (1979)
  8. G. Z. Wang and J. H. Chen, Metall. and Mat. Trans. 27A, 1909 (1996) https://doi.org/10.1007/BF02651940
  9. G. R. Odette, Scripta Metallurgica 17, 1183 (1983) https://doi.org/10.1016/0036-9748(83)90280-6
  10. V. K. Sikka and J. Moteff, J. Nucl. Mat. 54, 325 (1974) https://doi.org/10.1016/0022-3115(74)90144-5
  11. K. Wallin, Eng. Frac. Mech. 19, 1085 (1984) https://doi.org/10.1016/0013-7944(84)90153-X
  12. K. Wallin, Eng. Frac. Mech. 22, 149 (1985) https://doi.org/10.1016/0013-7944(85)90167-5
  13. ASTM standard E23-07 (2007)
  14. ASTM standard E208-06 (2006)
  15. ASTM Standard E1921-08 (2008)
  16. S. H. Kim, S. H. Lee, and Y. J. Oh, J. Kor. Inst. Met. & Mater. 40, 266 (2002)
  17. ASME B & PV Code Sec. II, Part A, SA508 (2005)
  18. Y. S. Ahn, Y. J. Oh, H. D. Kim, G. M. Kim and J. H. Hong, J. Kor. Inst. Met. & Mater. 38, 466 (2000)
  19. H. Kotilainen, Metals Laboratory Report 41, p. 26, Technical Research Center of Finland (1979)
  20. K. Wallin, K. Torronen, R. Ahlstrand, B. Timofeev, V. Rybin, V. Nikolaev, and A. Morozov, Nucl. Eng. Design 135, 239 (1992) https://doi.org/10.1016/0029-5493(92)90225-K
  21. F. B. Pickering, Physical Metallurgy and the Design of Steels, p. 14, Applied Science Publishers, (1978)
  22. B. V. Narasimha Rao and G. Thomas, Metal. Trans. A 11A, 441 (1980)
  23. S. Atamert and J. Stekly, Microstructure, Surface Eng. 9, 231 (1993) https://doi.org/10.1179/sur.1993.9.3.231
  24. S. G. Park, M. C. Kim, B. S. Lee, and D. M. Wee, J. Kor. Inst. Met. & Mater. 46, 771 (2008)
  25. P. Brozzo, G. Buzzichelli, A. Mascanzoni, and M. Mirabile, Met. Sci. 11, 132 (1977)
  26. J. P Naylor and P. R. Krahe, Metall. Trans. 5, 1699 (1984) https://doi.org/10.1007/BF02646351
  27. F. B. Pickering and T. Gladman, Iron and Steel Inst., Spec. Rep. No 93, 10 (1963)
  28. H. Otani, F. Terasaki, and T. Kunitake, Trans. Iron Steel Inst. 201, 5 (1972)
  29. A. From and R. Sandstrom, Materials Characterization 42, 111 (1999) https://doi.org/10.1016/S1044-5803(98)00051-5
  30. C. Wang, M. Wang, J. Shi, W. Hui, and H. Dong, Scripta Materialia 58, 492 (2008) https://doi.org/10.1016/j.scriptamat.2007.10.053
  31. A. D. Schino and C. Guarnaschelli, Materials Letters Accepted
  32. W. J. Yang, M. Y. Huh, S. J. Roh, B. S. Lee, Y. J. Oh, and J. H. Hong, J. Kor. Inst. Met. & Mater. 38, 675 (2000)
  33. D. A. Curry, Met. Sci. 14, 319 (1980) https://doi.org/10.1179/msc.1980.14.8-9.319
  34. R. H. Van Stone, T. B. Cox, J. R. Low, and J. A. Psioda, Inter. Met. Review 30, 157 (1985)
  35. R. O. Ritchie, J. F. Knott, and J. R. Rice, J. Mech. Phys. Solids. 21, 395 (1973) https://doi.org/10.1016/0022-5096(73)90008-2
  36. W. J. Yang, B. S. Lee, M. C. Kim, J. H. Hong, and M. Y. Huh, J. Kor. Inst. Met. & Mater. 41, 855 (2003)
  37. H. J. Rack, Scripta Metallurgica 13, 577 (1979) https://doi.org/10.1016/0036-9748(79)90112-1
  38. A. A. Griffith, Philosophical Transactions 221, 163 (1920)
  39. S. Lee, S. Kim, B. Hwang, B. S. Lee, and C. G. Lee, Acta Materialia 50, 4755 (2002) https://doi.org/10.1016/S1359-6454(02)00313-0
  40. B. Tanguy, J. Besson, and A. Pineau, Scripta Materialia 49, 191 (2003) https://doi.org/10.1016/S1359-6462(03)00239-2
  41. D. Bhattacharjee, C. L. Davis, and J. F. Knott, Ironmaking and Steelmaking 30, 249 (2003) https://doi.org/10.1179/030192303225003908