Nuclear Engineering and Technology

  • 제53권2호
  • /
  • Pages.572-582
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  • 2021
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  • 1738-5733(pISSN)
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  • 2234-358X(eISSN)
한국원자력학회 (Korean Nuclear Society)
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Creep and creep crack growth behaviors for base, weld, and heat affected zone in a grade 91 weldment

  • 투고 : 2020.04.16
  • 심사 : 2020.07.12
  • 발행 : 2021.02.25
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초록

This study investigated the creep and creep crack growth (CCG) behavior of the base metal (BM), weld metal (WM), and heat affected zone (HAZ) in a Gr. 91 weldment, which was made by a shield metal arc weld process. A series of tensile, creep, and CCG tests were performed for the BM, WM, and HAZ at 550 ℃. Creep behavior of the BM, WM, and HAZ was analyzed in terms of various creep laws; Norton's power-law, Monkman-Grant relation and damage tolerance factor (λ), and their constants were determined. In addition, each CCGR law for the BM, WM, and HAZ was proposed and compared in terms of a C*-fracture parameter. The WM and HAZ revealed faster creep rate, lower rupture ductility, and faster CCGRs than the BM, but they showed a similar behavior in the creep and CCG. The CCGRs obtained in the present study exhibited a marginal difference when compared with those of RCC-MRx of currently elevated design code in France. A creep crack path in the HAZ plane progressed towards a weak fine-grained HAZ adjacent to the BM.

키워드

과제정보

This work was supported by the National Research Foundation (NRF) grant funded by the Korea government (2020M2D4A2068407).

참고문헌

  1. W.G. Kim, J.Y. Park, H.Y. Lee, S.D. Hong, Y.W. Kim, S.J. Kim, Time-dependent crack growth behavior for a SMAW weldment of Gr. 91 steel, Int. J. Pres. Ves. Pip. 110 (2013) 66-71. https://doi.org/10.1016/j.ijpvp.2013.04.024
  2. B.K. Choudhary, E. Issac Samual, Creep behavior of modified 9Cr-1Mo ferritic steel, J. Nucl. Mater. 412 (2011) 82-89. https://doi.org/10.1016/j.jnucmat.2011.02.024
  3. K.M. Nikbin, D.J. Smith, G.A. Webster, An engineering approach to the prediction of creep crack growth, Trans. ASME. 108 (1986) 186-191.
  4. W.G. Kim, J.Y. Park, S.D. Hong, S.J. Kim, Probabilistic assessment of creep crack growth rate for Gr. 91 steel, Nucl. Eng. Des. 241 (2011) 3580-3586. https://doi.org/10.1016/j.nucengdes.2011.06.042
  5. Y. Takahasi, T. Igari, F. Kawashima, S. Date, N. Isobe, T. Itoh, Y. Noguchi, K. Kobayashi, High-temperature crack growth behavior of high-chromium steels, SMiRT 18 (7) (2005) 1904-1915. SMiRT18-G11.
  6. E.I. Samuel, B.K. Choudhary, W.G. Kim, Reliability Analysis on Long-Term Creep Life Prediction of Grade 91 Steel Weld Joints, 7th International Conference on Creep, Fatigue and Creep-Fatigue Interaction (CF-7), Tamil Nadu, India, 2016, pp. 923-928.
  7. Y. Wang, L. Li, R. Kannan, Transition from Type IV to Type I cracking in heat-treated grade 91 steel weldments, Mater. Sci. Eng. 714 (2018) 1-13. https://doi.org/10.1016/j.msea.2017.12.052
  8. M. Yamamoto, N. Miura, T. Ogata, Applicability of C* parameter in assessing Type-IV creep cracking in mod. 9Cr-1Mo steel welded joint, Eng. Fract. Mech. 77 (2010) 3022-3034. https://doi.org/10.1016/j.engfracmech.2010.04.023
  9. D.J. Abson, J.S. Rothwell, Review of Type IV cracking of weldments in 9-12%Cr creep strength enhanced ferritic steels, Int. Mater. Rev. 58 (8) (2013) 437-473. https://doi.org/10.1179/1743280412Y.0000000016
  10. ASTM E139-17, Standard Test Method for Conducting Creep, Creep-Rupture and Stress Rupture Tests of Metallic Materials, ASTM standard, 2017.
  11. ASTM E1457-17, Standard Test Method for Measurement of Creep Crack Growth Rates in Metals, ASTM standard, 2017.
  12. B. Dogan, B. Petrovski, Creep crack growth of high temperature weldments, Int. J. Pres. Ves. Pip. 78 (2001) 795-805. https://doi.org/10.1016/S0308-0161(01)00092-8
  13. W.G. Kim, J.Y. Park, I.M.W. Ekaputra, S.J. Kim, M.H. Kim, Y.W. Kim, Creep deformation and rupture behavior of Alloy 617, Eng. Fail. Anal. 58 (2015) 441-451. https://doi.org/10.1016/j.engfailanal.2015.07.041
  14. K. Guguloth, N. Roy, Creep deformation behavior of 9CrMoVNb (ASME Grade 91) steel, Mater. Sci. Eng. 680 (2017) 386-404.
  15. B.K. Choudhary, Tertiary creep behaviour of 9Cr-1Mo ferritic steel, Mater. Sci. Eng. 585 (2013) 1-9. https://doi.org/10.1016/j.msea.2013.07.026
  16. W.G. Kim, J.Y. Park, I.M.W. Ekaputra, S.J. Kim, J. Jang, Influence of hold time and stress ratio on cyclic creep properties under controlled tension loading cycles of Grade 91 steel, Nucl. Eng. Tech. 49 (2017) 581-591. https://doi.org/10.1016/j.net.2016.11.007
  17. G. Qin, S.V. Hainsworth, A. Strang, P.F. Morris, P.D. Clarke, A.P. Backhouse, TEM studies of microstructural evolution in creep exposed E911, in: I.A. Shibli, S.R. Holdsworth (Eds.), Proceedings of the 2nd ECCC Creep Conf. On Creep & Fracture in High Temperature Components, Zurich ETD, 2009, pp. 889-899.
  18. A. Saxena, Nonlinear Fracture Mechanics for Engineers, CRC Press, New York, USA, 1997.
  19. Afcen RCC-MRx, Code Section III - Tome 6, Probationary phase rules, France, 2015.
  20. M. Swei, A.S. Sedmak, B. Petrovski, Z.Z. Golubovi, S.A. Sedmak, M. Katini, K.I. Azzabi, Creep crack growth behavior of P91 steel weldments, Therm. Sci. 23 (2B) (2019) 1203-1209. https://doi.org/10.2298/TSCI170729240S