Nuclear Engineering and Technology

  • 제56권1호
  • /
  • Pages.1-8
  • /
  • 2024
  • /
  • 1738-5733(pISSN)
  • /
  • 2234-358X(eISSN)
한국원자력학회 (Korean Nuclear Society)
권호 표지
DOI QR코드

DOI QR Code

Thermal aging of Gr. 91 steel in supercritical thermal plant and its effect on structural integrity at elevated temperature

  • Min-Gu Won (Korea Atomic Energy Research Institute) ;
  • Si-Hwa Jeong (Korea Atomic Energy Research Institute) ;
  • Nam-Su Huh (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology) ;
  • Woo-Gon Kim (Korea Energy Technology Group) ;
  • Hyeong-Yeon Lee (Korea Atomic Energy Research Institute)
  • 투고 : 2022.11.18
  • 심사 : 2023.07.07
  • 발행 : 2024.01.25
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

In this study, the influence of thermal aging on structural integrity is investigated for Gr. 91 steel. A commercial grade Gr. 91 steel is used for the virgin material, and service-exposed Gr. 91 steel is sampled from a steam pipe of a super critical plant. Time versus creep strain curves are obtained through creep tests with various stress levels at 600 ℃ for the virgin and service-exposed Gr. 91 steels, respectively. Based on the creep test results, the improved Omega model is characterized for describing the total creep strain curve for both Gr. 91 steels. The proposed parameters for creep deformation model are used for predicting the steady-state creep strain rate, creep rupture curve, and stress relaxation. Creep-fatigue damage is evaluated for the intermediate heat exchanger (IHX) in a large-scale sodium test facility of STELLA-2 by using creep deformation model with proposed creep parameters and creep rupture curve for both Gr. 91 steels. Based on the comparison results of creep fatigue damage for the virgin and service-exposed Gr. 91 steels, the thermal aging effect has been shown to be significant.

키워드

과제정보

This research was supported by the International Research & Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2019K1A3A7A03113575, 2021K1A3A1A78097845 and 2021R1l1A2057941).

참고문헌

  1. T. Sakthivel, S.P. Selvi, P. Paramenswaran, K. Laha, Influence of thermal ageing on microstructure and tensile properties of P92 steel, High Temp. Mater. Process. 37 (5) (2018) 425-435, https://doi.org/10.1515/htmp-2016-0040. 
  2. T. Lucas, A. Forsstrom, T. Saukonen, R. Ballinger, H. Hanninen, Effects of thermal aging on material properties, stress corrosion cracking, and fracture toughness of AISI 316L weld metal, Metall. Mater. Trans. 47 (2016) 3956-3970, https://doi.org/10.1007/s11661-016-3584-6. 
  3. M. Li, W. Chen, K. Natesan, Development of a Mechanistic Thermal Aging Model for Grade 91, Argonne Natl. lab., 2018, https://doi.org/10.2172/1485132. ANL-ART-150. 
  4. M. Li, K. Natesan, W. Chen, Report on Understanding and Predicting Effects of Thermal Aging on Microstructure and Tensile Properties of Grade 91 Steel for Structural Components, Argonne Natl. lab., 2017, https://doi.org/10.2172/1409212. ANL-ART-108. 
  5. M. Li, W.Y. Chen, Microstructure-based prediction of thermal aging strength reduction factors for grade 91 ferritic-martensitic steel, Mater. Sci. Eng. 798 (2020) 1-15, https://doi.org/10.1016/j.msea.2020.140116, 140116. 
  6. J.R. DiStefano, V.K. Sikka, J.J. Blass, C.R. Brinkman, J.M. Corum, J.A. Horak, R.L. Huddleston, J.F. King, R.W. McClung, W.K. Sartory, Summary of Modified 9Cr-1Mo Steel Development Program 1975-1985, Oak Ridge Natl. Lab., 1986, https://doi.org/10.2172/712852. ORNL-6303. 
  7. R. Viswanthan, Damage Mechanisms and Life Assessment of High Temperature Components, ASM International, Metals Park, Ohio, 1995. 
  8. W.J. Evans, J.P. Jones, S. Williams, The interactions between fatigue, creep and environmental damage in Ti 6246 and Udimet 720li, Int. J. Fatig. 27 (10-12) (2005) 1473-1484, https://doi.org/10.1016/j.ijfatigue.2005.06.029. 
  9. S.-P. Zhu, Y.,-J. Yang, H.-Z. Huang, Z. Lv, H.-K. Wang, A unified criterion for fatigue-creep life prediction of high temperature components, Proc. Ins. Mech. Eng. G J Aerosp Eng 231 (4) (2017) 677-688. https://doi:10.1177/0954410016641448. 
  10. ASME Boiler and Pressure Vessel Code, Section III, Rules for Construction of Nuclear Power Plant Components, Division 5, High Temperature Reactors, ASME, 2015. 
  11. RCC-MRx, Section III, Subsection B, Class 1 N1RX Reactor Components its Auxiliary Systems and Supports, AFCEN, 2015. 
  12. J. Foulds, W. Ren, Thermal aging effects on the yield and tensile strength of 9Cr-1Mo-V (Grade 91), J. Pressure Vessel Technol. 144 (6) (2022) 1-13, https://doi.org/10.1115/1.4054341, 061505. 
  13. G. Zhang, Z. Zhou, K. Mo, Y. Miao, S. Xu, H. Jia, X. Liu, J.F. Stubbins, The effect of thermal-aging on the microstructure and mechanical properties of 9Cr ferritic/martensitic ODS alloy, J. Nucl. Mater. 522 (2019) 212-219, https://doi.org/10.1016/j.jnucmat.2019.05.023. 
  14. C. O'Murchu, S.B. Leen, P.E. O'Donoghu, R.A. Barrett, Characterization of thermal aging effects on the creep performance of T91 using small punch creep testing, Fatig. Fract. Eng. Mater. Struct. 44 (8) (2021) 2000-2014, https://doi.org/10.1111/ffe.13471. 
  15. V. Lok, T.G. Le, J.M. Yu, Y.W. Ma, V.P. Nguyen, S.T. Choi, K.B. Yoon, Changes in creep property and precipitates due to aging of T91 steel after long-term service, J. Mech. Sci. Technol. 34 (2020) 3283-3293, https://doi.org/10.1007/s12206-020-0720-4. 
  16. C.G. Panait, A. Zielinska-Lipiec, T. Koziel, A. Czyrska-Filemonowicza, A.F. Gourgues-Lorenzonb, W. Bendick, Evolution of dislocation density, size of subgrains and MX-type precipitates in a P91 steel during creep and during thermal ageing at 600 ℃ for more than 100,000 h, Mater. Sci. Eng. 527 (2010) 4062-4069, https://doi.org/10.1016/j.msea.2010.03.010. 
  17. W.G. Kim, S.H. Kim, C.B. Lee, Long-term creep characterization of Gr. 91 steel by modified creep constitutive equations, Met. Mater. Int. 17 (2011) 497-504, https://doi.org/10.1007/s12540-011-0630-1. 
  18. H.-Y. Lee, D.-W. Lim, J.-Y. Jeong, Effects of long-time service at high temperature on the material strength and J-R curve of Grade 91 steel, Eng. Fract. Mech. 178 (2017) 445-456, https://doi.org/10.1016/j.engfracmech.2017.02.022. 
  19. W.G. Kim, J.Y. Park, M.G. Won, H.Y. Lee, N.S. Huh, Non-linear modeling of stress relaxation curves for Grade 91 steel, J. Mech. Sci. Technol. 32 (2018) 1143-1151, https://doi.org/10.1007/s12206-018-0217-6. 
  20. Dassault Systemes, User's Manual ABAQUS (2013), Version 6.13. 
  21. RCC-MRx, Section III, Tome 6, Probationary Phase Rules, AFCEN, 2015. 
  22. S. Holmstrom, P. Auerkari, V. Friedmann, A. Klenk, B. Leibing, P. Buhl, M. Spindler, A. Riva, Long term stress relaxation modelling, in: ECCC Conference Creep & Fracture in High Temperature Component Design and Assessment, 2014. Rome, Italy, May 5-7. 
  23. M.G. Won, J.B. Choi, N.S. Huh, H.Y. Lee, W.G. Kim, Finite element simulation of creep deformation for Gr. 91 steel at 600 ℃ using garofalo model, in: Proceeding of ASME 2016 Press, 2016, https://doi.org/10.1115/PVP2016-63445. Vessel. Piping Conf. PVP2016-63445, Vancouver, Canada, July 17-21. 
  24. H.Y. Lee, M.G. Won, S.K. Son, N.S. Huh, Development of a program for high-temperature design evaluation according to RCC-MRx, Nucl. Eng. Des. 324 (2017) 181-195, https://doi.org/10.1016/j.nucengdes.2017.08.034. 
  25. L.K. Severud, Creep-fatigue assessment methods using elastic analysis results and adjustments, J. Pressure Vessel Technol. 113 (1991) 34-40, https://doi.org/10.1115/1.2928725. 
  26. K.R. Rao, Companion Guide to the ASME Boiler & Pressure Vessel Code, volume 1, third ed., ASME, 2008. 
  27. H.Y. Lee, M.G. Won, N.S. Huh, HITEP_RCC-MRx program for the support of elevated temperature design evaluation and defect assessment, J. Pressure Vessel Technol. 141 (2019) 1-13, https://doi.org/10.1115/1.4043916, 051205.