Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of Tensile Property of Austenitic Alloys Exposed to High-Temperature S-CO2 Environment

고온 S-CO2 환경에 노출된 오스테나이트계 합금의 인장특성 평가

  • Kim, Hyunmyung (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology) ;
  • Lee, Ho Jung (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology) ;
  • Jang, Changheui (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology)
  • 김현명 (한국과학기술원 원자력 및 양자공학과) ;
  • 이호중 (한국과학기술원 원자력 및 양자공학과) ;
  • 장창희 (한국과학기술원 원자력 및 양자공학과)
  • Received : 2014.03.15
  • Accepted : 2014.07.29
  • Published : 2014.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

Super-critical $CO_2$ ($S-CO_2$) Brayton cycle has been considered to replace the current steam Rankine cycle in Sodium-cooled Fast Reactor (SFR) in order to improve the inherent safety and thermal efficiency. Several austenitic alloys are considered as the structural materials for high temperature $S-CO_2$ environment.. Microstructural change after long-term exposure to high temperature $S-CO_2$ environment could affect to the mechanical properties. In this study, candidate materials (austenitic stainless steels and Alloy 800HT) were exposed to $S-CO_2$ to assess oxidation resistance and the change in tensile properties. Loss of ductility was observed for some austenitic stainless steels even after 250 h exposure. The contribution of $S-CO_2$ environment on such changes was analyzed based on the characterization of the surface oxide and carburization of the materials in which 316H and 800H showed different oxidation behaviors.

소듐냉각고속로(Sodium-cooled Fast Reactor, SFR)의 증기 Rankine 싸이클 발전시스템을 높은 열효율과 안전성을 가지는 초임계 이산화탄소(Supercritical carbon dioxide, $S-CO_2$) Brayton 싸이클로 대체하는 방안이 고려되고 있다. 다양한 오스테나이트계 합금이 고온 $S-CO_2$ 환경 열교환시스템 구조재료로 제시되고 있다. 구조재료는 장시간 고온 $S-CO_2$ 환경에 노출됨에 따라 미세구조에 변화가 일어나고, 나아가 기계적 특성의 저하가 발생할 수 있다. 본 연구에서는 오스테니틱 스테인리스강들과 Alloy 800HT를 고온 $S-CO_2$ 환경에 노출시키고, 그에 따른 부식특성 및 인장특성을 평가하였다. 그 결과 $650^{\circ}C$, 250시간 노출 후 316H SS와 800HT에서 큰 연신율 감소를 보였다. $S-CO_2$ 환경이 인장특성 변화에 미치는 영향을 표면 산화막 및 탄화거동을 통해 분석한 결과, 316H 와 800H 의 거동이 큰 차이를 보였다.

Keywords

References

  1. Chang, Y. I., Finck, P. J. and Grandy, C., 2006, Advanced Burner Test Reactor Preconceptual Design Report, Argonne National Laboratory report ANL-ABR-1 (ANL-AFCL-173).
  2. Dong, Z., Li, Y., Lin, M. and Li, M., 2013, "A Study of the Mechanism of Enhancing Oil Recovery Using Supercritical Carbon Dioxide Microemulsion," Petroleum Sci., Vol. 30, No. 1, pp. 91-96.
  3. Beech, D. J. and May, R., 1999, "Gas Reactor and Associated Nuclear Experience in The UK Relevant to High Temperature Reactor Engineering," Proceedings of the First Information Exchange Meeting on Basic Studies on High-Temperature Engineering, Paris, France.
  4. Nam, H. Y., Kim, J. B., Lee, J. H. and Park, C. G., 2011, "Concept Development and Review of Current Technical Issues for SFR Steam Generator," Trans. Korean Soc. Mech. Eng. A, Vol. 35, pp.1083-1090. https://doi.org/10.3795/KSME-A.2011.35.9.1083
  5. Dostal, V., Driscoll, M. J. and Hejzlar, P., 2004, A Supercritical Carbon Dioxide Cycle for Next Generation Nuclear Reactors, MIT Annual and Progress Reports, MITANP-TR-100.
  6. Corradini, M., 2010, Advanced Burner Reactor Sodium Technology Gap Analysis, U.S. DOE Report FCR&D-REAC-2010-000034, Sandia National Laboratories.
  7. Pillai, S. R. and Khatak, H. S., 2002, "Corrosion of Austenitic Stainless Steel in Liquid Sodium," Corrosion of Austenitic Stainless Steels: Mechanism, Mitigation and Monitoring, ISBN 1085573-613-6 chapter 10, pp. 241-264.
  8. Natesan, K., Li, M., Chopra, O.K. and Majumdar, S., 2009, "Sodium Effects on Mechanical Performance and Consideration in High Temperature Structural Design for Advanced Reactors," J. of Nucl. Mat., Vol. 392, pp. 243-249. https://doi.org/10.1016/j.jnucmat.2009.03.039
  9. Cao, G., Firouzdor, V., Sridharan, K., Anderson, M. and Allen, T.R., 2012, "Corrosion of Austenitic Alloys in High Temperature Supercritical Carbon Dioxide," Corrosion Science, Vol. 60, pp. 246-255. https://doi.org/10.1016/j.corsci.2012.03.029
  10. Sridharan, K., 2013, Corrosion in Supercritical Carbon Dioxide: Materials, Environmental Purity, Surface Treatments, and Flow Issues, Final Report 10-872, University of Wisconsin.
  11. Faooq, M., 2013, Strengthening and Degradation Mechanisms in Austenitic Stainless Steels at Elevated Temperature, KTH Sweden Doctoral Thesis.
  12. Was, G., 2013, Corrosion and Creep of Candidate Alloys in High Temperature Helium and Steam Environments for NGNP, U.S. Nuclear Energy University Programs Final report NEUP 09-678, University of Michigan.
  13. Fulger, M., Ohai, D., Mihalache, M., Pantiru, M. and Malinovschi, V., 2009, "Oxidation Behavior of Incoloy 800 under Simulated Supercritical Water Conditions," J. Nucl. Mat. Vol. 385, pp. 288-293. https://doi.org/10.1016/j.jnucmat.2008.12.004
  14. Moore, R. and Conboy, T., 2012, Metal Corrosion in a Supercritical Carbon Dioxide - Liquid Sodium Power Cycle, Milestone Report, M3AR12SN08010601, Sandia National Laboratories.