Transactions of the Korean Society of Pressure Vessels and Piping (한국압력기기공학회 논문집)

Korean Society of Pressure Vessels and Piping (한국압력기기공학회)
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High-Temperature Tensile Strengths of Alloy 617 Diffusion Weldment

Alloy 617 확산용접재의 고온 인장강도

  • 사인진 (한국원자력연구원 고온가스로개발부) ;
  • 황종배 (충남대학교 신소재공학과) ;
  • 김응선 (한국원자력연구원 고온가스로개발부)
  • Received : 2018.04.15
  • Accepted : 2018.06.18
  • Published : 2018.06.30
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Abstract

A compact heat exchanger is one of critical components in a very high temperature gas-cooled reactor (VHTR). Alloy 617 (Ni-Cr-Co-Mo) is considered as one of leading candidates for this application due to its excellent thermal stability and strengths in anticipated operating conditions. On the basis of current ASME code requirements, sixty sheets of this alloy are prepared for diffusion welding, which is the key technology to have a reliable compact heat exchanger. Optical microscopic analysis show that there are no cracks, incomplete bond, and porosity at/near the interface of diffusion weldment, but Cr-rich carbides and Al-rich oxides are identified through high resolution electron microscopic analysis. In high-temperature tensile testing, superior yield strengths of the diffusion weldment compared to the code requirement are obtained up to 1223 K ($950^{\circ}C$). However, both tensile strength and ductility drop rapidly at higher temperature due to the insufficient grain boundary migration across the interface of diffusion weldment. Best fit curves for minimum yield strength and average tensile strength are drawn from the experimental tensile results of this study.

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References

  1. Chang, J., Kim, Y.-W., Lee, K.-Y, Lee, Y.-W., Lee, W. J., Noh, J.-M., Kim, M.-H., Lim, H. -S., Shin, Y.-J., Bae, K.-K., and Jung, K.-D., 2007, "A Study of a Nuclear Hydrogen Production Demonstration Plant," Nucl. Eng. Technol., Vol. 39, No. 2, pp. 111-122. https://doi.org/10.5516/NET.2007.39.2.111
  2. Lee, W. J., Kim, Y. W., and Chang, J., 2009, "Perspectives of Nuclear Heat and Hydrogen," Nucl. Eng. Technol., Vol. 41, No. 4, pp. 413-426. https://doi.org/10.5516/NET.2009.41.4.413
  3. Locatelli, G., Mancini, M., and Todeschini, N., 2013, "Generation IV Nuclear Reactors: Current Status and Future Prospects," Energ. Policy, Vol. 61, pp. 1503-1520. https://doi.org/10.1016/j.enpol.2013.06.101
  4. Song, K.-N., Hong, S.-D., and Park, H.-Y., 2012, "High-Temperature Structural Analysis on the Small-Scale PHE Prototype under the Test Condition of Small-Scale Gas Loop," Transactions of the Korean Society of Pressure Vessel and Piping, Vol. 8, No.1, pp. 1-7 (in Korean).
  5. Song, K.-N., Hong, S.-D., and Park, H.-Y., 2012, "High-Temperature Structural Analysis on the Medium-Scale PHE Prototype under the Test Condition of Small-Scale Gas Loop," Transactions of the Korean Society of Pressure Vessel and Piping, Vol. 8, No.1, pp. 33-38 (in Korean).
  6. Takeda, T., Kunitomi, K., Horie, T., and Iwata, K., 1997, "Feasibility Study on the Applicability of a Diffusion-Welded Compact Intermediate Heat Exchanger to Next-Generation High Temperature Gas-Cooled Reactor," Nucl. Eng. Des., Vol. 168, pp. 11-21. https://doi.org/10.1016/S0029-5493(96)01361-1
  7. Clark, D. E., Mizia, R. E., Glazoff, M. V., Sabharwall, P., and McKellar, M. G., 2012, "Diffusion Welding of Alloys for Molten Salt Service-Status Report," INL/EXT-12-24589 Rev. 1, Idaho National Laboratory.
  8. Nestell, J., and Sham, T.-L., 2015, "ASME Code Consideration for the Compact Heat Exchanger," ORNL/TM-2015/401, Oak Ridge National Laboratory.
  9. Miwa, Y., Noishiki, K., Suzuki, T., and Takatsuki, K., 2013, "Manufacturing Technology of Diffusion-Bonded Compact Heat Exchanger (DCHE)," Kobelco Technology Review, No. 32, pp. 51-56.
  10. Kim, J. K., Shim, D. N., Seon, C. Y., Yang, K. H., Park, H. J., and Kim, D. J., 2017, "Development of Printed Circuit Heat Exchanger for Hydrogen Station Using Diffusion Bonding," J. of Welding and Joining, Vol. 35, No. 5, pp. 57-64 (in Korean). https://doi.org/10.5781/JWJ.2017.35.5.8
  11. Hong, S., Kim, S. H., Jang, C., and Sah, I., 2015, "The Effect of Post-Bond Heat Treatment on Tensile Property of Diffusion Bonded Austenitic Alloys," Trans. Korean Soc. Mech. Eng. A, Vol. 39, No. 2, pp. 1221-1227 (in Korean). https://doi.org/10.3795/KSME-A.2015.39.12.1221
  12. Sah, I., Hwang, J.-B, Hong, S.-I., Kim, E.-S., and Kim, M.-H., 2017, "Effect of Heat Treatment on the Diffusion-Bonded Ni-Base Alloy Hastelloy X," Korean J. Met. Mater., Vol. 55, No. 2, pp. 114-123 (in Korean).
  13. Sah, I., Kim, D., Lee, H. J., and Jang, C., 2013, "The Recovery of Tensile Ductility in Diffusion-Bonded Ni-Base Alloys by Post-Bond Heat Treatments," Mater. Design, Vol. 47, pp. 581-589. https://doi.org/10.1016/j.matdes.2012.12.061
  14. Totemeier, T. C., Tian, H., Clark, D. E., and Simpson, J. A., 2005, "Microstructure and Strength Characteristics of Alloy 617 Welds," INL/EXT-05-00488, Idaho National Laboratory.
  15. Basuki, W. W., Kraft, O., and Aktaa, J., 2012, "Optimization of Solid-State Diffusion Bonding of Hastelloy C-22 for Micro Heat Exchanger Applications by Coupling of Experiments and Simulations," Mat. Sci. Eng. A-Struct., Vol. 538, pp. 340-348. https://doi.org/10.1016/j.msea.2012.01.056
  16. Mizia, R. E., Clark, D. E., Glazoff, M. V., Lister, T. E., and Trowbridge, T. L., 2013, "Optimizing the Diffusion Welding Process for Alloy 800H: Thermodynamic, Diffusion Modeling, and Experimental Work," Metall. Mater. Trans. A, Vol. 44A, pp. S154-S161.
  17. Suzumura, A., Onzawa, T., and Tamura, H., 1983, "Solid State Diffusion Weldability of High Temperature Alloy A286 and Hastelloy X," Transactions of the Japan Welding Society, Vol. 14, No. 2, pp. 26-32.
  18. Ravisankar, B., Krishnamoorthi, J., Ramakrishnan, S. S., and Angelo, P. C., 2009, "Diffusion Bonding of SU 263," J. Mater. Process. Tech., Vol. 209, pp. 2135-2144. https://doi.org/10.1016/j.jmatprotec.2008.05.015
  19. Song, C. H., Yoon, S. H., and Choi, J. S., 2015, "A Study of Diffusion Bonding Process for High Temperature and High Pressure Micro Channel Heat Exchanger using Inconel 617," Korean J. Air-Cond. Refrig. Eng., Vol. 27, No. 2, pp. 87-93 (in Korean). https://doi.org/10.6110/KJACR.2015.27.2.087
  20. Wright, J. K., 2015, "Draft ASME Boiler and Pressure Vessel Code Case for Use of Alloy 617 for Class A Elevated Temperature Service Construction," INL/EXT-15-36305, Idaho National Laboratory.
  21. Sham, T.-L., Eno, D. R., and Jensen, K. P., 2008, "Treatment of High Temperature Tensile Data for Alloy 617 and Alloy 230," Proceedings of PVP2008, Chicago, July 27-31, PVP2008-61128.
  22. Kim, W.-G., Yin, S.-N., Park, J.-Y., Hong, S. -D., and Kim, Y.-W., 2012, "An Improved Methodology for Determining Tensile Design Strengths of Alloy 617," J. Mech. Sci. Technol., Vol. 26, No. 2, pp. 379-387. https://doi.org/10.1007/s12206-011-1024-5
  23. ASME Section VIII Code Case 2621-1, 2015 Edition.