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Avoidance Method Study for SAGBO Cracking During Heat Treatment of a ITER CS Model Coil Conductor Using Incoloy 908 Jacket

  • T. Kato
  • K. Hamada
  • K. Yamamoto
  • I. Watanabe
  • K. Ishio
  • T. Ando
  • H. Tsuji
  • T. Abe
  • K. Kikuchi
  • N. Minakawa
  • M. Tsuchiya
  • M. Tsubota
  • Y. Katayama
  • S. Ikeda
  • H. Ogata
  • T. Fujioka
  • A. Osaki
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)

Abstract

Incoloy 908, which is chosen as the ITER CS model coil conductor jacket material, exhibits a characteristic problem that is oxygen embrittlement along grain boundaries as a result of heating in an oxygen atmosphere in the presence of tensile surface stress, causing intergranular cracking during heat treatment from oxidation along grain boundaries (SAGBO:, Stress Accelerated Grain Boundary Oxidation). To consider real manufacturing process of the CS model coil, it was found that avoidance of SAGBO during an actual CS model coil conductor heat treatment is only to attain a SAGBO-free oxygen atmosphere such as 0.1 ppm for both of the conductor jacket outer surface and the inner surface. A baking process and an impurity gases burn-out process are developed for an actual conductor heat treatment, which will accomplish such oxygen atmosphere. These processes are just applied to the Japanese first heat treatment of the conductor.

Keywords

Residual Stress Intergranular Crack Shot Peening International Thermonuclear Experimental Reactor Boundary Oxidation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Reference

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    N. Michell. et al., ITER CS Model Coil Project, Proc. of 16th International Cryogenic Engineering Conference: 763 (1996)Google Scholar
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    T. Ando, et al., Design of the ITER Model Coil-Outer Module, Proc. of 16th International Cryogenic Engineering Conference: 767 (1996)Google Scholar
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    S. Shimamoto, et al_, Construction of ITER Common Test Facility for CS Model Coil, IEEE Trans. on Magnetics, Vol. 32, No. 4: 3049 (1996)ADSCrossRefGoogle Scholar
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    M.M. Morra, R.G. Ballinger, and I.S. Hwang, INCOLOY 908, a low coefficient of expansion alloy for high strength cryogenic applications, Metallurgical Trans. A, 23A: 317 (1992)CrossRefGoogle Scholar
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    M.M. Morra, Stress Accelerated Grain Boundary Oxidation of INCOLOY alloy 908 in High Temperature Oxygenous Atmosphere, Doctoral thesis, Massachusetts Institute of Technology (1995)Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • T. Kato
    • 1
  • K. Hamada
    • 1
  • K. Yamamoto
    • 1
  • I. Watanabe
    • 1
  • K. Ishio
    • 1
  • T. Ando
    • 1
  • H. Tsuji
    • 1
  • T. Abe
    • 1
  • K. Kikuchi
    • 1
  • N. Minakawa
    • 1
  • M. Tsuchiya
    • 1
  • M. Tsubota
    • 2
  • Y. Katayama
    • 2
  • S. Ikeda
    • 2
  • H. Ogata
    • 2
  • T. Fujioka
    • 2
  • A. Osaki
    • 2
  1. 1.Japan Atomic Energy Research InstituteNaka, IbarakiJapan
  2. 2.Toshiba CorporationTokyoJapan

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