Investigation of Materials and Welds for the Precompression Structure of the ITER Central Solenoid Articles uri icon

authors

  • Sgobba, Stefano
  • AVILES SANTILLANA, IGNACIO
  • LANGESLAG, STEFANIE A. E.
  • FERNANDEZ PISON, MARIA DEL PILAR
  • FREIJEDO MENENDEZ, PAULA
  • ARNAU IZQUIERDO, GONZALO
  • LIBEYRE, PAUL
  • HUGHES, DUKE

publication date

  • April 2018

start page

  • 1

end page

  • 4

issue

  • 3,4202504

volume

  • 28

International Standard Serial Number (ISSN)

  • 1051-8223

Electronic International Standard Serial Number (EISSN)

  • 1558-2515

abstract

  • The central solenoid (CS) is the backbone of the ITER magnet system. It consists of six independent coils held
    together by a vertical precompression structure that must react to tensile loads and provide sufficient preload to maintain coil-to-coil
    contact during all stages of plasma operation. Material selection and specifications applicable to the structural components of the
    precompression structure are particularly demanding. These include large forgings manufactured from a high-strength austenitic
    stainless steel (FXM-19) with a stringent specification in terms of microstructure and maximum allowed magnetic permeability.
    Stringent requirements are also imposed on all welded joints. In particular, the attachment welds of the cooling pipes to the
    structure are subject to challenging restrictions in terms of weld imperfections and geometry. They must induce limited distortion
    of the components and are submitted to inspections carried out in accordance with the most severe acceptance levels of applicable
    national and international standards. The results of a campaign of tests covering nondestructive and destructive evaluation of
    samples from different components and welds are summarized in this paper, particularly focusing on the quality achieved at the
    microstructural and macrostructural level. The influence of the microstructure on the final properties and on the inspectability of
    the material by nondestructive examinations is also discussed.

subjects

  • Mechanical Engineering

keywords

  • austenitic stainless steels; fxm-19; iter cs; microstructural investigations; superconducting fusion magnets