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Fatigue Crack Thresholds of a Nickel-Iron Alloy for Superconductor Sheaths at 4 K

  • R. L. Tobler
  • I. S. Hwang
Part of the An International Cryogenic Materials Conference Publication book series (ACRE, volume 40)

Abstract

Short crack simulation (SCS) tests were used to characterize the fatigue crack growth rates da/dN and thresholds ΔKTh of a Ni-Fe superalloy proposed for conduit sheath applications in superconducting magnets at 4 K. Experiments described demonstrate the reproducibility of the SCS data and confirm that this alloy has a relatively high fatigue crack growth rate threshold at 4 K. The effects of plate thickness and thermal treatment (650°C, 180 h) on near-threshold fatigue properties are minor compared with a strong cryogenic temperature effect that increases the fatigue threshold from about 2 MPa·m1/2 at room temperature to 9 or 10 MPa·m1/2 at 4 K.

Keywords

Fatigue Crack Growth Austenitic Stainless Steel Crack Opening Displacement Fatigue Crack Growth Rate Electron Beam Welding 
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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Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • R. L. Tobler
    • 1
  • I. S. Hwang
    • 2
  1. 1.Materials Reliability DivisionNational Institute of Standards and TechnologyBoulderUSA
  2. 2.Department of Materials Science and EngineeringMassachusetts Institute of TechnologyCambridgeUSA

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