Advertisement

Simulations on Jacket Material Failure of NET-Superconductors by Surface Crack Growth in 316LN Type Materials at 12K

  • Arman Nyilas
  • Bernhard Obst
  • Albert Ulbricht
Part of the An International Cryogenic Materials Conference Publication book series (ACRE, volume 40)

Abstract

Two-dimensional fatigue crack growth rate (FCGR) properties of 316LN type stainless steels were investigated at 12K. The investigations were done with plate material in as received condition and with cold worked jacket material. Using a new tensile specimen configuration, sinusoidal and triangular cyclic load tests with constant and alternating amplitude, respectively, were performed. The FCGR of the plate material was found to be lower by a factor of about 3 compared with that of the cold drawn U-section jacket material. To simulate the loading under magnet operational condition, specimens were tested under constant stresses making use of a calculated peak load vs. crack length function. These tests were carried out between 0.5 and 2.5 mm surface crack length. From this investigation a prediction for the material’s cyclic life number could be derived. Further, surface FCGR tests under pure 4-point cyclic bending load were performed and a comparison between different crack growth shapes obtained under bending and tensile loads were given. Plate materials “short crack” behaviour were determined from constant K-max, AK-decreasing test.

Keywords

Crack Length Surface Crack Insulation Layer Fatigue Crack Growth Rate Short Crack 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J.C.Newman Jr., A review and assessment of the stress-intensity factors for surface cracks, ASTM STP 687, (1979) pp. 16–42Google Scholar
  2. 2.
    A. Nyilas, J. Zhang, B. Obst, and A. Ulbricht, Fatigue and FCGR of Incoloy 908 and 316LN at 12K, Adv, in Cry. Eng., Vol. 38 Part A (Materials), (1991) pp. 133–140Google Scholar
  3. 3.
    Ren-ji Yu, Zi-hong Jin, Kang-sian Li, and Kai-zuo Lian, A study of surface crack propagation on wide plates under bending loads, Proc. of 2nd Int. Conf. on Fatigue and Fatigue Thresholds 1984 Birmingham UK Vol III pp. 1705–1718Google Scholar
  4. 4.
    W. A. Herman, R. W. Hertzberg, C. H. Newton, and R Jaccard, A re-evaluation of fatigue threshold test methods,”Fatigue 87”, EMAS, Ltd. (1987) UK pp.819–828Google Scholar

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • Arman Nyilas
    • 1
  • Bernhard Obst
    • 1
  • Albert Ulbricht
    • 1
  1. 1.Kernforschungszentrum Karlsruhe, ITPKarlsruheGermany

Personalised recommendations