JAEA Fatigue Analysis of EBR-II Duplex Tubing

Jackson, J. H. ; Porter, D. L. ; Lloyd, W. R.

Idaho National Laboratory

关键词: Duplex Tubing;    Crack Propagation;    36 Materials Science;    Nickel;    Oxidation;   

DOI  :  10.2172/966150
RP-ID  :  INL/EXT-09-16354
RP-ID  :  DE-AC07-99ID-13727
RP-ID  :  966150

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来源: UNT Digital Library

【 摘 要 】

This work addresses questions brought up concerning the mechanisms associated with fatigue crack growth retardation and/or arrest within the nickel bond layer in duplex 2¼ Cr-1Mo steel superheater tubes. Previous work performed at the Idaho National Laboratory (INL) indicated that the nickel bond layer did not function as a crack arrestor during fatigue crack propagation with the exception of one, isolated case involving an exceptionally low fatigue load and a high temperature (400 0C) environment. Since it is atypical for a fatigue crack to propagate from a relatively soft material (the nickel bond layer) to a harder material (the 2¼ Cr-1Mo steel) there has been speculation that the nickel bond layer was hardened in service. Additionally, there are questions surrounding the nature of the fatigue crack propagation within the nickel bond layer; specifically with regard to the presence of voids seen on micrographs of the bond layer and oxidation within the steel along the edge of the nickel bond layer. There is uncertainty as to the effect of these voids and/or oxide barriers with respect to potential fatigue crack arrest.