High temperature embrittlement of Ni and Ni-Cr alloys by trace elements
The effects of Sb, Sn, and Zr additions on the creep properties of Ni and Ni + 20 pct Cr are reported. Antimony and tin additions ( about 1 wt pct) induce extensive grain boundary cavitation in nickel, while smaller antimony additions had little effect on Ni + 20 pct Cr. Addition of 0.11 pct Zr to Ni + 20 pct Cr greatly inhibited grain boundary cavitation and reduced its Coble creep rate. Auger electron spectroscopy of cavitated specimens provided direct evidence of impurity segregation to cavity surfaces. Residual sulfur segregated most strongly, and was observed on cavity surfaces in all cavitated specimens. Tin segregated somewhat less intensely than sulfur, and antimony segregated only slightly. Segregation of antimony and sulfur to uncavitated portions of Ni + 1 pct Sb grain boundaries was also observed. These results are discussed in terms of segregation effects on energetic and transport properties of the grain boundaries and cavity surfaces.
- Research Organization:
- Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, TN 37830
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5581676
- Journal Information:
- Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 14A; ISSN MTTAB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360103* -- Metals & Alloys-- Mechanical Properties
ADDITIVES
ALLOYS
ANTIMONY ADDITIONS
ANTIMONY ALLOYS
CAVITIES
CHROMIUM
CREEP
CRYSTAL STRUCTURE
ELEMENTS
EMBRITTLEMENT
GRAIN BOUNDARIES
INHIBITION
MECHANICAL PROPERTIES
METALS
MICROSTRUCTURE
NICKEL
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONMETALS
PNICTIDES
SULFUR
TEMPERATURE DEPENDENCE
TIN ADDITIONS
TIN ALLOYS
TRACE AMOUNTS
TRANSITION ELEMENTS
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS