Journal
MATERIALS LETTERS
Volume 62, Issue 28, Pages 4351-4353Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.matlet.2008.07.032
Keywords
Hastelloy X; fatigue; crack initiation site; grain boundary; cyclic stress response
Funding
- MKE (Ministry of Knowledge Economy) [R-2007-1-003-03]
- MEST (Ministry of Education, Science and Technology) [UCN.134-2751.C]
Ask authors/readers for more resources
The low cycle fatigue tests of Ni-base superalloy Hastelloy X have been carried out in the temperature range of 650 - 870 degrees C with various total strain ranges. A change of slope in the Coffin-Manson (C-M) plot was found at 870 degrees C: the fatigue life significantly decreased at the total strain range less than 0.6% The fatigue cracks. initiated at the surface of the specimens and propagated transgranularly, regardless of test condition. However, the fatigue crack initiation site on the surface shifted from grain interior to grain boundary (GB) predominantly when the discontinuity of slope in the C-M plot began to occur. The fatigue crack tended to initiate preferentially at the oxidized GB rather than grain interior at 870 degrees C with total strain range below 0.6%. Under this condition, cyclic stability was pronounced. while cyclic hardening occurred at the rest of test conditions. The dislocation structures responsible for the cyclic stress response may partly account for the determination of major fatigue crack initiation site. (C) 2008 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available