Low cycle fatigue and creep-fatigue behavior of Ni-based alloy 230 at 850 C

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Materials Science and Engineering A

DOI:https://doi.org/10.1016/j.msea.2012.11.063· OSTI ID:1057497

Chen, Xiang ^[1]; Yang, Zhiqing ^[1]; Sokolov, Mikhail A ^[1]; ERDMAN, III, DONALD L ^[1]; Mo, Kun ^[1]; Stubbins, James ^[1]

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1. ORNL

Strain-controlled low cycle fatigue (LCF) and creep-fatigue testing of Ni-based alloy 230 were carried out at 850 C. The material creep-fatigue life decreased compared with its low cycle fatigue life at the same total strain range. Longer hold time at peak tensile strain further reduced the material creep-fatigue life. Based on the electron backscatter diffraction, a novel material deformation characterization method was applied, which revealed that in low cycle fatigue testing as the total strain range increased, the deformation was segregated to grain boundaries since the test temperature was higher than the material equicohesive temperature and grain boundaries became weaker regions compared with grains. Creep-fatigue tests enhanced the localized deformation, resulting in material interior intergranular cracking, and accelerated material damage. Precipitation in alloy 230 helped slip dispersion, favorable for fatigue property, but grain boundary cellular precipitates formed after material exposure to the elevated temperature had a deleterious effect on the material low cycle fatigue and creep-fatigue property.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Shared Research Equipment Collaborative Research Center
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1057497
• Journal Information: Materials Science and Engineering A, Vol. 563; ISSN 0921-5093
• Country of Publication: United States
• Language: English

Related Subjects

Creep-fatigue
Nickel based superalloys
EBSD
High-temperature deformation
Precipitation
Failure