1. Fatigue and creep-fatigue crack growth in alloy 709 at elevated temperatures.
- Author
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Shaber, N., Stephens, R., Ramirez, J., Potirniche, G. P., Taylor, M., Charit, I., and Pugesek, H.
- Subjects
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FATIGUE crack growth , *HIGH temperatures , *CRACK closure , *FRACTURE mechanics , *FINITE element method , *CREEP (Materials) - Abstract
Fatigue crack growth (FCG) and creep-fatigue crack growth (CFCG) in austenitic stainless-steel Fe-25Ni-20Cr (Alloy 709) were measured experimentally and simulated using the finite element method. Temperature conditions investigated were 550°C, 600°C and 700°C, with load hold times of 0 s, 60 s and 600 s. Fracture surface was investigated using scanning electron microscopy and optical imaging. Experiments indicated that crack growth exhibits minimal sensitivity to the various loading conditions evaluated. At 600°C, crack growth rates were independent of hold time or loading frequency. At 700°C, there was a small increase in crack growth rate as a function of hold time, with a 600s hold time causing a factor of 2 increase in crack growth rate over FCG. Finite element simulations were performed to compute plasticity-induced crack closure in the presence of creep deformations at the crack tip. The simulations produced FCG and CFCG rates similar to the experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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