High R-ratio near-threshold fatigue crack growth rates of high strength steels in sea water
- Florida Atlantic Univ., Boca Raton, FL (United States). Dept. of Ocean Engineering
Near-threshold fatigue crack growth rate determinations have been made for four high strength steels in sea water under free corrosion and at cathodic potentials of {minus}0.80v, {minus}0.95v and {minus}1.10v versus SCE for stress ratio 0.8 and the results compared with previous data for stress ratio 0.5. Results for cathodically polarized specimens fatigued at different frequencies showed that the lower the frequency, the higher the threshold. It was also found that the fatigue crack growth rate under cathodic polarization in sea water was dependent upon the magnitude of initial {Delta}K, implying that the da/dN-{Delta}K relation was not unique. The data are discussed in terms of calcareous deposit induced crack closure, and a model is proposed which explains the relative influence of hydrogen and calcareous deposits upon da/dN as influenced by potential, R, initial {Delta}K and frequency.
- OSTI ID:
- 27927
- Report Number(s):
- CONF-940230-; ISBN 0-7918-1266-9; TRN: IM9516%%52
- Resource Relation:
- Conference: 13. international conference on offshore mechanics and Arctic engineering (OMAE-13), Houston, TX (United States), 27 Feb - 3 Mar 1994; Other Information: PBD: 1994; Related Information: Is Part Of OMAE 1994. Volume 3: Materials Engineering; Salama, M.M.; Toyoda, Masao; Lui, S.; Dos Santos, J.F.; Kocak, M.; Patterson, E.A.; Berge, S. [eds.]; PB: 438 p.
- Country of Publication:
- United States
- Language:
- English
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