The effect of testing frequencies at levels of 50 and 100 Hz on the shape of the S/N curves of an EnlA steel has been investigated. Axial loadings of the zero to peak (R = 0) and completely reversed (R = −1) types were applied to plain testpieces and the results are compared with rotating cantilever testing. At 50 Hz two discontinuities were observed in the S/N curves for both R=O and R=−1 loadings. At 100 Hz there was no lower discontinuity and the fatigue limit was significantly higher than that obtained at 50 Hz. The role of strain-ageing effects on these observations is discussed.
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References
1.
LUTHERR. G. and WILLIAMST. R. G.: Metals and Materials, 1973,7, (Aug.), 357.
2.
FORSYTHP. J. E. and SMALEA. C.: RAE Tech. Rep. 68205, 1968.
3.
COTTRELLA. H. and BILBYB. A.: Proc. Phys. Soc., A, 1949, 62, 49.
4.
TRICOTR., MONNOTJ., and LLUANSIM.: Met. Eng. Q., 1972, 12, (2) May, 39.
5.
SCOTTD., LAYB., and MILLSG.: NEL Rep. No. 321, 1967.
6.
VILLAINJ. P. and de FOUQUETJ.: Rev. Mét., 1962, 59, 286.
7.
BROOMT., MAZZAJ. A., and WHITTAKERV. N.: J. Inst. Metals, 1957 –58, 86, 17.
8.
WINTERA. T. and ANTONOPOULOSJ. G.: private communication, Cavendish Laboratory, Univ. Cambridge (awaiting publication).
9.
FLOMANC. G.: Acta Met., 1964, 12, 1071.
10.
MINTZB. and WILSOND. V.: ibid., 1965, 13, 947.
11.
BRITTAINJ. O. and BRONISZS. E.: Trans. Met. Soc. AIME, 1960, 218, 289.
