FATIGUE LIFE ASSESSMENT OF HIGH-STRENGTH, LOWALLOY STEEL AT HIGH FREQUENCY

A fatigue experimental assessment is described for an HSLA steel (high-strength, low-alloy steel) D38MSV5S on very high cycle fatigue (VHCF) up to 10^10 cycles. The fatigue testing has been conducted at load ratio, R = 0.1 and –1, under 20 kHz and 35 Hz. Herein, it will be observed that the test frequency does not have any effect on fatigue data. The fatigue failure can occur over 10^7 cycles. The fatigue endurance continues to decrease with an increasing number of cycles for R = –1, but, for R = 0.1 no fatigue failure happened over 10^7 cycles. Finally, the same crack initiation mechanism that has been observed by other researchers on VHCF (termed fish-eye failure), has been found during our fractographic analysis.