Validation of a new high frequency testing technique in the VHCF regime – Fatigue properties of a 42CrMoS4 and X5CrNiCuNb16-4 steel

In times of highly loaded components, effort is put into lightweight concepts and to increase service life. The investigation of material fatigue has become very important. In the last years, the ultrasonic testing equipment (UTE) lead to numerous scientific work in the very high cycle fatigue (VHCF) regime. In this work fatigue results are shown, which were determined by a new high frequency vibration technique (HFVT). This facility operates at a frequency of f = 928 ± 8 Hz respectively f = 930 ± 5 Hz. The materials used in this investigation are a 42CrMoS4 (M-A) and a X5CrNiCuNb16-4 (M-B) steel. High frequency fatigue tests were compared with conventional servo-hydraulic fatigue tests at 30 Hz. An increase of fatigue strength was determined (higher strain rate) for both material configurations. In the area of high stress amplitudes and low stress amplitudes material dependent differences were observed. In general, it can be said that this effect decreased towards lower stress amplitudes.