Further developments in high-speed detection of rail rolling contact fatigue using ACFM techniques

The performance of existing ultrasonic and magnetic flux leakage techniques in detecting rail surface-breaking defects such as head checks and gauge corner cracking is inadequate during high-speed inspection, while eddy current sensors suffer from lift-off effects. Early detection of such rail defects is of paramount importance since a single crack can potentially lead to fatigue failure. The results obtained through rail inspection experiments under simulated conditions using an alternating current field measurement (ACFM) micro-pencil probe suggest that this technique can be applied for the accurate and reliable detection of surface-breaking defects at high inspection speeds.