Mechanism study for directivity of TR probe when applying Eddy current testing to ferro-magnetic structural materials

Transmitter/receiver (TR) pancake probes are widely used in eddy current testing (ECT) owing to their multi-axial structure and sensitivity different directions. However, the behavior of ECT signal affected by directivity TR probe has not been discussed, especially when considering magnetic properties materials. The present paper therefore investigates for angles between crack orientation centerline experiments numerical analysis. In experiments, sample plates ferromagnetic carbon steel SM490 non-ferromagnetic stainless AISI316 employed investigation. Slits fabricated on simulate cracks. Numerical analysis adapts a finite element method, A r method. change amplitude with scanning angle an obvious difference two materials both experimental simulation results. presence flux leakage around slit material is assumed as main reason subsequently examined results reveal that field detected superposition induced leakage. study confirms explains This work contributes more reasonable signals measured using detecting cracks evaluation orientation.