Probe for non-destructive flux leakage testing of hot-rolled seamless ferromagnetic steel pipe, has toroidal and circular coils with different sensitivity which is dependent on orientation of near-surface defects in steel pipe

摘要

The probe has toroidal and circular coils (2,3) that are arranged for detection of near-surface defects in a hot-rolled seamless ferromagnetic steel pipe, where the coils are provided with different sensitivity which is dependent on orientation of near-surface defects in the steel pipe. The toroidal coil has high sensitivity for longitudinal defects (F1) or transverse defects (F2). The coils are comprised with pairs of windings (2a,3a) whose connections are switched.