Nondestructive evaluation of material degradation and sub-millimeter sized defect detection in steel using magnetic measurements

This paper investigates the possibility of simultaneous nondestructive evaluation of material degradation and detection of sub-millimeter sized defects using magnetic methods. We confirmed by FEM simulation that assessment of both degradation and small defects in steel is possible using a single-yoke probe. This was also verified experimentally. The hysteresis loop measurements were sensitive to degradation in the material, and the scanning flux distribution could be effectively used for detecting sub-millimeter sized defects. The degradation and small defects can also be evaluated separately with this single measurement configuration.