Inspection of Local Wall Thinning by Different Magnetic Methods

The applicability of three different magnetic methods, Magnetic flux leakage technique (MFL), Magnetic adaptive testing and Metal memory method (MMM) was tested for detection of an artificial slot in a system of three steel plates. It was found that MAT resulted in the best signal/noise ratio, and it is capable to detect the bottom side slot even in the three layer configuration. MFL also resulted in acceptable signal/noise ratio in the two layer configuration, but it was not able to detect the slot through two other plates. MMM was not found to be suitable for unstressed and un-magnetized slot detection in the given experimental arrangement.