2004 Volume 47 Issue 1 Pages 19-26
Magnetic flux leakage testing (MFLT) is a reliable inspection method for far-side metal loss type flaws. Corrosion products of ferromagnetic substances are generated in wet environments, so may affect the application of MFLT to real tank bottom floors. This study investigated the influence of corrosion products on MFL signals. Rectangular grooves with various depths and widths were cut in test specimens and filled with various ratios of iron oxides as corrosion products. Magnetic flux leakage density distributions from the grooves were measured with a Hall probe. Analytical models for magnetic leakage field from flaws containing corrosion products were also considered using the three-dimensional finite element method. From the experimental and analytical results, the influence of corrosion products on MFL signals in inspections was discussed.
