Three-Dimensional Finite Element Modeling of Magnetic Flux Leakage Technique for Detection of Defects in Carbon Steel Plates

W.S. Singh, S. Thirunavukkarasu, S. Mahadevan, C. Mukhopadhyay, B.P.C. Rao, and T. Jayakumar
Non Destructive Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam Tamil Nadu, India

Three-dimensional finite element (FE) modeling of magnetic flux leakage (MFL) technique has been performed using COMSOL 3.4 for prediction of leakage fields from surface and sub-surface defects in a 12 mm thick carbon steel plate. The tangential and normal components of leakage fields have been predicted to study the influence of defect location and depth on the detectability of sub-surface defects by the MFL technique. The effect of lift-off on MFL signals has also been studied for enhancing the reliability of detection of defects.