Numerical Simulation and Experiment on Magnetic Flux Leakage Inspection of Cracks in Steels

摘要

The magnetic flux leakage inspection method is widely used in the detection of pipelines, storage tanks and other steel materials. Especially in corrosion pits detection, it has become a matured technology. As cracks may exist in the steels which may lead to big hazards, its detection becomes very important. Meanwhile, the cracks evaluation by MFL inspection can be determined by many parameters, it has much difficulty to implement due to its weaker signals compared with pits. In this research, the finite element model for cracks' MFL is established and corresponding method are carried out. Furthermore, parameters such as depth,width, angle of cracks and scanning direction are analyzed. Also, the experiments are done which show great reliability comparing with numerical simulations. The results show that the cracks can not be detected when the scanning direction parallels with it. So the cross-scanning method is recommended for MFL inspection on cracks.