Hybrid RFEC and Transmission NDT for Detection of Lead-Steel Multilayers

摘要

Lead-steel multilayered material has high thickness and is bonded of layers of ferromagnetic metal and non-ferromagnetic metal. Hence, it is challenging to inspect inner defects in steel layers. To achieve simultaneous inspection, a hybrid remote-field eddy current testing (RFECT) and transmitting-receiving (TR) testing method has been proposed and validated through numerical simulations. This testing system contains both UTC-based RFEC and transmission probes. To get satisfactory sensibilities of defects of different sizes at different depths, parameters of the probes are optimized through simulations. The mean sensibilities of 4 given crack positions of the optimized model have increased 1.84,1.91,3.926 and 0.714%. In addition, the simulation result can be used to supervise experiment investigation.