Corrosion detection of jacketed inner tube based on pulsed eddy current technology

The jacketed structure of the transportation pipeline is widely used in the petrochemical industry and other fields. However the corrosion detection of the inner pipe is a problem to be solved. Pulsed eddy current testing technology has the ability to detect thick-walled ferromagnetic pipes. And the corrosion detection of inner jacketed pipes is carried out without removing the outer pipe of the jacketed pipe. A finite element simulation model for pulse eddy current detection of the jacket was established to obtain the distribution characteristics of the eddy current field of the inner and outer tubes of the jacket. The simulation results showed that the eddy current field generated by the pulse excitation method can effectively reach the inner tube of the jacketed tube in the later stage of excitation. A U-shaped probe was used to detect the inner tube of the jacketed tube with artificial stepped corrosion defects. And the experimental results showed that the pulsed eddy current method can effectively detect the corrosion defects of the inner tube of the jacketed tube.