Pulsed eddy-current inspection of thin-walled stainless steel tubing

Corrosion Steel Inspection under Steel Plate Using Pulsed Eddy Current Testing

Pulsed eddy current inspection techniques were derived from the conventional eddy current testing technology, based on the fundamental principle of an eddy current coil, but using periodic ultrasound pulses. The authors first introduce the principle of pulsed eddy current inspection and some experimental measurement results using pulsed eddy current equipment. This technology can be applied to ...

Differential Hall-sensor Pulsed Eddy Current Probe for the Detection of Wall thinning in an Insulated Stainless Steel Pipe

Pulsed eddy current empirical modeling

The pulsed eddy current responses to varying material thickness and conductivity are modeled using an electrical circuit ideal transformer non-linear model. The Levenberg-Marquardt algorithm is used to curve fit the experimental signal to the model. The resulting synthetic signal is examined for its ability to preserve experimental signal features such as lift-off point of intersection (LOI), a...

Eddy current detection of changes in stainless steel after cold reductions

Cold rolling of austenitic stainless steel results in increase of residual stresses, hardness, and tensile strength and dislocation density. We have studied the response of eddy current impedance to austenitic change, hardness and its lift off phase in stainless steels during cold reductions. A series of samples of austenitic stainless steel alloys were cold rolled and found that only percentag...

Application of a Saddle-Type Eddy Current Sensor in Steel Ball Surface-Defect Inspection

Steel ball surface-defect inspection was performed by using a new saddle-type eddy current sensor (SECS), which included a saddle coil and a signal conditioning circuit. The saddle coil was directly wound on the steel ball's outer bracket in a semi-circumferential direction. Driven by a friction wheel, the test steel ball rotated in a one-dimensional direction, such that the steel ball surface ...