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...

In applications related to electrical power engineering, the displacement current existing in a metallic conductor is negligible compared with the conduction current. In such situations, the displacement currents may be dropped from Maxwell’s equations and one obtains a magneto-quasistatic sub-model usually called the eddy current problem. The eddy current problem is generally posed in the whol...

Eddy current induced in a metal by a coil carrying an alternating current may be perturbed by the presence of any macroscopic defects in the material, such as cracks, surface indentations, or inclusions. In eddy-current nondestructive evaluation, defects are commonly sensed by a change of the coil impedance resulting from perturbations in the electromagnetic field. This paper describes theoreti...

There are many approaches to 3D eddy current analysis. Typical methods for the eddy current analysis are the A-¢ method and the T-w method. Both methods require variables in space as well as in a conductor. We have already proposed the T method [1, 2, 3], where a magnetic scalar potential w is not included and we do not need variables in space. But the method has a disadvantage that a large cor...

Eddy current (EC) nondestructive testing (NDT) based on probe impedance changes in the crack regions is considered in this paper. For this a numerical simulation is introduced for the development of the EC-NDT system using 3D finite element software. This model is used to simulate the rectangular cracks with various dimension and prepares the data required for artificial neural network. The neu...

Vector hysteresis models are applied to an eddy-current analysis. The vector hysteresis models are composed by play hysterons and stop hysterons. The eddy-current analysis shows that both play and stop hysteron models can effectively describe isotropic vector hysteretic behavior. The stop hysteron model is more efficient in analyzes using the magnetic vector potential than the play model becaus...

Oil and gas transmission pipelines are critical items of infrastructure in providing energy sources to regions and countries. Steel pipes are commonly used which can be subject to both internal and external corrosion. This paper presents an advanced nondestructive inspection technique for detection of oil-gas pipeline corrosion defect. The Pulsed Eddy Current (PEC) method has been successfully ...

The large-scale features of the global ocean circulation and the sensitivity of these features with respect to forcing changes are critically dependent upon the influence of the mesoscale eddy field. One such feature, observed in numerical simulations whereby the mesoscale eddy field is at least partially resolved, is the phenomenon of eddy saturation, where the time-mean circumpolar transport ...

Photoinductive imaging is a newly devised technique for photothermal imaging based on eddy-current detection of thermal waves [1]. Thermal waves produce a localized modulation in the specimen's electrical conductivity, which can be detected by its effect on the impedance of a nearby eddy-current coil. This photoinductive effect can be used to image surface or near-surface cracks, voids, or incl...

A modified boundary integral equation/boundary element method (BIE/BEM) is being developed for eddy current problems in three dimensions. Maxwell’s equations governing the eddy current problems are formulated in two sets of BIE’s, one for the electric field and the other for the magnetic field. These BIE’s involve both the field and the normal derivative of the field, for both exterior (air) an...