Scanning steel junctions using eddy current probe

Abstract

The aim of this research is the process of developing a miniature probe for studying electrical steel. The issue of safety when using the products made of this type of steel, assessment and forecast of their quality make this topic relevant. We have found it possible to study the characteristics of steel at different depths by changing the signal amplitude generated by the eddy current probe. The novelty of this research is due to the use of a superminiature eddy current probe of a transformer type that can perform point measurements (0.05 mm sections) of ferromagnetic materials using the eddy current method and is based on the study of conductivity of electrical steel. A hardware and software package is designed based on the developed probe. It can test steel at its boundary with a dielectric. A system that can automatically move the probe over a controlled object at a preset speed has been developed. The study consisted of continuous and discrete measurements that were made by moving the probe over a ferromagnetic and dielectric material at a given speed and scanning the object in 0.1 mm increments. The results of the test performed on samples at different measurements and at different frequencies from 2000 to 20000 Hz are indicated. The study showed that the magnetic field lines of steel, which occur as a result of the impact of the eddy current probe on the ferromagnetic material, have a strong effect on the signal received by the eddy current probe after it is removed from the controlled object at a distance of 1 mm. The signal frequency on the exciting coil of the eddy current probe has a significant influence on this process. The conducted tests have demonstrated the nonlinear nature of the dependency of the probe response when it passes through the steel-dielectric boundary; the mathematical regularity of this dependency is revealed. The effect of the gap between the eddy current probe and the object of study is also analyzed.