Analysis for Hydrogen Concentration in Titanium Alloys Using Multifrequency Eddy Current

In this article, multifrequency eddy current testing is proposed to detect hydrogen concentration in alloy titanium. The effect of hydrogen on the titanium alloy was explored across the surface layer of the material. The sample has a fixed surface area, and the samples with the same thickness and different hydrogen concentrations are analyzed. Output voltage amplitudes and dielectric loss tangent in hydrogen-filled titanium VT1-0 were studied in the range of hydrogen concentration from 0.019 to 0.290 wt.% using the instrument Micromagnetic Multiparameter Microstructure and Stress Analysis (3MA-II) at the frequency from 200 to 1000 kHz. This article proposes a method of analyzing the internal conductivity of metals by eliminating surface effects. The linear relationship between hydrogen concentration and conductivity is obtained, and the experimental results that are closer to the theory than the four-probe method and the inclusion surface are obtained. The results show that the output signal amplitudes decreased with an increase of the hydrogen concentration and frequency, and in addition, the dielectric loss tangent obtains a similar result at the hydrogen concentra- tion >0.100 wt.%. It is shown that this method can be used to evaluate the concentration of hydrogen in metal.