Evaluation of Absorption of Electrochemical Hydrogen by MAE Parameters

A solenoid electrochemical cell was prepared to study the effect of hydrogen absorbed from the electrolyte on the magnetoelastic acoustic emission (MAE) parameters. Cylindrical specimens made of cold-rolled 15 steel (see Appendix) were investigated. The electrochemical cell is filled with 0.1 N NaOH solution, which provides high electrical conductivity, and does not promote the release of electrolysis by-products other than hydrogen and oxygen. As with gas-phase hydrogen charging, during electrolytic hydrogen charging, a significant increase in the power of MAE signals is noticeable for hydrogen-charged samples compared to non-hydrogen-charged ones. Comparing the obtained results for electrolytic hydrogen charging with the results for hydrogen charging from the gas phase, it is possible to note a significantly higher sensitivity of MAE parameters during cathodic hydrogen charging. This can be explained by the role of diffusion-mobile hydrogen in the electrolysis conditions and its absence in experiments with gaseous hydrogen charging. The results of the research are described in detail in this chapter of the monograph.