Fig. 2

A figure showing the conditions where hydrogen loss caused by the migration of hydrogen (protons) to the electrode. The degree of hydrogen loss can be characterized by a non-dimensional parameter, \( \xi\;\left(\equiv \frac{l}{d}\propto \frac{E}{\omega}\right) \) (l is the mean distance of hydrogen migration by the electrical field, d is the thickness of the specimen). If ξ ≥ 1, substantial hydrogen loss will occur, whereas if ξ ≪ 1, hydrogen loss is not important. This factor is highly sensitive to the (lowest) frequency and the voltage used. Using high frequencies and/or low voltage, the hydrogen loss can be minimized