Abstract
The time dependence of hydrogen concentrations in steel was investigated using immersion, galvanostatic-charging, and potentiostatic-charging methods in various environments in order to establish a method for stable hydrogen entry into steel. Stable hydrogen charging conditions can be obtained under galvanostatic-charging in a deaerated buffer solution of a pH more than 5.0. Hydrogen can also stably enter into steel in immersion tests such as those in the environment of a pH more than 5.0 with poisonous substances such as H2S and ammonium thiocyanate. A different hydrogen concentration can be accurately obtained by an immersion test with different concentrations of poisonous substances such as H2S or ammonium thiocyanate or with a different pH, and it is also obtained by applying the different low current densities under galvanostatic-charging.
