Stable Charging Conditions for Low Hydrogen Concentrations in Steels

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.

Hydrogen embrittlement characteristics of two tempered martensitic steel alloys for high-strength bolting

“…Under conditions of cathodic hydrogen charging, H 2 gas adsorbs onto the surface of the sample, then the material absorbs H + ions that diffuse inward through matrix. 12 The concentration of hydrogen in the critical volume surrounding the tip of the notch reaches equilibrium fairly rapidly as a function of Sieverts’ Law (equation (1)). With the passage of time during the experiment, the hydrogen equilibrium concentration remains relatively constant while the volume at equilibrium increases inward by diffusion into the specimen.…”