Hydrogen Entry Behavior into Steel in Alkaline Environment

Abstract

Hydrogen entry behavior into steel in alkaline environment was investigated using hydrogen permeation method and thermal desorption analysis method from the viewpoint of hydrogen concentration in steel and hydrogen over-potential. Hydrogen permeation current density was proportional to the square root of applied current density. Hydrogen concentration in steel in Ca(OH)₂ solution was higher than that in NaOH solution from hydrogen permeation method and thermal desorption analysis. This result was the same as the result reported by Lillard and Scully. The critical hydrogen over-potential that hydrogen can enter into steel in alkaline environment was 0.05 V. Here, hydrogen was not able to enter into steel in this immersion test from the viewpoint of hydrogen over-potential because the corrosion potential in alkaline environment was −0.6 V (SCE). Finally, logarithm of hydrogen permeability was proportional to hydrogen over-potential in alkaline environment as well as in acid and neutral environments.