DIFFUSION COEFFICIENT OF HYDROGEN IN IRON BETWEEN 230 AND 300 K.

Abstract

The electrochemical permeation method is widely used for measuring the diffusion coefficient of hydrogen in the vicinity of room temperature. However, the method is not applicable to the temperatures below the freezing point of aqueous solution used as the electrolyte. In this work, hydrogen permeation through single and polycrystalline specimens of fully annealed iron was measured at temperatures between 230 and 300 K by an improved electrochemical method in which alcoholic solutions were used as electrolytes. The obtained hydrogen permeation curves were analyzed, with special emphasis on the variation of the hydrogen concentration at the cathode surface during the measurement.