Hydrogen absorption behavior of the steels containing Cr and Ni under cathodic polarization in sulfate solutions

摘要

Hydrogen absorption behavior of the steels containing Cr and Ni has been investigated under cathodic polarization in sulfate solutions by means of conventional electrochemical hydrogen permeation test. Good agreement of the empirical with the theoretical transient curves of hydrogen permeation current density suggested quasi-equilibrium condition to the absorption-desorption reaction of hydrogen at the surface. In addition, a diffusion coefficient obtained from the transient curve decreased with an increase in a concentration of the additional elements, and the decrement was enhanced much more by Cr than by Ni. A hydrogen concentration at the hydrogen absorption surface was almost proportional to a square root of the cathodic current density for any specimens. The slope increased with an increase in a content of the additional elements, and the increment was enhanced much more by Cr than by Ni. The two findings suggested that the additional elements of Cr and Ni attract hydrogen, and that the attraction effect of Cr was much more than that of Ni.