Absorption of Hydrogen by Very Strong Steels During Cadmium Plating: Part II—Hydrogen Absorption during Electrodeposition from Cd-TiO₃ Baths

Summary

The effect of composition of cadmium-plating baths and current density on absorption of hydrogen by steel has been investigated using (a) volumetric estimation of hydrogen (b) permeation of hydrogen to assess the effect of variables on hydrogen entry into steel. Studies of NaOH/KCN ratios have shown that hydrogen permeation is linearly related to i^½ and that maximum permeation occurs when the solution contains 0·1 N NaOH + O·1 N KCN. The action of pertitanate in decreasing absorption appears to be due to the fact that it is reduced to a lower oxide which forms a film on the steel surface which acts as a barrier to hydrogen entry. This effect is most pronounced when the steel is given an initial strike so that film formation precedes cadmium deposition and hydrogen evolution. The other per-compounds investigated were not cathodically reduced and did not affect hydrogen entry.