INVESTIGATION OF HYDROGEN ADSORPTION BY STEEL DURING ELECTRODEPOSITION OF CADMIUM.

During cadmium plating from all the investigated electrolytes, except the cyanide electrolyte, the hydrogen content was lower at the periphery of the sample than at the center, and this difference was greatest in the hydrofluoboric acid electrolyte with addition of glue. It is highly likely that this is due to the different throwing powers of the electrolytes; with a relatively low throwing power the current density and hydrogen content should be greater at the edge of the plate than at the center. The cadmium-plating electrolytes can be arranged in the following order of increasing hydrogen adsorption: hydrofluoboric acid electrolyte with additions of phenylthiourea and benzoylpiperidine less than hydrofluoboric acid electrolyte with addition of glue less than ammonium chloride electrolyte less than cyanide electrolyte. During cadmium plating from the recommended electrolyte with additions of phenylthiourea and benzoylpiperidine the hydrogen content in the coated article and in the steel base is less than that obtained during cadmium plating from the previously proposed electrolytes, which are customarily accepted as not leading to hydrogen adsorption (ammonium chloride, hydrofluoboric acid electrolyte with the addition of glue).