ELECTROPLATING BATHS FOR ULTRA-HIGH-STRENGTH STEELS PART I - USE OF ALIPHATIC AMlNO ACIDS IN CADMIUM BATHS TO REDUCE HYDROGEN EMBRITTLENT

摘要

Non-cyanide aqueous baths containing β-alanine or an a-amino acid (glycine, n-butyric, isobutyric, n-caproic, or isocaproic) were investigated over a wide pH range (or their characteristics in plating cadmium on ultra-high-strength steel. Polarographic half-wave potentials are presented as a function of pH and of amino acid concen¬tration. Plating evaluation included Hull cell and throwing-power tests; and embrittling characteristics were deter¬mined by the delayed-fracture test using notched bars in tension. The results of delayed-fracture tests indicate that plating from an ammoniacal cadmium bath (adjusted to the 1 optimum pH range) containing salts of amino acids results in markedly lower hydrogen embrittlement than plating from the standard cyanide bath.