IMPROVEMENTS IN OR RELATING TO ELECTRODEPOSITING CHROMIUM USING LEAD BASE ALLOYS

1294174 Electro-depositing chromium; lead alloys M & T CHEMICALS Inc 2 June 1970 [5 June 1969] 26593/70 Headings C7A and C7B Chromium is deposited from an aqueous acidic chromium electro-plating bath using as anode an alloy of:- Pb 90-99% Sn 1-7% one or more of Te, T1, Cd 0À005-5%. The bath may contain chromic acid and sulphate ion, e.g. as sulphuric acid or strontium sulphate and silicofluoride ion, e.g. as hydrofluorsilicic acid. Temperatures of 15-95‹ C. and plating currents of 1-60 amps/sq. dm. may be used.