EVALUATION OF VARIABLES WHICH AFFECT THE HARDNESS OF NICKEL PLATE DEPOSITED FROM WATTS-TYPE BATHS

摘要

In the course of the Cascade Improvement Program many component equipment parts will be electroplated with nickel for corrosion protection. The maximum hardness which will be acceptable in the electroplated deposit is specified in Union Carbide's Job Specification JS-1396, Revision 3, entitled Electroplated Nickel Coatings on Steel Parts. The hardness speci¬fication is intended primarily as a control over both organic and inorganic impurities in the deposit.nThis report covers a study evaluating several of the numerous controllable variables which influence the hardness of the nickel plate deposited from a Watts-type bath. The variables tested were: l) bath composition, 2) pH, 3) current density, 4) anode-cathode area ratio, and 5) bath temperature. Within the tested ranges of the variables studied, the pH and current density had the most influence on the plate hardness. The softest deposit was obtained with a bath pH of 1.5» a current density of 30 to ^0 amperes/square foot, and with the anode-cathode area ratio in the range of 3:1 to 1:1.