Abstract
The effects of various electrolytic conditions such as bath temperature, pH, and current density on corrosion resistance of electro-deposited nickel layer were determined by measuring the corrosion potential.
The distribution of corrosion resistance due to the difference in the distribution of current density was determined by measuring the weight loss of specimens dipped in CASS solution.
The following results were obtained:
(1) The corrosion potential was constant and no effects were confirmed in the range of 30-50°C of the plating bath temperature.
(2) The maximum corrosion potential was obtained at pH=3.4. However, pH utilized in practice would be in the range of 4.0-4.2.
(3) The minimum corrosion potential was obtained at average current density of 4.0Amp./dm2. However, the current density lower than 4.0Amp./dm2 would preferably be utilized in practice in consideration of the distribution of thickness.
(4) The corrosion resistance to CASS solution was lower in the part of higher current density than in the part of lower current density. The difference between the two parts was the least at 4.0Amp./dm2 of higher current density.
