抄録
The effects of chloride on chromium deposits in low concentration CrO3 bath (CrO3 50g/l, H2SO4 0.5g/l, and Na2SiF6 0.5g/l) and its removal were investigated, and the following results were obtained. When copper was a substrate, parts of no plating due to low current density were corroded at 10mg/l of chloride concentration. The area of the corroded parts was enlarged when the chloride concentration was higher, and finally, bright chromium plating was not obtained at a chloride concentration of higher than 30mg/l. However, in bright nickel plating, the covering power was not much decreased up to 100mg/l of chloride concentration and the corrosion of substrate and decrease of brightness were not observed. The chloride in the chromium plating bath was oxidized at anode and removed under ordinary plating conditions, and also it was proved to be removed by the addition of lead peroxide, which would suggest that the chloride mixed in the plating solution was decomposed by the lead peroxide produced at anode during and at a standstill of plating operation so that it was not a very harmful impurity unless its presence was in too much quantity for a while.
