Corrosion of nickel electroplates in neutral and acidic salt-spray-fog

By gravimetric method, the corrosion rate of Ni electroplates is determined during the accelerated tests in neutral and acidic salt fog of 5% NaCl sol ution. In neutral fog, the electroplates corrode uniformly with a small mas s loss even during long-term exposure. In acidic fog, corrosion is twice mo re intense: not only the surface passive layer of dull electroplates become s broken down, but also, with an increase in the exposure time, surface def ects form, which cause even greater losses of metal. Bright Ni electroplate s, differing in surface morphology from dull Ni coatings corrode intensely but uniformly. Corrosion of composite Ni-Al2O3 electroplates decelerates wi th time, and they demonstrate corrosion resistance in accelerated tests in both types of media.