Galvanic deposition of a chromium microcracked structure by means of tension to copper-plated or nickel-plated sheet

摘要

A micro-cracked chromium layer is electro-deposited on an object, e.g. on a nickel electroplated layer applied over a copper flash to a steel body, in a single stage from a plating bath containing 225-275 g/l CrO3, 3.5-6 g/l SiF6 ion e.g. Na2 SiF6 and H2SO4 in a concentration such that the weight ratio of CrO3 to H2SO4 is 130-250; the current density is 100-300 A.S.F. and the bath temperature is 100-130 DEG F. The electrolyte may contain trivalent Cr.