REMOVAL OF COPPER KISS FROM PICKLING HIGH COPPER ALLOYS

摘要

When iron group, especially high nickel, metal alloys that contain substanti al amounts of copper are pickled, a displacement coating of copper that is call ed a "copper kiss" often forms on the pickled surface from the dissolved copper ions in t he pickling solution before the pickling solution can be rinsed away. Traditionally this has been removed by treatment with aqueous ammonia, an annoying and potentially hazardous reagent that in many instances requires expensive pollution abatement device s. In this invention, copper kiss is equally effectively removed by treatment with a mixture of sulfuric acid and hydrogen peroxide, optionally also containing hydrofluoric acid.