Bath and method for gleaming of workpieces (do with upper surfaces of iron or iron alloys

摘要

The metal work piece is placed into aqs. soln. containing 20-100 g./l. H2O2, 10-80 g./l. ammonium bifluoride, 0.5-30 g./l. oxalic or glycolic acid, and 2-20 g./l. sulphamic acid, or a neutral salt of such acids. An aromatic carboxylic acid may also be present (as stabiliser) as may a non-ionic wetting agent. The pH is pref. kept at 3.5-5 during treatment at 70-100 degrees F.