METHOD FOR MANUFACTURING A METAL BELT COATED WITH A COATING MADE OF CHROME AND CHROME OXIDE BASED ON AN ELECTROLYTIC SOLUTION WITH A TRIVALENT CHROME COMPOUND

摘要

The present invention relates to a method for manufacturing a metal belt (M) coated with a coating (B), in which the coating (B) contains chromium metal and chromium oxide and is applied electrolytically from a electrolytic solution (E), which contains a trivalent chromium compound, on the metal strap (M), in which the metal strap (M), switched as a cathode, is placed in contact with the electrolytic solution (E) for a electrolysis period. Efficient deposition of a coating with a high percentage of chromium oxide is achieved if the metal belt (M) is conducted in a direction of belt walking through several electrolysis tanks (1a, 1b, 1c, 1a to 1h) successively arranged in a belt travel direction at a predetermined belt speed (v), where at least in the last electrolysis tank (1 c, 1 h) seen in the belt travel direction or in a rear group of fuel tanks electrolysis (1g, 1 h), the electrolytic solution (E) has an average temperature over the electrolysis tank volume of a maximum of 40 ° C and the electrolysis time (t _E ), in which the metal band (M) stays in contact, electrolytically effectively, with the electrolytic solution (E) in the last electrolysis tank (1c) or in the rear group of electrolysis tanks (1g, 1h) is less than 2.0 seconds.