Method for the Production of a Metal Strip Coated with a Coating of Chromium and Chromium Oxide Using an Electrolyte Solution with a Trivalent Chromium Compound

A method for production of a metal strip coated with a coating, said coating containing chromium metal and chromium oxide and being electrolytically deposited from an electrolyte solution which contains a trivalent chromium compound onto the metal strip by bringing the metal strip, which is connected as a cathode, during an electrolysis time into contact with the electrolyte solution, the method comprising:

• successively passing the metal strip at a predefined strip travel speed through a plurality of electrolysis tanks successively arranged in a strip travel direction,
• wherein the plurality of electrolysis tanks comprises a front group of electrolysis tanks including at least one front electrolysis tank;
• a middle group of electrolysis tanks including at least one middle electrolysis tank;
• and a rear group of electrolysis tanks including at least one rear electrolysis tank, with the middle group of electrolysis tanks follows the front group of electrolysis tanks in the strip travel direction and the last group of electrolysis tanks follows the middle group of electrolysis tanks in the strip travel direction;
• wherein the at least one rear electrolysis tank includes a last electrolysis tank;
• wherein the electrolyte solution at least in the last electrolysis tank, or in the rear group of electrolysis tanks has a temperature, averaged across the electrolyte solution volume, of less than 40° C., and the electrolysis time, during which the metal strip is in electrolytically effective contact with the electrolyte solution, in the last electrolysis tank or in the rear group of electrolysis tanks is less than 2.0 seconds.