CHROMIUM-CHROMIUM OXIDE COATINGS APPLIED TO STEEL SUBSTRATES FOR PACKAGING APPLICATIONS AND A METHOD FOR PRODUCING SAID COATINGS

摘要

A coated steel substrate for packaging applications, the substrate containing (1) a recrystallisation annealed single or double reduced packaging steel blackplate, or (2) a cold-rolled and recovery annealed blackplate, wherein one or both sides of the substrate is coated with a chromium metal-chromium oxide coating layer produced in a single process step by using a trivalent chromium electroplating process. A process for obtaining the coated steel substrate.

主权项

1. A process for producing a coated steel substrate for packaging applications by depositing a chromium metal-chromium oxide coating on the substrate for packaging applications containing
(a) a recrystallisation annealed single or double reduced packaging steel blackplate, or (b) a cold-rolled and recovery annealed blackplate,comprising electrolytically depositing on said substrate said chromium metal-chromium oxide coating in a single process step from a plating solution comprising a mixture of a trivalent chromium compound, a chelating agent, an optional conductivity enhancing salt, an optional depolarizer, an optional surfactant, to which an acid or base is optionally added to adjust the pH, wherein the plating solution does not contain a buffering agent, and wherein a sufficiently high cathodic current density is being applied to deposit chromium metal.