The hexavalent chromium plating process is an electrochemical treatment that occurs by means of a potential difference applied between the cathode and the anode and the consequent passage of current in a galvanic solution.

This passage of current occurs through the transfer of hexavalent ions of the metal to be deposited on the surface of the object, on which a layer of metallic chromium is deposited.

This treatment is under heavy scrutiny due to the high toxicity of hexavalent chromium and will most likely be replaced over time by the less toxic trivalent chromium technology.

In the industrial sector, chrome plating differs in terms of the thickness of the deposited chromium and the application:

• Decorative chrome plating: a very thin layer of chromium (0.05–0.5 µm) is deposited to give the object a shiny appearance. It is typically applied to a nickel or copper substrate to ensure corrosion resistance.

• Hard chrome plating: a thicker layer of chromium (5-500 µm) is deposited which gives the material greater hardness, resistance to wear and corrosion.

The hexavalent chromium plating process is very often used in the coating of plastic surfaces, more precisely in ABS (acrylonitrile-butadiene-styrene).