PAO Severstal has mastered the manufacture of zinc-coated rolled steel products with the environmental friendly trivalent chromium coating. Such steel products are in high demand with European customers of SIA Severstal Distribution, whose products have to meet the requirements of the EU environmental directives. Unlike hexavalent chromium, trivalent chromium is not banned by the Directive 2011/65/EU (RoHS 2) and, when you use it in electrical and electronic equipment, it is not harmful for human health and environment.
Passivation of zinc-coated metal with trivalent chromium is possible for all steel grades indicated in EN 10346 – starting with ordinary grades and finishing with higher strength steels (S250GD, S220GD, S350GD). Currently, Cr3 coating can be done for rolled steel products having the following characteristics:
At the moment, rolled products with Cr3 coating are only manufactured in one of four galvanizing lines at Cherepovets Still Mill, but in the future, it is planned to fit all other galvanizing lines with the equipment required for safe passivation.
Coating with trivalent chromium is reflected in quality certificates, and the coils, for the purposes of easy identification in the warehouses, have an additional distinctive marking – tag ECO Cr3 (see the picture).
In addition to environmental safety, rolled steel products with Cr3 coating have a more attractive appearance compared to the standard Cr6.
Those European customers who received the first batches of rolled steel products with trivalent passivation, highly appreciated their quality and stated their willingness to extend cooperation in this field.