Managing the transition to hexavalent chromium free anti-corrosion coatings

Abstract

Hexavalent chromium is a well established material used in the commercial production of sacrificial zinc coatings for anti-corrosion applications. However, environmental and legislative pressures have been the catalyst for adopting alternatives based upon trivalent chromium and chromium-free materials. This change has wide implications within the global supply chain. End users and applicators must consider strategic issues such as product availability, cost implications and specific application needs. Experience with the change has illustrated the need for cooperation along the entire supply chain. The chemical supplier becomes the conduit between applicator and end user, and can facilitate a managed change of the process. Suppliers are ideally placed to establish best practice techniques at the applicator, and can work in partnership to achieve lowest operating cost with maximum performance. Developments in trivalent passivates for blue and iridescent colour films will be described, followed by discussion of the use of an audit approval programme to manage the transition to hexavalent chromium free products.