Surface Properties and Utilisation of Pre-coated and Pre-painted Steel: Existing Products and New Developments

Usinor has developed organic and inorganic films, for many automotive applications. The surface post-treatments made by the coil-coater provide additional functions to the metallic coated steel, such as lubrication or corrosion protection, and offer an excellent compromise between car manufacturing, steel utilisation and costs saving. Even though the organic coating thickness can reach 8 μm, steel products can be welded and electro-painted, thanks to metallic pigments within the coating, which make the polymer conductive. In some particular cases, where high flexibility and formability are required, the best solution is organic non-pigmented systems with lower thickness from 1 to 2 μm. Other pre-painted steel systems with thicker organic coatings have the potential to replace ED-paint or to remove Primer-Surfacer on paint lines by the car manufacturer.