STEEL SHEET INCLUDING A MULTILAYER COATING

摘要

A steel sheet is provided. The steel sheet includes a multilayer coating including at least one zinc-based layer being 0.1% to 20% magnesium by weight which is covered by a fine temporary protective layer of 5 to 100 nm. The fine temporary protective layer is composed of metal or metal oxide selected from the group consisting of aluminum, chromium, aluminum oxides AlOx, with x being strictly between 0.01 and 1.5 and chromium oxides CrOy, with y being strictly between 0.01 and 1.5. The at least one zinc-based layer is not alloyed with the temporary protective layer. Manufacturing methods for a sheet and part are also provided.