Method for passivating tinplate

摘要

The invention relates to a method for passivating the surface of a tinned steel strip which is moved through a coating system at a strip speed of at least 200 m/min. After the steel strip is tinned, the surface is anodically oxidized, and a liquid solution of a chromium-free aftertreatment agent is applied onto the oxide layer. The invention further relates to a tinned steel strip or sheet with a support layer made of a fine or ultrafine sheet of steel, a tin layer which is deposited thereon, and a surface layer of a chromium-free aftertreatment agent. An oxide layer is formed between the tin layer and the surface layer of the aftertreatment agent, said oxide layer substantially consisting of tetravalent tin oxide (SnO