METHOD OF PASSIVATING WHITE TIN Russian patent published in 2016 - IPC C25D11/34 C25D5/48 

FIELD: technological processes.

SUBSTANCE: invention relates to passivation of the surface-tinned strip steel. Disclosed is a method for production of the tinned strip steel with passivated surface, which involves movement of strip steel through system of electrochemical tinning of the strip steel with speed equal to at least 200 m/min, in which after tinning the strip steel surface is first subjected to anode oxidizing thus to form an oxide layer consisting of tetravalent tin oxide (SnO₂), and then on an oxide layer is applied a liquid solution not containing chrome agent for subsequent processing. Also disclosed is a tinned flat steel obtained using said method and containing a supporting layer of thin or extra thin steel sheet deposited on the layer of tin and surface layer not containing chrome agent for subsequent processing; between the layer of tin and surface layer agent for subsequent processing is formed an oxide layer consisting of tetravalent oxide of tin (SnO₂).

EFFECT: invention allows high speed of steel sheet passivation, which provides improved adhesion of varnish and a higher resistance to acids contained in food products.

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