Utilisation of an aqueous treatment solution containing sulphate ions for treating the surface of galvanised steel sheet to provide temporary corrosion protection and lubrication during shaping

摘要

Aqueous treatment solution contains sulphate ions (SO 42->) at a concentration of greater than or equal to 0.02 mol/l, for the treating the surface of a steel sheet with a zinc or zinc alloy based coating on at least one of its surfaces. The treatment is aimed at reducing the formation of powder or metal particles generated by the degradation of the coating during the shaping of the sheet. Independent claims are also included for: (a) lubrication of a coated steel sheet using the aqueous treatment solution; (b) utilisation of the aqueous treatment solution for treating coated steel sheet to improve temporary protection against corrosion.