Abstract: A surface coated steel strip having improved corrosion resistance, comprising a steel strip, a zinc alloy (e.g. Zn-Ni, Zn-Mn, Zn-Co, etc.) layer electroplated on the strip, a chromate film formed on the zinc alloy layer in a weight of 2 to 60 mg/m.sup.2, and a polyethylene coating cured to the chromate film and weighing 0.3 to 5 g/m.sup.2 is prepared by applying a chromate solution to the zinc alloy plated strip and drying it into the chromate film, and applying an aqueous composition of a carboxylated-polyethylene resin, a melamine resin, and colloidal silica to the chromated strip and drying and curing the composition into the coating at elevated temperatures of at least 130.degree. C.

Abstract: Coated electrical steel sheets having excellent punchability, weldability and insulation resistance are produced by applying an electrical steel sheet with a treating dispersion obtained by compounding the particle separating resin emulsion and the compatible resin to an aqueous solution containing chromic acid in the particularly defined amount and baking the thus applied steel sheets. To the treating dispersion may be added saccharides or polyhydric alcohols as a reducing agent or boric acid or phosphoric acid.