CHROMIUM-FREE SURFACE TREATING SOLUTION HAVING ENHANCED RESISTANCE TO CORROSION AND SULPHIDE STAIN AND SURFACE TREATING METHOD FOR SN-BASED ELECTROLYTICALLY COATED STEEL SHEET USING IT

摘要

A chromium-free post-treating solution having enhanced resistance to corrosion and sulfide stain and a post-treating method of an electroplating steel sheet using the same are provided to include potassium zirconium carbonate and potassium carbonate so as to secure a deposit amount of a film. A post-treating solution includes 60 to 70g of potassium zirconium carbonate and 15 to 30g of potassium carbonate per 1L water. A post-treating process of an electroplated steel sheet using the solution is performed at pH 10~11 and 30~50°C. The post-treating process includes at least one of a dipping method, a spray submerging method, cathode electrolysys, and anodic electrolysis.