ORGANIC-COATED STEEL SHEET EXCELLENT IN CORROSION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide an organic-coated steel sheet capable of giving excellent corrosion resistance even if the application of a chromate film as a chemical conversion coating to be a ground coat is omitted and further capable of giving excellent chromium elusion resistance as well as corrosion resistance in the case where a chromate film is applied as a chemical conversion coating. SOLUTION: A chemical conversion coating is formed on the surface of a galvanized steel sheet or an aluminum coated steel sheet. Further, an organic film of 0.1-5μm film thickness, containing a reaction product of film forming organic resins (A) and active-hydrogen-containing compounds (B) where a part or all of the compounds are composed of hydrazine derivatives (C) having active hydrogen, is formed on the above chemical conversion coating.