Metal surface treatment composition, metal surface treatment method, and galvanized steel plate

摘要

It is an object of the present invention to provide a metal surface treatment composition and a metal surface treatment method superior in stability, which can apply a good chemical conversion treatment to a galvanized steel plate without requiring a burden of waste water treatment, and a galvanized steel plate superior in a rust-preventive property and adhesion, which is obtained by such a metal surface treatment method. A metal surface treatment composition comprising niobium oxide colloidal particles, wherein the niobium oxide colloidal particles are derived from a niobium oxide sol which is stabilized by containing citric acid or salts thereof in an amount of 0.02 to 1.0 by a mole ratio relative to Nb.