| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an Sn-Zn plated steel plate with excellent corrosion resistance, film adhesion and spot weldability which is subjected to rust prevention treatment using a chromate-free aqueous metal surface treatment agent. <P>SOLUTION: The Sn-Zn steel plate with excellent corrosion resistance, film adhesion and spot weldability includes a steel plate, an Sn-Zn plating layer formed on one surface or both surfaces of the steel plate, and a composite film formed on the Sn-Zn plating layer. The composite film contains a predetermined organic silicon compound, at least one fluoro compound selected from a titanium hydrofluoric acid and a zircon hydrofluoric acid, a phosphoric acid, and a heteropoly acid compound. The organic silicon compound, the fluoro compound and the phosphoric acid are in a predetermined mass ratio. <P>COPYRIGHT: (C)2012,JPO&INPIT |
