| 摘要 |
Provided is a method for producing a surface-treated steel plate which involves immersing a steel plate (1) in an electrolytic treatment solution (31) containing Zr ions and F ions, continuously performing an electrolytic treatment (31), and as a result, forming a film having a ZrO compound as the principal component thereof on the steel plate (1), in a manner such that the amount of Zr in the film is 30mg/m2 or more, the method for producing the surface-treated steel plate being characterized in that: the concentration of Zr ions in the electrolytic treatment solution (31) is 3,000-10,000 wt ppm; the pH is 2-4; and the electrolytic treatment solution (31) is continuously supplied with a first supply fluid having a pH of 5 or less and containing a zirconium fluoride compound (A) in an amount such that the Zr ion concentration thereof is in the range of 10,000-250,000 wt ppm, and a second supply fluid having a pH of 5 or less and containing a non-fluorinated zirconium compound (B) in an amount such that the Zr ion concentration thereof is in the range of 10,000-200,000 wt ppm. |
