| abstract |
PROBLEM TO BE SOLVED: To provide a chemical conversion treatment liquid and a method capable of imparting excellent corrosion resistance and paint adhesion without using hexavalent Cr to a metal material and having high anti-sludge property. SOLUTION: Water-soluble trivalent Cr compound component (A), water-soluble Ti and / or Zr compound component (B), water-soluble nitric acid compound component (C), water-soluble Al compound component (D) and F compound component ( The aqueous acidic chemical conversion treatment solution containing E) and adjusted to pH = 2.3 to 5.0 is brought into contact with the surface of the metal material for 1 to 60 seconds, washed with water and dried to obtain 0.02 to 1 mmol / m. includes 2 of Cr and 0.02～1Mmol / m 2 of Ti and / or Zr, forming a conversion coating having a thickness of 1 to 100 nm. [Selection figure] None |