To provide a chromate treatment solution and a treatment method by which a chromate film having excellent adhesion of a coating film and corrosion resistance can be deposited even when aqueous cleaning is performed in a chromate treatment solution using an oxycarboxylic compound as a reducing agent.
An oxycarboxylic compound is added in 0.3 to 1.1 by molar ratio to the total Cr. Further, ammonia is added thereto in 0.01 to 3.0 by molar ratio to the total Cr. When phosphoric acid or a phosphoric compound is added to the chromate treatment solution in the ratio of P/total Cr of 0.01 to 2.0, or, water dispersible organic resin is added thereto in 20 to 500 g/L, the corrosion resistance of the film further improves. The chromate treatment solution is applied on the material to be treatment such as a metallic material. After that, drying is performed without water washing to deposit the chromate film.
YAMAMOTO MASAYA
TAKETSU HIROBUMI
