摘要 |
The invention provides an electrolytic phosphating treatment method that forms a film by causing a large current to flow at a voltage as low as possible and can improve efficiency. Namely, the invention provides an electrolytic phosphating treatment method for forming a film containing a metal precipitating from a nitrate, and a phosphate, by executing electrolysis between a metal that is the same as a metal of a nitrate of a treatment bath as an electrode and a work by using a D.C. power source, the treatment bath comprising phosphoric acid, zinc, iron or manganese as a metal capable of dissociating phosphoric acid and dissolving in phosphoric acid, and a solution dissolving a nitrate of a metal to become a film component, wherein anions other than nitrate ions and metal ions other than the metal ions to become the film component are present at not greater than 0.5 g/L, the metal ion dissolving from the nitrate is present at greater than 10 g/L and phosphoric acid and phosphate ion are present at not greater than ½ of the metal ion dissolving from the nitrate.
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