1. Phosphating film is not generated

The surface of the standard parts is hardened by cold work, the sulphate content in solution increases, the phosphating solution is mixed with residue, the phosphorus penoxide content is too low, the strong alkali etched surface is used to expose the metal crystal, the sulphate is solved by barium carbonate, the phosphating solution should be removed to fill the polyphosphate.

2. Phosphating film has blank sheet

Nitrate is not enough, phosphorus penoxide content is too low, the temperature is too low, acid bath aluminum sulfate salt increase, plus zinc nitrate, plus polyphosphate, rising solution temperature, should be removed for hydrochloric acid solution.

3. Phosphating parts are yellow and white

Precipitation, component rivet corrosion, precipitation in the solution, nitrate is not enough, phosphating solution did not wash, seek tank precipitation, fill zinc nitrate, remove phosphating film in acid solution phosphating again.

4. The anti-corrosion ability of phosphating film is reduced

Phosphating film with yellow rust crystals thick or too thin, phosphating parts with residual salt surface, metal material over erosion, mineral acid acid too high, polyphosphate lack, adjust the ratio of mineral acid acid and total acidity, improve the medium and hand washing before phosphating, operating phosphating constant frequency, fill zinc nitrate, fill phosphate.

5, phosphating film is too thin, crystal is too thin