METHOD OF RECEIVING OF PHOSPHATE COATING Russian patent published in 2009 - IPC C23C22/14 C23C22/18 

FIELD: metallurgy.

SUBSTANCE: method includes surface treatment of metal by water solution of phosphating, containing ions of zinc, phosphate, nitrate, chlorates and ions of manganese at following content of components, g/l: Zn²⁺ 2.00-3.15, P₂O₅ 3.80-7.14, NO₃- 1.10-1.95, ClO₃- 0.18-0.51, Mn²⁺ 0.002-0.21. Metal surface treatment by mentioned water solution of phosphating is implemented at the temperature 35-40°C during the time from 2 up to 5 minutes, at that before start of treatment water solution of phosphating is corrected at the temperature 20-25°C by value of free acidity up to 0.4-0.9 points by means of addition NaOH or Na₂CO₃.

EFFECT: phosphate coating with high corrosion stability.

4 ex