High- and medium-temperature phosphating processes are widely used in industrial sectors such as construction, machinery, household appliances, and household hardware. However, high-temperature phosphating process requires heating during construction, large energy consumption, easy decomposition of bath solution, and strict requirements on the pre-treatment. Jinan Paint Factory Xue Yi and Han Denglin introduced a normal temperature multi-functional phosphating agent. The three processes of oil removal, rust removal and phosphating can be completed at one time. It can both remove the oil stains and rust stains remaining on the surface of steel workpieces, and it can also carry out Phosphate treatment. The construction process is simple, the production efficiency is high, and the cost is low. Room temperature multi-functional phosphating agent composition: PO43-: 15% to 20%; Zn2+: 0.5% to 1%; NO3-: .5 to 0.8%; Additive: 0.5% to 1%; Surfactant: 0.3% to 0.8 %.
Phosphating construction process: (1) Impregnation treatment: The bath temperature is maintained at 25 to 30°C and the processing time is about 15 minutes. Do not stack the workpiece in the bath. Moving the workpiece at regular intervals can improve the processing results. The surface oil and bottom sludge should be removed regularly. (2) Brushing and spraying: Brushing with hard nylon brush is repeated on the surface of the workpiece several times to make surface rust remaining on the surface of the workpiece. Light rust is removed until the phosphating solution is applied. Heat 35 to 40°C is better. Spraying: Using a compressed air spraying device, the phosphating agent preheated to 35-40°C is sprayed directly on the surface of the workpiece and should be sprayed several times. (3) The phosphatized parts should not be cleaned, naturally dried in a dry and ventilated place, but also dried with hot air or dry compressed air. If electrophoretic painting is used, the phosphorized dry parts shall be washed with water (or passivated) and then entered into the electrophoresis tank to ensure that the electrophoretic paint will not be contaminated.