Metal part anti-rust technology

[0026] Example 1:

[0027] An anti-rust process for metal parts includes the following steps:

[0028] (1) Degreasing

[0029] The metal parts are polished and put into PA30-2M degreasing solution for dipping and degreasing, the temperature of the degreasing is 50°C, and the time of the dipping and degreasing is 5 minutes;

[0030] (2) Washing

[0031] Then clean the degreased metal parts with water. The cleaning is divided into two steps. The first step is to wash the degreased metal parts with tap water for 2 minutes, and the second step is to wash them with deionized water twice;

[0032] (3) Pickling

[0033] Put the washed metal parts in an etching acid and soak for 3 minutes at 30°C. The composition of the etching acid is 300mL/L HNO3 and 6g/L NH4HF2 aqueous solution. The total acidity of the etching acid is 55 points;

[0034] (4) Wash again

[0035] Soak the acid-etched metal parts in tap water for 20 minutes, then take them out and wash them with running water twice;

[0036] (5) Phosphating

[0037] Then the metal parts are immersed in the prepared phosphating solution for phosphating treatment to form a phosphating film on the surface of the metal parts. The soaking time is 6 hours. The composition of the phosphating solution is 20% zinc oxide and copper carbonate. 2%, nitric acid 19%, phosphoric acid 7%, urotropine 3.5%, sodium fluoride 5.3%, zinc nitrate 35%, the preparation steps of the phosphating solution are as follows: ①First, weigh zinc oxide and carbonic acid Put copper into glassware and dilute with distilled water at the same time; ②Put urotropine, sodium fluoride and zinc nitrate into another glassware, add distilled water to dilute; ③Pour nitric acid into zinc oxide and copper carbonate solution, At the same time, stir with a glass rod, then add phosphoric acid, stirring time is 10min, and finally add distilled water to dilute; ④ Mix the two prepared liquids and stir to form the phosphating solution;

[0038] (6) Post-processing

[0039] The phosphated metal parts are passivated in a passivation solution consisting of 50g/L potassium dichromate and 2g/L sodium carbonate. The passivation treatment time is 10 minutes, and the passivation The temperature is 70℃;

[0040] (7) Saponification

[0041] After passivation, saponification is performed. The reagent for saponification is sodium stearate, the amount of sodium stearate is 30g/L, the saponification temperature is 80°C, and the saponification time is 10min ;

[0042] (8) Oil seal

[0043] Then, the metal piece is immersed in the dehydrated rust preventive oil for oil sealing, the time of the oil seal is 5 min, and the temperature of the oil seal is 90°C.

[0044] Example 2:

[0045] An anti-rust process for metal parts includes the following steps:

[0046] (1) Degreasing

[0047] The metal parts are polished and put into PA30-2M degreasing solution for dipping and degreasing, the temperature of the degreasing is 55° C., and the time of dipping and degreasing is 6 min;

[0048] (2) Washing

[0049] Then clean the degreased metal parts with water. The cleaning is divided into two steps. The first step is to wash the degreased metal parts with tap water for 3 minutes, and the second step is to wash them with deionized water three times;

[0050] (3) Pickling

[0051] Put the washed metal parts in an etching acid and soak for 4.5 min at 45°C. The composition of the etching acid is 350mL/L HNO3 and 7g/L NH4HF2 aqueous solution. The total acidity of the etching acid 65 points;

[0052] (4) Wash again

[0053] Soak the acid-etched metal parts in tap water for 25 minutes, then take them out and wash them with running water 3 times;

[0054] (5) Phosphating

[0055] Then the metal parts are immersed in the prepared phosphating solution for phosphating treatment, and a phosphating film is formed on the surface of the metal parts. The immersion time is 7 hours, and the composition of the phosphating solution is 20.5% zinc oxide and copper carbonate. 2.5%, nitric acid 20%, phosphoric acid 8%, urotropine 3.6%, sodium fluoride 5.4%, zinc nitrate 40%, the preparation steps of the phosphating solution are as follows: ①First, weigh zinc oxide and carbonic acid Put copper into glassware and dilute with distilled water at the same time; ②Put urotropine, sodium fluoride and zinc nitrate into another glassware, add distilled water to dilute; ③Pour nitric acid into zinc oxide and copper carbonate solution, At the same time, stir with a glass rod, then add phosphoric acid, stirring for 15 minutes, and finally add distilled water to dilute; ④ Mix the two prepared liquids and stir to form the phosphating solution;

[0056] (6) Post-processing

[0057] The phosphated metal parts are passivated in a passivation solution consisting of 65 g/L potassium dichromate and 3 g/L sodium carbonate. The passivation treatment time is 12.5 min, and the passivation The temperature is 80℃;

[0058] (7) Saponification

[0059] After passivation, saponification is performed. The reagent for saponification is sodium stearate, the amount of sodium stearate is 40g/L, the saponification temperature is 85°C, and the saponification time is 15min ;

[0060] (8) Oil seal

[0061] Then, the metal piece is immersed in the dehydrated anti-rust oil for oil sealing, the time of the oil seal is 6 minutes, and the temperature of the oil seal is 100°C.

[0062] Example 3:

[0063] An anti-rust process for metal parts includes the following steps:

[0064] (1) Degreasing

[0065] The metal parts are polished and put into PA30-2M degreasing solution for dipping and degreasing, the temperature of the degreasing is 60°C, and the time of the dipping and degreasing is 7 minutes;

[0066] (2) Washing

[0067] Then clean the degreased metal parts with water. The cleaning is divided into two steps. The first step is to wash the degreased metal parts with tap water for 4 minutes, and the second step is to wash them with deionized water 4 times;

[0068] (3) Pickling

[0069] Put the washed metal parts in an etching acid and soak for 6 min at 60°C. The composition of the etching acid is 400mL/L HNO3 and 8g/L NH4HF2 aqueous solution. The total acidity of the etching acid is 75 points;

[0070] (4) Wash again

[0071] Soak the acid-etched metal parts in tap water for 30 minutes, then take them out and wash them with running water 4 times;

[0072] (5) Phosphating

[0073] Next, the metal parts are immersed in the prepared phosphating solution for phosphating treatment, and a phosphating film is formed on the surface of the metal parts. The soaking time is 8 hours. The composition of the phosphating solution is 21% zinc oxide and copper carbonate. 3%, nitric acid 21%, phosphoric acid 9%, urotropine 3.7%, sodium fluoride 5.5%, zinc nitrate 45%, the preparation steps of the phosphating solution are: ①First, weigh the zinc oxide and carbonic acid Put copper into glassware and dilute with distilled water at the same time; ②Put urotropine, sodium fluoride, and zinc nitrate into another glassware, add distilled water to dilute; ③Pour nitric acid into zinc oxide and copper carbonate solution, At the same time, stir with a glass rod, then add phosphoric acid, stirring for 20 minutes, and finally add distilled water to dilute; ④ Mix the two prepared liquids and stir them to form a phosphating solution;

[0074] (6) Post-processing

[0075] The phosphated metal parts are passivated in a passivation solution consisting of 80 g/L potassium dichromate and 4 g/L sodium carbonate. The passivation treatment time is 15 minutes, and the passivation The temperature is 90℃;

[0076] (7) Saponification

[0077] After passivation, saponification is performed. The reagent for saponification is sodium stearate, the amount of sodium stearate is 50g/L, the saponification temperature is 90°C, and the saponification time is 20min ;

[0078] (8) Oil seal

[0079] Then, the metal piece is immersed in the dehydrated rust preventive oil for oil sealing, the time of the oil seal is 7 minutes, and the temperature of the oil seal is 110°C.

[0080] Test items Example 1 Example 2 Example 3 Existing technical indicators Corrosion inhibition rate (%) 95.2 96.7 96.9 94.8 Polarization resistance (Ω) 2014.6 2022.9 1999.8 1600.7 Corrosion current density (mA/cm2) 0.0119 0.0084 0.0126 0.0421

[0081] According to the data in the above table, when the parameters of the embodiment 2 are used, the metal after the anti-rust treatment has higher corrosion inhibition rate and polarization resistance than the metal after the anti-rust treatment of the prior art, and the corrosion current density is higher than that of the prior art anti-corrosion. After the rust treatment, the output is low, which is more conducive to the anti-rust treatment of the metal parts.

[0082] The present invention provides an anti-rust process for metal parts. The cleaning is divided into two steps. On the one hand, the degreasing liquid can be washed away, and on the other hand, the influence of other ions on the surface of the steel on the film formation can be eliminated. The composition ratio and the configuration method can make the phosphating film formed by the phosphating of metal parts have an ideal anti-rust effect and have a wide application prospect. The saponification treatment after the medium passivation can achieve a longer-term anti-rust and anti-corrosion effect. The use of this kind of anti-rust technology has the advantages of good anti-rust effect and good corrosion resistance, with huge market potential and broad prospects.