RU2111282C1 - Solution for phosphatation of metal surface - Google Patents

Abstract

FIELD: corrosion protection. SUBSTANCE: phosphate coating is deposited from solution containing, g/l: nickel ions, 0.03-0.5; phosphate ions (on conversion to $$$), 1.7-7.0; nitrate ions, 1.5-5.2; fluoride ions, 0.05-0.5; zinc concentrate (production waste), 3-25; and manganese(II) nitrate waste, 2-20. Zinc concentrate contains, wt.-%: total $$$, at least 25; zinc, at least 25; manganese, 4-8; and water, at most 30. Manganese(II) nitrate waste contains 72-80.3% Mn(II) ions and one or several admixtures from the following group: aluminum perchlorate, formic acid, ammonium formate, manganese citrate, manganese hydroxides. EFFECT: decreased frictional wear and increased corrosion immunity of coating. 1 tbl

Description

 The invention relates to chemical surface treatment of metals by applying a phosphate coating and can be used in the automotive industry, metallurgical and hardware industries to obtain corrosion-resistant phosphate layers.

 A known solution for phosphating iron and zinc, containing from 0.1 to 1.5 g / l of zinc ions, from 5 to 50 g / l of phosphate ions, from 0 to 4 g / l of manganese ions, 0.05 g / l of ions fluoride and accelerator [1].

 The closest in technical essence and the achieved effect to the proposed is a solution containing ions of zinc, manganese, nickel, phosphate, nitrate, fluorine [2].

 Distinctive features of the invention from the prototype is the use of Zn ion sources - production waste - zinc concentrate, and Mn ion source - manganese (II) nitrate waste.

The disadvantages of the above solutions are
low corrosion resistance;
significant running-in time and a large amount of wear of the rubbing parts.

 The objective of the invention is to create a solution for phosphating, which allows to improve the running-in of the rubbing parts and to reduce their wear during prolonged use, as well as to increase the corrosion resistance of the phosphate coating.

The problem is achieved in that the phosphate coating is carried out in a solution containing ions of nickel, phosphate, nitrate, fluorine, zinc and manganese, as well as production waste - zinc concentrate and waste manganese (II) nitrate in the following ratio of components, g / l:
Ni ²⁺ - 0.03 - 0.5
P ₂ O ₅ - 1.7 - 7.0
NO ₃ - 1.5 - 5.2
F ^- - 0.05 - 0.5
Zinc concentrate production waste - 3 - 25
Manganese (II) nitrate waste - 2 - 20
moreover, the zinc concentrate has the following composition, wt. %:
Mass fraction of total P ₂ O ₅ - Not less than 25
Mass fraction of zinc (Zn) - Not less than 25
Mass fraction of manganese (Mn) - 4 - 8
Water - No more than 30
and the waste of manganese nitrate has the following composition,%:
Mn ²⁺ - 72 - 80.3
One or more of the following impurities: Al perchlorate, formic acid, ammonium formate, manganese citrate, manganese hydroxides - Else
Running-in represents an increase in the bearing surfaces of machine parts rubbing against each other. Even thorough mechanical surface treatment does not avoid the fact that the first contact of rubbing against each other surfaces will be point, and the resulting compression loads will be very unevenly distributed over the entire surface,
The proposed solution provides the creation on the metal surface of a non-metallic separating layer, the risk of welding in the initial phase of the starting cycle is significantly reduced.

 As a result of friction, a smooth, mirrored, run-in surface is formed, contributing to an unhindered running-in process.

Ni ^{2+ ions} can be introduced into the phosphating solution in the form of nitrates, phosphate ions with phosphate acid, nitrate ions with nitric acid, nitrates Zn ²⁺ , Mn ²⁺ , Ni ²⁺ . Fluoride ions can be delivered with simple and complex fluorides, such as NaF, HF, H ₂ SiF ₆ , etc., Zn ²⁺ , Mn ²⁺ ions are introduced with process waste.

 A working solution for phosphating is prepared based on dilution with water of 20 - 150 g of a concentrated aqueous solution of up to 1 liter.

The selected ratios of the components of the solution make it possible to obtain stable phosphate coatings over a period of 2 to 10 minutes at a temperature of 40 to 70 ^o C, which improve the running-in time and reduce wear of parts during prolonged use, as well as increase corrosion resistance.

 The running-in time and wear of parts during long-term operation is determined on samples made of steel 45, with a diameter of 40 mm and a generatrix of 10 mm. The surface preparation of the samples (steel 45 and steel 08 KG) is carried out according to the following scheme.

1. Degreasing with PTS-5 detergent composition (TU 113-0203659-30-92)
Concentration, g / l - 15 - 30
Temperature, ^o C - 50 - 60
Processing time, min - 10
2. Flushing with hot water:
Temperature, ^o C - 60 - 70
Time, min - 0.9
3. Rinsing with cold water:
Temperature, ^o C - 15 - 30
Time, min - 0.9
4. Phosphating with prepared solutions:
Phosphating time, min - 10
The temperature of the solution, ^o C - 60
Processing Method - Dipping
5. Rinsing with cold water:
Temperature, ^o C - 15 - 30 min
Time, min - 2
6. Oiling 3 VVS-1 (TU 38401673-87)
The temperature of the solution, ^o C - 15 - 30
Processing time, min - 0.5
7. Drying at 40 - 60 ^o C for 10 minutes

 A steel wire with a diameter of 1.7 mm is prepared as follows.

 Etched in 15% sulfuric acid, washed, treated in a solution in accordance with the invention of the prototype, washed, treated in a 0.5% solution of laundry soap and dried.

The phosphating temperature is 60 ^° C., the phosphating time is 10 minutes.

 The test results of solutions for phosphating a metal surface and a solution of the prototype are shown in the table.

 Determining the running-in time of the rubbing parts and wear during long-term operation was carried out according to the methods.

Corrosion resistance is determined in hours. For this, the samples were placed in a salt spray chamber, where a 3% sodium chloride solution was continuously sprayed. The temperature is maintained automatically in the range 34 - 37 ^o C. Inspection of the samples is carried out with the naked eye in natural ambient light. Tests were carried out until the first visible corrosion points appeared. The longer the time before corrosion, the higher the corrosion resistance of the phosphate coating.

As can be seen from examples 2 - 4, 7 - 9, 12 - 14, 17 - 19, 22 - 24, 27 - 29, 31 - 33 tables with the content of Ni ^{2+ ions} from 0.03 to 0.5 g / l, phosphate ions (in terms of P ₂ O ₅ ) from 1.7 - 7.0 g / l, nitrate ions from 1.5 - 5.2 g / l, F ions from 0.05 - 0.5 g / l and zinc concentrate from 3 to 25 g / l, manganese (II) nitrate waste from 2 to 20 g / l, a phosphate coating is formed, which has the ability to reduce the running-in time of rubbing parts, wear during prolonged use, and increase corrosion resistance.

 Reducing or increasing the content of all components (examples 1, 5, 6, 10, 11, 15, 16, 20, 21, 25, 26, 30) leads to an increase in running-in time and increased wear during prolonged operation.

The use of the proposed solution for phosphating provides the following technical and economic advantages:
shortening the service life of parts, engines, etc., increasing wear resistance;
reduction of production costs and expansion of the raw material base of production.

 Example 34 describes the properties of the coating of the prototype.

 The solution according to the invention improves the starting characteristics of the elements of wires and motors, leads to a noticeable decrease in long-term wear of parts, facilitates the process of cold deformation, increases corrosion resistance.

Literature
1. USA N 4961794, cl. C 23 C 22/18 (analogue).

 2. EP N 0381190, class C 23 C 22/36, 1990 (prototype).

Claims (1)

A solution for phosphating a metal surface containing nickel, phosphate, nitrate, fluorine, zinc and manganese ions, characterized in that it contains zinc waste as sources of zinc ions, and zinc concentrate as sources of manganese ions - manganese (II) nitrate waste in the following ratio of components, g / l:
Nickel ions - 0.03 - 0.5
Phosphate ions (in terms of P ₂ O ₅ ) - 1.7 - 7.0
Nitrate ions - 1.5 - 5.2
Fluorine ions - 0.05 - 0.5
Waste production - zinc concentrate - 3 - 25
Manganese (II) nitrate waste - 2 - 20
moreover, the waste product zinc concentrate contains, wt.%:
Total P ₂ O ₅ - At least 25
Zinc - At least 25
Manganese - 4 - 8
Water - No more than 30
and the waste of manganese (II) nitrate contains,%:
Manganese ions - 72.0 - 80.3
One or more impurities from the group aluminum perchlorate, formic acid, ammonium formate, manganese citrate, manganese hydroxides -

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