RU2131451C1 - Component of lubricating materials - Google Patents

Abstract

FIELD: lubricating agents. SUBSTANCE: invention describes the use of serpentinite as a component of lubricating materials. New application of serpentinite provides the improvement of antioxidant, antiscuff, anti-wearing and antifriction properties of lubricating agents, enhances the effectiveness of hydrogen wearing control and fretting-corrosion of friction surfaces. EFFECT: improved quality and properties of the lubricating agents. 4 dwg, 6 tbl, 8 ex

Description

 The invention relates to lubricants intended to optimize the operation of friction mechanisms.

 It is known the use of graphite as an ingredient in lubricants - as a solid lubricant (Small Soviet Encyclopedia. M., State Scientific Publishing House "Big Soviet Encyclopedia, 1959, v. 3, p. 114) [1] or as an additive to lubricating oils or greases, for example, lubricants based on petroleum oil (USSR Author's Certificate N 1583437 C 10 M 125/02, 1990) [2].

 However, graphite does not exhibit universal properties: the lubricants obtained with its use are intended only for certain friction units; in other mechanisms, they do not have sufficient operational properties.

 It is known to use colloidal graphite in combination with diamond powder as a lubricant ingredient — an additive to lubricating oils (USSR Author's Certificate N 1635904, C 10 M 125/02, 1991) [3].

 However, the grease obtained in this case is used only for running in the mechanisms and is not intended for their operation. In addition, one of the components of this known additive is an expensive diamond powder.

 It is known to use graphite modified with epoxy resin or organopolysiloxane as an ingredient in a lubricant — an additive to a grease (USSR Author's Certificate N 297668, С 10 М 125/02, 1969) [4].

 However, the operational properties of the resulting lubricant are not universal, and the technology for producing this known lubricant (additive) ingredient is complex.

 Known lubricant ingredients — lubricant additives — are ultrafine titanium carbide powder (USSR Author's Certificate N 1669975, С 10 М 125/08, 1991) [5], ultrafine titanium carbonitride powder (Author's certificate N 1669976, С 10 М 125/20 , 1991) [6], a mixture of fine diamond powder in combination with an iron-containing powder obtained by complex technology (RF Patent N 1730842, C 10 M 125/04, 1994) [7], cobalt powder (RF Patent N 2028370, C 10 M 125/04, 1994) [8], iron powder (USSR Author's Certificate N 197843, C 10 M 125/02, 1966) [9].

 However, lubricants containing these known ingredients (additives) are not universal and highly effective in combating various types of wear, and the manufacture of these additives is a complex technological process.

 It is known to use boron nitride metallized with an alloy based on non-ferrous metals, as an ingredient in a lubricant, additives to a plastic lubricant based on lithium soap of stearic acid and tilium soap of oleic acid. (USSR Author's Certificate N 910750 C 10 M 125/00, 1980) [10].

 However, the operational properties obtained with this lubricant are not high enough, and the technology for producing the additive is complicated.

 Known lubricant ingredients — additives for greases — are copper powder (USSR Author's Certificate N 658165, C 10 M 125/04, 1976) [11], tin, lead and bismuth alloy powder (USSR Author's Certificate N 827538, 1978) [12 ], a mixture of powders of aluminum, antimony and magnesium (USSR Author's Certificate N 1011678, C 10 M 125/04, 1981) [13], a mixture of powders of copper oxide, Nickel and gallium (USSR author's certificate N 1049529, C 10 M 125/04 , 1982) [14], powder of an alloy of aluminum with iron (USSR Author's Certificate N 1595883, С 10 М 125/04, 1990) [15].

 However, these known additives are difficult to access, their production is time-consuming, requiring a high degree of purity of the powders, and they can only be introduced into greases for certain friction units, which limits their scope. As solid lubricants, these known materials are not used.

 Known serpentinite (serpentine) - a metamorphic ultrabasic rock consisting of serpentine, chrysotile, antigorite, magnetic and chromium iron ore and residues of primary minerals: olivine or pyroxenes. The use of serpentinite as a fertilizer is known in the manufacture of refractories and in the manufacture of handicrafts (Small Sov. Encyclopedia, M., State Scientific Publishing House "Big Sov. Encyclopedia", 1959, v. 3, p. 1139, article "Coil" ) [fifteen].

 However, the use of serpentinite as a solid lubricant or universal additive to oil and plastic lubricants has not been described.

 The technical result achieved by the implementation of the present invention is to identify the universal properties of the available material, which can be used both as a solid lubricant and as a universal additive that improves the antiwear, extreme pressure, antifriction properties of oil oils and greases, preserve their rheological, anticorrosion properties, improve antioxidant properties, increase their effectiveness in the fight against hydrogen adhesive (mechanical), abrasive wear, fretting - corr Ziya friction surfaces, as well as ease of preparation technology lubricants with a new ingredient - an additive. This is achieved by the fact that as a lubricant ingredient used in its pure form as a solid lubricant or as an additive (additive) to lubricating oils or greases, serpentinite is used.

 It was established for the first time that the available natural material - the serpentinite rock - can be used as a solid lubricant or added to lubricating oils and greases as an additive to improve their performance.

 Figure 1 presents a histogram of the mass wear of the pair Sch25 - St15 when testing known lubricants containing or not containing a new friction modifier - serpentinite.

 Figure 2 presents the values of the friction coefficients (μ) averaged over several tests of the pair SCh25 - St15.

 Figure 3 presents the vibrograms taken before and after the test of the bearing using grease TsIATIM-202 containing a new additive.

 In FIG. Figure 4 presents graphically averaged over several tests the values of the friction coefficients (μ) of the Sch25 - St15 pair when using petroleum jelly in combination with the new modifier.

 The following are examples illustrating the invention.

 For use as a solid lubricant or as an additive to lubricating oils, petroleum jelly, greases, crushed rock serpentinite was used. The fractional composition of the obtained powder is presented in table 1 (table. 1-6 see at the end of the description).

Example 1. The effect of new (serpentinite powder) and known (Cu ₂ O powder) additives on the properties of Litol-24 lubricant under hydrogen and abrasive wear was investigated. In the test, crushed serpentinite with a particle size distribution of up to 7 μm was used (a fraction of more than 7 μm was not more than 5%). The tests were carried out on samples of titanium alloy - the material most subjected to hydrogen wear.

Samples from titanium alloys (VT 1, VTZ - 1) were tested on a MFK - 1 unit in the conditional boundary friction mode on nominally motionless contacting surfaces with relative vibrational motion. Steel ШХ - 15 was used as an indenter material. The indenter contact area with both a fixed titanium specimen and a movable titanium specimen (counter-specimen) was S = 0.5 cm ² .

As a known additive, powder of copper oxide (Cu ₂ O) was chosen as a well-known effective tool in the fight against hydrogen wear.

 The results of a comparative assessment of the effectiveness of the studied lubricants in the fight against hydrogen and abrasive wear, presented in table 2, indicate that the mass wear of the samples under the same test conditions was 30-40% less when working with a lubricant containing a new additive - serpentinite powder, than when working with a lubricant with a known additive. Moreover, the content of the new additive in the lubricant was 5 to 20 times lower than the tested content of the known additive.

 Example 2. Conducted tests on the effectiveness of the use of a new material (serpentinite powder) as an additive to lubricants in the fight against fretting corrosion.

 The tests were carried out on the MFK-1 installation, which provides reciprocating friction at the ends of the samples, which are cylinders with a height of h = 25 mm and a diameter of ⌀ = 20 mm, one of which (a movable sample) is made of St15 steel, and the second (a stationary sample ) made of gray cast iron Sch25.

The contact area S = 1.0 cm ² , the maximum number of cycles N = 10 ⁶ , the sliding amplitude A = 100 μm, the oscillation frequency v = 30 Hz (1800 cycles per minute), and the specific load P = 20 MPa. The test results are shown in FIG. 1 and FIG. 2 and indicate the high efficiency of the new additive introduced into the MS-20 oil into the Litol-24 grease, as well as the high efficiency of using serpentinite as a solid lubricant in dry friction.

 Example 3. Conducted a test with ball bearing light series N 204.

Bearing dimensions: outer race diameter - 47 mm
diameter of an internal holder - 20 mm
bearing width - 15 mm.

 A sleeve with an internal diameter of 16 mm was pressed into the inner race.

 The bearing was mounted on the lower spindle of the friction machine and its inner cage was fixed with a nut. The upper clip through a special block was pressed by the upper spindle and did not rotate during testing. Before testing, the bearing did not have radial and lateral clearances. Before testing, the bearing was washed in turpentine, degreased, rubbed with acetone, weighed and filled with Tsiatim-202 grease containing 0.6% serpentinite powder.

Bearing tests were carried out with a rotational speed of the inner cage equal to 1800 min ^-1 and a load on the upper stationary cage of 1200 N.

 As an assessment of the effect of a lubricant with a new additive on the condition and performance of a ball bearing, the method of mechanical vibrations in the frequency spectra was chosen as one of the most sensitive methods. For bearings, the most informative is the frequency spectrum from 1 to 1 kHz.

 To measure vibration levels and 1/3 octave analysis (25%), we used equipment consisting of a DI-4 vibration sensor with a PM-3 preamplifier, VSHV-003 vibration registry, 1/3 octave analyzer 01018 (RFT) and a logarithmic level recorder 02013 (RFT).

Vibrograms, taken at the beginning of bearing tests and at the end (after operating it with 1.5 • 10 ⁶ cycles), are shown in Fig. 3 and indicate that they practically did not change during the specified operating period.

 Differences in vibration levels in the upper region of the frequency range are 0.3-1.5 dB and are within the accuracy range.

The bearing temperature during testing was in the range of 25-28 ^o C. After the end of the test, the bearing was removed, degreased, wiped with acetone and dried at a temperature of 80 ^o C.

Inspection and measurements showed that the values of the radial and lateral clearances, as well as the mass of the bearing, remained practically unchanged. Measurement values are within the error range. No traces of rubbing on balls and cage tracks were found. Tests allow us to conclude that the operation of the N 204 bearing on the modified TsIATIM-202 lubricant with the operating time of 1.5 • 10 ⁶ cycles had practically no effect on the state of the bearing, which suggests the reliability of the operation of bearings containing a new additive.

 Example 4. For the final conclusion about the feasibility of using serpentinite powder to combat fretting corrosion, comparative tests were conducted to evaluate the effectiveness of various technological solutions.

For a comparative evaluation of the effectiveness, the results of the following groups of samples manufactured on Sch-25 were used:
1. Samples without coating.

 2. Samples sprayed with copper 0.2 mm thick by the thermal method.

 3. Samples with galvanic coating of copper with a thickness of 60 microns.

 4. Samples coated with a fluorocarbon composition 40 to 50 A.

 5. Samples of liquid polymer sealant GIPK - 244 based on the composition of SKN - 26 - 1 butadiene acrylonitrile rubber with target additives.

 6. Samples with hard-lubricated coating VFP-5, 25 microns thick.

 7. Samples lubricated with technical petroleum jelly.

 8. Samples lubricated with technical petroleum jelly with 2% serpentinite.

 9. Samples lubricated with technical petroleum jelly with 5% serpentinite.

 10. Samples with graphite lubricant.

 11. Samples with graphite lubricant with 2% serpentinite.

The test conditions are the same as in example 2, the difference: S = 0.5 cm ² A = 20 μm, v = 250 cycles per minute, P = 85 MPa. Coatings were applied to fixed samples.

The test results are shown in table 3. An analysis of the results indicates that the most appropriate ways to combat fretting corrosion of the SCh-25 - St 15 pair are the use of hard-lubricating coatings VFP-5 and the use of greases with serpentinite. It should be noted that the application of VFP-5 is a complex technological process and requires heating the part above 200-250 ^o C. A new additive is available (it is a rock) and its important property is the simplicity of its introduction into lubrication.

 Example 5

 To determine the permissible loads when using a new additive, the lubricant properties of petroleum jelly + 2% serpentinite were studied when testing the friction pair Sch 2 5-St 15 under the conditions of Example 4 with the difference: A = 50 μm, P = var, v = 30 Hz (1800 cycles per minute).

 The results are shown in FIG. 4 and indicate that the performance properties of the grease with the new additive improve with increasing load.

 Example 6

Comparative tests of new (serpentinite) and known (MoS ₂ ) additives in a dispersion medium and in the composition of oils are carried out.

 The tests were carried out on a four-ball friction machine (CWM) for one hour at a load of 20 kg.

The oil is intended for lubrication of chains of conveyors operating at elevated temperatures (180-250 ^o C). Tested ICP-20 oil and its modifications. The basis of ICP-20 oil is the base residual oil of selective purification. The composition of the ICP-20 oil contains a number of additives, including the expensive and scarce MoS ₂ additive. Table 4 shows the comparative test results of ICP-20 oil (sample No. 1) of the same oil, but with the replacement of 0.5% MoS ₂ with 0.5% serpentinite of different dispersion (samples No. 2, 3), base (base oil) in combination with serpentinite (sample N 4).

The results are shown in table 4, from which it follows that with the introduction of ICP-20 or its base 0.5% serpentinite instead of 0.5% MoS ₂ into the composition of the lubricant, an improvement in the wear rate is observed both in experiments with the base oil and in experiments with the composition (see table 4).

 The results of testing motor oil (M) with an oil-soluble anti-wear additive (PIP), as well as with or without PIP in combination with serpentinite, shown in Table 5, indicate that with an increase in the amount of serpentinite from 0.5% to 1.5 % the diameter of the wear spot is reduced.

 Example 7

 Bench tests on a diesel engine 24 8.5 / 11 showed that with the introduction of serpentinite, the process of oxidation of lubricating oils fundamentally changes. In the process of production and addition of serpentinite, the total alkaline number increases by 20-30% and then remains almost constant, which indicates the stabilization of the oxidation process of lubricating oil and the possibility of its permanent operation.

 The dynamics of the viscosity change is such that after the administration of serpentinite at the first stage (operating time ≈ 100-150 hours), it decreases by 20-25%, then a gradual increase and stabilization.

 In addition to changing the viscosity and total alkaline number during the studies, the ability of serpentinite to bind and transfer water compounds and molecules to the process, to prevent the formation of low-temperature deposits in the crankcase, oil lines, filters when the engine is running at low loads, as well as the ability to reduce the intensity of corrosion and formation, was established carbon deposits on hot surfaces of parts and coking piston rings of diesel engines. Therefore, serpentinite is an effective additive contributing to a significant reduction in the intensity of the aging process of lubricating oil and achieving its permanent operation in a diesel engine.

 Example 8

 We studied the possibility of practical application of serpentinite in industry.

Studied industrial suspension industrial oils Itsp-20 and ITD-680, which include an expensive and scarce powder of molybdenum disulfide (MoS ₂ ) brand DM-1. The purpose of the oil ИЦп-20 is indicated in Example 5. Oil ITD-680 is intended for lubrication of gear systems of metallurgical equipment.

 Along with industrial designs, oils with an additive composition including serpentinite powder were tested.

The composition of the oil type ICP-20, wt.%:
Detergent-dispersant - 1.5
Antioxidant Additive - 2.0
Depressor Additive - 2.0
Serpentinite - 1.0
Residual component of selective purification - Else
The composition of the oil type ITD-680, wt.%:
Detergent-dispersant additive - 2.25
Antioxidant Additive - 3.0
Depressor Additive - 3.0
Residual component - 5.25
Serpentinite - 1.5
The basis of industrial oil P-40 - Else
As a result of the studies, the correspondence of the physicochemical and anticorrosion properties, thermo-oxidative and colloidal stability of commercial oils and prototypes presented above was established.

 Comparative tests of tribological properties are presented in table 6. The tests were carried out on a four-ball friction machine ChShM.

The content of MoS ₂ in the commercial oil ICP-20 = 0.6 wt.%, In ITD-60 = 1.5 wt. %

According to the test results, it can be concluded that the new additive - serpentinite powder, can replace the expensive and scarce additive MoS ₂ in lubricants used in industry.

 Thus, serpentinite has a positive effect on various lubricants for all types of wear and is an effective tool to increase the durability of the tribodes. Serpentinite does not worsen the anticorrosive properties of lubricants, improves their antioxidant properties, and reduces adhesive (mechanical), abrasive, hydrogen and fretting wear.

Claims (1)

 The use of serpentinite as an ingredient in lubricants.

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