RU2443795C2 - MULTI-FUNCTION ANTIFRICTION NANOSTRUCTURE WEAR-RESISTANT DAMPING ALLOYS WITH SHAPE MEMORY EFFECT ON METASTABLE BASIS OF IRON WITH STRUCTURE OF HEXAGONAL ε-MARTENSITE, AND ITEMS USING THESE ALLOYS WITH EFFECT OF SELF-ORGANISATION OF NANOSTRUCTURE COMPOSITIONS, SELF-STRENGTHENING AND SELF-LUBRICATION OF FRICTION SURFACES, WITH EFFECT OF SELF-DAMPING OF VIBRATIONS AND NOISES - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: alloy contains the following, wt %: carbon 0.001 - 0.3, manganese 5.0 - 44.0, nitrogen 0.03 - 0.12, and iron is the rest; at that, its structure contains 5 - 95% of ε-martensite phase, and γ-austenite and/or α-martensite is the rest. Alloy can also contain 0.5 - 8.0 wt % of silicium and/or cobalt and one or several elements of the group: titanium 0.06 - 1.0, vanadium 0.06 - 0.20 and niobium 0.05 - 0.20.

EFFECT: alloy has high damping and antifriction properties, wear resistance and shape memory effect, which allows using it for manufacture of items having the effect of self-organisation of nanostructure compositions on intense friction surfaces, effect of self-strengthening, self-lubrication, self-damping of vibrations and noises, which are used for operation at normal and negative temperatures.

9 cl, 13 dwg, 4 tbl

Description

The invention relates to ferrous metallurgy, in particular to traditional and powder, cast and powder alloys based on iron and an iron-manganese system with a hexagonal έ-martensite structure, antifriction nanostructured wear-resistant damping with shape memory effect, high-strength metastable and products using this alloy for work at normal and negative temperatures with universal application in the construction of general and special engineering.

SUMMARY OF THE INVENTION A multifunctional antifriction nanostructured wear-resistant damping with a shape memory effect is proposed for high-strength alloy based on metastable iron and Fe-Mn system, characterized in that it additionally contains nitrogen in the following ratio of components, wt.%:

manganese 5.0-44.0 carbon 0.001-0.3 nitrogen 0.03-0.12 iron rest,

moreover, the structure contains 5-95% of the ε-martensite phase, the rest of the phase is γ-austenite and / or α-martensite.

The alloy may additionally contain, wt.%:

silicon and / or cobalt 0.5-8.0 one or more elements from the group containing: titanium 0.06-1.0 vanadium 0.06-0.2 niobium 0.05-0.20

The inventive alloy is characterized in that it has a twinning effect.

The proposed product, made entirely and / or containing a working surface of antifriction nanostructured wear-resistant damping with a memory effect of the shape of a high-strength metastable alloy based on iron with the structure of hexagonal ε-martensite, characterized in that it is made of this alloy containing, wt.%: Manganese 5.0-44.0, carbon 0.001-0.3, nitrogen 0.03-0.12, iron the rest and having a structure containing 5-95% phases of ε-martensite, the rest is metastable phases γ-austenite and / or α martensite. The alloy may additionally contain silicon and / or cobalt in the following ratio of components, wt.%: 0.5-8.0, as well as one or more elements from the group containing titanium 0.06-1.0, vanadium 0.06- 0.20, niobium 0.05-0.20 (Fig. 8-13), providing the claimed products with a unique set of properties: the effect of self-organization of nanostructured compositions, the effect of self-hardening and self-lubrication of friction surfaces, the effect of self-quenching of vibrations and noise.

The invention is illustrated by graphs.

Figure 1 is a phase diagram of iron-manganese steels and alloys obtained by traditional and powder metallurgy methods, in the claimed range of manganese content of 5-44%.

Figure 2 - structure of hexagonal ε-martensite of the Fe-Mn system in the state after quenching (× 1000).

Figure 3 - comparative mechanical and antifriction properties of the inventive nanostructured and standardly used antifriction materials.

Figure 4 - change in the tribological and dissipative properties of ferromanganese alloys depending on the manganese content.

5 is a change in the structural and phase composition on the surfaces of intense friction.

6 is a change in the structure and phase composition, microhardness along the depth of the hardened nanostructured layer of an antifriction alloy based on metastable ε-martensite.

7 - fractograms of the surfaces of fractures of shock samples of α-, ε- and γ-alloys of the Fe-Mn system at temperatures of the upper (a, c, e) and lower (b, d, e) cold brittleness thresholds (× 1000).

Fig - parts made from a new class of antifriction nanostructured materials. Motor bushing.

Fig.9 - sleeve hydraulic system.

10 is a thrust bearing of the hydraulic drive system.

11 - gear - the shaft of the oil pump with the tooth module 2.5-3.5.

Fig - sleeve oil pump.

Fig - engine parts: flanges, hubs, separators, bushings, glasses, nipples, seals.

The invention relates to ferrous metallurgy, in particular to traditional and powder, and relates to antifriction nanostructured wear-resistant damping with memory effect forms of high-strength metastable alloys, both cast and powder based on iron, containing manganese as the main alloying element, characterized in that they additionally contain nitrogen, as well as products made from the inventive alloys. The inventive alloys can be obtained in the form of castings, forgings, sheet or long products, in the form of powder and compact products from them.

The presence of manganese in the claimed alloys as the main alloying element is not a sufficient condition for achieving the claimed complex of physical, mechanical and special properties. Necessary conditions are: the presence in the initial phase structure of ε-martensite with a hexagonal close-packed (hcp) lattice formed during quenching by the reaction γ → ε (cooling martensite); the optimal ratio in the initial structure of metastable phases is γ-austenite and ε-martensite, which provide the formation of ultrafine phases of deformation, consisting of strain martensite formed by the reactions γ → ε, γ → α, γ → ε → α (tripp effect), and twins deformation and packaging defects of high dispersion and density (twinning effect) [monograph "High manganese steels and alloys", TF Volynova, M .: Metallurgy, 1988. 343 S.].

The presence of nitrogen in the inventive alloys provides an increase in strength, hardness, ductility, wear resistance both in the state after quenching and after cold deformation. Nitrogen grinds the grain and reduces the tendency to grain growth when heated to hardening; affects the morphology and chemical composition of the hardening phases - nitrides and carbonitrides, the amount and degree of dispersion of which increases with increasing nitrogen content. Nitrogen reduces the energy level of the stacking fault of manganese austenite, which leads to an increase in the dispersion of deformation structures: high-density split mobile dislocations associated with stacking faults and deformation twins [monograph “High-nitrogen steels. Metallurgy under pressure ”, Tsolo V. Rashev, Sofia .: Publishing house of the Bulgarian Academy of Sciences, 1995. 268 pp.].

For the first time, alloys based on the Fe-Mn system containing the maximum possible amount of ε-martensite (up to 95%) were obtained (Figs. 1, 2), on the basis of which the inventive compositions were developed. There are no analogues in world and domestic practice.

Since ferromanganese alloys with the claimed unique set of properties were not used both in the world and in domestic practice, analogues and prototype were selected according to the following criteria: purpose (antifriction, damping, with shape memory effect), strength level; manganese content; the content of ε-martensite in the structure.

Antifriction alloys. Known anti-friction materials for sliding friction units: cast iron, bronze, low-melting alloys - babbits based on lead, tin, zinc or aluminum. The best antifriction materials are bronzes, and of bronzes - tin (~ 10% Sn). However bronze can not withstand high pressures because of the low strength (Figure 3) (when changing alloy powder density of from 15 to 80% tensile strength - σ _in ranges from 10 to 120 MPa in tin and up to 320 MPa in aluminum bronzes) and due to the relatively small heating (low melting point). In addition, bronzes are made up of scarce elements such as copper, tin, lead, and parts made of bronzes are very expensive. Bronzes are inferior to the claimed alloys by dissipative properties - the damping decrement of the claimed alloys Ψ = 40%, standard bronzes <5%. The second place after bronze is occupied by bearings made of iron alloys, including powder and cast irons. The strength of cast iron reaches 500 MPa (figure 3), however, their use is limited by low loads and low speeds. One of the latter is aluminum-based bearings, which are widely used for internal combustion engines.

Theoretical prerequisites for using the structural features of ε-martensite having an hcp lattice as the basis for the development of a new class of antifriction materials, as well as damping and with shape memory effect [monograph “High manganese steels and alloys”, TF Volynova, Metallurgy, 1988 g., 343 pp.]:

- the ratio of the axes with / α = 1.604, close to ideal, providing the smallest number of existing slip systems and the preferential development of basic sliding (the smallest coefficient of friction with an ideal ratio with / α = 1.63);

- instability of the structural components of the Fe-Mn system, the presence in the system of all three martensitic transformations known for iron-based alloys (γ → ε, γ → α, γ → ε → α) that can occur simultaneously and ensure self-organization of nanostructured compositions on the surfaces of intense friction;

- low energy level of stacking fault manganese austenite, providing the possibility of the formation of a high degree of dispersion of stacking faults and deformation twins of metastable deformation nanostructures - twmning effect.

The experimental results confirmed the theoretical premises: a clear correlation was established between the friction coefficient, wear resistance and the amount of ε-martensite; materials with a hexagonal structure compared to other lattices (bcc and fcc) have higher wear resistance: wear rate I = 0.018 for ε alloys, I = 0.045 for α alloys, I = 0.083 mg / m ² m for γ alloys) and lower coefficient of friction (Figure 4).

The closest in technical essence and the achieved result, in composition and structure to the claimed alloy is an antifriction alloy based on iron [3]. In the prototype alloy [3] data on the damping properties and the shape memory effect, on the morphology and kinetics of the formation of nanostructured compositions on friction surfaces, providing an increase in the tribological properties of the claimed alloys (hardness, wear resistance, friction coefficient) and unique properties of products made from these alloys , no.

Alloy [3] contains, wt.%

manganese 10.0-33.0 carbon 0.002-0.20 iron rest

may additionally contain, wt.%:

silicon and / or cobalt 0.5-8.0

The prototype alloy has the following properties: tensile strength: σ _in = 600-850 MPa with a coefficient of friction K _{TP. WITHOUT LUBRICATION} = 0.25-0.35, K _{TP. GREASED} = 0.01. The disadvantage of the prototype alloy [3], as a structural material, is the mismatch of the level of structural strength with ever-increasing requirements for antifriction materials in terms of sliding speeds and specific loads in friction units of modern mechanisms and machines. The task of increasing the strength in the prototype alloy and the claimed solved by increasing the amount of ε-martensite due to alloying with cobalt (0.5-8.0) and / or silicon (0.5-8.0), and providing a level for the prototype alloy strength σ _in = 600-850 MPa, insufficient for the inventive alloy. The task of further increasing the strength in the inventive alloy by Δσ _at = 50-100 MPa can be solved through doping with nitrogen N, as well as additional doping with carbide and nitride-forming: titanium, niobium, vanadium (Ti, Nb, V), where for the first time a combination of high strength , low coefficient of friction and high wear resistance is achieved due to solid solution hardening and the use of the ability to harden metastable manganese austenite due to the formation of deformation phases (known tripp effect) and a high degree of defect deformation twins and stacking faults are the twinnig effect due to self-organization of controlled nanostructured compositions on the friction surface.

Known antifriction powder material based on iron [1], containing, wt.%:

graphite 0.5-1.5 silicon 1.0-2.5 copper 21.0-26.0 manganese 7.5-11.5 tin 1.0-2.5 iron rest

Based on the chemical composition and density (20-30% pore), we can assume that this material has the following mechanical properties: σ _in = 200-250 MPa; δ <2%; T ₅₀ = (+ 400) - (+ 450) ° C; To _{TR. WITHOUT LUBRICATION} = 0,1; To _{TR. GREASED} = 0.006.

At a low coefficient of friction, a significant disadvantage of the alloy [1] is low strength with almost zero ductility, low manufacturability and high labor costs in manufacturing. Moreover, the alloy [1] has limitations on loads and sliding speeds and is significantly inferior to the claimed alloys in strength and durability.

Known antifriction material based on iron - cast iron of the following composition [2], wt.%:

carbon 2.8-3.6 silicon 2.1-3.8 manganese 0.7-1.2 antimony 0.02-0.07 aluminum 0.01-0.03 calcium 0.02-0.06 vanadium nitrides 0.06-0.15 yttrium 0.002-0.01 iron rest

Alloy [2] has the following mechanical and tribological properties: σ _B = 334-556 MPa; To _TR. = 0.026-0.121. Based on the chemical composition, the damping index is not higher than 5%.

Powdered sintered iron-based alloys [1], like cast irons [2], have satisfactory antifriction properties and have limitations in application in terms of sliding speed and load; when they increase, the thickness of the oil film decreases unacceptably. The lower strength compared to cast bearings is due to the significant porosity of the powder alloys, which causes increased sensitivity to shock and pressure on the edge.

The chemical composition of the inventive antifriction alloys and prototype [3] are presented in table No. 1, mechanical and tribological properties - in table No. 2.

Damping alloys. The implementation of the high damping properties of the claimed materials based on the Fe-Mn system provides self-extinguishing and reducing the level of vibration and noise arising from the work in friction units of mechanisms and machines, and therefore, increasing the vibration and dynamic strength, reliability, durability and service life made of the claimed alloys details of friction units. The use of damping materials makes it possible to prevent the transmission of vibrations to the basic structure, to improve environmental working conditions by reducing the impact of harmful vibrations and vibrations on the human body. The ability to absorb the energy of mechanical vibrations of these alloys is due to high internal friction.

The well-known classical damping alloys based on Mg, Cu-Mn are not widely used in industry, and are not used as structural alloys, since in most cases they either have low mechanical or technological properties, or the elements included in their composition are scarce or expensive . The inventive alloys are superior in strength to the classic damping alloys by 2.5-5 times: the tensile strength of magnesium alloys is σ _B = 100-160 MPa, the alloys of the Mn-Cu system are 400-500 MPa, the inventive alloys of the Fe-Mn system are ≥ 950 MPa.

Analogs and prototypes of damping alloys were selected according to the same criteria as antifriction ones: strength level, manganese content and ε-martensite phase.

To achieve high damping ability of the claimed alloys, the necessary and sufficient conditions are: the presence of manganese as the main alloying element and the presence of έ-martensite with an hcp lattice in the phase structure. The damping ability of ferromanganese alloys is directly dependent on the amount of phase ε-martensite (Fig. No. 4). An increase in the content of phases of α-martensite and / or γ-austenite leads to a decrease in dissipative properties. The negative effect of α-martensite with a bcc lattice affects a decrease in the ability to form packaging defects and their mobility, a sharp decrease in damping ability, and an increase in the temperature of the cold brittleness threshold.

Known steel for sound absorption and vibration [4], having a structure with an average grain size of ferritic grain, containing, wt.%:

manganese 0.1-1.5 silicon 0.4-4.0 iron rest

Based on the chemical composition, it can be assumed that this steel has the following mechanical properties: σ _B = 600-650 MPa; δ = 2-5%; T ₅₀ = + 250 ° C.

Having a ferrite structure (body-centered crystal lattice), this steel does not undergo martensitic transformations and does not have easily moving two-dimensional defects such as dislocations or stacking faults in its structure. Therefore, its damping ability at a relative deformation of ~ 10 ^-3 is equal to Q ^-1 = (20-45) × 10 ^-4 . Silicon in the range of 0.4-4.0 wt.% Increases the hardness and strength of the α-solid solution and sharply reduces hot ductility during rolling. In addition, when the silicon content is more than 2 wt.%, The relative elongation and toughness decrease, the brittleness of steel in the cold state increases.

The chemical and phase composition of the claimed damping alloys and prototype alloy [3] are shown in table No. 1, dissipative and mechanical properties in table No. 3.

Shape memory alloys.

For alloys with a shape memory effect, systems with thermoelastic martensitic transformation are used, which, along with the effect of memory and superelasticity, provide high damping properties. A relatively limited number of alloys has “shape memory” - these are alloys of alloying systems Ni-Ti, Cu-Zn-Al, C-Al-Ni and some alloys based on iron. This effect is most pronounced in the NiTi intermetallic compound. The Fe-Mn system is interesting in that, as a result of heat treatment (quenching), several elastically coupled martensite modifications with different alternations of densely packed layers can occur simultaneously in the alloys of this system.

Based on the chemical composition, it can be assumed that the prototype alloy [3] has the following level of indicators of the shape memory effect:

the degree of recovery of the form of SVF,% ≤2 temperature of the onset of martensitic transformation M _N , ° С 20-50 hysteresis of the martensitic transformation (M _H –A _H ), ° C 120-250

The prototype alloy has high values of M _N (above normal temperature). The increase in the parameters of the shape recovery of alloys of the Fe-Mn system is achieved through the introduction of silicon and nitrogen.

Known classic alloy with a reversible shape memory effect [5] - nitinol containing, wt.%:

nickel 48-54 titanium 52-46

to increase thermocyclic strength, the alloy may contain, wt.%:

carbon 0.06-0.12 boron 0.001-0.5

This alloy has the following mechanical and special properties:

yield strength, σ _0.2 , MPa 180-250 the degree of recovery of the form of SVF,% 6-8 martensitic onset temperature conversions M _N , ° C (-100) - (+ 120) hysteresis of the martensitic transformation (M _H –A _H ), ° C thirty, damping ability at small amplitudes,% 5-10 at large amplitudes 20-30

With high damping and shape memory effect, a significant drawback of nitinol is its low structural strength (σ _0.2 ) and low technological properties, low hysteresis of the martensitic transformation (M _H –A _H ), a strong dependence of M _N on the composition, and high cost. As alloys with a bcc lattice, nitinols have low antifriction properties.

The chemical and phase composition of the inventive alloys and alloys with the shape memory effect and prototype alloy [3] are shown in table No. 1, the characteristics of the shape memory effect and mechanical properties are shown in table No. 4.

The prototype alloy [3] is the closest to the claimed composition and structure, which has anti-friction, wear-resistant, damping properties and shape memory effect. In the prototype alloy [3] data on the damping properties and the shape memory effect, on the morphology and kinetics of the formation of nanostructured compositions on friction surfaces, on the twinning effect, providing an increase in the complex of unique properties (tribological, dissipative, shape memory effect) of the claimed alloys and products made from these alloys, no.

The technical effect of the invention is:

1. In the creation of a fundamentally new class of multifunctional antifriction nanostructured wear-resistant damping with a memory effect of the form of high-strength metastable alloys based on iron and the Fe-Mn system with the structure of hexagonal ε-martensite having a twinning effect, and products made from the inventive alloy entirely and / or containing a working surface and inheriting the properties of the alloy, with self-organizing nanostructured compositions on friction surfaces, providing a unique set of exploitation tation properties: self-hardening, self-lubrication, self-extinguishing of vibrations and noise, for operation at normal and negative temperatures, with universal use in the construction of general and special engineering;

2. In a unique opportunity to combine in one composition of the inventive alloy different classes of materials:

- the best anti-friction bronze (figure 3, 4):

coefficient of friction K _{tr. without lubricant} ≤0.15-0.30, K _{tr with lubricant} ≤0.010-0.020;

- the best high-strength anti-friction cast irons (figure 3):

σ _in = 600-800 MPa, (σ _in ≥950 MPa of the claimed alloys);

- highly damping alloys (figure 4):

damping ability:

Q ^-1 = (240-270) × 10 ^-4 at τ = 50 MPa (amplitude-dependent internal friction),

Q ^-1 = (10-15) × 10 ^-4 at f = (8-12) kHz (amplitude-independent internal friction);

- materials with a low cold brittleness threshold (Fig.7):

T ₅₀ = (- 120) ÷ (-160) ° С;

- materials with shape memory effect,

the degree of recovery of the form of SVF,

lowering the temperature of the beginning of the martensitic transformation M _N , ° C to (-20) ÷ (+20)

hysteresis of the martensitic transformation (M _H -A _H ), ° C 160-200

3. In using the additional advantages of the claimed alloys:

- high ductility (δ = 40%, ψ = 7-5%);

- superplasticity at the γ → ε transition:

- high impact strength KCV ⁺²⁰ = 1.1-1.7 MJ / m ² and a low cold brittleness threshold T ₅₀ = (- 120) ÷ (-160) ° C (Fig.7), provide the possibility of using products from the inventive alloy in the region of negative temperatures while maintaining a low coefficient of friction: K _TP with decreasing temperature to (-160) ° C increases to 0.3 against 0.2 at normal temperature;

- non-magnetic: magnetic susceptibility ǽ = 9.9 × 10 ^-6 ;

- Invar effect: reduction of the coefficient of thermal expansion to α = (12-15) × 10 ^-6 deg ^-1 ;

- high processability during smelting (can be obtained by methods of both traditional and powder metallurgy), with deformation-thermal redistribution; simplicity of heat treatment, good weldability by all types of welding;

- high profitability.

4. For the first time, it became possible to create controlled nanostructured self-organizing compositions on friction surfaces (Figs. 5, 6), which provide the effect of self-hardening and self-lubrication, the effect of self-quenching of vibrations and noise and reducing their harmful effects on mechanisms and the human body. The technical effect of the use of products made from a new class of the claimed antifriction nanostructured wear-resistant damping materials with memory effect in intensive friction units instead of the standard bronzes will provide:

- increase the strength of the material by 2-5 times;

- increase in durability and reliability of machine parts and assemblies by 2-2.5 times;

- prevention of emergency types of wear (setting, seizing, seizure);

- high efficiency of the claimed materials and products made from them, when replacing:

- classic antifriction bronzes, non-ferrous metal savings are in kg / t: Cu 800-900, Sn 50-100, Pb 30-50, Ni 30-50, Al 60-110;

- classic damping alloys of the 30Сu - 70Мn type save in kg / t: Cu 300-400, Mn 600-700;

- of classical alloys with a shape memory effect of the type (48-54) Ni - (46-52) Ti, the savings are in kg / t: Ni ~ 510, Ti ~ 490.

- reduction of costs for materials products by 10 times.

The most effective application of the inventive metastable alloys with an hcp lattice in highly loaded friction units, where the antifriction and dissipative characteristics of the crystal are realized, is closely related to the anisotropy of its properties, the deformability and hardenability of the metastable austenitic matrix in a thin surface layer: sliding bearings and their bearings, bushings , rolling bearing cages, etc., as well as structural parts operating under conditions of dry friction and lubrication, at high sliding speeds and high their specific loads of mechanisms and machines in all sectors of general and special engineering.

In the inventive alloy, the formation on the friction surface of a thin hardened nanostructured layer with a depth of 10-20 μm with a hardness of ≥5000 MPa (while maintaining the hardness of the base metal at the level of HB240) (Fig. 5), with a dispersion of deformation structures from less than 0.1 μm to (0.2-0.5) microns (Fig.5, 6) provides the claimed alloys with high tribological properties: high wear resistance and low friction coefficient (K _{tr with lubricant} 0,010-0,020, K _{tr without lubricant} ≤0,15- 0.30) (figure 4), increases the service life of the claimed products. In the separation layer, consisting of finely divided wear products, where the deformation has limiting values, hardening is achieved due to deformation α-martensite formed from the metastable phases of γ-austenite and / or ε-martensite according to the reactions γ → α, ε → α or γ → ε → α (Figs. 5, 6). An important feature of the claimed alloys is the possibility of their use for the manufacture of not only self-strengthening, but also self-lubricating sliding bearings (which is especially important in conditions of imperfect lubrication or friction without lubrication), for the manufacture of which alloys based on molybdenum and tungsten are currently used.

5. The technical effect of the invention is to increase the strength properties of the inventive alloys by Δσ _B = (50-100) MPa due to an increase in the amount of ε-martensite phase (5-95%) (alloying with cobalt and silicon), hardening of the solid solution (alloying with nitrogen and the formation of carbides and carbonitrides (one or more elements from the group: titanium, vanadium, niobium); in a decrease in the coefficient of friction (from K _{tr without lubricant} ≤0.20-0.35 to K _{tr without lubricant} ≤0.15-0 , 30); in increasing the wear resistance by 1.7-2.5 times due to twinning and tripp effects, spontaneous formation of nan Structured compositions and the separation layer under the influence of the deformation by friction, self-lubricating effect of providing products and in improving damping properties in both amplitude-dependent [Q ^-l × April ¹⁰ = (240 ÷ 270) × (10 ^-3 ÷ 10 ^-4) at the amplitude of the applied stresses τ = 50 MPa], and in the amplitude-independent region [Q ^-1 × 10 ⁴ = (10 ÷ 15) × 10 ^-4 at a frequency f = (8 ÷ 12) kHz], providing products with unique ability in friction units - the effect of self-extinguishing and reducing the level of vibration and noise by 1.7-2.5 times; in increasing the degree of shape recovery.

To achieve the technical effect of the invention to create a fundamentally new class of antifriction nanostructured alloys with a high level of antifriction and damping properties, the shape memory effect of the proposed alloy contains manganese, carbon and nitrogen, the rest is iron, in the following ratio, wt.%:

manganese 5.0-44.0 carbon 0.001-0.3 nitrogen 0.03-0.12 iron rest,

which provide in the structure of 5-95% of the phase ε-martensite, the rest are metastable phases γ-austenite and / or α-martensite.

To increase strength, while maintaining high antifriction and damping properties, the shape memory effect alloys may contain, wt.%:

silicon and / or cobalt 0.5-8.0 one or more elements from the group containing titanium 0.06-1.0 vanadium 0.06-0.20 niobium 0.05-0.20

The chemical composition of the claimed alloys with the phase structure ε-martensite (5-95%) and prototype [3] are presented in table No. 1; mechanical and antifriction properties - in table No. 2; mechanical and damping properties - in table No. 3; mechanical properties and the degree of shape recovery of alloys with the shape memory effect - in table No. 4.

The inventive alloy containing manganese from 5.0 to 44%, differs in that it contains nitrogen and its basis is the metastable phase έ-martensite (5-95)% (table No. 1). When the manganese content is less than 5.0% as a result of the martensitic γ → α transformation, up to 100% α-martensite is formed, which leads to a sharp increase in the friction coefficient (positions, 18, 19, table No. 2) and a decrease in damping ability (positions 18, 19 , table No. 3), the degree of restoration of the form of the SVF → 0 (positions 11, 12, table No. 4). When the manganese content exceeds 44.0%, the alloys consist 100% of the γ phase, which in terms of friction coefficient (positions 20, 21, table No. 2), damping ability (positions 20, 21, table No. 3), shape memory effect (table No. 4, positions 13, 14) are approaching α-alloys (positions 18, 19, tables 2, 3).

In the inventive alloy, the carbon content in an amount of 0.001-0.3 is necessary for guaranteed obtaining in the structure (5-95)% of the ε-martensite phase at (5.0-44.0)% manganese. An increase in carbon content in excess of 0.30% as an austenite-forming element is accompanied by a decrease in the amount of ε-martensite, which leads to an increase in the friction coefficient (positions 20, 21, table No. 2), and a decrease in damping ability (positions 20, 21, table No. 3) , negatively affects the degree of restoration of the form (positions 12, 14, table No. 4). The higher the purity by impurities, the higher the content of the ε-martensite phase [monograph “High-manganese steels and alloys”, T.F. Volynova, Metallurgy, 1988. 343 pp.]. In the inventive alloys, the range for the carbon content of 0.001-0.3 versus 0.002-0.2 wt.% In the prototype alloy is extended.

The purpose of additional doping with cobalt and / or silicon in an amount of 0.5-8.0 wt.% Is to guarantee an increase in the ε-martensite phase amount in the structure (5-95%) and increase the tensile strength (items 5, 10, 15, table No. 2, 3; items 4–7, table No. 4) compared with alloys containing carbon and manganese in the same quantities [monograph “High manganese steels and alloys”, T.F. Volynova, Metallurgy, 1988, 343 pp. ] while maintaining the coefficient of friction without lubrication level (0.15-0.30) (table №2), damping capacity at Q ^-1 = (240-270) × 10 ^-4 at τ = 50 MP (Table №3), shape memory effect of not less than 2% (Table №4). A decrease in the content of silicon and cobalt below 0.5% is impractical, since it leads to a decrease in the amount of ε-martensite, to an increase in the coefficient of friction, to a decrease in the increase in strength less than 50 MPa (Δσ _B → 0) (position 18-21, tables No. 2, No. 3; items 11-14, table No. 4). An increase in the content of silicon and cobalt over 4 wt.% Leads to stabilization of austenite with respect to γ → α and γ → ε transformations, a decrease in the amount of ε-martensite (% ε → 0), and, as a consequence, an increase in the friction coefficient (positions 20, 21, table No. 2), a decrease in the damping ability, (positions 20, 21, table No. 3), a negative effect on the SVF (positions 11-14, table No. 4), to a sharp decrease in technological properties. Silicon and cobalt shift the boundaries of the region of existence of ε-martensite towards a higher manganese content and thereby expand the concentration range for the use of real compounds.

The purpose of additional alloying of alloys of the Fe-Mn and Fe-Mn-C systems with nitrogen is to strengthen the solid solution, which is most effective when simultaneously doping with one or more elements from the group: titanium, vanadium, niobium, with the ratio (Nb + V) / (N + C) <1.2 and N / C <2. Strength increase (Δσ _B = 50-100 MPa) to values of σ _B ≥950 MPa is achieved through grain refinement during quenching due to the formation of sparingly soluble NbN nitrides (item 6, table No. 4), and when doped with vanadium and nitrogen (items 8.10, table No. 4), there is the possibility of additional hardening due to dispersion hardening during the formation of nitrides of the type VN, (Nb, V) N and carbonitrides of the type (Nb, V) CN with the ratio N / C <2. The weakening of the intergrain bond due to the allocation of excess phases along the grain boundaries has a stronger effect on the level of mechanical and special properties than the grain size. The reduction in wt.%: Carbon less than 0.001, nitrogen less than 0.03, titanium and / or vanadium less than 0.06, and / or niobium less than 0.05 does not cause a significant decrease in antifriction and damping properties and due to the small volume fraction formed nitrides and carbonitrides. An increase in the content of vanadium over 0.20, niobium over 0.20, nitrogen over 0.12 and / or carbon over 0.30 wt.% (Positions 12, 14, table No. 4) leads to a sharp increase in the proportion of nitrides and carbonitrides and the proportion of these elements in a solid solution, which leads to a decrease in damping properties (positions 20, 21, table No. 3) and the shape memory effect (positions 12, 14, table No. 4). The titanium content in the amount of 0.06-1.0% provides an increase in mechanical and damping properties, prevents the formation of cementite type carbides and inhibits the tendency to delayed destruction (items 6, 8, table No. 4). Grinding grain leads to an additional increase in strength. Due to the optimal amount of titanium and / or niobium and / or vanadium remaining after the formation of nitrides and carbonitrides in the solid solution, the shape memory effect is increased (positions 4-10, table No. 4).

The proposed product is made of antifriction nanostructured wear-resistant damping with a memory effect of the form of a high-strength metastable alloy based on iron, characterized in that it is made entirely and / or containing a working surface of the inventive alloy containing, wt.%: Manganese 5.0-44, 0, carbon 0.001-0.3, nitrogen 0.03-0.12, the rest is iron and having a structure containing 5-95% ε-martensite phase, the rest is metastable γ- and / or α-phase. The alloy may contain, wt.%: 0.5-8.0 silicon and / or cobalt, as well as one or more elements from the group comprising titanium 0.06-1.0, vanadium 0.06-0.2, niobium 0.05-0.20 (FIGS. 8-13), with the structure of hexagonal έ-martensite (5-95%), which provides the claimed products with a twmnning effect, the self-organization effect of nanostructured compositions, the effect of self-hardening and self-lubrication of friction surfaces, the effect of vibration damping and noise, characterized by universality of application - in the friction units of mechanisms and machines of general and special engineering.

A patent search showed that parts made of ferromanganese alloys having a unique set of properties (high strength and wear resistance, low friction coefficient + high dissipative properties + shape memory effect) were not previously used. Therefore, as a prototype, similar in technical essence, were selected sliding parts made of a material based on iron - high carbon steel [6], containing wt.%:

carbon 0.6-1.2 silicon <3 manganese <3 chromium 6.0-10.0 molybdenum 0.1-1.5 vanadium 0.01-1.0 iron rest

Based on the chemical composition, the parts made from this material have low strength and a high coefficient of friction (K _TP = 0.6-0.8), low run-in, low dissipative properties (structural heterogeneity is not realized). Highly antifriction products are offered, made entirely or containing the working surface of the inventive alloy (Figs. 8-13), operating at high sliding speeds (~ 5 m / s) and high contact loads: bushings, bushings, bearings and bearing bearings, cages; structural parts of engines, chassis, hydraulic drive, pumps; drill tool crowns. The chemical and phase composition and properties of the prototype alloy and products are presented in table 1.

Despite the high carbon content (0.6-1.2 wt.%) In the steel for the prototype part, the wear resistance of the friction surfaces in the inventive products is much higher, although the carbon and nitrogen content in the inventive alloy is in wt.%: C = 0.001- 0.30, N = 0.03-0.12. The twinning effect and the formation under the influence of deformation of nanostructured compositions (Fig. 5) and a solid separation film of secondary structures of wear products (Figs. 5, 6) provide the inventive products with a self-lubrication effect and eliminate the possibility of catastrophic wear such as setting or seizing, eliminates the need introducing lubricant into the friction units when the lubrication process is difficult or impossible to carry out by conventional methods.

In contrast to the adopted prototype [3, 6], the claimed alloy and products from it have a different quantitative composition: the intervals for the manganese content in wt.% Are expanded: 5-44 instead of 10-33, carbon in wt.%; 0.001-0.03 instead of 0.002-0.02. The inventive alloy is additionally doped with nitrogen, titanium, vanadium, niobium, has a twinning effect, has a fundamentally different structure - nanostructured compositions in the deformation zone, which meets the criterion of "novelty." The amount of ε-martensite in the structure of ferromanganese alloys is a decisive factor, providing high damping and antifriction properties, the effect of shape memory, high strength.

When analyzing the patent literature, no complex technical solutions with the signs of a proposal were found, alloys having a complex of unique properties were not found, which allows us to conclude that the criterion of "significant differences" is met.

The strength and durability of bearings and motor bushings (Fig. 8, 13) and the hydraulic drive system (Fig. 9, 10) made of the inventive alloys increases by more than 2 times. High dissipative properties of the claimed material, used as structural and antifriction, allowed to reduce the level of vibration and engine noise by 1.7-2.5 times (Fig, 13).

Bushings with an outer diameter of up to 20 mm (Figs. 9, 10) are used in instrumentation, where, in addition to antifriction and dissipative properties, non-magnetic and cryogenic properties are required. The low cold brittleness threshold of the claimed alloys [T ₅₀ = (- 120) - (- 160) ° C] ensures the operation of products at low temperatures.

The gear shafts of the oil pumps of tracked vehicles with a tooth module 2.5-3.5 (Fig. 11) are distinguished by the fact that they can be made of cast or powder alloys. The requirements for the dynamic and static strength of the tooth are ensured by the high structural strength of the claimed material (σ _in ≥950 MPa), durability and reliability - by high dissipative properties. Possible operation at temperatures below - 100 ° C.

The running gear guide bush (Fig. 12) is made of a powder alloy, which increases the service life by 1.7 times compared to the standard steel used. The inventive material is highly run-in, does not require complex heat treatment. The hardness of the surface layer hardened by slip deformation extends to a depth of 10-20 μm and is 5000 MPa (Fig.6). This eliminates the need for complex heat treatment, carried out earlier to harden the surface of the product using expensive methods of chemothermal treatment, HDTV or the application of wear-resistant coatings.

On Fig presents the claimed engine parts (flanges, hubs, separators, bushings, glasses, holders, nipples, etc.) made of the inventive alloys instead of steels [6] and non-ferrous metals (figure 3) (type bronze AZhMts 10- 3-1.5, LS brass 59), from which, under the working conditions, a set of properties is required: high structural (strength, ductility, viscosity), tribological and dissipative properties. Replacement with the inventive alloy will reduce the level of vibration and noise by 1.7-2.5 times, increase the wear resistance and durability of friction units by 2 times.

The manufacture of separators (Fig.13) from the claimed materials instead of the standardly used antifriction bronzes (type АЖМц 10-3-1.5, etc.) and brass (type ЛС 59-1, Л 63, etc.) will increase the wear resistance and durability of the separators 2 times by increasing strength (figure 3)

[brass LS 59-1 (t) σ _B = 620 MPa; bronze АЖМц 10-3-1.5 (t) - σ _B = 600 MPa; Fe-Mn σ _B ≥950 MPa] and hardness of the base metal [brass LS 59-1 (t) - HB 150; bronze АЖМц 10-3-1.5 (t) - HB 170; Fe-Mn - HB 240], the twinning effect provides an increase in the hardness of the strain hardened surface nanostructured layer to 5000 MPa (Fig.6). The inventive separators can operate at higher speeds and specific loads compared to non-ferrous alloys.

The inventive parts can be obtained by traditional and powder metallurgy. Products made by powder metallurgy methods have higher antifriction and dissipative properties in comparison with casts of the same composition. In powder alloys, there is an additional possibility of influencing tribological and dissipative properties, the shape memory effect through regulated fractional composition: a decrease in the initial particle size distribution of the powders is accompanied by an increase in strength, a decrease in the friction coefficient while maintaining high dissipative properties, an increase in the shape memory effect, which is explained by the phenomena of superplasticity in the boundary layer and different from cast phase composition under the influence of deformation. When using powder alloys in products, additional advantages are realized compared to cast ones, such as the possibility of using bearings in the pendulum motion and low sliding speeds, where the cast bearings do not have a continuous oil film, and also the ability to install them in angularly and vertically arranged bearings (in such grease is leaking from plain bearings made of cast alloys).

The name of the application does not indicate a method for producing a metallurgical billet and product. The text of the application states that the inventions relate to traditional and powder metallurgy, which makes it possible to use any methods for producing a compact billet using both traditional and powder metallurgy methods, including composite material and products for the option: “containing a working surface”. The applicant has an example of a patent that can be used when choosing a method for obtaining material and products - Patent No. 2008371 dated 01/30/1994, “Multilayer composite material, the method of its manufacture and the product obtained from this material” [7].

Literature

1. USSR copyright certificate, No. SU - 1397534 A1, cl. C22C 38/16, 33/02, 1985.

2. Copyright certificate of the USSR, No. SU - 1366549 A1, cl. C22C 37/10, 1982.

3. RF patent, No. RU - 2023737 C1, cl. C22C 33/02, 38/04, 38/10, F16C 33/12, 1994.

4. Japan patent No. 52 - 34341, cl. C22C 38/04, 1977.

5. Copyright certificate No. 1036064, cl. C22C 14/00, C22C 19/03, 1981.

6. Japan Patent No. 62-14624, cl. C22C 38/24, 38/00, 38/60, B21D 39/20.

7. RF patent, No.RU - 2006371 C1, B32B 13/18, B22 10/02, C22C 38/02, C22C 38/56, 1994.

Claims (9)

1. Antifriction nanostructured wear-resistant damping with a shape memory effect, high-strength metastable iron-based alloy with the structure of hexagonal ε-martensite containing manganese and carbon, characterized in that it additionally contains nitrogen in the following ratio, wt.%:
Manganese 5.0-44.0 Carbon 0.001-0.300 Nitrogen 0.03-0.12 Iron Rest,
moreover, the structure contains 5-95% of the ε-martensite phase, the rest is γ-austenite and / or α-martensite. 2. The alloy according to claim 1, characterized in that it further comprises silicon and / or cobalt in the following ratio of components, wt.%:
Manganese 5.0-44.0 Carbon 0.001-0.300 Nitrogen 0.03-0.12 Silicon and / or cobalt 0.5-8.0 Iron Rest 3. The alloy according to claim 1, characterized in that it further comprises one or more elements from the group: titanium, vanadium and niobium in the following ratio, wt.%:
Manganese 5.0-44.0 Carbon 0.001-0.300 Nitrogen 0.03-0.12 Titanium 0.06-1.0 Vanadium 0.06-0.20 Niobium 0.05-0.20 Iron Rest 4. The alloy according to claim 2, characterized in that it additionally contains one or more elements from the group: titanium, vanadium and niobium in the following ratio, wt.%:
Manganese 5.0-44.0 Carbon 0.001-0.300 Nitrogen 0.03-0.12 Silicon and / or cobalt 0.5-8.0 Titanium 0.06-1.0 Vanadium 0.06-0.20 Niobium 0.05-0.20 Iron Rest 5. The alloy according to any one of claims 1 to 4, characterized in that it additionally has a twinning effect. 6. The product is made using antifriction nanostructured wear-resistant damping with a memory effect of the shape of a high-strength metastable alloy based on iron with the structure of hexagonal ε-martensite according to claim 1. 7. An article made using an antifriction nanostructured wear-resistant damping with a memory effect of the shape of a high-strength metastable iron-based alloy with a hexagonal ε-martensite structure according to claim 2. 8. A product made using an antifriction nanostructured wear-resistant damping with a memory effect of the shape of a high-strength metastable iron-based alloy with the structure of hexagonal ε-martensite according to claim 3. 9. An article made using an antifriction nanostructured wear-resistant damping with a memory effect of the shape of a high-strength metastable alloy based on iron with a hexagonal ε-martensite structure according to claim 4.

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