Wear-resistant complex brass material and preparation method and application thereof

Abstract

The invention discloses a wear-resistant complex brass material as well as a preparation method and application thereof. The wear-resistant complex brass material comprises the following components in percentage by mass: 54-60% of Cu, 0.3-1.5% of Pb, 1.5-3% of Mn, 0.1-0.5% of Fe, 1.5-3% of Ni, 0.5-1.2% of Si and the balance of Zn and inevitable impurities. The structure of the wear-resistant complex brass material comprises a beta phase and a (Ni, Mn) xSi gamma phase, the area ratio of the beta phase is 75-85%, the area ratio of the (Ni, Mn) xSi gamma phase is 15-25%, x / y is equal to 1-3, and the size of the (Ni, Mn) xSi gamma phase is 2-10 microns. The wear-resistant complex brass material has excellent tensile strength, extensibility, heat conductivity, fatigue resistance and corrosion resistance, and can meet the long-time working requirement of a high-pressure hydraulic pump.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of brass and particularly relates to a wear-resistant complex brass material and a preparation method and application thereof. BACKGROUND

[0002] The hydraulic pump is the "heart" of the hydraulic system, and its core function is to convert mechanical energy into hydraulic energy to provide a continuous controllable power source for the entire system. The working pressure of the hydraulic pump for engineering machinery is 21-45 MPa, and the realization of high-pressure working capacity mainly depends on the sliding shoe static pressure balance technology, so that the oil film stiffness is >1*109N / m, the oil distribution plate is wear-resistant and the structure is designed, and the main material is manganese brass.

[0003] The sliding shoe, the oil distribution plate and the ball hinge constitute the "dynamic sealing-precise flow distribution-force transmission" golden triangle, and the failure of any one will lead to system collapse. The main function of the sliding shoe is that high-pressure oil enters the oil chamber at the bottom of the sliding shoe, and the pressure is generally 90% of the pump outlet pressure, forming an oil film of 5-20 un. The shear heat of the oil film is dissipated through the back of the sliding shoe, and the heat flux is >3W / mm 2 . The rupture of the oil film causes metal contact, and the instantaneous temperature rise is >300℃, resulting in failure of the copper material.

[0004] The sealing band design of the oil distribution plate includes high-pressure side and low-pressure side. The high-pressure side resists material deformation, and the low-pressure side reduces lubricating oil leakage. The damping groove is designed to reduce pressure impact. When the flatness error is >1.2um / 50mm, the leakage amount ↑200%, and the scratch depth is >5um, the lubricating oil will leak, resulting in power drop.

[0005] The ball hinge will fail due to fretting wear, fatigue spalling and seizure failure. In severe working conditions, it is subjected to a large pressure impact, and the peak pressure of 35MPa exceeds the material fatigue limit by 2.5 times. The boundary lubrication is poor, and the actual contact pressure is >1.2GPa when the oil film thickness is <1um. The service life of the conventional sliding shoe is 380h, and the main failure mode is that the copper layer is worn out, and the thinnest part is only 0.1mm. The service life of the ball hinge is generally 650h, and the failure characteristics are cracking and crack depth >1.2mm. The service life of the oil distribution plate is generally 420h, and the failure characteristics are oil leakage up to 200% of the rated value. Finally, the service life of the hydraulic pump is short.

[0006] The patent application with the publication number CN118222878A discloses a brass rod, the mass percentage of each component of the brass rod is: Cu: 57-59%, Al: 1.3-2.3%, Mn: 1.5-3.0%, Si: 0.3-1.3%, Pb: 0.2-0.8%, Sn <0.4%, Fe <1.0%, Ni <1.0%, and the balance is Zn and inevitable impurity elements. The structure of the brass rod is alpha phase, beta phase, Mn5Si3 phase and Pb phase, the beta phase is the matrix phase, the alpha phase is distributed at the beta phase interface, and the area percentage of the alpha phase is 3%-15%. The residual stress inside the brass rod is relatively low, so that the size change of the brass rod is small during standing and service. However, the wear resistance and corrosion resistance of the brass disclosed by the patent application still cannot meet the requirements of the shoe, oil distribution disc and ball hinge.

[0007] The patent application with the publication number CN112695216A discloses a preparation method of a manganese brass alloy with three kinds of strengthening phases. The composition comprises Cu, Zn, Co, Mn, Si, Ni, Fe, Al, Pb and Ce. The alloy is first mixed and smelted according to the proportion, then the melt is treated by molten salt electrolysis, then it is cast into a ingot with good uniformity and small grain size, and finally it is treated by water sealing extrusion, quenching, stretching, skinning, annealing and straightening. The alloy has high hardness, high tensile strength and yield strength, high elongation, good wear resistance and good thermal stability, which meets the needs of the present age. However, the thermal conductivity, wear resistance and fatigue resistance of the brass alloy disclosed by the patent application are low, which cannot meet the use requirements of the shoes, oil distribution discs and ball hinges of the hydraulic pump.

[0008] Therefore, in view of the shortcomings of the above-mentioned traditional manganese brass materials, it is of great significance to seek a material with higher strength and better wear resistance. SUMMARY

[0009] The present application provides a wear-resistant complex brass material, which has excellent tensile, elongation, thermal conductivity, fatigue resistance and corrosion resistance, and can meet the needs of long-term work of high-pressure hydraulic pumps.

[0010] The present application provides a wear-resistant complex brass material, which comprises the following components in mass percentage: Cu: 54-60%, Pb: 0.3-1.5%, Mn: 1.5-3%, Fe: 0.1-0.5%, Ni: 1.5-3%, Si: 0.5-1.2%, and the balance is Zn and inevitable impurities. The structure of the wear-resistant complex brass material comprises beta phase and (Ni, Mn) x Siᵧ phase, wherein the area percentage of the beta phase is 75-85%, the area percentage of the (Ni, Mn) xSiᵧ phase area ratio 15-25%, wherein x / γ=1-3, the (Ni, Mn) x Siᵧ phase size is between 2-10um.

[0011] The present application provides a suitable amount and size of (Ni, Mn) x Siᵧ phase can improve the wear resistance of the material, the hardness reaches HV 280-320 (much higher than the HV 130-170 of the matrix), directly withstands friction load, reduces matrix wear, in hydraulic pump shoes, oil distribution plates and other parts, nickel manganese silicon phase effectively resists hard contaminants embedded, less wear rate, cooperates with lead (Pb) to provide self-lubrication, reduces the boundary friction coefficient. It can also inhibit high temperature softening: the nickel manganese silicon phase remains stable at 200-300℃, delays the recrystallization of the matrix, and the high temperature strength retention rate of the alloy is >70%. Thermal conductivity optimization: although the thermal conductivity of the nickel manganese silicon phase is lower than that of the copper matrix (about 132 W / (m•K)), its dispersion distribution still guarantees the overall thermal conductivity and avoids local overheating; it can also promote the generation of dense oxide film (ZnO•MnO2), and the corrosion rate in hydraulic oil containing Cl - is <0.08 mm / y (ordinary brass is 0.25 mm / y). It can also fine-grain strengthen: the manganese silicon phase pins the grain boundary, refines the grain size, and the yield strength is increased to >280 MPa. Load transfer effect: the hard phase bears most of the stress, so that the tensile strength of the alloy reaches ≥540 MPa, and the elongation after fracture remains ≥15%.

[0012] The Pb provided by the present application is mainly distributed in the form of free in the grain boundary position of the material, becomes a chip breaking point during cutting, can improve the cutting performance of the material, and secondly, lead itself has a lubricating effect, can improve the wear resistance of the material. When the content of Pb is low, the surface roughness of the material is too large during machining, which increases wear, and when the content of Pb is high, the plasticity of the material at high temperature is reduced, and the material is prone to cracking when red punching process is used to produce related parts.

[0013] Preferably, the microstructure of the wear-resistant complex brass material further comprises α phase, Pb phase and Fe-rich phase, wherein the area ratio of the α phase is ≤1%, and the area ratio of the Fe-rich phase is ≤2%.

[0014] The present application controls the content of Fe to refine the grain structure of the material, reduce the thermal expansion coefficient of the material, and reduce the deformation of the material, and by controlling the content of Fe, a suitable amount of Fe-rich phase (Fe3Zn 10 ) network is formed to hinder the welding of the soft matrix and the steel inclined disc, improve the wear resistance of the material, pin dislocations, improve the strength of the material, and reduce the plasticity of the material. At the same time, the high content of Fe-rich phase increases the brittleness of the material and increases the failure risk of the material.

[0015] Further preferably, the number of Pb particles in the microstructure of the wear-resistant complex brass material is 5000-15000 per mm 2 .

[0016] Preferably, the grain size of the wear-resistant complex brass material is 0.005-0.05 mm.

[0017] Preferably, the mass percentage of the impurities is ≤0.3%.

[0018] Preferably, the mass ratio of Mn, Si and Ni is: Mn:Si=2.5-4, Ni:Mn=0.5-1.5, Ni:Si=2-3. The present application can form more amounts of the second hard phase by further limiting Mn, Si and Ni.

[0019] In another aspect, the present application also provides a preparation method of the wear-resistant complex brass material, and the process flow of the preparation method comprises: smelting → horizontal continuous casting → water-sealed extrusion → first stretching → quenching → second stretching → annealing. According to the mass percentage of each component of the wear-resistant complex brass material, ingredients are prepared and smelting is performed. The temperature of the quenching is 650-750℃, and the time is 20-80 min.

[0020] The present application controls the temperature and time of quenching, so that the solid-solved manganese element replaces part of the nickel element in nickel silicon to form an appropriate amount of (Ni, Mn) x Siᵧ phase.

[0021] Preferably, the temperature of the water-sealed extrusion is 550-800℃. The present application controls the temperature of the water-sealed extrusion, so that the matrix phase is less, and the appropriate amounts of Mn, Si and Ni are combined, and each element is uniformly dispersed, to create conditions for the subsequent formation of uniformly dispersed (Ni, Mn) x Siᵧ phase, and avoid nickel-manganese-silicon phase segregation and size growth.

[0022] Further preferably, the water-sealed extrusion ratio of the water-sealed extrusion is 7-322. The present application provides a suitable water-sealed extrusion ratio to break the grains, and combines a suitable water-sealed extrusion temperature to avoid grain growth, so as to obtain a suitable grain size.

[0023] Further preferably, the water-sealed extrusion speed is 3-14 mm / s. The present application controls the water-sealed extrusion speed, so that the surface quality of the blank is better.

[0024] Preferably, the processing rate of the first stretching is 0-60%. The present application controls the processing rate of the first stretching to provide more energy for phase change, which is more conducive to obtaining a suitable grain size.

[0025] Preferably, the processing rate of the second stretching is 0-40%. The application controls the processing rate of the second stretching to improve the mechanical properties of the material.

[0026] Preferably, the annealing temperature is 250-400℃, and the time is 2-5h.

[0027] Preferably, the process of the horizontal continuous casting is electromagnetic stirring, stop, and flame spraying. The casting temperature is 950-1100℃, the drawing speed is 3-15mm / s, the stop time is 0.1-1s, the flame spraying temperature is 1050-1080℃, the electromagnetic stirring frequency is 3-10HZ, the current is 40-150A, and the cooling intensity is 0.2-0.6MPa.

[0028] In another aspect, the application also provides an application of the wear-resistant complex brass material in a hydraulic pump.

[0029] Compared with the prior art, the application has the following beneficial effects: The application controls the adding amount and ratio of Si, Ni, and Mn, and the heat treatment process to obtain a suitable area ratio of (Ni, Mn) x Siᵧ, the (Ni, Mn) x The Siᵧ phase is distributed in the β phase (Cu-Zn solid solution) matrix in the form of fine and dispersed particles to form a strengthening framework of "soft matrix + hard phase", so that the synergistic effect of the two phases is better, the high-temperature wear resistance and corrosion resistance of the material are improved while the strength of the alloy is ensured, the stability of the material at high temperature is ensured, and the long-time working requirement of the high-pressure hydraulic pump is met. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 The metallographic phase diagram of the brass prepared for Example 1; Fig. 2 The metallographic phase diagram of the brass prepared for Example 2; Fig. 3 The metallographic phase diagram of the brass prepared for Example 3; Fig. 4 The metallographic phase diagram of the brass prepared for Comparative Example 1; Fig. 5 The metallographic phase diagram of the brass prepared for Comparative Example 2; Fig. 6 The metallographic phase diagram of the brass prepared for Comparative Example 3. DETAILED DESCRIPTION

[0031] The melting and horizontal continuous casting parameters of Examples 1-3 of the application are shown in Table 1, the component content, phase organization content, and performance data of Examples 1-3 and Comparative Example 1 of the application are shown in Tables 2, 3, and 4.

[0032] Example 1 Horizontal continuous casting smelting: cathode copper, lead ingot, Cu-Si intermediate alloy, electrolytic manganese, electrolytic nickel, zinc ingot, according to the mass percentage smelting, starting electromagnetic stirring, stop process, production Φ254mm ingot.

[0033] Water sealed extrusion: water sealed extrusion is carried out by using 3150t, water sealed extrusion specification Φ18mm, water sealed extrusion temperature 640℃, water sealed extrusion speed 6mm / s.

[0034] Pickling: the water sealed extrusion blank is put into the pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface oxide scale.

[0035] Stretching: the Φ18mm rod after pickling is stretched to Φ15mm in the straight drawing machine.

[0036] Quenching: the Φ15mm rod is quenched at 700℃ for 30min.

[0037] Pickling: the quenched blank is put into the pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface oxide scale.

[0038] Stretching: the Φ15mm rod after quenching is stretched to Φ14mm in the straight drawing machine.

[0039] Annealing: the Φ14mm is annealed at 300℃ for 3h.

[0040] Straightening: the product after annealing is straightened in the Schumag straightening machine.

[0041] Sizing: the product after straightening is sawn and flattened.

[0042] Chamfering: the product after sizing is chamfered.

[0043] Inspection / packaging: the product after chamfering is inspected and packaged.

[0044] Ten samples of finished products are taken for performance testing, and the average value is taken.

[0045] Example 2 Horizontal continuous casting smelting: cathode copper, lead ingot, Cu-Si intermediate alloy, electrolytic manganese, electrolytic nickel, zinc ingot, according to the mass percentage smelting, starting electromagnetic stirring, stop process, production Φ254mm ingot.

[0046] Water sealed extrusion: water sealed extrusion is carried out by using 3150t, water sealed extrusion specification Φ18mm, water sealed extrusion temperature 640℃, water sealed extrusion speed 6mm / s.

[0047] Pickling: the water sealed extrusion blank is put into the pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface oxide scale.

[0048] Stretching: Stretch the Φ18mm bar after pickling to Φ15mm in straight drawing machine.

[0049] Quenching: Quench the Φ15mm bar at 680℃ for 30min.

[0050] Pickling: Put the quenched billet into the pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface scale.

[0051] Stretching: Stretch the Φ15mm bar after quenching to Φ14mm in straight drawing machine.

[0052] Annealing: Anneal the Φ14mm at 300℃ for 3h.

[0053] Straightening: Straighten the annealed product in Schumag straightening machine.

[0054] Cutting: Cut the straightened product to flat head.

[0055] Chamfering: Chamfer the cut product.

[0056] Inspection / Packaging: Inspect and package the chamfered product.

[0057] Take 10 samples of finished product to test performance and take average value.

[0058] Example 3 Horizontal continuous casting smelting: Smelt the cathode copper, lead ingot, Cu-Si intermediate alloy, electrolytic manganese, electrolytic nickel and zinc ingot according to mass percentage, start electromagnetic stirring and stop drawing process to produce Φ254mm ingot.

[0059] Water sealed extrusion: Use 3150t to perform water sealed extrusion, water sealed extrusion specification Φ18mm, water sealed extrusion temperature 640℃, water sealed extrusion speed 6mm / s.

[0060] Pickling: Put the water sealed extruded billet into the pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface scale.

[0061] Stretching: Stretch the Φ18mm bar after pickling to Φ15mm in straight drawing machine.

[0062] Quenching: Quench the Φ15mm bar at 720℃ for 30min.

[0063] Pickling: Put the quenched billet into the pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface scale.

[0064] Stretching: Stretch the Φ15mm bar after quenching to Φ14mm in straight drawing machine.

[0065] Annealing: Anneal the Φ14mm at 300℃ for 3h.

[0066] Straightening: The annealed product is straightened in a Schmaus straightening machine.

[0067] Cutting to length: The straightened product is cut to length.

[0068] Chamfering: The cut-to-length product is chamfered.

[0069] Inspection / packaging: The chamfered product is inspected and packaged.

[0070] Ten samples of finished product are taken for performance testing, and the average value is taken.

[0071] Comparative Example 1 A Φ14 mm water-sealed extruded and drawn bar product with a trade name of HMn57-2-2-1 is purchased on the market.

[0072] Comparative Example 2 Horizontal continuous casting smelting: The cathode copper, lead ingot, Cu-Si intermediate alloy, electrolytic manganese, electrolytic nickel, and zinc ingot are smelted according to the mass percentage, and the electromagnetic stirring and stop-drawing process are started to produce Φ254 mm ingots.

[0073] Water-sealed extrusion: Water-sealed extrusion is performed using a 3150t, with a water-sealed extrusion specification of Φ18 mm, a water-sealed extrusion temperature of 640℃, and a water-sealed extrusion speed of 6 mm / s.

[0074] Pickling: The water-sealed extruded billet is placed in a pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface scale.

[0075] Drawing: The Φ18 mm bar after pickling is drawn to Φ15 mm on a straight drawing machine.

[0076] Quenching: The Φ15 mm bar is quenched at 520℃ for 40 min.

[0077] Pickling: The quenched billet is placed in a pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface scale.

[0078] Drawing: The Φ15 mm bar after quenching is drawn to Φ14 mm on a straight drawing machine.

[0079] Annealing: The Φ14 mm bar is annealed at 300℃ for 3 h at low temperature.

[0080] Straightening: The annealed product is straightened in a Schmaus straightening machine.

[0081] Cutting to length: The straightened product is cut to length.

[0082] Chamfering: The cut-to-length product is chamfered.

[0083] Inspection / packaging: The chamfered product is inspected and packaged.

[0084] Ten samples were taken for performance testing, and the average value was taken.

[0085] Comparative Example 3 Horizontal continuous casting smelting: The cathode copper, lead ingot, Cu-Si intermediate alloy, electrolytic manganese, electrolytic nickel, and zinc ingot were smelted according to the mass percentage, and electromagnetic stirring, stop-drawing process was started to produce Φ254 mm ingot.

[0086] Water sealed extrusion: Water sealed extrusion was performed using 3150t, the water sealed extrusion specification was Φ18 mm, the water sealed extrusion temperature was 650℃, and the water sealed extrusion speed was 6 mm / s.

[0087] Pickling: The water sealed extrusion blank was placed in a pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface oxide scale.

[0088] Stretching: The Φ18 mm rod after pickling was stretched to Φ15 mm in a straight drawing machine.

[0089] Quenching: The Φ15 mm rod was quenched at 500℃ for 60 min.

[0090] Pickling: The quenched blank was placed in a pickling tank containing sulfuric acid and nitric acid for pickling to remove the surface oxide scale.

[0091] Stretching: The Φ15 mm rod after quenching was stretched to Φ14 mm in a straight drawing machine.

[0092] Annealing: The Φ14 mm rod was annealed at 300℃ for 3 h at low temperature.

[0093] Straightening: The annealed product was straightened in a Schumag straightening machine.

[0094] Sizing: The straightened product was sawn and trimmed.

[0095] Chamfering: The sized product was chamfered.

[0096] Inspection / packaging: The chamfered product was inspected and packaged.

[0097] Ten samples were taken for performance testing, and the average value was taken.

[0098] Performance testing standards: (1) Tensile strength, yield strength and elongation: detected according to GB / T228.12021 “Metallic materials – Tensile testing – Part 1: Method of test at room temperature”.

[0099] (2) Corrosion resistance: the detection standard is GB / T10125-2012.

[0100] (3) Wear resistance: using a large load friction and wear testing machine, under the condition of load 100KN, temperature 25℃, friction speed 200r / min, friction mode is dry friction.

[0101] (4) Thermal conductivity: test standard GB / T 3525-2019.

[0102] (6) Thermal expansion coefficient: test standard ASTM E228-2017.

[0103] As shown in Table 4, the brass alloys prepared in Examples 1-3 have good mechanical properties, and also have high thermal conductivity, fatigue strength, thermal expansion coefficient and wear resistance.

[0104] As shown in Table 4, the brass alloys prepared in Examples 1-3 have good mechanical properties, and also have high thermal conductivity, fatigue strength, thermal expansion coefficient and wear resistance. Figs. 1-3 As shown in Table 4, the brass alloys prepared in Examples 1-3 have good mechanical properties, and also have high thermal conductivity, fatigue strength, thermal expansion coefficient and wear resistance. x Siᵧ, x / γ=1-3, finely and uniformly distributed on the β phase matrix, (Ni, Mn) x Siᵧ phase size is between 2-10um.

[0105] As shown in Table 4, the brass alloys prepared in Examples 1-3 have good mechanical properties, and also have high thermal conductivity, fatigue strength, thermal expansion coefficient and wear resistance. Figs. 4-6 As shown in Table 4, the brass alloys prepared in Examples 1-3 have good mechanical properties, and also have high thermal conductivity, fatigue strength, thermal expansion coefficient and wear resistance.

[0106] Table 1 is the parameters of melting and horizontal continuous casting of Examples 1-3 and Comparative Examples 2-3

[0107] Table 2 is the component content of the brass provided in Examples 1-3 and Comparative Examples 1-3

[0108] Table 3 is the phase organization content of the brass provided in Examples 1-3 and Comparative Examples 1-3

[0109] Table 4 is the performance data of the brass provided in Examples 1-3 and Comparative Examples 1-3

Claims

1. A wear-resistant complex brass material, characterized in that, It includes the following components by mass percentage: Cu: 54-60%, Pb: 0.3-1.5%, Mn: 1.5-3%, Fe: 0.1-0.5%, Ni: 1.5-3%, Si: 0.5-1.2%, with the balance being Zn and unavoidable impurities; The microstructure of the wear-resistant complex brass material includes β phase and (Ni, Mn) phase. x The Siγ phase, in which the β phase accounts for 75-85% of the area, (Ni, Mn) x The Siγ phase accounts for 15-25% of the total area, x / γ = 1-3, and the (Ni, Mn) phase... x The size of the Siγ phase is 2-10 μm.

2. The wear-resistant complex brass material according to claim 1, characterized in that, The microstructure of the wear-resistant complex brass material also includes an α phase, a Pb phase, and an Fe-rich phase, wherein the area ratio of the α phase is ≤1% and the area ratio of the Fe-rich phase is ≤2%.

3. The wear-resistant complex brass material according to claim 2, characterized in that, In the microstructure of wear-resistant complex brass materials, the number of Pb particles is 5000-15000 / mm². 2 .

4. The wear-resistant complex brass material according to claim 1, characterized in that, The grain size of the wear-resistant complex brass material is 0.005-0.05 mm.

5. The wear-resistant complex brass material according to claim 1, characterized in that, The mass percentage of the impurities is ≤0.3%.

6. The wear-resistant complex brass material according to claim 1, characterized in that, The mass ratio of Mn, Si and Ni is: Mn:Si=2.5-4, Ni:Mn=0.5-1.5, Ni:Si=2-3.

7. A method for preparing a wear-resistant complex brass material according to any one of claims 1-6, characterized in that, The process flow of the preparation method includes: smelting → horizontal continuous casting → water seal extrusion → first stretching → quenching → second stretching → annealing. The materials are prepared and smelted according to the mass percentage of each component of the wear-resistant complex brass material as described in any one of claims 1-6; The quenching temperature is 650-750℃ and the time is 20-80min.

8. The method for preparing wear-resistant complex brass material according to claim 7, characterized in that, The temperature of the water seal extrusion is 550-800℃.

9. The method for preparing wear-resistant complex brass material according to claim 7, characterized in that, The water seal extrusion ratio is 7-322.

10. The application of a wear-resistant complex brass material according to any one of claims 1-6 in a hydraulic pump.

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