CN117020204A - 20CrNiMo bearing piece and preparation method and application thereof - Google Patents
20CrNiMo bearing piece and preparation method and application thereof Download PDFInfo
- Publication number
- CN117020204A CN117020204A CN202311060412.XA CN202311060412A CN117020204A CN 117020204 A CN117020204 A CN 117020204A CN 202311060412 A CN202311060412 A CN 202311060412A CN 117020204 A CN117020204 A CN 117020204A
- Authority
- CN
- China
- Prior art keywords
- 20crnimo
- temperature
- sintering
- percent
- density
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 57
- 239000000843 powder Substances 0.000 claims abstract description 51
- 238000005238 degreasing Methods 0.000 claims abstract description 48
- 239000000463 material Substances 0.000 claims abstract description 43
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 40
- 239000000956 alloy Substances 0.000 claims abstract description 40
- 239000011230 binding agent Substances 0.000 claims abstract description 34
- 238000001746 injection moulding Methods 0.000 claims abstract description 17
- 239000011261 inert gas Substances 0.000 claims abstract description 5
- 238000005245 sintering Methods 0.000 claims description 75
- -1 polypropylene Polymers 0.000 claims description 23
- 239000004743 Polypropylene Substances 0.000 claims description 14
- 235000021355 Stearic acid Nutrition 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 14
- 238000002156 mixing Methods 0.000 claims description 14
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 claims description 14
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 claims description 14
- 229920001155 polypropylene Polymers 0.000 claims description 14
- 239000008117 stearic acid Substances 0.000 claims description 14
- 239000012188 paraffin wax Substances 0.000 claims description 9
- 239000004698 Polyethylene Substances 0.000 claims description 7
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- 235000013869 carnauba wax Nutrition 0.000 claims description 7
- 239000004203 carnauba wax Substances 0.000 claims description 7
- 239000005038 ethylene vinyl acetate Substances 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 7
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims description 7
- 229920000573 polyethylene Polymers 0.000 claims description 7
- 229920006324 polyoxymethylene Polymers 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 238000002347 injection Methods 0.000 abstract description 27
- 239000007924 injection Substances 0.000 abstract description 27
- 238000001513 hot isostatic pressing Methods 0.000 abstract description 19
- 238000004663 powder metallurgy Methods 0.000 abstract description 6
- 229910052751 metal Inorganic materials 0.000 abstract description 5
- 239000002184 metal Substances 0.000 abstract description 5
- 238000010438 heat treatment Methods 0.000 description 24
- 230000000052 comparative effect Effects 0.000 description 23
- 238000011282 treatment Methods 0.000 description 17
- 238000000280 densification Methods 0.000 description 12
- 238000004321 preservation Methods 0.000 description 12
- 239000000047 product Substances 0.000 description 12
- 230000003197 catalytic effect Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 230000005540 biological transmission Effects 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 7
- 239000002245 particle Substances 0.000 description 7
- 239000007921 spray Substances 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 6
- 238000000889 atomisation Methods 0.000 description 6
- 239000011148 porous material Substances 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 238000004898 kneading Methods 0.000 description 5
- 238000005979 thermal decomposition reaction Methods 0.000 description 5
- 238000009692 water atomization Methods 0.000 description 5
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000000197 pyrolysis Methods 0.000 description 3
- 238000000638 solvent extraction Methods 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- 229910000851 Alloy steel Inorganic materials 0.000 description 2
- 229930040373 Paraformaldehyde Natural products 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000005255 carburizing Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 238000005324 grain boundary diffusion Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000010587 phase diagram Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000004513 sizing Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010622 cold drawing Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000009766 low-temperature sintering Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
- B22F3/225—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip by injection molding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/103—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/1017—Multiple heating or additional steps
- B22F3/1021—Removal of binder or filler
- B22F3/1025—Removal of binder or filler not by heating only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/12—Both compacting and sintering
- B22F3/14—Both compacting and sintering simultaneously
- B22F3/15—Hot isostatic pressing
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/02—Making ferrous alloys by powder metallurgy
- C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
- C22C33/0264—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements the maximum content of each alloying element not exceeding 5%
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
Abstract
The invention relates to a 20CrNiMo bearing piece, and a preparation method and application thereof, belonging to the technical field of powder metallurgy and aiming at solving one of the problems of low density, large grain size, short service life and the like of the 20CrNiMo bearing piece prepared by the existing method. According to the method, the 20CrNiMo alloy powder and the binder are mixed and granulated to prepare the injection material, porous metal parts with certain shapes are formed through injection molding and degreasing procedures, the degreased blank is sintered for the first time in a vacuum environment or inert gas atmosphere to ensure that the density of the material is more than 92%, and then the material is sintered for the second time at high temperature and high pressure in hot isostatic pressing to ensure that the density of the 20CrNiMo bearing piece reaches 100%.
Description
Technical Field
The invention relates to the technical field of powder metallurgy, in particular to a 20CrNiMo bearing piece and a preparation method and application thereof.
Background
The development of low carbon in automobiles has put new demands on automobile materials and manufacturing processes. Under the 'double carbon' goal, the energy-saving, green and cyclic process becomes the development trend of new automobile materials and new processes, and the light-weight, green materials and cyclic utilization become the main development direction of new automobile materials. The automobile engine part, the generator part, the turbocharger part and the transmission part comprise precise power transmission structures such as shafts, gears, guide wheels, brackets and the like with various structures, and the running requirements such as rotating speed, torque, direction change and the like are realized by utilizing the meshing of the gears with different diameters. The precise power transmission structure has very complex production process, and casting is the simplest process, but has general performance and is more suitable for the condition of larger product size; the forging has better fatigue performance, but the structural freedom degree is greatly limited; extrusion and cold drawing also face the problems of large subsequent machining amount and low material utilization rate; powder metallurgy is suitable for forming various products such as gears and the like with uniform shapes, but is also not suitable for manufacturing support structures with special-shaped thin-wall complex structures, air holes in powder metallurgy products cannot be completely eliminated, and fatigue performance of the products is not as high as that of forgings.
The metal powder injection molding technology (Metal powderinjection molding, MIM) was produced in the 70 s of the 20 th century, and is a rapid net-shape powder forming technology formed by introducing a modern plastic injection molding process into the field of powder metallurgy. As an advanced technology in the field of powder metallurgy, MIM can be used for near-net forming of parts with fine grains, complex structure and small surface roughness, and is suitable for mass and high-efficiency production. With the push of light weight and dual carbon targets, the MIM technology is gradually replacing the traditional processing and molding technology, and is more applied to the production of parts in the fields of automobiles, electronic instruments and the like.
The 20CrNiMo low-carbon alloy steel is high-quality low-carbon fine grain alloy steel, and the composition of the alloy steel is similar to that of American SAE8620H and Japanese SNCM 220. The steel is added with a small amount of nickel element and molybdenum element, so that the steel can bear a certain high temperature, and the hardenability and toughness are improved. The 20CrNiMo has small heat treatment deformation, no tempering brittleness, relatively high hardness and wear resistance on the carburized surface, good toughness in the central part, and high impact load bearing, and may be used widely in producing automobile transmission gear, gear shaft, stepped shaft, guide wheel, transmission support and other parts with high impact resistance and wear resistance, and in producing the connecting rod valve section part of turbine gear whole rotor internal combustion engine.
At present, the research on 20CrNiMo steel is limited in China, mainly focuses on the aspects of steel grade development, heat processing and heat treatment process optimization, and has less research on MIM forming. Compared with MIM forming technology, the traditional hot working and cold working processes are more and more complex, and are inferior in the aspects of degree of freedom of formed parts, material utilization rate, energy consumption, pollution emission and the like. However, due to inherent process characteristics of MIM technology, the formed 20CrNiMo gear steel can form tiny holes which are dispersed and distributed in a part after sintering, and the density of the product is difficult to exceed 7.55g/cm 3 (corresponding to 96% of theoretical density). The porosity has less influence on the static mechanical properties of the material, but the dynamic mechanical properties of the material, especially toughness and fatigue properties, are very sensitive to a small amount of porosity. A small number of holes can lead to shortened service life of the material, and cannot meet the use requirements of high-quality automobile transmission parts.
Disclosure of Invention
In view of the analysis, the invention aims to provide a 20CrNiMo bearing piece, and a preparation method and application thereof, which are used for solving one of the problems of low density, large grain size, low material utilization rate, poor fatigue durability and the like of the 20CrNiMo bearing piece prepared by the existing method.
In a first aspect, the invention provides a method for preparing a 20CrNiMo bearing member, which comprises the following steps:
(1) Mixing alloy powder with a binder for feeding, injection molding and degreasing to obtain a green body;
(2) And (3) in vacuum or inert gas atmosphere, preserving heat for 60-360 min at 1000-1250 ℃, performing primary sintering, performing secondary sintering at 780-1100 ℃ under 100-180 MPa of hot isostatic pressure for 90-240 min, and cooling to obtain the 20CrNiMo bearing piece.
Further, in the step (1), the alloy powder comprises the following elements in percentage by mass: 0.17 to 0.23 percent of C, 0.17 to 0.37 percent of Si, 0.60 to 0.95 percent of Mn, less than or equal to 0.035 percent of S, less than or equal to 0.035 percent of P, 0.40 to 0.70 percent of Cr, 0.35 to 0.75 percent of Ni, 0.2 to 0.3 percent of Mo, and the balance of Fe and other unavoidable impurities.
Further, in the step (1), the binder comprises 48 to 70 mass percent of paraffin wax, 0 to 10 mass percent of carnauba wax, 20 to 40 mass percent of polypropylene and 1 to 5 mass percent of stearic acid;
or the binder comprises 40-70% of polyformaldehyde, 10-25% of polyethylene, 10-25% of ethylene-vinyl acetate copolymer, 1-5% of polypropylene and 1-5% of stearic acid.
Further, in the step (1), the alloy powder accounts for 55 to 65 percent and the binder accounts for 35 to 45 percent according to the volume ratio.
Further, in the step (2), when the temperature is lower than 900 ℃, the temperature rising rate is 3-6 ℃/min, and when the temperature is higher than 900 ℃, the temperature rising rate is 1-3 ℃/min.
Further, in the step (2), the temperature rising rate of the second sintering is 3-15 ℃/min.
Further, in the step (2), after the first sintering, the density of the material is 92-95.5%, and the density of the 20CrNiMo bearing piece is 100%.
Further, in the step (2), the temperature of the second sintering is lower than that of the first sintering.
In a second aspect, the invention provides a 20CrNiMo load bearing member prepared by the method.
In a third aspect, the invention provides an application of the 20CrNiMo bearing piece prepared by the method in automobiles.
Compared with the prior art, the invention has at least one of the following beneficial effects:
(1) According to the method, the 20CrNiMo alloy powder and the binder are mixed and granulated to prepare injection materials, porous metal parts with certain shapes are molded through injection molding and degreasing procedures, the degreased blank is sintered for the first time in a vacuum environment or inert gas atmosphere to ensure that the density of the product is more than 92%, and then the sintered for the second time at high temperature and high pressure in hot isostatic pressing to carry out densification treatment to ensure that the density of the 20CrNiMo bearing part reaches 100%;
(2) The temperature and time of the first sintering are controlled, so that the density of the product is more than 92%, the grain growth is reduced as much as possible, and the mechanical property of the final product is improved; meanwhile, the second sintering is carried out under a high-temperature and high-pressure environment, the sintering temperature, time and pressure are controlled, so that the internal pores of the 20CrNiMo bearing piece are eliminated, densification is further carried out, and the density of the finally prepared material is 100%;
(3) The second sintering temperature is lower than the first sintering temperature, so that the growth of crystal grains caused by long-time action of high temperature is avoided, the average grain size of the prepared bearing piece material is 22-39 mu m, and the density of the material can reach theoretical density after the twice sintering treatment.
In the invention, the technical schemes can be mutually combined to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, like reference numerals being used to refer to like parts throughout the several views.
FIG. 1 is a golden phase diagram of a 20CrNiMo load bearing member prepared in example 3 of the present invention;
FIG. 2 is a golden phase diagram of a 20CrNiMo load bearing member prepared in accordance with comparative example 1 of the present invention.
Detailed Description
The following detailed description of preferred embodiments of the invention is made in connection with the accompanying drawings, which form a part hereof, and together with the description of the embodiments of the invention, are used to explain the principles of the invention and are not intended to limit the scope of the invention.
The invention discloses a preparation method of a 20CrNiMo bearing piece, which comprises the following steps:
(1) Mixing alloy powder with a binder for feeding, injection molding and degreasing to obtain a green body;
(2) The green body is subjected to primary sintering at 1000-1250 ℃, such as 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃, 1200 ℃, 1250 ℃, 60-360 min, such as 60min, 80 mm, 100min, 120min, 140min, 160min, 180min, 200min, 220min, 240min, 260min, 280min, 300min, 320min, 340min, 360min, and then subjected to secondary sintering at 780-1100 ℃, such as 780 ℃, 840 ℃, 860 ℃, 900 ℃, 940 ℃, 980 ℃, 1020 ℃, 1100 ℃, 100-180 MPa, such as 100MPa, 110MPa, 120MPa, 130MPa, 140MPa, 150MPa, 160MPa, 170MPa, 180MPa, 90-240 min, such as 90min, 100min, 110min, 120min, 130min, 140min, 150min, 160min, 170min, 180min, 190min, 200min, 210min, 220, 230min, 240min, and 20 ℃ to obtain the sintering product.
Compared with the prior art, the method provided by the invention has the advantages that the injection material is prepared by mixing and granulating the 20CrNiMo alloy powder and the binder, the porous metal part with a certain shape is molded through injection molding and degreasing procedures, the degreased blank is sintered for the first time in a vacuum environment or inert gas atmosphere to ensure that the compactness of the material is 92-95.5%, and then the densification treatment is performed by sintering for the second time at high temperature and high pressure in hot isostatic pressing to ensure that the compactness of the material reaches 100%.
Further, in the step (1), the alloy powder comprises the following elements in percentage by mass: 0.17 to 0.23 percent of C, 0.17 to 0.37 percent of Si, 0.60 to 0.95 percent of Mn, less than or equal to 0.035 percent of S, less than or equal to 0.035 percent of P, 0.40 to 0.70 percent of Cr, 0.35 to 0.75 percent of Ni, 0.2 to 0.3 percent of Mo, and the balance of Fe and other unavoidable impurities.
The preparation of the alloy powder adopts one or more of the methods of the prior art, such as a water atomization method, a water-gas combined atomization method or an air atomization method, the alloy powder is nearly spherical, the granularity is between 0.5 and 22 mu m, the D50 particle size is between 4 and 15 mu m, and the tap density of the alloy powder is more than 4.3g/cm 3 . By the technical scheme, ideal powder stacking density can be obtained, feeding viscosity is reduced, and injection performance and degreasing and shape retention of the powder are effectively considered.
In one embodiment, in the step (1), the binder comprises 48 to 70% of paraffin wax, 0 to 10% of carnauba wax, 20 to 40% of polypropylene and 1 to 5% of stearic acid according to mass percent;
wherein, paraffin wax and carnauba wax are used as sizing materials, polypropylene is used as a framework material, and stearic acid is used as an additive.
Or the binder comprises 40-70% of polyformaldehyde, 10-25% of polyethylene, 10-25% of ethylene-vinyl acetate copolymer, 1-5% of polypropylene and 1-5% of stearic acid;
wherein, the polyformaldehyde is used as sizing material, the polyethylene, the ethylene-vinyl acetate copolymer and the polypropylene are used as framework materials, and the stearic acid is used as additive.
The two binder formulations are selected by combining the factors of economy, viscosity, injection molding property, green strength, degumming and the like, and the selected binder has low cost, easy mixing and low pyrolysis temperature, and ensures that the viscosity, density, thermodynamic property, pyrolysis property and the like of the prepared feed meet the production requirements.
In one embodiment, in step (1), the alloy powder is 55 to 65% and the binder is 35 to 45% by volume.
The present inventors have found through a large number of experiments that the injection molding effect is better by using the above volume ratio.
In one embodiment, in step (1), the feeding is specifically: adding alloy powder and a binder into a kneader together, kneading for 30-120 min at 110-175 ℃, uniformly mixing, and granulating to obtain a feed for later use.
In one embodiment, in step (1), the injection molding is specifically: the feed is injection molded on an injection machine to obtain the required injection blank, and specifically, the injection parameters are controlled as follows: the temperature of the spray pipe is 135-180 ℃, the temperature of the nozzle is 160-210 ℃, the injection pressure is 60-140 Mpa, and the temperature of the die is 70-100 ℃.
In one embodiment, in the step (1), the degreasing treatment may be a solvent extraction-pyrolysis two-step degreasing method or a catalytic degreasing method depending on the kind of the binder.
When the binder is selected from paraffin 48-70%, carnauba wax 0-10%, polypropylene 20-40% and stearic acid 1-5%, the degreasing treatment adopts an extraction-thermal decomposition two-step degreasing method.
When the binder is 40-70% of polyformaldehyde, 10-25% of polyethylene, 10-25% of ethylene-vinyl acetate copolymer, 1-5% of polypropylene and 1-5% of stearic acid, the degreasing treatment adopts a catalytic degreasing method.
Specifically, the extraction-thermal decomposition two-step degreasing method is specifically as follows: the solvent extraction adopts n-heptane or trichloroethane, the degreasing temperature is 60-95 ℃ and the degreasing time is 3-4 h, so as to remove the stoneWax component, opening pore channels. Thermal degreasing is carried out at 50% H 2 And 50% N 2 In the mixed atmosphere, the temperature is raised to 400 ℃ at 1.5-2.5 ℃/min, each time the temperature is raised to 100 ℃, 200 ℃, 300 ℃ and 400 ℃, the temperature is kept for 50-80 min, the temperature is raised to 600 ℃ at 1-2 ℃/min, the temperature is kept for 60-180 min, and finally the temperature is raised to 800-920 ℃ at 1-3 ℃/min, and the temperature is kept for 30-60 min.
The extraction-thermal decomposition two-step degreasing method has the advantages of simple process, no generation of pollutant, low equipment investment, high degreasing speed, no deformation or crack of the degreased workpiece, and certain strength of the degreased workpiece by adding a high-temperature heat preservation after thermal degreasing.
Specifically, the catalytic degreasing method is as follows: catalytic degreasing is carried out in fuming nitric acid atmosphere at 110-145 ℃ with acid flow of 3-5 ml/min, and degreasing time is 1.5-5.5 h according to the product size and wall thickness.
The catalytic degreasing method has short degreasing time, does not generate liquid phase during degreasing, is beneficial to controlling the deformation of a green body, ensures the dimensional accuracy of a sintered workpiece, and can produce a workpiece with larger size.
In one embodiment, in step (2), the temperature is raised at a rate of 3 to 6 ℃/min when the temperature is less than 900 ℃ and 1 to 3 ℃/min when the temperature is greater than 900 ℃ during the first sintering.
After one sintering, the density of the material reaches 7.35-7.55 g/cm 3 The density is 92-95.5%.
In one embodiment, in step (2), the rate of temperature rise for the second sintering is 3 to 15 ℃/min.
In one embodiment, in the step (2), after the first sintering, the density of the material is 92-95.5%, and the density of the 20CrNiMo bearing piece is 100%.
The sintering process is a densification process in which powder particles are bonded together when the material is heated to a high temperature, and sintering densification in conventional powder injection molding processes is performed near the melting point of the material by virtue of grain boundary diffusion and migration, with atoms moving along the grain boundaries between two nearly complete grain regions, forming a continuous flow of material, eliminating or reducing voids. However, grain boundary diffusion inevitably causes grain growth, affecting the service properties of the final product. The densification surface diffusion is usually dominant in the low-temperature sintering stage, and the invention rapidly sinters at low temperature and slowly heats at high temperature by controlling the temperature rising rate, sintering temperature and time of the first sintering, so as to reduce the heat preservation temperature and the heat preservation time as much as possible. The first sintering temperature exceeds the austenite transformation temperature, but is lower than the conventional injection molding sintering temperature, and the density of the material after the first sintering is controlled to be 92-95.5%; the second sintering temperature may be lower than or exceeding the austenite transformation temperature, but is generally lower than the first sintering temperature, both controlling grain growth and ensuring densification of the material.
In addition, according to the growth kinetics of the crystal grains, along with the increase of the heating temperature and the extension of the heat preservation time, the diffusion capability of atoms is enhanced, the crystal grains are mutually engulfed, the surface area of the crystal grain boundary is reduced, and the crystal grains grow up. The temperature and time of the first sintering are controlled, so that the density of the product is more than 92-95.5%, the grain growth is reduced as much as possible, and the mechanical property of the final product is improved; meanwhile, the second sintering is carried out under a high-temperature and high-pressure environment, the sintering temperature, time and pressure are controlled, so that the internal pores of the 20CrNiMo bearing piece are eliminated, the densification is further carried out, and the density of the finally prepared 20CrNiMo bearing piece is 100%.
The second sintering temperature is lower than the first sintering temperature, so that the growth of crystal grains caused by long-time action of high temperature is avoided, the average grain size of the material prepared by the method is 22-39 mu m, and the density of the material can reach theoretical density after the twice sintering treatment.
In another embodiment of the invention, a 20CrNiMo force bearing member prepared by the method is disclosed.
The invention discloses an application of the 20CrNiMo bearing piece prepared by the method in automobiles.
The 20CrNiMo bearing piece comprises a small shaft, a gear, a guide wheel, a bracket and other precise power transmission structures used in automobiles.
The method has scientific raw material selection and strict proportion, and can realize the mass production and the stable production of the high-quality automobile 20CrNiMo bearing parts with fine grains by regulating and controlling all relevant parameters in the material production process. The 20CrNiMo special-shaped piece with high density and fine crystal grains can be successfully prepared through reasonable powder particle size collocation, binder selection, a high-efficiency degreasing method and a lower sintering temperature, and the material can obtain excellent strength, toughness, wear resistance and fatigue performance matching through proper tempering treatment or carburizing treatment according to the subsequent specific use requirements, so that the light-weight and high-performance requirements of the vehicle material are met.
The method of the invention has low production energy consumption, and no harmful substances are generated in the process to cause harm to the environment. The existing parts are replaced in the precise power transmission structure of the automobile shaft, the gear, the bracket and the like, so that the structural strength and the safety performance of the automobile can be improved, the dynamic performance of the automobile can be improved, the dye consumption can be reduced, and the exhaust pollution can be reduced.
The technical scheme of the invention is further explained below by combining specific examples.
Example 1
A preparation method of a 20CrNiMo bearing piece comprises the following steps:
(1) Mixing and feeding alloy powder and a binder, wherein the alloy powder comprises the following elements in percentage by mass: 0.21% of C, 0.29% of Si, 0.76% of Mn, 0.013% of S, 0.018% of P, 0.53% of Cr, 0.51% of Ni, 0.21% of Mo, and the balance of Fe and other unavoidable impurities. The preparation method of the alloy powder is that the powder is mixed by a water atomization method and an air atomization method to obtain the alloy powder with the D50 particle diameter of 12 mu m and the tap density of 4.6g/cm 3 ；
The adhesive comprises 58% of paraffin, 10% of carnauba wax, 30% of polypropylene and 2% of stearic acid according to mass percent;
adding alloy powder and a binder into a kneader together, kneading for 30min at 140 ℃ and uniformly mixing, and granulating to obtain a feed for later use, wherein the alloy powder content accounts for 55% of the total volume fraction, and the binder content accounts for 45% of the total volume fraction;
injection molding the prepared feed on an injection machine to obtain injection blanks, wherein injection parameters are controlled as follows: the temperature of the spray pipe is 180 ℃, the temperature of the spray nozzle is 190 ℃, the injection pressure is 125Mpa, and the temperature of the die is 80 ℃;
degreasing the injection blank by adopting an extraction-thermal decomposition two-step degreasing method to obtain a green body, wherein the solvent extraction adopts trichloroethane, the degreasing temperature is 90 ℃, the degreasing time is 3.5H, so as to remove paraffin components, open pore channels, and the thermal degreasing is carried out at 50% of H 2 And 50% N 2 In the mixed atmosphere, heating to 400 ℃ at 1.5 ℃/min, respectively preserving heat for 60min each time when heating to 100 ℃, 200 ℃, 300 ℃ and 400 ℃, heating to 600 ℃ at 1.5 ℃/min, preserving heat for 90min, and finally heating to 800 ℃ at 2 ℃/min, preserving heat for 30min;
(2) At H 2 +N 2 In an atmosphere environment, the green body is subjected to primary sintering at 1100 ℃ for 60min, wherein the heating rate is 6 ℃/min when the temperature is lower than 900 ℃ in the heating stage, and the heating rate is 3 ℃/min when the temperature is higher than 900 ℃; and then performing densification at high temperature and high pressure in hot isostatic pressing for the second sintering treatment, wherein the hot isostatic pressing temperature is 1000 ℃, the hot isostatic pressing pressure is 120MPa, the hot isostatic pressing heat preservation time is 90min, the heating rate is 15 ℃/min, and the power is cut off and the temperature is reduced along with the furnace after heat preservation is finished, so that the 20CrNiMo bearing piece is obtained.
The 20CrNiMo bearing piece of the embodiment has the density of 93% after the first sintering and the density of 100% after the second sintering.
Example 2
A preparation method of a 20CrNiMo bearing piece comprises the following steps:
(1) Mixing and feeding alloy powder and a binder, wherein the alloy powder comprises the following elements in percentage by mass: 0.22% of C, 0.23% of Si, 0.82% of Mn, 0.01% of S, 0.013% of P, 0.44% of Cr, 0.58% of Ni, 0.25% of Mo, and the balance of Fe and other unavoidable impurities. The preparation method of the alloy powder is that the powder is mixed by a water atomization method and an air atomization methodThe synthesized D50 particle size is 10 mu m, and the tap density of the alloy powder is 4.52g/cm 3 ；
The adhesive comprises 65% of paraffin, 9% of carnauba wax, 30% of polypropylene and 1% of stearic acid according to mass percent;
adding alloy powder and a binder into a kneader together, kneading for 45min at 130 ℃ and uniformly mixing, and granulating to obtain a feed for later use, wherein the alloy powder content accounts for 60% of the total volume fraction, and the binder content accounts for 40% of the total volume fraction;
injection molding the prepared feed on an injection machine to obtain injection blanks, wherein injection parameters are controlled as follows: nozzle temperature 1750deg.C nozzle temperature 190 deg.C, injection pressure 130Mpa, and mold temperature 75 deg.C;
degreasing the injection blank by adopting an extraction-thermal decomposition two-step degreasing method to obtain a green body, wherein the solvent extraction adopts trichloroethane, the degreasing temperature is 80 ℃, the degreasing time is 4 hours, paraffin components are removed, pore channels are opened, and the thermal degreasing is carried out at 50% of H 2 And 50% N 2 In the mixed atmosphere, the temperature is raised to 400 ℃ at 2 ℃/min, each time the temperature is raised to 100 ℃, 200 ℃, 300 ℃ and 400 ℃ for 60min, then the temperature is raised to 600 ℃ at 1.5 ℃/min, the temperature is raised to 90min, and finally the temperature is raised to 800 ℃ at 2.5 ℃/min, and the temperature is kept for 30min;
(2) At N 2 In an atmosphere environment, the green body is subjected to primary sintering at 1000 ℃ for 300min, wherein the heating rate is 6 ℃/min when the temperature is lower than 900 ℃ in the heating stage, and the heating rate is 2 ℃/min when the temperature is higher than 900 ℃; and then performing densification at high temperature and high pressure in hot isostatic pressing for the second sintering treatment, wherein the hot isostatic pressing temperature is 950 ℃, the hot isostatic pressing pressure is 140MPa, the hot isostatic pressing heat preservation time is 120min, the heating rate is 10 ℃/min, and the power is cut off and the temperature is reduced along with the furnace after heat preservation is finished, so that the 20CrNiMo bearing piece is obtained.
The 20CrNiMo bearing piece of the embodiment is subjected to primary sintering, the density of the material is 94%, and the density of the material is 100% after secondary sintering.
Example 3
A preparation method of a 20CrNiMo bearing piece comprises the following steps:
(1) Mixing and feeding alloy powder and a binder, wherein the alloy powder comprises the following elements in percentage by mass: 0.22% of C, 0.35% of Si, 0.72% of Mn, 0.017% of S, 0.018% of P, 0.49% of Cr, 0.47% of Ni, 0.22% of Mo, and the balance of Fe and other unavoidable impurities. The preparation method of the alloy powder is that the powder is mixed by a water atomization method and an air atomization method to obtain the alloy powder with the D50 particle diameter of 15 mu m and the tap density of 4.84g/cm 3 ；
The adhesive comprises, by mass, 50% of polyoxymethylene, 20% of polyethylene, 25% of ethylene-vinyl acetate copolymer, 3% of polypropylene and 2% of stearic acid; adding alloy powder and a binder into a kneader together, kneading for 90min at 170 ℃ and uniformly mixing, and granulating to obtain a feed for later use, wherein the alloy powder content accounts for 58% of the total volume fraction, and the binder content accounts for 42% of the total volume fraction;
injection molding the prepared feed on an injection machine to obtain injection blanks, wherein injection parameters are controlled as follows: the temperature of the spray pipe is 160 ℃, the temperature of the spray nozzle is 180 ℃, the injection pressure is 125Mpa, and the temperature of the die is 100 ℃;
degreasing by adopting a catalytic degreasing method to obtain a green body, wherein fuming nitric acid atmosphere is selected for catalytic degreasing, the degreasing temperature is 115 ℃, the acid introducing amount is 3.6ml/min, and the degreasing time is 2.5h;
(2) At N 2 In an atmosphere environment, the green body is subjected to primary sintering at 1050 ℃ for 120min, wherein the heating rate is 5 ℃/min when the temperature is lower than 900 ℃ in the heating stage, and the heating rate is 1.5 ℃/min when the temperature is higher than 900 ℃; and then performing densification at high temperature and high pressure in hot isostatic pressing for the second sintering treatment, wherein the hot isostatic pressing temperature is 880 ℃, the hot isostatic pressing pressure is 180MPa, the hot isostatic pressing heat preservation time is 120min, the heating rate is 15 ℃/min, and the power is cut off and the temperature is reduced along with the furnace after heat preservation is finished, so that the 20CrNiMo bearing piece is obtained.
The 20CrNiMo bearing piece of the embodiment has the density of 93% after the first sintering and the density of 100% after the second sintering.
Example 4
A preparation method of a 20CrNiMo bearing piece comprises the following steps:
(1) Mixing and feeding alloy powder and a binder, wherein the alloy powder comprises the following elements in percentage by mass: 0.19% of C, 0.27% of Si, 0.76% of Mn, 0.023% of S, 0.02% of P, 0.52% of Cr, 0.49% of Ni, 0.26% of Mo, and the balance of Fe and other unavoidable impurities. The preparation method of the alloy powder is that the powder is mixed by a water atomization method and an air atomization method to obtain the alloy powder with the D50 particle diameter of 13 mu m and the tap density of 4.72g/cm 3 ；
The adhesive comprises, by mass, 70% of polyoxymethylene, 15% of polyethylene, 10% of ethylene-vinyl acetate copolymer, 3% of polypropylene and 2% of stearic acid; adding alloy powder and a binder into a kneader together, kneading for 80min at 185 ℃ and uniformly mixing, and granulating to obtain a feed for later use, wherein the alloy powder content accounts for 55% of the total volume fraction, and the binder content accounts for 45% of the total volume fraction;
injection molding the prepared feed on an injection machine to obtain injection blanks, wherein injection parameters are controlled as follows: the temperature of the spray pipe is 165 ℃, the temperature of the spray nozzle is 185 ℃, the injection pressure is 110Mpa, and the temperature of the die is 90 ℃;
degreasing by adopting a catalytic degreasing method to obtain a green body, wherein fuming nitric acid atmosphere is selected for catalytic degreasing, the degreasing temperature is 125 ℃, the acid introducing amount is 3.8ml/min, and the degreasing time is 3h;
(2) At N 2 In an atmosphere environment, the green body is subjected to primary sintering at 1150 ℃ for 240min, wherein the heating rate is 6 ℃/min when the temperature is lower than 900 ℃ in the heating stage, and the heating rate is 2.5 ℃/min when the temperature is higher than 900 ℃; and then performing densification at high temperature and high pressure in hot isostatic pressing for the second sintering treatment, wherein the hot isostatic pressing temperature is 920 ℃, the hot isostatic pressing pressure is 140MPa, the hot isostatic pressing heat preservation time is 150min, the heating rate is 4 ℃/min, and the power is cut off and the temperature is reduced along with the furnace after heat preservation is finished, so that the 20CrNiMo bearing piece is obtained.
The 20CrNiMo bearing piece of the embodiment is sintered for the first time, the density of the material is 95.2 percent, and the density of the material is 100 percent after the second sintering.
Comparative example 1
The method for producing the 20CrNiMo bearing of this comparative example was the same as in example 3, except that in step (2), only the first sintering treatment was performed, and the second sintering treatment was not performed.
Comparative example 2
The method for preparing the 20CrNiMo carrier of this comparative example was the same as in example 1, except that in step (2), the temperature of the first sintering was 1280 ℃.
Comparative example 3
The method for preparing the 20CrNiMo bearing of this comparative example was the same as in example 1, except that in step (2), the first sintering temperature was 1000 ℃ and the second sintering temperature was 1100 ℃.
Comparative example 4
The method for preparing the 20CrNiMo bearing piece of the comparative example is the same as that of the example 2, except that in the step (2), normal-pressure sintering is adopted for the second sintering.
Comparative example 5
The method for preparing the 20CrNiMo bearing member of this comparative example was the same as in example 2, except that in step (2), both the first sintering and the second sintering were conducted under a pressure of 140 MPa.
Test example 1
The performance indexes of the 20CrNiMo load bearing members prepared in test examples 1 to 4 and comparative examples 1 to 7 are shown in Table 1.
TABLE 1
| Group of | Theoretical Density (g/cm) 3 ) | Density (g/cm) 3 ) | Average grain size (μm) |
| Example 1 | 7.85 | 7.856 | 39 |
| Example 2 | 7.85 | 7.861 | 32 |
| Example 3 | 7.85 | 7.856 | 22 |
| Example 4 | 7.85 | 7.858 | 31 |
| Comparative example 1 | 7.85 | 7.5 | 21 |
| Comparative example 2 | 7.85 | 7.857 | 47 |
| Comparative example 3 | 7.85 | 7.856 | 48 |
| Comparative example 4 | 7.85 | 7.69 | 44 |
| Comparative example 5 | 7.85 | -- | -- |
As can be seen from the table above, comparative example 1 compares with example 3: and the second sintering treatment is not performed, pores exist in the material, the density is about 95% of the theoretical density, and the service life of the 20CrNiMo bearing piece after final heat treatment is influenced.
Comparative example 2 compares with example 1: when the temperature of the first sintering is higher than the temperature of the first sintering, the average grain size of the 20CrNiMo bearing piece is obviously increased.
Comparative example 3 compares with example 1: when the temperature of the second sintering is higher than that of the first sintering, the average grain size of the 20CrNiMo bearing piece is obviously increased.
Comparative example 4 compares with example 2: the density can not reach 100% and the grain size is obviously increased.
Comparative example 5 compares with example 2: after the first sintering, the product is deformed and cracked to become waste.
In addition, the metallographic phase of the 20CrNiMo bearing member prepared in example 3 is shown in FIG. 1, and the metallographic phase of the 20CrNiMo bearing member prepared in comparative example 1 is shown in FIG. 2. As can be seen from the graph, after the invention is adopted for twice sintering, no holes appear, and the product can reach theoretical density with density of 100%. The 20CrNiMo workpiece prepared by the method can show final performance after proper quenching, tempering, carburizing and other treatments.
The inventors have also made the above experiments on other embodiments, and the results are substantially consistent and will not be listed again due to limited space.
The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.
Claims (10)
1. The preparation method of the 20CrNiMo bearing piece is characterized by comprising the following steps of:
(1) Mixing alloy powder with a binder for feeding, injection molding and degreasing to obtain a green body;
(2) And (3) in vacuum or inert gas atmosphere, preserving heat for 60-360 min at 1000-1250 ℃, performing primary sintering, performing secondary sintering at 780-1100 ℃ under 100-180 MPa of hot isostatic pressure for 90-240 min, and cooling to obtain the 20CrNiMo bearing piece.
2. The method for manufacturing a 20CrNiMo bearing member according to claim 1, wherein in the step (1), the alloy powder comprises the following elements in percentage by mass: 0.17 to 0.23 percent of C, 0.17 to 0.37 percent of Si, 0.60 to 0.95 percent of Mn, less than or equal to 0.035 percent of S, less than or equal to 0.035 percent of P, 0.40 to 0.70 percent of Cr, 0.35 to 0.75 percent of Ni, 0.2 to 0.3 percent of Mo, and the balance of Fe and other unavoidable impurities.
3. The method for preparing a 20CrNiMo bearing member according to claim 1, wherein in the step (1), the binder comprises 48-70% of paraffin wax, 0-10% of carnauba wax, 20-40% of polypropylene and 1-5% of stearic acid according to mass percent;
or the binder comprises 40-70% of polyformaldehyde, 10-25% of polyethylene, 10-25% of ethylene-vinyl acetate copolymer, 1-5% of polypropylene and 1-5% of stearic acid.
4. A method for producing a 20CrNiMo load bearing member according to any one of claims 1 to 3, wherein in step (1), the alloy powder is 55 to 65% and the binder is 35 to 45% by volume.
5. A method of producing a 20CrNiMo load carrier according to any one of claims 1 to 3, wherein in step (2), the rate of temperature rise is 3 to 6 ℃/min when the temperature is less than 900 ℃ and 1 to 3 ℃/min when the temperature is greater than 900 ℃ during the first sintering.
6. A method of producing a 20CrNiMo load carrier according to any one of claims 1 to 3, wherein in step (2), the rate of temperature rise of the second sintering is 3 to 15 ℃/min.
7. The method for manufacturing a 20CrNiMo bearing member according to claim 1, wherein in the step (2), after the first sintering, the density of the material is 92-95.5%, and the density of the 20CrNiMo bearing member is 100%.
8. The method of claim 1, wherein in step (2), the second sintering temperature is less than the first sintering temperature.
9. A 20CrNiMo load carrier prepared by the method of any one of claims 1-8.
10. Use of a 20CrNiMo force carrier prepared by the method of any one of claims 1 to 8 in an automobile.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311060412.XA CN117020204A (en) | 2023-08-22 | 2023-08-22 | 20CrNiMo bearing piece and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311060412.XA CN117020204A (en) | 2023-08-22 | 2023-08-22 | 20CrNiMo bearing piece and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117020204A true CN117020204A (en) | 2023-11-10 |
Family
ID=88624355
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311060412.XA Pending CN117020204A (en) | 2023-08-22 | 2023-08-22 | 20CrNiMo bearing piece and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117020204A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5266264A (en) * | 1991-12-31 | 1993-11-30 | The Japan Steel Works Ltd. | Process for producing sinters and binder for use in that process |
| CN101353768A (en) * | 2008-09-26 | 2009-01-28 | 北京科技大学 | Nitrogen-containing nickel-free stainless steel and metallurgy forming process for powder thereof |
| CN102251131A (en) * | 2011-06-30 | 2011-11-23 | 北京科技大学 | Method for preparing injection-molding nickel-base ODS (oxide dispersion strengthened) alloy |
| CN103240412A (en) * | 2013-05-22 | 2013-08-14 | 北京科技大学 | Method for preparing powder super-alloy by near net shape |
| CN108101541A (en) * | 2017-12-21 | 2018-06-01 | 洛阳名力科技开发有限公司 | A kind of ejection forming method of non-bond cemented carbide |
| CN109940164A (en) * | 2019-04-01 | 2019-06-28 | 广东省材料与加工研究所 | A kind of wearable device titanium raw material and its near clean shaping preparation method |
| US20200198013A1 (en) * | 2018-12-24 | 2020-06-25 | University Of Science And Technology Beijing | Metal Material Sintering Densification and Grain Size Control Method |
-
2023
- 2023-08-22 CN CN202311060412.XA patent/CN117020204A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5266264A (en) * | 1991-12-31 | 1993-11-30 | The Japan Steel Works Ltd. | Process for producing sinters and binder for use in that process |
| CN101353768A (en) * | 2008-09-26 | 2009-01-28 | 北京科技大学 | Nitrogen-containing nickel-free stainless steel and metallurgy forming process for powder thereof |
| CN102251131A (en) * | 2011-06-30 | 2011-11-23 | 北京科技大学 | Method for preparing injection-molding nickel-base ODS (oxide dispersion strengthened) alloy |
| CN103240412A (en) * | 2013-05-22 | 2013-08-14 | 北京科技大学 | Method for preparing powder super-alloy by near net shape |
| CN108101541A (en) * | 2017-12-21 | 2018-06-01 | 洛阳名力科技开发有限公司 | A kind of ejection forming method of non-bond cemented carbide |
| US20200198013A1 (en) * | 2018-12-24 | 2020-06-25 | University Of Science And Technology Beijing | Metal Material Sintering Densification and Grain Size Control Method |
| CN109940164A (en) * | 2019-04-01 | 2019-06-28 | 广东省材料与加工研究所 | A kind of wearable device titanium raw material and its near clean shaping preparation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109848420A (en) | A kind of 440C stainless steel metal powder injection forming method and its product | |
| CN109695004B (en) | Manufacturing method of iron-based powder metallurgy part | |
| CN108311701B (en) | Preparation process of turbocharger nozzle ring blade for gasoline engine | |
| CN101905411B (en) | Method for manufacturing coupler for distributor of automobile engine | |
| US4121927A (en) | Method of producing high carbon hard alloys | |
| CN101342591A (en) | Method of manufacturing powder metallurgy nitrogen/high nitrogen containing stainless steel parts | |
| CN108441664B (en) | Ultrahigh-strength coatable TiCN-based cobalt-containing steel bonded hard alloy and preparation method thereof | |
| CN110257688B (en) | High-speed steel containing boride powder and preparation method thereof | |
| CN109277574B (en) | Preparation method of air-conditioning compressor rocker | |
| CN113106355B (en) | High-hardness 316L stainless steel and preparation method and application thereof | |
| CN111304552A (en) | 3D printing high-wear-resistance stainless steel material, preparation method and application thereof | |
| CN112077313A (en) | Method for preparing low-density steel complex parts by adopting powder metallurgy | |
| CN104368816A (en) | Method for manufacturing iron-based powder metallurgy components | |
| KR20140048428A (en) | Method for manufacturing of control finger using with metal powder injection molding | |
| WO2011150854A9 (en) | Method for manufacturing resonant poles, resonant poles and cavity filters | |
| CN106002131A (en) | Alloy-inserted high-performance shearing circular knife and processing method thereof | |
| CN110408830A (en) | A kind of Ti (C, N) base metal-ceramic material and its Carbon balance control method | |
| CN110512119B (en) | Injection molding nickel-based alloy powder, injection molding method and nickel-based alloy product | |
| CN117020204A (en) | 20CrNiMo bearing piece and preparation method and application thereof | |
| CN109868422B (en) | Powder metallurgy rigid wheel and preparation method thereof | |
| US20090142219A1 (en) | Sinter-hardening powder and their sintered compacts | |
| CN115805312A (en) | Preparation method of high-strength iron-based powder metallurgy gear | |
| CN111922345B (en) | Comprehensive utilization method of powder by-product generated in spray forming process and application of product | |
| CN114686745A (en) | Powder metallurgy modified low-alloy ultrahigh-strength steel and preparation method thereof | |
| CN113649560A (en) | Preparation method of special mixed powder for automobile gear hubs |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |