CN112059169A - Production method of iron-based premixed powder for engine rotor - Google Patents
Production method of iron-based premixed powder for engine rotor Download PDFInfo
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- CN112059169A CN112059169A CN202010802327.6A CN202010802327A CN112059169A CN 112059169 A CN112059169 A CN 112059169A CN 202010802327 A CN202010802327 A CN 202010802327A CN 112059169 A CN112059169 A CN 112059169A
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- 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
Abstract
The invention provides a production method of iron-based premixed powder for an engine rotor, which comprises the following components: base powder LAP100.29D1, graphite, cutting agent and lubricant. The pine ratio of the mixed powder prepared by the invention is 3.1-3.15 g/cm3A fluidity of 31.5 to 32 sec/50g and a compressibility of 7.01 to 7.05 g/cm3(ii) a The invention takes the diffusion type alloy steel powder as the base powder, adds the graphite and the cutting auxiliary agent, the sintered product obtains enough high-pressure manufacturing performance, and simultaneously the uniformity of alloy components such as copper, nickel, molybdenum and the like is ensured, the performance of the sintered blank prepared by the mixed powder of the invention is as follows: the dimensional change rate is within-1.0 per thousand, the expansion rate is within-0.35 to-0.38 per thousand, the elongation is 1.3 to 1.33 percent, the tensile strength is 550-555 MPa, and the yield strength is 415-418 MPa.
Description
Technical Field
The invention relates to a production method of iron-based premixed powder for an engine rotor, belonging to the technical field of materials for the engine rotor.
Background
The rotary engine converts the combustion expansion force of combustible gas into driving torque, and compared with a reciprocating engine, the rotary engine omits useless linear motion, so that the rotary engine with the same power has the advantages of small size, light weight, low vibration and noise and great advantage. The engine fuel pump rotor produced by the powder metallurgy method is the most typical high-end powder metallurgy product and has the advantages of high production efficiency, low cost, long product wear-resisting life, good stability and the like.
The existing preparation method of iron-based premixed powder for the engine rotor is characterized in that pure iron powder is used as base powder, nickel powder, copper powder, molybdenum iron powder, graphite, a cutting aid and a lubricant are added, and the iron-based premixed powder is prepared by a direct mixing method.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a production method of iron-based premixed powder for an engine rotor, which aims to realize the following purposes:
(1) the element segregation is avoided, the stable performance of the finished piece is ensured, the size change rate is low, the strength is high, and the toughness is good;
(2) the fluidity of the mixed powder is good.
In order to solve the technical problems, the invention adopts the following technical scheme:
a method for producing an iron-based premixed powder for an engine rotor, the premixed powder comprising the following components:
base powder LAP100.29D1, graphite, cutting agent and lubricant.
The mixed powder comprises the following components in parts by weight:
LAP100.29D198.1-98.2 parts of base powder, 0.7-0.8 part of graphite, 0.35-0.45 part of cutting agent and 0.65-0.75 part of lubricant.
The mixed powder comprises the following components in parts by weight:
LAP100.29D198.15 parts of base powder, 0.75 part of graphite, 0.4 part of cutting agent and 0.7 part of lubricant.
The model of the graphite is TRSMGF-19998; the type of the cutting agent is T-1; the lubricant comprises SKZ-320 and SKZ-600 in a mass ratio of 5: 2.
The production method comprises the steps of feeding, mixing, screening and receiving materials; and the material feeding comprises the steps of firstly adding half of the base powder, then adding the cutting agent, the graphite and the lubricant, and then adding the other half of the base powder.
Mixing for 25-35min at 20-25 r/min.
Mixing, and controlling the temperature to be 25-40 ℃.
The mixed powder, D50 was 75 um.
Compared with the prior art, the invention has the following beneficial effects:
(1) the mixed powder prepared by the invention has the carbon content of 1.1-1.2 percent, the graphite content of 0.6-0.65 percent, the sulfur content of 0.02-0.025 percent, the nickel content of 1.72-1.73 percent, the molybdenum content of 0.51-0.52 percent, the copper content of 1.6-1.7 percent and the bulk ratio of 3.1-3.15 g/cm3A fluidity of 31.5 to 32 sec/50g and a compressibility of 7.01 to 7.05 g/cm3。
(2) The invention takes the diffusion type alloy steel powder as the base powder, adds the graphite and the cutting auxiliary agent, ensures the uniformity of alloy components such as copper, nickel, molybdenum and the like when the sintered product obtains enough high-pressure manufacturing performance, is beneficial to the consistency of product precision, strength and the like among batches, and the sintered blank prepared by the mixed powder has the following properties: the dimensional change rate is within-1.0 per thousand, the expansion rate is within-0.35 to-0.38 per thousand, the elongation is 1.3 to 1.33 percent, the tensile strength is 550-555 MPa, the yield strength is 415-418 MPa, the consistency of products among batches is high, the standard deviation of the expansion rate is 0.28 to 0.32 per thousand, the standard deviation of the elongation is 0.13 to 0.15 percent, the standard deviation of the tensile strength is 8.5 to 8.6 MPa, and the standard deviation of the yield strength is 11.2 to 11.3 MPa.
(3) The material has the advantages of uniform components, high compressibility, high flow rate, good filling performance, consistent sintered part size, high strength and toughness and the like, and can meet various requirements of the powder for the rotor.
Drawings
FIG. 1 is a diagram of a sample for measuring mechanical force;
FIG. 2 is an electron micrograph of the mixed powder prepared in example 1.
Detailed Description
EXAMPLE 1 production method of iron-based premixed powder for engine rotor
The production method is a stirring type direct mixing method; the method comprises the following specific steps:
(1) charging of
Adding base powder and auxiliary materials which are prepared in advance according to a single material into a BR-71 type high specific weight powder flexible mixer, and adding half of the base powder, a cutting agent, graphite and a lubricant in the feeding sequence, and then adding the other half of the base powder;
the mass ratio of the base powder to the graphite to the cutting agent to the lubricant is as follows: 98.15:0.75:0.4: 0.70;
the base powder comprises the following components: LAP100.29D1 (alloyed with Ni, Mo and Cu), diffusion type alloy steel powder, manufactured by Laiwu Steel group powder metallurgy Co., Ltd.;
the cutting agent is a T-1 cutting agent, and the effective component is CaF, produced by Guangzhou Qing sailing new material Co., Ltd;
the lubricant is SKZ-320, and is produced by Guangzhou Qingfan Xiang new material Co.Ltd;
the graphite is produced by TRSMGF-19998, Ningbo Haisha Timber company.
(2) Mixing
After the feeding is finished, the mixer is started to mix for 30min at the rotating speed of 22 r/min.
(3) Screening, receiving and packaging
And (3) starting screening after the material mixing is finished (the screen adopts a Taylor standard 60-mesh screen with the aperture of 250 mu m), directly connecting the undersize into a packaging bag for packaging while screening, firstly placing a special wood tray on the scale surface, sleeving the packaging bag on a packaging frame sleeve, then lifting a hydraulic platform to the highest point, then sequentially opening a discharge valve of the mixing machine, a straight-line screen and a pneumatic butterfly valve of a material receiving pipe for starting material receiving, properly descending the hydraulic platform when the material receiving pipe is full of the screening machine and stops under the action of a material level meter, automatically starting the screening machine again to continue material receiving, stopping descending the hydraulic platform when the weight of the electronic scale shows 900kg, closing the pneumatic butterfly valve of the material receiving pipe after the screening machine stops again, putting down the hydraulic lifting platform, finishing material receiving and obtaining mixed powder.
D50 (median diameter) of the mixed powder is 75um, and the purpose of screening is to remove trace agglomerates generated in the mixing process of individual light materials; the appearance quality requirement is as follows: no oxidation, agglomeration, inclusion and the like.
The detection of the physical properties of the finished product is all carried out according to relevant national standards. The bulk ratio is measured according to a method for measuring the bulk density of GB/T1479.1-2011 metal powder, powder falls into a cup with a known volume from a standard funnel in a loose state, and the mass of the powder in a unit volume is measured, wherein the unit is as follows: g/cm3. The fluidity is measured according to the GB/T1482-2010 standard funnel method (Hall flow meter), and specifically means the time, unit, required for 50g of metal powder to pass through a standard funnel with a specified pore diameter: sec/50 g. The apparent density and fluidity were measured using a Hall flow meter. The particle size detection adopts an S49-200 type vibrating screen machine, and measures the particle size composition of metal powder according to GB/T1480-2012 (dry screening method), the principle is that a set of test screens which are sequentially combined according to the sizes of screen holes are used, the metal powder is screened into different particle size grades by means of vibration, the powder amount on each screen and on a chassis is weighed, the percentage content of each particle size grade is calculated, and thus the particle size composition and unit of the powder are obtained: % by mass. The compressibility is detected by using a YAW-300 BII type microcomputer control electro-hydraulic servo pressure tester, and metal powder (excluding hard alloy powder) is compressed in a uniaxial pressing mode according to GB/T1481-2012The principle of the method for measuring the properties is that a powder sample is pressed under a predetermined pressure, and the obtained green density represents the compressibility of the powder under the predetermined pressure, in units of: g/cm3. In the process of measuring the compressibility of the powder, the demolding force can be directly read from a compression tester at the time of demolding, and the unit: kN.
Different from pure iron powder, the mixed powder is added with a lubricant which is mostly hydrocarbon or polymer, so that the carbon content of a finished product is higher than the addition amount of actual graphite. In order to accurately check the carbon content of the finished product, the mixed powder sample needs to be placed in SX2Roasting in a-5-12 type box-type resistance furnace at the high temperature of 500 ℃ for 30min, roasting and dewaxing the powder, and detecting the powder to obtain the carbon content which can be approximate to the graphite addition (the difference of the graphite content before and after roasting is the carbon content of the lubricant, and the addition can be roughly converted according to the molecular weight of the lubricant). C. The content of S was measured using a Beijing Nake CS-2800 carbon sulfur instrument, unit: % by mass. Ni, Mo, Cu were measured directly using a Plasma 1000 type ICP-AES spectrometer with the units: % by mass.
Sintering property test the forming pressure was 600MPa, and the dimensional change rate, elongation, tensile strength, impact power and the like of the sample after sintering were measured by pressing a tensile test specimen (execution standard: GB/T228.1-2010), an impact test specimen (execution standard: GB/T5318-1985). The mechanical test bars are shown in FIG. 1. Sintering temperature 1150 deg.C, using H2Protecting and keeping the temperature for 60 min. Performing heat treatment at 850 ℃ for 1h, taking out, and quickly putting into 10# engine oil for cooling; and (4) deoiling the cooled sample, putting the sample into the resistance furnace again, preserving the heat at 200 ℃ for 1h, and taking out the sample for air cooling. The test density was measured by draining. Analyzing the tensile strength of the sintered blank by a mechanical tensile test; the impact work was measured using an impact tester.
The performance indexes of the mixed powder prepared in example 1 are shown in table 1, and the scanning electron micrograph of the product is shown in fig. 2.
Table 1: physical and chemical property detection results of the mixed powder finished product prepared in example 1
CAfter burningIs the carbon content after removal of the lubricant by low temperature heating (200 deg.c), indicating the mass fraction of graphite.
According to the results in table 1, the mixed powder prepared in example 1 has stable chemical components and meets the standard requirements, and the physical properties, the bulk density and the compressibility meet the requirements, but the flowability is different from the requirements, the flowability is one of the important process parameters of powder metallurgy, the quality of the flowability directly affects the production efficiency, and for complex-shaped parts, elongated parts, large-height parts and the like, the poor flowability causes poor filling of a mold during powder filling and even bridging to affect the forming and density uniformity of the parts. Many factors affect the fluidity, including loose packed density, particle size composition, particle morphology, lubricant, etc., and in the case of determining the base powder graphite, cutting agent, etc., the most important factor affecting the fluidity of the mixed powder is the lubricant.
In order to improve the flow properties of the mixed powder prepared in example 1, example 2 was optimized with respect to the type and ratio of the lubricant.
Example 2
Taking Fe-C-Cu series iron-based powder metallurgy materials which are most widely applied as an example, water atomized pure iron powder LAP100.29 produced by the company is used as base powder, 200-mesh copper powder FTD-3 produced by Beijing Sukiku-Miao material company and graphite F10 produced by Swiss with extra density are used as alloy element powder, and W-special, E-206, SUW-5000B, MP32, SKZ-600, Lubricant-C-wax and SKZ-320 are respectively selected as lubricating agents, and 7 tests are carried out by using a direct mixing method according to the same mixture ratio of Fe +0.8% C +2.0% Cu +0.8% Lub. Each batch of the finished products was sampled 3 times, and the bulk, flowability, compressibility, and mold release force were measured and averaged, and the results are shown in Table 2.
Table 2: results of physical Properties measurements of Mixed powders Using different lubricants
Analysis of table 2 shows that different lubricants have significant impact on the physical properties of the finished powder blend when the same process and blend ratio are used. In terms of fluidity, the worst 7# sample differs from the fastest 5# sample by 6.8sec/50 g.
The 7# sample has the advantages of good lubricity, low press release force, high green density but poor flow properties, while the 5# sample has good flow properties but high press release force.
In order to ensure at the same time a high bulk and compressibility of the mixed powder and a fast flow rate, in combination with the above results, the lubricant was adjusted to SKZ-320: SKZ-600= 5:2, and the test is carried out again according to the formula and the process (Fe +0.8% C +2.0% Cu +0.8% Lub), and the detection results of the finished products are shown in table 3.
TABLE 3 physical Properties of the powders tested with lubricants
From Table 3, the combination of lubricants SKZ-320: SKZ-600= 5:2, the pressing performance of the mixed powder finished product is kept at a higher level, and meanwhile, the demoulding force is low, the bulk ratio is high, and the flowing performance is excellent.
Example 3
When the direct mixing method is used, the phenomena of poor product flowing performance, low loose ratio and the like tend to occur in winter.
The temperature difference between winter and summer in northern China is 50-60 ℃, so that the lubricant is easy to agglomerate and is difficult to separate in the direct method mixing process due to the huge temperature difference, white spots which can be identified by naked eyes appear in mixed powder, and the apparent density and low flow property are poor in quality.
The properties of the mixed powders prepared at different mixing temperatures are shown in Table 4.
Table 4: physical property detection result of mixed powder at different mixing temperatures
According to the results in Table 4, when the lubricant is used in a low temperature environment, the apparent density is reduced, the fluidity is remarkably deteriorated, and when SKZ-320 is used as the lubricant, the fluidity index of 1# is larger than that of 2# by 2.1 sec/50g, and the fluidity index of 3# in which heat transfer oil is introduced at 40 ℃ is smaller than that of 2# by 2.5 sec/50g, the difference is remarkable (in the field, the fluidity difference is 1 sec/50g, which is a very remarkable difference).
Through the tests, the mixture ratio is adjusted to LAP100.29D1+0.75% of C +0.4% of CaF +0.5% of Lub (SKZ-320) +0.2% of Lub (SKZ-600), meanwhile, heat conduction oil with the temperature of 40 ℃ is introduced into the equipment in cold weather, the preparation method of the mixed powder is the same as that of example 1, and the test production is carried out again, and the results of the finished product are shown in Table 5.
The base powder comprises the following components: LAP100.29D1 (alloyed with Ni, Mo and Cu), diffusion type alloy steel powder, manufactured by Laiwu Steel group powder metallurgy Co., Ltd.;
the cutting agent is a T-1 cutting agent, and the effective component is CaF, produced by Guangzhou Qing sailing new material Co., Ltd;
the graphite is produced by TRSMGF-19998, Ningbo Haisha Timber company;
the D50 (median diameter) of the prepared mixed powder is 75 um.
TABLE 5 results of physicochemical Properties measurements of the Mixed powders prepared according to the present invention
Further sintering property results are shown in table 6. The dimensional change rate is within-1.0 per mill, the strength is high, the toughness is good, and the sintering performance index can meet the requirement.
TABLE 6 sintering Property test results
Unless otherwise specified, the proportions used in the present invention are mass ratios, and the percentages used are mass percentages.
Claims (8)
1. A production method of iron-based premixed powder for an engine rotor is characterized by comprising the following steps: the mixed powder comprises the following components:
base powder LAP100.29D1, graphite, cutting agent and lubricant.
2. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 1, wherein: the mixed powder comprises the following components in parts by weight:
LAP100.29D198.1-98.2 parts of base powder, 0.7-0.8 part of graphite, 0.35-0.45 part of cutting agent and 0.65-0.75 part of lubricant.
3. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 1, wherein: the mixed powder comprises the following components in parts by weight:
LAP100.29D198.15 parts of base powder, 0.75 part of graphite, 0.4 part of cutting agent and 0.7 part of lubricant.
4. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 1, wherein: the model of the graphite is TRSMGF-19998; the type of the cutting agent is T-1; the lubricant comprises SKZ-320 and SKZ-600 in a mass ratio of 5: 2.
5. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 1, wherein: the production method comprises the steps of feeding, mixing, screening and receiving materials; and the material feeding comprises the steps of firstly adding half of the base powder, then adding the cutting agent, the graphite and the lubricant, and then adding the other half of the base powder.
6. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 5, wherein: mixing for 25-35min at 20-25 r/min.
7. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 5, wherein: mixing, and controlling the temperature to be 25-40 ℃.
8. The method for producing an iron-based premixed powder for an engine rotor as claimed in claim 5, wherein: the mixed powder, D50 was 75 um.
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Citations (5)
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|---|---|---|---|---|
| CN1631583A (en) * | 2004-12-24 | 2005-06-29 | 上海汽车股份有限公司 | Powder metallurgy manufacturing method of inside and outside rotor in oil pump |
| CN102069187A (en) * | 2011-03-01 | 2011-05-25 | 杭州寰宇粉体科技有限公司 | Mixing method of iron-based powder metallurgy bonding powder |
| CN102179519A (en) * | 2011-03-09 | 2011-09-14 | 宁波甬台粉末冶金有限公司 | Powder metallurgy transmission gear and manufacturing method thereof |
| CN105537580A (en) * | 2015-12-28 | 2016-05-04 | 钢铁研究总院 | Iron-based premixed powder for powder metallurgy and preparation method of iron-based premixed powder |
| CN105945276A (en) * | 2016-07-27 | 2016-09-21 | 黄宇 | Novel high-performance metallurgy powder |
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2020
- 2020-08-11 CN CN202010802327.6A patent/CN112059169B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1631583A (en) * | 2004-12-24 | 2005-06-29 | 上海汽车股份有限公司 | Powder metallurgy manufacturing method of inside and outside rotor in oil pump |
| CN102069187A (en) * | 2011-03-01 | 2011-05-25 | 杭州寰宇粉体科技有限公司 | Mixing method of iron-based powder metallurgy bonding powder |
| CN102179519A (en) * | 2011-03-09 | 2011-09-14 | 宁波甬台粉末冶金有限公司 | Powder metallurgy transmission gear and manufacturing method thereof |
| CN105537580A (en) * | 2015-12-28 | 2016-05-04 | 钢铁研究总院 | Iron-based premixed powder for powder metallurgy and preparation method of iron-based premixed powder |
| CN105945276A (en) * | 2016-07-27 | 2016-09-21 | 黄宇 | Novel high-performance metallurgy powder |
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