CN114959412B - Method for improving structure and performance of additive manufacturing alloy steel - Google Patents
Method for improving structure and performance of additive manufacturing alloy steel Download PDFInfo
- Publication number
- CN114959412B CN114959412B CN202210607202.7A CN202210607202A CN114959412B CN 114959412 B CN114959412 B CN 114959412B CN 202210607202 A CN202210607202 A CN 202210607202A CN 114959412 B CN114959412 B CN 114959412B
- Authority
- CN
- China
- Prior art keywords
- powder
- alloy steel
- additive manufacturing
- mixed
- laser
- 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.)
- Active
Links
Images
Classifications
-
- 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
-
- 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
- B22F1/14—Treatment of metallic powder
- B22F1/142—Thermal or thermo-mechanical treatment
-
- 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
- B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
- B22F10/30—Process control
- B22F10/32—Process control of the atmosphere, e.g. composition or pressure in a building chamber
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y10/00—Processes of additive manufacturing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
- B33Y40/10—Pre-treatment
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Abstract
The invention belongs to the technical field of additive manufacturing alloy steel, and particularly relates to a method for improving the structure and the performance of additive manufacturing alloy steel, which comprises the following specific steps: uniformly mixing the mixed REO powder and the alloy steel powder in a certain proportion by adopting a ball milling method, and then sealing and storing; drying and dehumidifying the uniformly mixed powder; grinding the surface of a base material by using abrasive paper by using Q235 steel as the base material for later use; and putting the dried powder into laser additive manufacturing equipment, performing metal additive manufacturing on a base material under the protection of inert gas, and obtaining the alloy steel after laser, scanning, powder feeding and deposition. According to the invention, the problems of coarse grains in the alloy steel manufactured by additive manufacturing, different structure transformation processes at different positions and the like are solved by adding the multiple rare earth oxide mixed powders, and the obtained alloy steel has compact and uniform laser deposition structure and good comprehensive mechanical properties.
Description
Technical Field
The invention belongs to the technical field of additive manufacturing alloy steel, and particularly relates to a method for improving the structure and performance of additive manufacturing alloy steel by adding rare earth oxide.
Background
The 34CrNiMo6 steel has high strength, good ductility and excellent corrosion resistance, is widely applied to core components of large-scale members, and parts of the 34CrNiMo6 steel usually bear dynamic and random load effects and fail in the service process, so that great disasters and economic losses can be caused. The defects of low material utilization rate, long manufacturing period, high cost and the like exist in the process of preparing large and complex 34CrNiMo6 steel parts by using the traditional processing method, so that the further development and application of the 34CrNiMo6 steel are restricted to a great extent. The appearance of the laser three-dimensional forming technology shortens the manufacturing period of parts, saves the manufacturing cost and greatly improves the forming efficiency. In addition, because the manufacturing process is near-net-shape forming, only simple subsequent processing is needed, the manufacturing cost is greatly reduced, and high-performance complex structural parts are applied to many industries. Like common laser processing, the change of temperature gradient and solidification speed in the laser three-dimensional forming process forms unique supercooling degree, so that the crystal grains in the material are large, the structure transformation processes at different positions are different, and the service performances such as mechanical property and the like of parts are influenced.
The method for improving the structure and mechanical properties of the additive manufacturing alloy steel mainly comprises the step of adding some common metal oxide powder into alloy steel powder to improve the structure and mechanical properties of the additive manufacturing alloy steel. In the Chinese patent with the application number of 2017107068032, the self-melting performance of alloy steel powder is improved by mixing stainless steel powder in the alloy steel powder, so that the compact, uniform and good comprehensive mechanical property of an alloy steel laser deposition structure is obtained, but the amount of the stainless steel powder added is large, and the performance of the original alloy steel is influenced to a certain extent.
In view of the above, there is a need to find a method for effectively improving the structure and mechanical properties of the alloy steel for additive manufacturing.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to solve the problems of coarse grains, non-uniform structure and poor mechanical property of alloy steel in the additive manufacturing process, and provides a method for improving the structure and the performance of alloy steel manufactured by laser additive manufacturing.
In order to achieve the above object, the present invention provides a method for improving the structure and properties of an additive manufacturing alloy steel, comprising the following specific steps:
s1, uniformly mixing mixed REO powder and alloy steel powder in a certain proportion by adopting a ball milling method, and then sealing and storing;
s2, drying and dehumidifying the uniformly mixed powder in the S1, wherein the preset drying temperature is 120 ℃, the drying time is not less than 5h, cooling to room temperature in a drying furnace after drying, and dehumidifying for later use; adopting Q235 steel as a base material, polishing the surface of the base material by using sand paper, cleaning by using acetone and drying for later use; the polishing of the substrate is not required to be excessively bright, so that the laser is prevented from being burnt out due to high reflection.
And S3, putting the powder in the S2 into laser additive manufacturing equipment, performing metal additive manufacturing on the base material under the protection of inert gas, and obtaining the alloy steel after laser, scanning, powder feeding and deposition. Specifically, the inert gas is argon, and the argon is used for protection in the whole processing process and the powder feeding process.
The Rare Earth Oxide (REO) can effectively refine crystal grains and reduce the defects in the parts, a new phase can be formed in a sample by adding the mixed Rare Earth Oxide in the technical scheme, and the mixed Rare Earth Oxide can act on the microstructure of 34CrNiMo6 steel in a synergistic manner, so that the mixed Rare Earth Oxide has strong adsorption property on peripheral substances, and meanwhile, because the mixed Rare Earth has small ionic radius difference and the adsorption strength is basically consistent, a large tearing force cannot be generated on peripheral crystal boundaries, and the displacement of crystal lattices and the deformation of the area of the crystal boundaries are effectively avoided.
Further, in the above technical solution, the content of the mixed REO powder is 1 to 4wt.% of the total amount of the mixed REO powder and the alloy steel powder.
Further, in the above technical scheme, the mixed REO powder is CeO 2 Powder and Y 2 O 3 The powder weight ratio is 1.
The inventors have found, through preliminary studies, that by adding CeO 2 The powder can also improve the structure and the performance of the alloy steel manufactured by laser additive to a certain extent, and the main action mechanism is that the powder is processedPart of CeO in the equation 2 The Ce is decomposed into Ce atoms, the rare earth Ce is used as an active agent in the forming process, and the pinning effect is realized through the movement between a phase boundary and crystal grains under the adsorption action, so that the crystal grains are refined; in addition, ceO partially unmelted 2 Can be used as a heterogeneous nucleation core to form new second phase particles which are used as impurity phases to keep partial melting and further refine grains, but the effect of the single rare earth oxide on parts is often highlighted and has limited improvement effect in a specific aspect. The inventors have found, through further studies, that CeO is added 2 Powder and Y 2 O 3 After powdering of two rare earth oxides, ce 4+ And Y 3+ The rare earth ions act on the microstructure in a synergistic manner, so that the microstructure has a strong adsorption property on peripheral substances, and simultaneously, the strength and the weakness of the adsorption are generally consistent due to small difference of radiuses of the two rare earth ions, so that a large tearing force cannot be generated on peripheral grain boundaries, the displacement of the crystal lattices and the deformation of the area of the grain boundaries can be effectively avoided, and the structure and the performance of the obtained additive manufacturing alloy steel are further improved.
Further, in the above technical scheme, the CeO 2 The powder has a particle size of 40-60nm, a purity of 99.9%, and a density of 0.96g/cm 3 (ii) a Said Y is 2 O 3 The powder has a particle size of 45-55nm, a purity of 99.9%, and a density of 0.48g/cm 3 。
The mixed REO powder has good alloying and solid solution strengthening effects, and can interact with elements such as Cr, ni, mo and the like, so that the microstructure of a deposited sample is improved.
Furthermore, the alloy steel powder in the technical scheme is spherical 34CrNiMo6 steel powder prepared by a plasma rotating electrode method, and the diameter is 53-150 μm.
Further, in the technical scheme S1, the ball milling method includes: the ball milling speed is 450-550r/min, the working mode of combining forward rotation for 20min, pause for 5min and reverse rotation for 20min is adopted, the ball milling time of each group is 5-7h, and the ball material ratio is 2.
Further, in the technical scheme S3, the power range of the laser is 1000-1800W, the scanning speed is 600-900mm/min, and the powder feeding speed is 7.5-17g/min.
Further, in the above technical solution S3, the power of the laser is 1000W, the scanning speed is 600mm/min, and the powder feeding rate is 10g/min.
Further, in the above technical solution S3, the deposition is performed in a manner of pausing for 15S after 30 layers are deposited each time. According to the invention, 30 layers are deposited each time and then are suspended for 15s in the forming process, so that the forming influence caused by excessive heat accumulation can be effectively avoided, and the forming precision is improved.
The invention has the beneficial effects that:
according to the invention, the formation of a new phase on the surface of a deposition layer can be effectively promoted by adding the mixed REO powder, the displacement of crystal lattices and the deformation of the area of crystal boundaries are avoided, the obtained alloy steel laser deposition structure is compact and uniform, the crystal grains are refined, and the integral comprehensive mechanical property of the part can be effectively improved.
The invention adopts laser additive manufacturing, not only overcomes the defects of low material utilization rate, long manufacturing period, higher cost and the like of large and complex 34CrNiMo6 steel parts prepared by the traditional processing method, but also effectively improves the structure and performance of alloy steel and improves the applicability of the alloy steel by adding mixed rare earth oxide.
Drawings
FIG. 1 is a schematic illustration of a laser additive manufacturing process of the present invention;
FIG. 2 shows CeO in the mixed REO powder of the present invention 2 SEM image of (50 nm);
FIG. 3 shows Y in the mixed REO powder of the present invention 2 O 3 SEM picture (50 nm);
FIG. 4 is a microstructure topography of 34CrNiMo6 steel samples manufactured by laser additive manufacturing with different rare earth oxide contents according to the invention;
FIG. 5 is a transmission electron micrograph of carbides in 34CrNiMo6 steel test samples manufactured by laser additive manufacturing with different rare earth oxide contents according to the present invention, wherein (a) is a deposited test sample of comparative example 1 without adding rare earth oxide, and (b) is a deposited test sample of comparative example 2 with 2wt.% CeO added 2 FIG. C shows the addition of 1wt.% CeO for example 1 2 +1wt.％Y 2 O 3 FIG. d shows comparative example 3 with 1wt.% CeO added 2 +1wt.％Y 2 O 3 The deposition sample (quenched and tempered state);
FIG. 6 is a stress-strain curve of the 34CrNiMo6 steel manufactured by laser additive manufacturing with different rare earth oxide contents according to the invention;
FIG. 7 is a comparison graph of average microhardness of deposited samples of 34CrNiMo6 steel manufactured by laser additive manufacturing with different rare earth oxide contents according to the invention;
FIG. 8 is an XRD spectrum of a 34CrNiMo6 steel deposition state sample manufactured by laser additive manufacturing with different mixed rare earth oxide contents.
Detailed Description
The experimental procedures in the following examples are all conventional ones unless otherwise specified. The raw materials in the following examples are all commercially available products and are commercially available, unless otherwise specified.
The invention relates to a method for improving the structure and performance of additive manufacturing alloy steel, and FIG. 1 is a schematic diagram of laser additive manufacturing processing, which comprises the following specific steps:
s1, mixing CeO in a certain proportion 2 、Y 2 O 3 Uniformly mixing the powder and 34CrNiMo6 alloy steel powder by adopting a ball milling method, and then sealing and storing; wherein, ceO 2 SEM photograph of the powder is shown in FIG. 2, Y 2 O 3 SEM photograph of powder is shown in FIG. 3, ceO 2 、Y 2 O 3 In a content of CeO 2 +Y 2 O 3 1-4wt.% of +34CrNiMo 6; specifically, the 34CrNiMo6 alloy steel powder is spherical, and the diameter is 53-150 μm; ceO (CeO) 2 The powder has a particle size of 40-60nm, a purity of 99.9%, and a density of 0.96g/cm 3 Rare earth oxide Y 2 O 3 The powder has a particle size of 45-55nm, a purity of 99.9%, and a density of 0.48g/cm 3 . The ball milling speed is 450-550r/min, the working mode of combining forward rotation for 20min, intermittent rotation for 5min and reverse rotation for 20min is adopted, the ball milling time of each group is 5-7h, and the ball material ratio is 2.
S2, drying and dehumidifying the uniformly mixed powder in the S1, wherein the preset drying temperature is 120 ℃, the drying time is not less than 5h, cooling to room temperature in a drying furnace after drying, and dehumidifying for later use; adopting Q235 steel as a base material, polishing the surface of the base material by using abrasive paper, cleaning by using acetone, and drying for later use;
and S3, putting the powder in the step S2 into laser additive manufacturing equipment, performing metal additive manufacturing on the base material under the protection of inert gas, and obtaining the alloy steel after laser, scanning, powder feeding and deposition. The inert gas is argon, and the argon is used for protection in the whole processing process and the powder feeding process. The laser power range is 1000-1800W, the scanning speed range is 600-900mm/min, and the powder feeding rate is 7.5-17g/min. Under the combined action of a laser and a powder feeder, after the mixed rare earth oxide is added, the mixed REO powder is cooperated with the microstructure of 34CrNiMo6 steel, so that the adsorption performance to peripheral substances is stronger, and the strength of the adsorption is generally consistent due to small difference of radiuses of two rare earth ions, so that large tearing force can not be generated to peripheral crystal boundaries, and displacement of crystal lattices and deformation of the area of the crystal boundaries are avoided.
The invention is described in further detail below with reference to the figures and examples:
example 1
A method for improving the structure and the performance of the additive manufacturing alloy steel comprises the following specific steps:
s1, mixing CeO in a certain proportion 2 、Y 2 O 3 Uniformly mixing the powder and 34CrNiMo6 alloy steel powder by adopting a ball milling method, and then sealing and storing; wherein, ceO 2 、Y 2 O 3 In a content of CeO 2 +Y 2 O 3 +34CrNiMo6 Total 2wt.%, ceO 2 、Y 2 O 3 Each at 1wt.%; ceO (CeO) 2 The powder had a particle size of 40nm, a purity of 99.9% and a density of 0.96g/cm 3 Rare earth oxide Y 2 O 3 The particle size of the powder was 50nm, the purity of the powder was 99.9%, and the density was 0.48g/cm 3 . The ball milling speed is 500r/min, the working mode of combining forward rotation for 20min, pause for 5min and reverse rotation for 20min is adopted, the ball milling time of each group is 6h, and the ball material ratio is 2.
S2, drying and dehumidifying the uniformly mixed powder in the S1, wherein the preset drying temperature is 120 ℃, the drying time is not less than 5h, and cooling to room temperature in a drying furnace after drying for dehumidification for later use; adopting Q235 steel as a base material, polishing the surface of the base material by using sand paper, cleaning by using acetone and drying for later use;
and S3, putting the powder in the step S2 into laser additive manufacturing equipment, performing metal additive manufacturing on the base material under the protection of inert gas, and obtaining the alloy steel after laser, scanning, powder feeding and deposition. Wherein the laser power is 1000W, the scanning speed is 600mm/min, the powder feeding speed is 10g/min, and the time is suspended for 15s after 30 layers are deposited each time.
Example 2
A method for improving the structure and the performance of the additive manufacturing alloy steel comprises the following specific steps:
s1, mixing CeO in a certain proportion 2 、Y 2 O 3 Uniformly mixing the powder and 34CrNiMo6 alloy steel powder by adopting a ball milling method, and then sealing and storing; wherein, ceO 2 、Y 2 O 3 In a content of CeO 2 +Y 2 O 3 +34CrNiMo6 Total 4wt.%, ceO 2 、Y 2 O 3 The contents of (b) are each 2wt.%; ceO (CeO) 2 The particle size of the powder was 60nm, the purity of the powder was 99.9%, and the density was 0.96g/cm 3 Rare earth oxide Y 2 O 3 The particle size of the powder was 55nm, the purity of the powder was 99.9%, and the density was 0.48g/cm 3 . The ball milling speed is 550r/min, the working mode of combining forward rotation for 20min, pause for 5min and reverse rotation for 20min is adopted, the ball milling time of each group is 7h, and the ball-material ratio is 2.
S2, drying and dehumidifying the uniformly mixed powder in the S1, wherein the preset drying temperature is 120 ℃, the drying time is not less than 5h, cooling to room temperature in a drying furnace after drying, and dehumidifying for later use; adopting Q235 steel as a base material, polishing the surface of the base material by using sand paper, cleaning by using acetone and drying for later use;
and S3, putting the powder in the S2 into laser additive manufacturing equipment, performing metal additive manufacturing on the base material under the protection of inert gas, and obtaining the alloy steel after laser, scanning, powder feeding and deposition. Wherein the laser power is 1800W, the scanning speed is 900mm/min, the powder feeding rate is 17g/min, and the time is suspended for 15s after 30 layers are deposited each time.
Comparative example 1
A machining method for additive manufacturing of alloy steel comprises the following specific steps: taking 34CrNiMo6 steel powder, and putting the single steel powder into laser three-dimensional forming equipment. Additive manufacturing is carried out on a Q235 steel substrate, the laser power is 1000W, the scanning speed is 600mm/min, and the powder feeding speed is 10g/min.
Comparative example 2
A method for improving the structure and performance of alloy steel made by additive features that the rare-earth oxide powder is CeO 2 Powder of CeO 2 The content of the powder is CeO 2 +34CrNiMo6 in 2wt.%, otherwise as in example 1.
Comparative example 3
A method for improving the structure and performance of alloy steel manufactured by additive manufacturing adopts a thermal refining method of preserving heat at 830 ℃ for 1h + oil quenching and preserving heat at 540 ℃ for 2h + air cooling in the processing process, and other methods are the same as the embodiment 1.
Test example 1
The microstructure morphology and carbide of the 34CrNiMo6 alloy steel samples prepared in examples 1-2 and comparative examples 1-3 were observed by scanning electron microscopy and transmission electron microscopy, and the results are shown in FIGS. 4 and 5, respectively.
As can be seen from FIG. 4, in FIG. (a), the microstructure of the deposit sample of comparative example 1, to which no rare earth oxide is added, is mainly composed of martensite and a small amount of bainite, and has a relatively coarse structure, and the austenite grains have an average size of about 20 to 30 μm; FIG. b shows comparative example 2 with 2wt.% CeO added 2 The microstructure appearance of the sediment sample is obviously refined, the average size of austenite grains is about 8-15 mu m, but the uniformity of the grain structure is poor; FIG. c shows the addition of 1wt.% CeO in example 1 2 +1wt.％Y 2 O 3 Compared with a martensite structure and a bainite structure in a graph (b), the microstructure appearance of the sediment sample is finer, the average size of austenite grains is about 5-10 mu m, and the uniformity of the grain structure is better; FIG. d shows the addition of 2wt.% CeO in example 2 2 +2wt.％Y 2 O 3 Is heavyAccumulating the microstructure appearance of the sample; FIG. e shows comparative example 3 with 1wt.% CeO added 2 +1wt.％Y 2 O 3 The microstructure morphology of the quenched and tempered sample mainly comprises tempered sorbite, more granular carbides are dispersed on the surface of the tempered sorbite, and the average size of austenite grains is about 10-25 mu m.
In conclusion, it can be concluded that the microstructure does not decrease gradually with the increase of the addition amount of the mixed rare earth oxide all the time, but example 2 adds 2wt.% of CeO 2 +2wt.％Y 2 O 3 The sizes of austenite grains, martensite and bainite are obviously increased compared with the size of the sample in the example 1, but are still better than the deposited sample without adding rare earth oxide in the comparative example 1; quenched and tempered 1wt.% CeO 2 +1wt.％Y 2 O 3 The austenite grain structure uniformity of the sample was deteriorated and the precipitation amount of carbides was increased.
FIG. 5 is a transmission electron micrograph of carbides in laser additive manufactured 34CrNiMo6 steel samples with different rare earth oxide contents, wherein (a) shows a deposited sample without rare earth oxide addition in comparative example 1, and (b) shows a deposited sample with 2wt.% CeO addition in comparative example 2 2 FIG. (c) shows example 1 with 1wt.% CeO added 2 +1wt.％Y 2 O 3 The as-deposited samples were examined by selecting diffraction spots to determine the carbides as epsilon-carbides, and (d) comparative example 3 with 1wt.% CeO added 2 +1wt.％Y 2 O 3 And (4) hardening and tempering the deposited sample. As can be seen from the combination of the figures, in examples 1 and 2, the carbide morphology is not obviously changed with the addition of the rare earth oxide, the length is reduced from about 100-250nm to 20-120nm, the width is reduced from about 60-100nm to 15-50nm, and the carbide distribution becomes more uniform and regular; comparative example 3 Heat treatment of a sample in a sedimentary state having a minimum carbide size, ε -carbide was converted into Fe 3 C, the number of carbides is slightly increased, the carbides are distributed unevenly, the size difference is large, and part of the carbides are spherical.
Test example 2
The 34CrNiMo6 alloy steel samples prepared in examples 1-2 and comparative examples 1-3 were subjected to tensile testing at room temperature by using an INSTRON 5543 precision electronic tensile testing machine, and the test results are shown in Table 1 and the stress-strain curve is shown in FIG. 6. The average microhardness of the as-deposited samples of each example was also measured, and the results are shown in FIG. 7.
TABLE 1 tensile test results of 34CrNiMo6 alloy steels at room temperature
| Group of | Tensile strength/MPa | Elongation after break/% | Reduction of area/%) |
| Example 1 | 1692 | 14.3 | 23.9 |
| Example 2 | 1582 | 13.1 | 27.8 |
| Comparative example 1 | 950 | 15.5 | 16.2 |
| Comparative example 2 | 1366 | 13.0 | 21.3 |
| Comparative example 3 | 1164 | 16.2 | 53.5 |
As can be seen from the results of Table 1 and FIG. 6, the addition of two rare earth oxides in examples 1 and 2 has the most significant effect on the tensile properties.
Example 1 addition of 1wt.% Y 2 O 3 +1wt.％CeO 2 The tensile strength of the sample is obviously higher than that of other samples, and reaches 1692MPa; compared with a sample which is not added with rare earth oxide and is increased by 742MPa, the amplification is about 75.1%; addition of CeO in comparison with comparative example 2 2 The elongation after fracture of the sample is slightly improved (14.3 percent) by 326 MPa; the elongation after fracture was slightly lower than that of the deposited sample of comparative example 1, to which no rare earth oxide was added, but reached 92.3% of that of the sample without rare earth oxide.
Example 2 addition of 2wt.% Y 2 O 3 +2wt.％CeO 2 The sample had a maximum reduction of area of 27.8%, but the tensile strength and elongation after fracture of the sample were both reduced to some extent by the addition of the mixed rare earth oxide, compared to example 1.
Compared with a sample without rare earth oxide, the tensile strength of the sample after the quenching and tempering treatment in the comparative example 3 is increased by 241MPa, the amplification is about 25.4 percent, and the elongation after fracture and the reduction of area are higher than those of other samples in a deposition state.
The comprehensive analysis can obtain: under the synergistic action of two rare earth oxides, austenite grains are further refined, Y 2 O 3 Compared with the addition of CeO alone 2 The elongation of the sample is obviously improved. The sample carbide after the quenching and tempering is converted into Fe from epsilon-carbide 3 The quantity of C is increased, the synergistic strengthening effect of the rare earth oxide is influenced, the tensile strength is reduced, however, the phase change stress is eliminated or reduced in the tempering process, and the plasticity is improved.
As can be seen from the results of FIG. 7, the addition of the mixed rare earth oxideThe microhardness value of the post-deposition sample is significantly improved. Example 1 addition of 1wt.% CeO 2 +1wt.％Y 2 O 3 The sample has the maximum average hardness value of 557HV; example 2 addition of 2wt.% CeO 2 +2wt.％Y 2 O 3 The average hardness value of the sample is slightly reduced to 508HV compared with that of the sample in example 1, which indicates that the hardness value is also influenced by excessive addition of the mixed rare earth oxide; comparative example 2 addition of CeO alone 2 The microhardness of the deposition test of (a) is inferior to that of examples 1 and 2 in addition of the mixed rare earth oxide; comparative example 3 addition of 1wt.% CeO 2 +1wt.％Y 2 O 3 The hardness of the sample is quenched and tempered, and is not obviously changed compared with the hardness of the sample without adding the rare earth oxide in the comparative example 1, and the average hardness is 339HV. Comprehensive analysis shows that rare earth oxide has little influence on the microstructure after quenching and tempering, austenite grains grow twice, mixed grains occur, the precipitation amount of carbide is increased, the size is slightly increased, and the microhardness value is reduced.
Test example 3
The 34CrNiMo6 steel as-deposited samples prepared in examples 1 and 2 were analyzed by XRD phase analysis, and the results are shown in FIG. 8.
As can be seen from FIG. 8, the as-deposited samples have martensite mainly and a small amount of retained austenite, the phase diffraction peak intensity of the as-deposited samples with different contents of misch metal oxides is significantly increased, and new phases such as CeNi are formed inside the as-deposited samples with the content of misch metal oxides increased 3 And NiY 3 Phase, Y 2 O 3 Decomposition into Y 3+ The formation of the new phase mark sample forms the minimum grain size, and the grain refining effect is verified to a certain extent; the generation of the new phase shows that the mixed rare earth oxide has good alloying and solid solution strengthening effects and can interact with elements such as Cr, ni, mo and the like, thereby improving the microstructure of a deposited sample.
In conclusion, the invention can effectively promote the formation of a new phase on the surface of a deposition layer by adding the mixed REO powder, avoids the displacement of crystal lattices and the deformation of crystal boundary area, and obviously improves the comprehensive mechanical properties of the obtained alloy steel, such as compact structure, refined crystal grains, good microstructure uniformity, tensile strength, reduction of area and the like.
Finally, it should be emphasized that the above-described preferred embodiments of the present invention are merely examples of implementations, rather than limitations, and that many variations and modifications of the invention are possible to those skilled in the art, without departing from the spirit and scope of the invention.
Claims (4)
1. A method for improving the structure and the performance of the additive manufacturing alloy steel is characterized by comprising the following specific steps:
s1, uniformly mixing mixed REO powder and alloy steel powder in a certain proportion by adopting a ball milling method, and then sealing and storing; the ball milling method comprises the following steps: the ball milling speed is 450-550r/min, the working mode of combining forward rotation for 20min, pause for 5min and reverse rotation for 20min is adopted, the ball milling time of each group is 5-7h, and the ball material ratio is 2;
s2, drying and dehumidifying the uniformly mixed powder in the S1, wherein the preset drying temperature is 120 ℃, the drying time is not less than 5h, cooling to room temperature in a drying furnace after drying, and dehumidifying for later use; adopting Q235 steel as a base material, polishing the surface of the base material by using sand paper, cleaning by using acetone and drying for later use;
s3, placing the powder in the step S2 into laser additive manufacturing equipment, performing metal additive manufacturing on a base material under the protection of inert gas, and obtaining alloy steel after laser, scanning, powder feeding and deposition; the power of the laser is 1000W, the scanning speed is 600mm/min, and the powder feeding speed is 10 g/min;
the content of the mixed REO powder accounts for 1-4wt.% of the total amount of the mixed REO powder and the alloy steel powder;
the mixed REO powder is CeO 2 Powder and Y 2 O 3 1 weight ratio of powder.
2. The method of claim 1, wherein the method comprises modifying a microstructure and properties of an additive manufactured alloy steelCharacterized in that the CeO 2 The powder has a particle size of 40-60nm, a purity of 99.9%, and a density of 0.96g/cm 3 (ii) a Said Y is 2 O 3 The powder has a particle size of 45-55nm, a purity of 99.9%, and a density of 0.48g/cm 3 。
3. The method for improving the structure and the performance of the additive manufacturing alloy steel according to claim 1, wherein the alloy steel powder is spherical 34CrNiMo6 steel powder prepared by a plasma rotating electrode method, and the diameter of the steel powder is 53-150 μm.
4. The method for improving the structure and the performance of the additive manufacturing alloy steel according to claim 1, wherein in S3, the deposition is carried out in a pause manner of 15S after 30 layers are deposited.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210607202.7A CN114959412B (en) | 2022-05-31 | 2022-05-31 | Method for improving structure and performance of additive manufacturing alloy steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210607202.7A CN114959412B (en) | 2022-05-31 | 2022-05-31 | Method for improving structure and performance of additive manufacturing alloy steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114959412A CN114959412A (en) | 2022-08-30 |
| CN114959412B true CN114959412B (en) | 2023-01-31 |
Family
ID=82956845
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210607202.7A Active CN114959412B (en) | 2022-05-31 | 2022-05-31 | Method for improving structure and performance of additive manufacturing alloy steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114959412B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103966598A (en) * | 2014-05-22 | 2014-08-06 | 山东大学 | Titanium alloy surface multi-element laser alloyed layer and preparation method thereof |
| CN106755728A (en) * | 2016-11-23 | 2017-05-31 | 东北大学 | Improve additional nano reinforcement agent and its preparation and application of steel mechanics performance |
| CN108642392A (en) * | 2018-06-12 | 2018-10-12 | 东北大学 | A kind of laser gain material manufacture low-carbon high-chromium alloy steel powder and preparation method |
| CN109396429A (en) * | 2017-08-17 | 2019-03-01 | 中国科学院金属研究所 | A kind of improvement laser gain material manufacture structural alloy steel microstructure and mechanical property method |
| CN110669997A (en) * | 2019-09-17 | 2020-01-10 | 中国人民解放军陆军装甲兵学院 | Method for laser melting deposition of 24CrNiMo alloy steel |
| CN111139467A (en) * | 2020-01-09 | 2020-05-12 | 中国民航大学 | Laser repair layer containing rare earth oxide on titanium alloy surface and preparation method thereof |
| CN111590079A (en) * | 2020-05-08 | 2020-08-28 | 华中科技大学 | Nano oxide dispersion strengthened steel part and rapid additive manufacturing method thereof |
| CN111778504A (en) * | 2020-07-20 | 2020-10-16 | 济南大学 | Laser cladding coating powder and preparation method thereof |
| CN112548094A (en) * | 2020-12-04 | 2021-03-26 | 东北大学 | 30Cr15MoY alloy steel powder for laser additive manufacturing or remanufacturing and using method thereof |
-
2022
- 2022-05-31 CN CN202210607202.7A patent/CN114959412B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103966598A (en) * | 2014-05-22 | 2014-08-06 | 山东大学 | Titanium alloy surface multi-element laser alloyed layer and preparation method thereof |
| CN106755728A (en) * | 2016-11-23 | 2017-05-31 | 东北大学 | Improve additional nano reinforcement agent and its preparation and application of steel mechanics performance |
| CN109396429A (en) * | 2017-08-17 | 2019-03-01 | 中国科学院金属研究所 | A kind of improvement laser gain material manufacture structural alloy steel microstructure and mechanical property method |
| CN108642392A (en) * | 2018-06-12 | 2018-10-12 | 东北大学 | A kind of laser gain material manufacture low-carbon high-chromium alloy steel powder and preparation method |
| CN110669997A (en) * | 2019-09-17 | 2020-01-10 | 中国人民解放军陆军装甲兵学院 | Method for laser melting deposition of 24CrNiMo alloy steel |
| CN111139467A (en) * | 2020-01-09 | 2020-05-12 | 中国民航大学 | Laser repair layer containing rare earth oxide on titanium alloy surface and preparation method thereof |
| CN111590079A (en) * | 2020-05-08 | 2020-08-28 | 华中科技大学 | Nano oxide dispersion strengthened steel part and rapid additive manufacturing method thereof |
| CN111778504A (en) * | 2020-07-20 | 2020-10-16 | 济南大学 | Laser cladding coating powder and preparation method thereof |
| CN112548094A (en) * | 2020-12-04 | 2021-03-26 | 东北大学 | 30Cr15MoY alloy steel powder for laser additive manufacturing or remanufacturing and using method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114959412A (en) | 2022-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113621843B (en) | High-strength and high-toughness corrosion-resistant FeCoNiCuAl high-entropy alloy wave-absorbing material, preparation method and application | |
| US4090874A (en) | Method for improving the sinterability of cryogenically-produced iron powder | |
| CN113134612B (en) | Method for preparing superfine high-purity high-solid solubility tungsten-based alloy powder | |
| CN107699795B (en) | A kind of processing method of high strength cast iron for building | |
| CN108588533B (en) | Ti (C, N) -based metal ceramic matrix material for CVD coating and preparation method thereof | |
| CN111593250B (en) | L12Precipitation strengthening high-entropy alloy and preparation method thereof | |
| CN112974813A (en) | Titanium-based composite powder and preparation method thereof, in-situ reinforced titanium-based composite coating and preparation method thereof | |
| CN111850372A (en) | A series of FeCoCrNiW (VC)XPreparation of high-entropy alloy and precipitation strengthening process thereof | |
| CN109295399B (en) | High-damping high-entropy alloy material and preparation method thereof | |
| CN115044794A (en) | Cu- (Y) with excellent performance 2 O 3 -HfO 2 ) Alloy and preparation method thereof | |
| CN114293087A (en) | Single-phase high-entropy alloy with micron/nano-crystalline grain composite structure | |
| CN114959412B (en) | Method for improving structure and performance of additive manufacturing alloy steel | |
| CN111531173B (en) | Yttrium-containing powder metallurgy high-speed steel and preparation method thereof | |
| CN111020347B (en) | High-density complex phase alloy material and preparation method thereof | |
| CN109732087B (en) | Preparation method of powder metallurgy Ti-Ta binary metal-based layered composite material | |
| CN102766795B (en) | Without magnetic moulding stock and preparation method thereof | |
| JPS5929646B2 (en) | Manufacturing method of steel for rolling bearings | |
| CN111893442B (en) | Molybdenum-tungsten sputtering target material and preparation method thereof | |
| CN112760547A (en) | Preparation method of high-strength high-hardness powder metallurgy high-speed steel | |
| WO2020149787A1 (en) | 3d printed high carbon content steel and method of preparing the same | |
| CN106591614B (en) | A kind of manufacturing process of high life heat screen arc molybdenum plate | |
| CN114939656B (en) | Method for improving performance of alloy steel manufactured by laser additive by adding rare earth oxide | |
| CN114645172B (en) | Submicron gradient hard alloy with surface layer having cubic phase removed and preparation method thereof | |
| JP4325522B2 (en) | Stainless steel plate with excellent workability and properties of processed part and method for producing the same | |
| Ghosh et al. | Microstructure, Texture, Grain Boundary Characteristics and Mechanical Properties of a Cold Rolled and Annealed Martensitic Steel |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |