Material for cutting type cutter used for anti-irradiation environment, preparation technology of material and cutter

Abstract

The invention discloses a material for a cutting type cutter used for an anti-irradiation environment, a preparation process of the material and the cutter, and the preparation process comprises the following steps that (1) steel alloy powder is used as a matrix, WC powder and / or TiC powder are / is used as a hard phase, the two kinds of powder are mixed, and the steel alloy powder is formed by pre-sintering Fe powder, Ni powder, Cr powder, C powder and Mo powder; (2) pressing; (3) vacuum sintering; (4) forging; and (5) heat treatment is conducted in the modes of quenching, first tempering, deep cooling and second tempering, and the material for the cutting tool is obtained. According to the preparation process, a special heat treatment process is adopted, the hardness of the material is improved, meanwhile, the toughness of the material is not reduced, the proportion of martensite to austenite in matrix components reaches an ideal value, and therefore the effect of improving the wear resistance of the material is achieved; and the toughness of the cutting tool in the radioactive environment is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical tool preparation, and in particular relates to a material for cutting tools used in radiation-resistant environments, a preparation process thereof, and a tool. Background Art

[0002] In a radioactive environment, the tool materials prepared by the existing process have insufficient wear resistance and limited service life. In order to improve the service life and wear resistance, the material preparation process needs to be optimized. The traditional preparation process is to preform powder by mixing element powder and WC powder, and then press and sinter, forge and perform conventional heat treatment. The materials prepared in this way have problems such as uneven WC distribution, low hardness, generally less than 62HRC, insufficient wear resistance, etc., which greatly reduces the service life. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a material for cutting tools used in radiation-resistant environments and its preparation process and tools in response to the above-mentioned deficiencies in the prior art, so as to solve the problems of low hardness and insufficient wear resistance of the tools under radiation conditions in the prior art. The prepared alloy is used in radiation environments. The alloy is a wear-resistant and impact-resistant steel-bonded cemented carbide, which greatly improves the toughness of cutting tools in radioactive environments.

[0004] The technical solution adopted to solve the technical problem of the present invention is to provide a preparation process for a material for cutting tools used in a radiation-resistant environment, comprising the following steps:

[0005] (1) Using steel alloy powder as a matrix and WC powder and / or TiC powder as a hard phase, the two powders are mixed, wherein the steel alloy powder is pre-sintered from Fe powder, Ni powder, Cr powder, C powder, and Mo powder;

[0006] (2) Suppression;

[0007] (3) Vacuum sintering;

[0008] (4) Forging;

[0009] (5) Heat treatment is performed by quenching, first tempering, deep cooling, and second tempering to obtain a material for cutting tools.

[0010] Preferably, in the mixture of the two powders in step (1), the mass of the hard phase powder is ≤30%.

[0011] Preferably, the particle size of the hard phase powder in step (1) is 2 to 3 μm.

[0012] Preferably, the specific method of pre-sintering the steel alloy powder in step (1) is gas atomization preparation, and the D50 of the steel alloy powder is less than 45 μm.

[0013] Preferably, the mixing time of the two powders in step (1) is 24 to 48 hours, and the ball-to-material ratio in the ball mill used for mixing is 4:1.

[0014] Preferably, the pressing in step (2) is performed by cold isostatic pressing, with a pressure of 100 to 150 MPa and a holding time of 10 to 12 min.

[0015] Preferably, during the vacuum sintering process in step (3), the pressure is increased to 1 MPa after the melt reaches the liquid phase, the sintering temperature is 1285-1295° C., and the maximum temperature holding time is 1-1.5 h.

[0016] Preferably, in step (4), free forging is used for forging, with an initial forging temperature of 1200° C., a final forging temperature of 1000° C., and a forging ratio of 1.6:1.

[0017] Preferably, in step (5), the quenching temperature is 1120° C. to 1175° C., and the temperature is kept for 0.5 h;

[0018] The first tempering temperature is 150℃~170℃, and the holding time is 3h;

[0019] The cryogenic temperature is -196℃~-70℃, and the temperature is kept for 1h;

[0020] The second tempering temperature is 150℃~170℃, and the holding time is 3h.

[0021] Preferably, the chemical elements mass percentage composition of the material in step (5) is: C 2.0-2.2%, Cr 0.6-0.8%, Ni 1.6-2.0%, Mo 0.6-0.8%, N0.00069-0.014%, P≤0.0094%, S≤0.018%, W and / or Ti 28.4-33.5%, and the balance is Fe.

[0022] Preferably, the hardness of the cutting tool material in step (5) is 66-68HRC, and the impact toughness is 16-30J / cm 2 , flexural strength is 2550~4000MPa, fracture toughness is 18~40MPa·m 1 / 2 .

[0023] The present invention also provides a material for cutting tools used in radiation-resistant environments, and the material is prepared by the above process.

[0024] The present invention also provides a cutting tool for use in a radiation-resistant environment, which is made of the above-mentioned material.

[0025] Compared with the prior art, the material for cutting tools of the present invention is made of a mixture of steel alloy powder prepared by aerosolization and hard phase powder. WC and / or TiC are used as hard phases to ensure that the material has good hardness and thus good wear resistance. Fe, Ni, Cr, C, and Mo are used as matrix phases, solid solution strengthening phases, and precipitation strengthening phases, so that the material has higher toughness.

[0026] The material for cutting tools used in radiation-resistant environments and its preparation process and tools in the present invention are as follows: the preparation process first uses steel alloy powder as a matrix, adds WC powder and / or TiC powder, and adopts mixing, pressing, sintering and other processes to prepare an ingot, which is then heat treated after forging. A special heat treatment process is adopted to improve the hardness of the material without reducing the toughness of the material, so that the ratio of martensite to austenite in the matrix component reaches an ideal value, thereby achieving the effect of improving the wear resistance of the material. The prepared alloy is used in an irradiated environment. The alloy is a wear-resistant and impact-resistant steel-bonded cemented carbide, which greatly improves the toughness of cutting tools in a radioactive environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The microstructure diagram of the material prepared in Example 2 of the present invention;

[0028] Figure 2 The microstructure diagram of the material prepared in Example 3 of the present invention;

[0029] Figure 3 The microstructure diagram of the material prepared in Example 4 of the present invention;

[0030] Figure 4 The microstructure diagram of the material prepared in Example 5 of the present invention;

[0031] Figure 5 This is a microstructure diagram of the material prepared in Example 6 of the present invention;

[0032] Figure 6 This is a microstructure diagram of the material prepared in Example 7 of the present invention;

[0033] Figure 7 The microstructure diagram of the material prepared in Comparative Example 1 of the present invention;

[0034] Figure 8 This is a microstructure diagram of the material prepared in Comparative Example 2 of the present invention;

[0035] Fig. 9 This is a microstructure diagram of the material prepared in Comparative Example 3 of the present invention;

[0036] Fig.10 This is a microstructure diagram of the material prepared in Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] Example 1

[0039] This embodiment provides a preparation process for a material for a cutting tool used in a radiation resistant environment, comprising the following steps:

[0040] (1) Using steel alloy powder as a matrix and WC powder and / or TiC powder as a hard phase, the two powders are mixed, wherein the steel alloy powder is pre-sintered from Fe powder, Ni powder, Cr powder, C powder, and Mo powder;

[0041] (2) Suppression;

[0042] (3) Vacuum sintering;

[0043] (4) Forging;

[0044] (5) Heat treatment is performed by quenching, first tempering, deep cooling, and second tempering to obtain a material for cutting tools.

[0045] This embodiment also provides a material for cutting tools used in radiation-resistant environments, and the material is prepared by the above-mentioned process.

[0046] This embodiment also provides a cutting tool for use in a radiation-resistant environment, which is made of the above-mentioned material.

[0047] The material for cutting tools used in radiation-resistant environments and its preparation process and tools in this embodiment are as follows: the preparation process first uses steel alloy powder as a matrix, adds WC powder and / or TiC powder, and adopts mixing, pressing, sintering and other processes to prepare an ingot, which is then heat treated after forging. A special heat treatment process is used to improve the hardness of the material without reducing the toughness of the material, so that the ratio of martensite to austenite in the matrix composition reaches an ideal value, thereby achieving the effect of improving the wear resistance of the material. The obtained alloy is used in an irradiated environment. The alloy is a wear-resistant and impact-resistant steel-bonded cemented carbide, which greatly improves the toughness of cutting tools in a radioactive environment.

[0048] Example 2

[0049] This embodiment provides a preparation process for a material for a cutting tool used in a radiation resistant environment, comprising the following steps:

[0050] (1) Using steel alloy powder as a matrix, and the steel alloy powder as a binder phase powder, and using WC powder and / or TiC powder as a hard phase, the two powders are mixed, wherein the steel alloy powder is pre-sintered from Fe powder, Ni powder, Cr powder, C powder, and Mo powder;

[0051] (2) Suppression;

[0052] (3) Vacuum sintering;

[0053] (4) Forging;

[0054] (5) Heat treatment is performed by quenching, first tempering, deep cooling, and second tempering to obtain a material for cutting tools.

[0055] Specifically, in this embodiment, the steel alloy is low alloy steel, and the low alloy steel is mixed with WC and / or TiC in the form of alloy powder.

[0056] The material for cutting tools in a radioactive environment in this embodiment uses a specific low-alloy steel as a matrix, WC and / or TiC as a hard phase, and is prepared by a sintering method. To ensure that the material has good hardness and thus good wear resistance, Fe, Ni, Cr, C, and Mo are used as a matrix phase, a solid solution strengthening phase, and a precipitation strengthening phase, so that the material has higher toughness.

[0057] This embodiment provides a powder mixing process for shearing tool materials, which uses steel alloy powder and hard phase powder to mix instead of element powder, thereby improving the uniformity of powder mixing while reducing powder mixing time and improving work efficiency.

[0058] Preferably, in the mixture of the two powders in step (1), the mass of the hard phase powder is ≤30%. When the two powders are mixed, the mass of the WC powder and / or TiC powder added is ≤30%.

[0059] Preferably, the particle size of the hard phase powder in step (1) is 2 to 3 μm.

[0060] Preferably, the specific method of pre-sintering the steel alloy powder in step (1) is gas atomization preparation, and the D50 of the steel alloy powder is less than 45 μm.

[0061] The specific method for preparing the steel alloy powder by gas atomization is to melt Fe powder, Ni powder, Cr powder, C powder and Mo powder first, and then spray the powder to obtain the steel alloy powder.

[0062] Preferably, the mixing time of the two powders in step (1) is 24 to 48 hours, and the ball-to-material ratio in the ball mill used for mixing is 4:1.

[0063] Preferably, the pressing in step (2) is performed by cold isostatic pressing, with a pressure of 100 to 150 MPa and a holding time of 10 to 12 min.

[0064] Preferably, during the vacuum sintering process in step (3), the pressure is increased to 1 MPa after the melt reaches the liquid phase, the sintering temperature is 1285-1295° C., and the maximum temperature holding time is 1-1.5 h.

[0065] Preferably, in step (4), free forging is used for forging, with an initial forging temperature of 1200° C., a final forging temperature of 1000° C., and a forging ratio of 1.6:1.

[0066] Preferably, in step (5), the quenching temperature is 1120° C. to 1175° C., and the temperature is kept for 0.5 h;

[0067] The first tempering temperature is 150℃~170℃, and the holding time is 3h;

[0068] The cryogenic temperature is -196℃~-70℃, and the temperature is kept for 1h;

[0069] The second tempering temperature is 150℃~170℃, and the holding time is 3h.

[0070] Preferably, the chemical elements mass percentage composition of the material in step (5) is: C 2.0-2.2%, Cr 0.6-0.8%, Ni 1.6-2.0%, Mo 0.6-0.8%, N0.00069-0.014%, P≤0.0094%, S≤0.018%, W and / or Ti 28.4-33.5%, and the balance is Fe and unavoidable impurities.

[0071] Preferably, the hardness of the cutting tool material in step (5) is 66-68HRC, and the impact toughness is 16-30J / cm 2 , flexural strength is 2550~4000MPa, fracture toughness is 18~40MPa·m 1 / 2 .

[0072] This embodiment discloses a new heat treatment process for improving the hardness of a blank prepared by a sintering process after forging.

[0073] After cryogenic treatment, the hardness of the material is further increased, while the impact toughness remains at a high level.

[0074] Specifically, the material for cutting tools in this embodiment has the following chemical element composition in terms of mass percentage: C: 2.0%, Cr: 0.6%, Ni: 1.6%, Mo: 0.6%, N: 0.00069%, P: 0.003%, S: 0.011%, W and Ti: 28.4%, the mass ratio of W to Ti is 5:1, and the remainder is Fe and unavoidable impurities.

[0075] Specifically, the method for preparing cutting tool materials of this embodiment includes the following steps:

[0076] (1) The alloy powder prepared by gas atomization was mixed with WC powder with a particle size of 2 μm and a content of 30%. The ball-to-material ratio of the ball mill used for mixing was 4:1, and the powder mixing time was 24 h.

[0077] (2) The cold isostatic pressing process is: pressure is 100 MPa, and pressure is maintained for 12 minutes.

[0078] (3) The sintering process is as follows: sintering temperature is 1285°C, pressure is increased to 1 MPa, and heat preservation is performed for 1 hour.

[0079] (4) The forging process is: initial forging temperature 1200°C, final forging temperature 1000°C, and forging ratio 1.6:1.

[0080] (5) Heat treatment process: quenching at 1170°C, holding for 0.5 h, first tempering at 150°C, holding for 3 h, deep freezing at -70°C, holding for 1 h, second tempering at 150°C, holding for 3 h.

[0081] This embodiment also provides a material for cutting tools used in radiation-resistant environments, and the material is prepared by the above-mentioned process.

[0082] This embodiment also provides a cutting tool for use in a radiation-resistant environment, which is made of the above-mentioned material.

[0083] The material for cutting tools used in radiation-resistant environments and its preparation process and tools in this embodiment are as follows: the preparation process first uses steel alloy powder as a matrix, adds WC powder and / or TiC powder, and adopts processes such as ball milling, pressing, sintering, etc. to prepare an ingot, which is then heat treated after forging. A special heat treatment process is used to improve the hardness of the material without reducing the toughness of the material, so that the ratio of martensite to austenite in the matrix composition reaches an ideal value, thereby achieving the effect of improving the wear resistance of the material. The obtained alloy is used in an irradiated environment. The alloy is a wear-resistant and impact-resistant steel-bonded cemented carbide, which greatly improves the toughness of cutting tools in a radioactive environment.

[0084] Example 3

[0085] This embodiment provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0086] The rest is the same as in Example 2, except that the pressure of the cold isostatic pressing process in step (2) is 150 MPa.

[0087] Example 4

[0088] This embodiment provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0089] The other steps are the same as those in Example 2, except that the powder mixing time in step (1) is 48 hours.

[0090] Example 5

[0091] This embodiment provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0092] The rest is the same as in Example 2, except that the sintering temperature in step (3) is 1290°C.

[0093] Example 6

[0094] This embodiment provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0095] The rest is the same as in Example 2, except that the first tempering temperature in step (5) is 170°C and the second tempering temperature is 170°C.

[0096] Example 7

[0097] This embodiment provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0098] The rest is the same as in Example 2, except that the quenching temperature in step (5) is 1170°C and the cryogenic treatment is -196°C.

[0099] Comparative Example 1

[0100] This comparative example provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0101] The element composition of the tool material of this comparative example is the same as that of Example 2, except that the preparation process of the tool material of this comparative example is as follows:

[0102] The heat treatment quenching process in step (5) is 950°C.

[0103] Comparative Example 2

[0104] This comparative example provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0105] The rest is the same as in Example 2, without the deep cold treatment process.

[0106] Comparative Example 3

[0107] This comparative example provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0108] The rest is the same as in Example 2, except that the quenching and holding time in step (5) is 2 h.

[0109] Comparative Example 4

[0110] This comparative example provides a preparation process for a material for cutting tools used in radiation-resistant environments:

[0111] The rest is the same as in Example 2, except that the first tempering time in step (5) is 1 hour, and the second tempering time is 1 hour.

[0112] Test Example 1

[0113] The performance of the cutting tools made of the materials of Examples 2-7 and Comparative Examples 1-4 was tested, and the results are shown in Table 1.

[0114] Table 1

[0115]

[0116] From the above table, it can be seen from the results of Example 2 and Example 7 that the best material performance is obtained by adopting the preparation process in Example 2.

[0117] Compared with Example 2, Comparative Example 1 has a lower quenching temperature, insufficient austenitization, limited martensite generated during the cooling process, and uneven distribution of residual austenite, resulting in decreased hardness and toughness.

[0118] Test Example 2

[0119] The microstructures of the tool materials prepared using the materials of Examples 2-7 and Comparative Examples 1-4 were tested respectively. Figure 1-10 shown.

[0120] Figure 1-7 , 10 The instrument used is DM2500 metallographic microscope, Figure 8 , 9 The instrument used was a Quanta 650 scanning electron microscope. Figure 1 The magnification is 100 times. Figure 2 The magnification is 500 times. Figure 3 The magnification is 200 times. Figure 4 The magnification is 500 times. Figure 5 The magnification is 500 times. Figure 6 The magnification is 100 times. Figure 7 The magnification is 200 times. Figure 8 The magnification is 500 times. Fig. 9 The magnification is 500 times. Fig.10 The magnification is 800 times.

[0121] From the microstructure analysis, it can be seen that the WC tool material prepared by the material process of this embodiment is evenly distributed without bridging, the material density reaches more than 99% of the theoretical density, the hardness meets the index requirements, and has good impact toughness.

[0122] However, a large number of holes can be seen in Comparative Examples 1 and 4, which greatly reduce the material properties. Comparative Example 2 does not achieve good metallurgical bonding and has a low density. A large number of bridging phenomena can be seen in Comparative Example 3.

[0123] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A process for preparing a material for cutting tools used in radiation-resistant environments, characterized in that: The following steps are involved: (1) Using steel alloy powder as a matrix and WC powder and / or TiC powder as a hard phase, the two powders are mixed, wherein the steel alloy powder is pre-sintered from Fe powder, Ni powder, Cr powder, C powder, and Mo powder; (2) Suppression; (3) Vacuum sintering; (4) Forging; (5) Heat treatment is performed by quenching, first tempering, deep cooling, and second tempering to obtain a material for cutting tools.

2. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: In the mixture of the two powders in step (1), the mass of the hard phase powder is ≤30%.

3. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: The particle size of the hard phase powder in step (1) is 2 to 3 μm.

4. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: The specific method for pre-sintering the steel alloy powder in step (1) is gas atomization preparation, and the D50 of the steel alloy powder is less than 45 μm.

5. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: The mixing time of the two powders in step (1) is 24 to 48 hours, and the ball-to-material ratio in the ball mill used for mixing is 4:

1.

6. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: The pressing in step (2) is performed by cold isostatic pressing, the pressure is 100-150 MPa, and the holding time is 10-12 min.

7. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: During the vacuum sintering process in step (3), the pressure is increased to 1 MPa after the melt reaches the liquid phase, the sintering temperature is 1285-1295° C., and the maximum temperature holding time is 1-1.5 hours.

8. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: In the step (4), free forging is adopted for forging, the initial forging temperature is 1200° C., the final forging temperature is 1000° C., and the forging ratio is 1.6:

1.

9. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: In the step (5), the quenching temperature is 1120° C. to 1175° C. and the temperature is kept for 0.5 h; The first tempering temperature is 150℃~170℃, and the holding time is 3h; The cryogenic temperature is -196℃~-70℃, and the temperature is kept for 1h; The second tempering temperature is 150℃~170℃, and the holding time is 3h.

10. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: The chemical elements mass percentage composition of the material in step (5) is: C 2.0-2.2%, Cr 0.6-0.8%, Ni 1.6-2.0%, Mo 0.6-0.8%, N 0.00069-0.014%, P≤0.0094%, S≤0.018%, W and / or Ti 28.4-33.5%, and the balance is Fe.

11. The process for preparing the material for cutting tools used in radiation-resistant environments according to claim 1, characterized in that: The hardness of the cutting tool material in step (5) is 66-68HRC, and the impact toughness is 16-30J / cm 2 , flexural strength is 2550~4000MPa, fracture toughness is 18~40MPa·m 1 / 2 .

12. A material for cutting tools used in radiation-resistant environments, characterized in that: The material is prepared by the process described in any one of claims 1 to 11.

13. A cutting tool for use in a radiation-resistant environment, characterized in that: It is prepared from the material according to claim 12.

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