Method for preparing ODS alloy based on 3D printing and ply rolling process

Abstract

The invention relates to the technical field of metal material preparation, and particularly discloses a method for preparing an ODS alloy based on a 3D printing and ply rolling process, and the method comprises the following steps: S1, uniformly mixing alloy powder with reaction element powder; s2, preparing the uniformly mixed powder into a block material; s3, stacking the blocks to form a sheathed steel material A, and carrying out hot isostatic pressing treatment; s4, hot rolling treatment is carried out, a sheath is removed, and a hot rolled plate is formed; cutting and processing the hot-rolled plate into thin plates with the same size; s5, repeating the steps S3 to S4 until the reaction elements are uniformly distributed to obtain a thin plate; s6, performing high-temperature oxygen permeation treatment; s7, the thin plates are stacked to form sheathed steel B, and hot isostatic pressing treatment is carried out; and S8, the sheathed steel B is subjected to hot forging, a sheath is removed, and the ODS alloy is obtained. The prepared ODS alloy has the advantages of high purity, high-uniformity oxidation phase, controllable crystal grains, stable quality and isotropy.

Description

Technical Field

[0001] This invention relates to the field of metal material preparation technology, and more specifically, to a method for preparing ODS alloys based on 3D printing and rolling processes. Background Technology

[0002] Oxide dispersion strengthening (ODS) technology introduces nano-oxides (usually Y2O3) to increase dislocation resistance and tail strength, which can significantly improve the high-temperature strength, low-temperature toughness and radiation resistance of alloys.

[0003] However, current ODS alloy preparation technology remains at the laboratory scale, which is the main bottleneck limiting its large-scale industrial application and commercialization. Therefore, developing advanced processes for the rapid and large-scale preparation of high-purity ODS steel has become a key technological focus both domestically and internationally. Currently, the main methods for preparing ODS alloys internationally include mechanical alloying, vacuum melting, and additive manufacturing.

[0004] Mechanical alloying is currently the mainstream method for preparing ODS alloys. Taking ODS steel as an example, it mainly involves uniformly dispersing Y or Y₂O₃ raw materials into the matrix through high-energy ball milling, achieving atomic-level mixing with the matrix elements. Then, the dispersion-strengthened alloy powder is sintered into bulk materials through isostatic pressing and other forming processes, and finally forged or extruded into structural materials. The outstanding advantage of this method is its ability to achieve controllable composition through solid-state alloying under non-equilibrium thermodynamic conditions, resulting in high-density dispersed particles and good mechanical properties. However, this process also has some drawbacks: 1. High-energy ball mills have small material loading capacity and long milling time, requiring multiple batches to prepare a larger billet, resulting in low material preparation efficiency and high production costs; 2. Mechanically alloyed powders have a large specific surface area, which easily adsorbs gaseous impurities into the powder, causing contamination. This can lead to differences in powders from different ball mill jars and poor process reproducibility. 3. Due to the limitations of the size of powder forming equipment and thermal processing equipment, it is difficult to prepare large-size materials.

[0005] The smelting method for preparing ODS alloys has advantages such as short process flow, large batch output, and low manufacturing cost, but the following problems still exist: 1. Oxides are prone to agglomeration and coarsening during the smelting process, and the resulting Y2O3 particles are usually micron-sized, making it difficult to achieve effective dispersion strengthening. 2. Due to the high reducing properties of rare earth elements, they are difficult to dissolve uniformly with oxygen atoms in molten steel, resulting in uneven distribution of oxides; 3. During the heating and melting process, alloying elements readily react with oxygen in the atmosphere, generating coarse oxides such as W₂O₃, Ta₂O₅, Fe₂O₃, and V₂O₅. These impurities are large in size and difficult to remove, severely impairing material properties. Therefore, this process is currently still in the research and development stage. To address these issues, various improved smelting processes have been proposed in existing technologies. For example: Chinese patent CN105274440A, entitled "Preparation Method of Oxide Dispersion Strengthened Steel and Martensitic Steel," proposes placing Fe2O3 powder directly into a mold and pouring in molten steel containing rare earth elements. The Fe2O3 floats, decomposes, and reacts with yttrium to generate Y2O3. However, this method cannot control the rapid solidification process of the billet, resulting in incomplete decomposition of the oxygen-rich precursor. The generated Y2O3 particles have a size exceeding 1 μm and a low particle density, thus limiting the strengthening effect on the matrix.

[0006] Chinese patent CN112481544A, entitled "A Method for Preparing High-Density Oxide Dispersion Strengthened Steel," proposes a stepwise melting process: first, an ingot containing oxygen carrier particles is prepared; then, molten steel containing rare earth elements is melted and the ingot is added; by controlling the melting process, some of the oxygen carrier is dissolved; finally, after cooling, rolling, and heat treatment, an ODS steel billet is obtained. While this method improves the uniformity of oxide distribution to some extent, it cannot completely avoid the problem of uneven particle dispersion.

[0007] With the continuous development of additive manufacturing technology, new technological approaches have emerged for the preparation of ODS alloys. Currently, laser additive manufacturing technology (including selective laser melting and direct energy deposition) is mainly used for the preparation of ODS alloys. This technology has advantages such as short process flow, high forming efficiency, and the ability to manufacture complex structural parts, but it still faces the following challenges: 1. Laser additive manufacturing processes are prone to defects such as porosity and incomplete fusion, leading to a decline in material properties; 2. High-temperature melting and rapid solidification processes can easily generate large residual stresses, causing component deformation or cracking; 3. Nanoscale oxides are prone to coarsening and segregation in the molten pool, making it difficult to achieve uniform dispersion; 4. Due to the characteristics of the deposition and solidification process, the prepared materials often exhibit significant anisotropy.

[0008] In summary, while existing methods for preparing ODS alloys each have their advantages, they also have certain limitations. Therefore, there is an urgent need to develop a new preparation process that can combine the advantages of existing methods, achieving high purity and high uniformity while also being efficient and scalable for mass production. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a method for preparing ODS alloy based on 3D printing and rolling processes. The ODS alloy prepared by the present invention has high purity, high uniformity of oxide phase, controllable grain size, stable quality and isotropy. The solution adopted by this invention to solve the technical problem is: A method for preparing ODS alloys based on 3D printing and rolling processes specifically includes the following steps: Step S1: Mix the alloy powder to be dispersed and strengthened with the reactive element powder under a protective gas atmosphere or vacuum ring to form a homogeneous powder. Step S2: Based on 3D printing technology, the mixed powder is prepared into a block material, and the surface of the block material is treated. Step S3: Stack the surface-treated blocks and vacuum seal them using a sleeve to form a sleeved steel material A. Then, perform hot isostatic pressing on the sleeved steel material A. Step S4: Hot-roll the hot isostatic pressing cladding steel A, remove the cladding after hot rolling to form a hot-rolled plate; cut the hot-rolled plate into thin plates of the same size and perform surface treatment. Step S5: Repeat steps S3 to S4 until the reactive elements are evenly distributed in the matrix to obtain a thin plate. Step S6: Perform high-temperature oxygen diffusion treatment on the thin plate to allow the reactive elements to undergo in-situ oxidation nucleation, and then perform surface treatment on the thin plate after high-temperature oxygen diffusion treatment. Step S7: Stack the thin plates after surface treatment in step S6, vacuum seal them with a sleeve to form a sleeve steel material B, and perform hot isostatic pressing on the sleeve steel material B. Step S8: Hot forge the cladding steel B after hot isostatic pressing, remove the cladding, and obtain the ODS alloy; complete the preparation.

[0010] In some possible implementations, when using 3D printing technology to prepare the block material in step S2, the printing speed is 700-1300 mm / s and the power is 200-300 W.

[0011] In some possible implementations, step S3 involves using a sleeve for vacuum sealing, specifically: First, the stacked blocks are packaged together in sets; Following this, the sheath is welded, with argon gas introduced during the welding process. After welding, the sheath is checked for airtightness, and the leakage rate is controlled to be ≤10%. -10 Pa·m 3 / s; The casing is evacuated and degassed using a vacuum tube installed on the casing for 2 to 20 hours, maintaining a vacuum level below 1.0 × 10⁻⁶. -3 Pa; The vacuum tube on the casing is heated and clamped, with a vacuum degree of 1.0 × 10⁻⁶ during clamping. -5 ~1.0×10 -2 Pa.

[0012] In some possible implementations, in step S3, when hot isostatic pressing is performed on the cladding steel A, the hot isostatic pressing temperature is 920℃~1300℃, the holding time is 2h~3h, the pressure is 120MPa~150MPa, the heating rate is 5℃ / min~10℃ / min, the cooling rate is 5℃ / min~7℃ / min, and the material is removed from the furnace after the temperature is below 150℃.

[0013] In some possible implementations, during the hot rolling process in step S4, the hot rolling temperature is 400℃~1100℃, the cladding steel A is heated at a rate of 5℃ / min~10℃ / min, and held at that temperature for 1h~2h.

[0014] In some possible implementations, during the hot rolling process, the reduction in pressure for each rolling pass is 0.5 mm to 5 mm and the reduction decreases gradually; when the final rolling temperature of the cladding steel A is 200°C lower than the hot rolling temperature, it is returned to the furnace for heat treatment for 10 to 30 minutes and hot rolling continues until the thickness is 2 mm to 8 mm.

[0015] In some possible implementations, when the thin plate is subjected to high-temperature oxygen permeation treatment in step S6, the oxygen concentration is 0.5% to 2%, the temperature is 600 to 1350°C, the heating rate is 10°C / min, and the holding time is 1 to 10 hours.

[0016] In some possible implementations, hot forging of the cladding steel B after hot isostatic pressing specifically refers to heating the steel to 800°C to 1300°C at a rate of 10°C per minute, holding it at that temperature for 1 hour, and then starting forging. During hot forging, the cladding steel B is hot-forged in multiple directions. When the final forging temperature of the cladding steel B is 200°C lower than the hot forging temperature, it is returned to the furnace and held for 30 minutes.

[0017] In some possible implementations, the 3D printing technology is any one of selective laser melting, direct energy deposition, or shape-depositing energy deposition.

[0018] In some possible implementations, the reactive element powder is any one of yttrium powder, yttrium hydride powder, aluminum powder, titanium powder, rhenium powder, zirconium powder, and hafnium powder; The particle size of the alloy powder is 15 micrometers to 53 micrometers, and the particle size of the reactive element powder is 20 micrometers to 30 micrometers. The mass percentage of alloy powder in the mixed powder is 95%-99.9%, and the mass percentage of reactive element powder in the mixed powder is 0.1%-5%.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention solves the problems of yttrium oxide coarsening and uneven distribution in the preparation of ODS alloys by smelting. Through multiple hot rolling and hot isostatic pressing, this invention solves the problems of low efficiency and difficulty in large-scale production of powder metallurgy, and the problems of defects such as porosity and cracking in additive manufacturing materials, as well as the problem of yttrium oxide coarsening and segregation. Through multiple stacked hot rolling, the diffusion of reactive elements in the matrix can be accelerated, making the reactive elements more uniform and refined at the same time. The 3D printing technology used in this invention enables the preparation of large-size alloys; at the same time, hot isostatic pressing, hot rolling and high-temperature oxygen infiltration heat treatment are all mature and stable metal material preparation processes that can be mass-produced industrially; therefore, this invention effectively breaks through the technical bottleneck of large-scale ODS alloy preparation, has a good foundation for process production, and at the same time has high production efficiency and economy, and has broad application prospects. This invention employs 3D printing to introduce unoxidized reactive element powder into an alloy. To ensure that the reinforcing phase element is introduced into the alloy without oxidation, 3D printing is performed under an inert gas atmosphere. Other 3D printing methods performed under an inert gas atmosphere are also applicable. The 3D printing parameters may differ for different ODS alloy combinations. This invention improves the uniformity of reactive element distribution through a layered rolling process. The material thickness decreases exponentially with each layered rolling, thereby significantly improving the uniformity of the microstructure, greatly improving the distribution of yttrium in low-activation steel, and accelerating the diffusion of reactive elements. At the same time, it can densify the bulk material obtained by additive manufacturing, thereby eliminating defects and improving performance. This invention utilizes an oxygen-permeating heat treatment process to uniformly infiltrate oxygen into the matrix, thereby causing the reactive elements to oxidize in situ and form uniformly dispersed oxides. This process is simple, effective, and can be mass-produced, making it convenient and reliable for practical engineering applications. Attached Figure Description

[0020] Figure 1 This is a flowchart of the present invention; Figure 2 The images show the microstructure of the ODS alloy prepared using this invention, before and after the oxygen diffusion treatment, under a transmission electron microscope. Figure 3 This is a comparison chart of the room temperature tensile properties of the ODS alloy prepared in Example 1 and the existing CLF-1 steel at different stages. Detailed Implementation

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] The present invention will now be described in detail.

[0023] A method for preparing ODS alloys based on 3D printing and rolling processes specifically includes the following steps: Step S1: The alloy powder to be dispersed and strengthened is mixed with the reactive element powder under a protective gas atmosphere or vacuum ring to form a homogeneous powder; the reactive element powder is an unoxidized element powder, specifically, any one of yttrium powder, yttrium hydride powder, aluminum powder, titanium powder, rhenium powder, zirconium powder, and hafnium powder; the particle size of the alloy powder is 15 micrometers-53 micrometers, and the particle size of the reactive element powder is 20 micrometers-30 micrometers; the mass percentage of the alloy powder in the homogeneous powder is 95%-99.9%, and the mass percentage of the reactive element powder in the homogeneous powder is 0.1%-5%.

[0024] Step S2: Based on 3D printing technology, the mixed powder is prepared into a block material, and the surface of the block material is treated. Step S3: Stack the surface-treated blocks and vacuum seal them using a sleeve to form a sleeved steel material A. Then, perform hot isostatic pressing on the sleeved steel material A. Step S4: Hot-roll the hot isostatic pressing cladding steel A, remove the cladding after hot rolling to form a hot-rolled plate; cut the hot-rolled plate into thin plates of the same size and perform surface treatment. Step S5: Repeat steps S3 to S4 until the reactive elements are evenly distributed in the matrix to obtain a thin plate. Step S6: Perform high-temperature oxygen diffusion treatment on the thin plate to allow the reactive elements to undergo in-situ oxidation nucleation, and then perform surface treatment on the thin plate after high-temperature oxygen diffusion treatment. Step S7: Stack the thin plates after surface treatment in step S6, vacuum seal them with a sleeve to form a sleeve steel material B, and perform hot isostatic pressing on the sleeve steel material B. Step S8: Hot forge the cladding steel B after hot isostatic pressing, remove the cladding, and obtain the ODS alloy; complete the preparation.

[0025] In some possible implementations, when using 3D printing technology to prepare the block material in step S2, the printing speed is 700-1300 mm / s and the power is 200-300 W.

[0026] In some possible implementations, step S3 involves using a sleeve for vacuum sealing, specifically: First, the stacked blocks are packaged together in sets; Following this, the sheath is welded, with argon gas introduced during the welding process. After welding, the sheath is checked for airtightness, and the leakage rate is controlled to be ≤10%. -10 Pa·m 3 / s; The casing is evacuated and degassed using a vacuum tube installed on the casing for 2 to 20 hours, maintaining a vacuum level below 1.0 × 10⁻⁶. -3 Pa; The vacuum tube on the casing is heated and clamped, with a vacuum degree of 1.0 × 10⁻⁶ during clamping. -5 ~1.0×10 -2 Pa.

[0027] In some possible implementations, in step S3, when hot isostatic pressing is performed on the cladding steel A, the hot isostatic pressing temperature is 920℃~1300℃, the holding time is 2h~3h, the pressure is 120MPa~150MPa, the heating rate is 5℃ / min~10℃ / min, the cooling rate is 5℃ / min~7℃ / min, and the material is removed from the furnace after the temperature is below 150℃.

[0028] In some possible implementations, during the hot rolling process in step S4, the hot rolling temperature is 400℃~1100℃, the cladding steel A is heated at a rate of 5℃ / min~10℃ / min, and held at that temperature for 1h~2h.

[0029] In some possible implementations, during the hot rolling process, the reduction in pressure for each rolling pass is 0.5 mm to 5 mm and the reduction decreases gradually; when the final rolling temperature of the cladding steel A is 200°C lower than the hot rolling temperature, it is reheated in the furnace for 10 to 30 minutes and then hot rolled again until the thickness is 2 mm to 8 mm.

[0030] In some possible implementations, when the thin plate is subjected to high-temperature oxygen permeation treatment in step S6, the oxygen concentration is 0.5% to 2%, the temperature is 600 to 1350°C, the heating rate is 10°C / min, and the holding time is 1 to 10 hours.

[0031] In some possible implementations, hot forging of the cladding steel B after hot isostatic pressing specifically refers to heating the steel to 800°C to 1300°C at a rate of 10°C per minute, holding it at that temperature for 1 hour, and then starting the forging process. During hot forging, the cladding steel B is hot-forged in multiple directions. When the final forging temperature of the cladding steel B is 200°C lower than the hot forging temperature, it is returned to the furnace for 30 minutes and then hot forging continues.

[0032] In some possible implementations, the 3D printing technology is any one of selective laser melting, direct energy deposition, or shape-depositing energy deposition.

[0033] In some possible implementations, The particle size of the alloy powder is 15 micrometers to 53 micrometers, and the particle size of the reactive element powder is 20 micrometers to 30 micrometers. The mass percentage of alloy powder in the mixed powder is 95%-99.9%, and the mass percentage of reactive element powder in the mixed powder is 0.1%-5%.

[0034] Specifically, this invention can be used to achieve dispersion strengthening of alloy powders, such as alloy steel powder and vanadium alloy powder.

[0035] Example 1: A method for preparing ODS alloys based on 3D printing and rolling processes, using CLF-1 steel powder combined with yttrium hydride powder, specifically includes the following steps: Step A1: Under an argon atmosphere, CLF-1 steel powder and yttrium hydride powder are initially mixed using mechanical mixing to obtain a homogenized powder; wherein the particle size of CLF-1 steel powder is 30 micrometers, the particle size of yttrium hydride powder is 10 micrometers, and the mass percentage of yttrium hydride powder is 0.5%; Step A2: Selective laser melting technology is used to prepare the mixed powder into a block material with a size of 110*100*10mm. The selective laser melting printing speed is 800mm / s and the power is 250W. An argon atmosphere is maintained during the printing process. During 3D printing, the yttrium hydrogen powder undergoes a decomposition reaction to form yttrium. Sand the block to expose a fresh surface, ultrasonically clean it with deionized water, wipe it with ethanol, and finally blow it with nitrogen. Step A3: Stack the three surface-treated blocks and put them into a sleeve made of 304 stainless steel. After the three surface-treated blocks are installed into the sheath, the sheath is first welded with argon gas. After welding, the sheath is checked for airtightness to ensure that the leakage rate is ≤10%. -10 Pa·m 3 / s; Next, the sheath was subjected to cold extraction and venting for 12 hours; The vacuum tube on the casing was then heated and clamped three times, maintaining a vacuum of 1.0 × 10⁻⁶ throughout the clamping process. -5 ~1.0×10 -2 Pa is vacuum-sealed using a sleeve; Finally, the cladding is welded to obtain cladding steel A, which is then subjected to hot isostatic pressing (HIP). The HIP temperature is 920℃, the holding time is 2.5h, the pressure is 130MPa, the heating rate is 10℃ / min, and the cooling rate is 5℃ / min. The cladding is then removed from the furnace when the temperature is below 150℃.

[0036] Step A4: Hot-roll the cladding steel A; specifically, the cladding steel A is first heated to 850°C at a rate of 10°C / min, and then heated to 1000°C at a rate of 5°C / min, and held at that temperature for 2 hours. During hot rolling, the rolling is carried out along the length direction. The section without the exhaust pipe on the sheath enters the rolling mill. The pressure is 2mm during hot rolling. The pressure is gradually reduced to 1mm as the number of rolling passes increases. The final rolling temperature is 850℃. If it is lower than 850℃, it is returned to the furnace for 30 minutes of heat treatment. After hot rolling to a thickness of 4mm, it is air-cooled. The cladding is removed by machining and the rolled steel is divided into 110*100*2mm thick and thin plates, followed by the same surface treatment as in step A2. Step A5: Repeat steps A3-A4 three times to obtain the thin sheet metal part; Step A6: Perform high-temperature oxygen diffusion treatment on the thin sheet material after surface treatment in step A5; Specifically, an argon-oxygen mixture with an oxygen concentration of 0.5% is introduced into the high-temperature oxygen infiltration treatment equipment, and the temperature is raised to 1300℃ at a rate of 10℃ / min. After holding at this temperature for 2 hours, the heating is stopped. By adding oxygen, yttrium undergoes an oxidation reaction to form yttrium oxide. Through high-temperature oxygen infiltration treatment, oxygen is uniformly penetrated into the thin plate, causing the reinforcing phase element to oxidize in situ to form a uniformly dispersed oxide. This method is simple, effective, and can be mass-produced. It is convenient and reliable for practical engineering applications.

[0037] like Figure 2 As shown in the figure, the microstructure of the nanoparticles before and after high-temperature oxygen infiltration is shown in the transmission electron microscope. It can be seen that oxygen is significantly enriched at the nanoparticles after high-temperature oxygen infiltration. It can be seen that yttrium nucleates into yttrium oxide under high-temperature oxygen infiltration treatment. The thin plate after high-temperature oxygen infiltration treatment is subjected to the same surface treatment as step A2. Step A7: Repeat step A3 to stack the surface-treated thin plates and vacuum seal them with a sleeve to obtain sleeved steel material B. Perform hot isostatic pressing on sleeved steel material B. Step A8: Hot forging is performed on the cladding steel B after hot isostatic pressing; The specific steps of hot forging are as follows: First, raise the temperature to 450°C at a rate of 10°C per minute and hold for 30 minutes; Then, the temperature was increased from 450°C to 1100°C at a rate of 10°C per minute, and the temperature was held for 1 hour before forging began; During the forging process, the cladding steel B needs to be hot forged in multiple directions. The final forging temperature is 800℃. If it is lower than the final forging temperature, it should be returned to the furnace for 30 minutes of heat treatment. After hot forging, the cladding is removed by machining to obtain ODS-CLF-1 steel; Its room temperature tensile properties were compared with those of conventional RAFM steel (CLF-1 steel), such as... Figure 3 As shown, this invention effectively improves the mechanical properties of materials prepared by 3D printing, and at the same time maintains high mechanical properties after high-temperature oxygen infiltration treatment. The ODS-CLF-1 steel prepared by this invention has good thermodynamic properties.

[0038] Example 2: This embodiment discloses a method for preparing ODS alloys based on 3D printing and rolling processes. The method involves combining V-4Cr-4Ti powder with yttrium powder. The V-4Cr-4Ti powder has a particle size of 15-53 micrometers, and the yttrium powder has a particle size of 20-30 micrometers. The mass percentage of yttrium powder in the mixed powder is 1.5%, and the mass percentage of V-4Cr-4Ti powder in the mixed powder is 98.5%. Step L1: Under an argon atmosphere, V-4Cr-4Ti powder and yttrium powder are initially mixed using a mechanical mixing method to obtain a homogenized powder; Step L2: Selective laser melting technology is used to prepare the mixed powder into 50*50*10mm blocks. The selective laser melting printing speed is 900mm / s and the power is 200W. An argon atmosphere is maintained during the printing process. Then, surface treatment is carried out. The block is sanded with sandpaper to expose a fresh surface, ultrasonically cleaned with deionized water, wiped with ethanol, and finally purged with nitrogen. Step L3: Stack the two surface-treated blocks and put them into a 304 stainless steel sleeve to obtain sleeve steel material A; First, the sheath is welded, with argon gas introduced during welding. After welding, the sheath is checked for airtightness to ensure a leakage rate of ≤10%. -10 Pa·m 3 / s, then the casing is subjected to cold evacuation and degassing for 12 hours, and finally the evacuation pipe on the casing is heated and clamped three times, with the vacuum level maintained at 1.0×10 throughout the clamping process. -5 ~1.0×10 -2 Pa is vacuum sealed using a cladding, followed by welding to obtain cladding steel A; Finally, the cladding steel A is subjected to hot isostatic pressing treatment; Specifically, the hot isostatic pressing temperature is 1000-1200℃, the pressure is held for 1-3 hours, the pressure is 150MPa, and the heating rate is 10℃ / min; then it is cooled at a rate of 5℃ / min, and removed from the furnace when the temperature is below 150℃. Step L4: Hot rolling of the cladding steel A; specifically: the cladding steel A is first heated to 400℃ at a rate of 10℃ / min and held at that temperature for 2 hours; during hot rolling, it is rolled along the length direction. The section of the cladding steel A without the exhaust pipe enters the rolling mill. During hot rolling, the reduction is 2mm, and the reduction is gradually reduced to 1mm as the number of rolling passes increases. The final rolling temperature is 300℃. If it is lower than this final rolling temperature, it is returned to the furnace and held at that temperature for 30 minutes until it is hot rolled to a thickness of 4mm and then air-cooled. The cladding is removed by machining and the rolled steel is divided into 50*50*2mm thick and thin plates, followed by the same surface treatment as step L2. Step L5: Repeat steps L3 and L4 three times to obtain a thin sheet. Through multiple stacked rolling processes, the uniformity of reactive elements will be effectively improved. The material thickness will decrease exponentially with each stacked rolling process, thereby significantly improving the uniformity of the microstructure, greatly improving the distribution of yttrium in low-activation steel, and accelerating the diffusion of reactive elements. At the same time, it can densify the bulk material obtained by additive manufacturing, thereby eliminating defects and improving performance.

[0039] Step L6. Perform high-temperature oxygen diffusion treatment on the thin sheet obtained in step L5; Specifically, an argon-oxygen mixture with an oxygen concentration of 0.25% to 1% is introduced into the high-temperature oxygen permeation treatment equipment, and the temperature is increased to 500 to 800°C at a rate of 10°C / min. The temperature is maintained for 2 hours and then heating is stopped.

[0040] like Figure 2 As shown in the figure, the transmission electron microscopy energy spectrum of the material before and after high-temperature oxygen infiltration shows that oxygen is significantly enriched at the nanoparticles after high-temperature oxygen infiltration. The thin plate after high-temperature oxygen infiltration undergoes the same surface treatment as step L2. Step L7: Repeat step A3 to stack the surface-treated thin plates and vacuum seal them with a sleeve to obtain sleeved steel B. Then hot isostatic pressing is applied to the sleeved steel B. Step L8: Hot forging is performed on the cladding steel B after hot isostatic pressing. The specific steps for hot forging are: heating at a rate of 10°C per minute to 900°C~1200°C, holding at that temperature for 1 hour, and then starting forging. The forging process requires hot forging of the cladding steel B in multiple directions. If the temperature is 200°C lower than the forging temperature, it should be returned to the furnace and held for 30 minutes. After hot forging, the cladding is removed by machining to obtain ODS-V-4Cr-4Ti.

[0041] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method for manufacturing ODS alloys based on 3D printing and accumulative roll bonding process, characterized in that, Specifically comprising the following steps: Step S1: mixing alloy powder and reaction element powder in a protective atmosphere or vacuum ring to form a mixed powder; Step S2: preparing the mixed powder into a block based on 3D printing technology, and performing surface treatment on the block; Step S3: stacking the surface-treated block, vacuum sealing the stack with a sleeve to form a sleeved steel A, and performing hot isostatic pressing on the sleeved steel A; Step S4: performing hot rolling on the hot isostatic pressed sleeved steel A, removing the sleeve after hot rolling to form a hot-rolled plate, dividing the hot-rolled plate into thin plates of the same size, and performing surface treatment on the thin plates; Step S5: repeating steps S3-S4 until the reaction elements are uniformly distributed, and obtaining a thin plate part; Step S6: performing high-temperature oxygen permeation treatment on the thin plate part to cause in-situ oxidation nucleation of the reaction elements, and performing surface treatment on the high-temperature oxygen permeation treated thin plate part; Step S7: stacking the surface-treated thin plate part in step S6, vacuum sealing the stack with a sleeve to form a sleeved steel B, and performing hot isostatic pressing on the sleeved steel B; Step S8: hot forging the hot isostatic pressed sleeved steel B, removing the sleeve, and obtaining an ODS alloy; and completing the preparation.

2. A method of manufacturing ODS alloys based on 3D printing and accumulative roll bonding process as claimed in claim 1, wherein, In step S2, the printing speed is 700-1300 mm / s and the power is 200-300 W when the block is prepared by using the 3D printing technology.

3. A method of manufacturing ODS alloys based on 3D printing and accumulative roll bonding process as claimed in claim 1, wherein, In step S3, the sleeve is used for vacuum sealing treatment, specifically: First, the stacked blocks are assembled with a sleeve; Subsequently, the cladding is welded, argon is passed during welding, and after welding, the cladding is checked for air tightness, and the cladding leakage rate is controlled to be ≤10 -10 Pa·m 3 / s; The can is cooled and evacuated for 2 to 20 hours through the evacuation pipe provided on the can, and the vacuum degree is kept below 1.0 x 10 -3 Pa. The suction pipe on the package is heated and clamped, and the vacuum degree during clamping is 1.0 x 10 -5 ~ 1.0 x 10 -2 Pa.

4. A method for manufacturing ODS alloys based on 3D printing and accumulative roll bonding process according to claim 1, characterized in that, In step S3, the hot isostatic pressing temperature of the sleeved steel A is 920-1300℃, the holding time is 2-3h, the pressure is 120-150MPa, the heating rate is 5-10℃ / min, the cooling rate is 5-7℃ / min, and the furnace is discharged when the temperature is lower than 150℃.

5. The method of claim 1, wherein the method is characterized by: In step S4, the hot rolling temperature is 400-1100℃, the sleeved steel A is heated at a rate of 5-10℃ / min, and the holding time is 1-2h.

6. A method of manufacturing ODS alloys based on 3D printing and accumulative roll bonding process as claimed in claim 5, wherein, In the hot rolling process, the downward displacement of each pass is 0.5-5mm, and the downward displacement decreases gradually; when the final rolling temperature of the sleeved steel A is lower than the hot rolling temperature by 200℃, the furnace is reheated and held for 10-30min for continuous hot rolling until the thickness is 2-8mm.

7. A method of manufacturing ODS alloys based on 3D printing and accumulative roll bonding process as claimed in claim, wherein, In step S6, the oxygen concentration is 0.5-2%, the temperature is 600-1350℃, the heating rate is 10℃ / min, and the holding time is 1-10h.

8. The method of claim 1, wherein the method is characterized by: Hot forging of the hot isostatic pressed sleeved steel B specifically refers to heating at a rate of 10℃ per minute to 800-1300℃, holding for 1 hour, and then starting forging; during hot forging, the sleeved steel B is forged in multiple directions; when the final forging temperature of the sleeved steel B is lower than the hot forging temperature by 200℃, the furnace is reheated and held for 30 minutes.

9. The method of claim 1, wherein the method is characterized by: The 3D printing technology is any one of selective laser melting, direct energy deposition, and shaped energy deposition.

10. The method of claim 1, wherein the method is characterized by: The reaction element powder is any one of yttrium powder, yttrium hydride powder, aluminum powder, titanium powder, rhenium powder, zirconium powder, and hafnium powder. The particle size of the alloy powder is 15-53 microns, and the particle size of the reactive element powder is 20-30 microns; The mass percentage of the alloy powder in the mixed powder is 95-99.9%, and the mass percentage of the reactive element powder in the mixed powder is 0.1-5%.

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