CN116287953A - Nuclear grade ferritic stainless steel with high-density nano-dispersed particles and preparation method thereof - Google Patents
Nuclear grade ferritic stainless steel with high-density nano-dispersed particles and preparation method thereof Download PDFInfo
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Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
- C22C33/06—Making ferrous alloys by melting using master alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
- C21C5/5211—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention discloses a nuclear grade ferrite stainless steel with high density nano dispersion particles and a preparation method thereof, wherein 5N grade pure iron, pure chromium, high purity titanium, 4N grade pure aluminum and nano yttrium oxide powder are used as raw materials, and an external field auxiliary induction smelting process protected by high purity argon is adopted to prepare Al-Y 2 O 3 Intermediate alloy, adopting vacuum arc melting technology to prepare Fe-Cr intermediate alloy, then carrying out vacuum arc melting in a vacuum arc melting furnace, and preparing nuclear grade ferrite stainless steel with high-density nano-dispersed particles after ingot casting is cooled to room temperature along with the furnace. The invention adopts the combination of the high-purity argon-protected external field auxiliary induction smelting process and the vacuum arc smelting process to prepare the fine matrix grains, and the nano-scale oxide dispersion particles are uniformly distributed on the matrix, so that the high-temperature mechanical property, the lead-bismuth corrosion resistance and the service safety of the material are greatly improved, and the material has better performance compared with common ferrite stainless steel.
Description
Technical Field
The invention belongs to the technical field of corrosion-resistant metal structural materials in extreme service environments, and particularly relates to nuclear grade ferrite stainless steel with high-density nano-dispersed particles and a preparation method thereof.
Background
As global climate warming increases, there is a need for people to seek energy modes for reducing carbon emissions to suppress the greenhouse effect, and the reduction of the use of renewable energy sources instead of fossil energy sources has become a broad consensus for people to reduce carbon emissions. The nuclear energy is highly focused by people because of the advantages of no carbon emission, stability, high efficiency and the like in the use process. The fourth generation nuclear reactor reference reactor type represented by the lead cold fast reactor is the first choice of the next generation green energy source of human beings. The lead-cooled fast reactor adopts lead/lead bismuth alloy as a coolant, has the characteristics of high safety, high economy, high sustainability and the like, and has great application potential. At present, many major problems related to lead cooled fast reactor designs have been addressed and solutions have been developed, but there is still a problem that must be solved: corrosion problems of liquid alloys to structural materials.
Stainless steel has excellent mechanical properties and corrosion resistance, and is low in cost, so that the stainless steel is widely applied to aspects of production and life. The fuel cladding of the lead-cooled fast reactor has a severe service environment, is soaked in liquid lead-bismuth eutectic for a long time and is subjected to high-dose neutron irradiation, so the cladding material must have excellent corrosion resistance and irradiation resistance. Although Fe has a neutron absorption cross section larger than Zr and is inferior to refractory alloys represented by zirconium alloys in neutron economy, stainless steel has excellent corrosion resistance and lower production cost and has potential for large-scale application to core components of lead-cooled fast reactors. Aluminum is added on the basis of the original ferritic stainless steel, so that the ferritic stainless steel has good irradiation resistance and excellent corrosion resistance, and becomes one of the most competitive cladding materials. At present, various preparation methods exist for ferrite stainless steel, but most of ferrite stainless steel is easy to introduce impurity elements, and has limited structure uniformity and stability, so that the high-temperature mechanical property and corrosion resistance of the material are reduced, and potential safety hazards are brought to the safe service of the cladding material.
Disclosure of Invention
The technical problem to be solved by the invention is to provide the nuclear grade ferrite stainless steel with high-density nano dispersion particles and the preparation method thereof, which are used for solving the technical problems of purification and large-scale production of the nuclear grade oxide dispersion strengthening steel and developing new ideas for the application of the Oxide Dispersion Strengthening (ODS) steel and other materials in the nuclear industry.
The invention adopts the following technical scheme:
a method for preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles, comprising the steps of:
Al-Y 2 O 3 And mixing the intermediate alloy and the Fe-Cr intermediate alloy, and then carrying out vacuum arc melting, and cooling to room temperature to prepare the nuclear grade ferrite stainless steel with high-density nano-dispersion particles.
A method for preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles, comprising the steps of:
Al-Y 2 O 3 And mixing the intermediate alloy and the Fe-Cr intermediate alloy, and then carrying out vacuum arc melting, and cooling to room temperature to prepare the nuclear grade ferrite stainless steel with high-density nano-dispersion particles.
Specifically, al-Y 2 O 3 In the intermediate alloy, the nano yttrium oxide accounts for 5.00 to 20.00 mass percent, and the rest is 4N grade pure aluminum.
Further, al-Y 2 O 3 The intermediate alloy is prepared by adopting an external field auxiliary induction smelting process protected by high-purity argon, placing an induction smelting furnace in a glove box, repeatedly vacuumizing and filling the high-purity argon for 3 times, exhausting residual gas in the glove box, filling the high-purity argon in the glove box, arranging a high-frequency ultrasonic generator in the induction furnace, placing an alumina crucible for smelting in the high-frequency ultrasonic generator, placing yttrium oxide powder at the bottom of the crucible, placing pure aluminum in the crucible during smelting, heating to 700-720 ℃, starting the ultrasonic generator to apply high-frequency oscillation to molten metal in the smelting process, simultaneously mechanically stirring by using an alumina stirring rod, pouring the molten metal into a casting mould after 10-15 min, and cooling to room temperature to obtain the alloy.
Specifically, in the Fe-Cr intermediate alloy, the mass percentage of pure chromium is 14.50-15.00%, the mass percentage of high-purity titanium is 0.45-0.55%, and the balance is 5N grade pure iron.
Further, the Fe-Cr intermediate alloy is prepared by adopting a vacuum arc melting process, each melting is carried out for 2-3 minutes, each sample is turned over and melted for 4-6 times, high-purity argon is pumped into the furnace again after each melting, high-purity titanium is pre-melted, a furnace chamber is cleaned for 3-5 times by adopting high-purity argon atmosphere before the melting, and then a cerium-tungsten electrode is adopted for arc striking under high current; before arc initiation, the raw materials are placed at the bottom of a water-cooled copper mold in sequence from low melting point to high melting point, the electric arc furnace chamber is vacuumized and continuously filled with high-purity argon, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber.
Further, before smelting, 5N grade pure iron, pure chromium, high purity titanium, 4N grade pure aluminum and nanometer yttrium oxide powder are sequentially washed by dilute hydrochloric acid and absolute ethyl alcohol in an ultrasonic manner, and are dried in vacuum for later use.
Specifically, al-Y 2 O 3 The mass ratio of the intermediate alloy to the Fe-Cr intermediate alloy is 19:1.
further, each sample is smelted for 2-3 minutes, each sample is overturned and smelted for 4-10 times, high-purity argon is pumped into the furnace again after each smelting, high-purity titanium is pre-smelted, the furnace chamber is cleaned for 3-5 times by adopting high-purity argon atmosphere before smelting, and then a cerium-tungsten electrode is adopted for arc striking under high current. Before arc initiation, the raw materials are placed at the bottom of a water-cooled copper mold in sequence from low melting point to high melting point, the electric arc furnace chamber is vacuumized and continuously filled with high-purity argon, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber.
The invention also provides a nuclear grade ferrite stainless steel with high density nano-dispersion particles, which comprises a metal matrix and nano-oxide dispersion particles, wherein the nano-oxide dispersion particles comprise the following components in percentage by weight: 3.60 to 5.23, cr:13.70% -14.33%, Y 2 O 3 :0.23 to 1.10 percent of Ti:0.43% -0.53%, and the balance of Fe and unavoidable trace impurities.
Specifically, the metal matrix is alpha-Fe, the average grain diameter is 110 mu m, the average grain diameter of the dispersed oxide particles is 200nm, and the average distribution density of the dispersed particles is 2.5X10 13 m -3 。
Compared with the prior art, the invention has at least the following beneficial effects:
the preparation method of the nuclear grade ferrite stainless steel with the high-density nano-dispersed particles is beneficial to component design, homogenization of raw materials and alloy tissues, melt clean purification treatment, homogenization distribution regulation and control of the dispersed particles and steel matrix grain morphology regulation and control of the ferrite stainless steel with the high-density nano-dispersed particles, so that the nuclear grade ferrite stainless steel with the high-density nano-dispersed particles has fine grains and uniformly distributed nano-grade oxide dispersed particles, various properties of the material are greatly improved, and the material has better properties compared with common ferrite stainless steel.
Further, the Al-Y is prepared by adopting an external field auxiliary induction smelting process protected by high-purity argon 2 O 3 Intermediate alloy, change Y in intermediate alloy 2 O 3 Can regulate and control the relative content of Y of alloy obtained by arc melting 2 O 3 The content of the nano yttrium oxide is reduced, and the phenomena of coarsening and agglomeration of the nano oxide caused by direct contact of the nano yttrium oxide with molten steel during direct smelting are avoided.
Further, the Al-Y is prepared by adopting the external field auxiliary induction smelting protected by high-purity argon 2 O 3 Intermediate alloy, avoiding the introduction of impurity elements and the burning loss of raw materialsThe oxide dispersion particles are uniformly distributed, so that the content of the oxide dispersion particles in the nuclear grade ferrite stainless steel is controlled, the introduction of impurity elements is effectively avoided, the purity of the prepared material is improved, the defects and inclusions of a sample are avoided to the greatest extent, and the service safety of the material is improved; the external field auxiliary induction smelting protected by high-purity argon is performed in a glove box, high-purity argon is introduced, and the like, so that the residual oxygen and nitrogen in the glove box are removed, and the burning loss of raw materials and the introduction of impurity elements in the smelting process are reduced; the high-frequency ultrasonic vibration and mechanical stirring are added, so that Y is effectively avoided 2 O 3 Coarsening and agglomerating of (C) to facilitate Y 2 O 3 Uniform distribution of particles in the matrix and refinement of the matrix structure.
Furthermore, the Fe-Cr intermediate alloy is prepared by a vacuum arc melting process, so that the component uniformity of an alloy matrix is improved while the yield of alloy elements is improved, and the component segregation of the alloy is avoided to the greatest extent.
Furthermore, the water-cooling copper mold vacuum arc furnace is adopted for smelting, so that the introduction of impurity elements is effectively avoided, the purity of the prepared material is improved, the defects and inclusions of a sample are avoided to the greatest extent, and the service safety of the material is improved; the operations of vacuumizing, introducing high-purity argon, pre-smelting high-purity titanium and the like are carried out before vacuum arc melting, so that the residual oxygen and nitrogen in the vacuum arc melting furnace chamber are removed, the reaction with raw materials in the melting process is avoided, the introduction of impurity elements is further avoided, the formation of defects and impurities is avoided, the structure form of steel is further optimized, and the service safety of the steel is improved.
Furthermore, the raw materials are added for cleaning treatment before smelting, and then smelting is carried out, so that various defects and inclusions in the preparation process of a smelting piece are reduced, the yield of the added elements is ensured, and the casting obtained by obtaining a compact and fine-structure sample has excellent thermal shock resistance, oxidation resistance, long fatigue life and high-temperature creep resistance; the fine dispersion particles are uniformly distributed on the matrix, so that the high-temperature mechanical property and the lead-bismuth corrosion resistance of the material are further improved.
Further, the method comprises the steps of,Al-Y 2 O 3 the intermediate alloy and the Fe-Cr intermediate alloy are subjected to vacuum arc melting according to a specific mass ratio, so that the yield of Al element is improved, the corrosion resistance of the alloy is improved, the thermal aging embrittlement tendency of a matrix is restrained, and the uniformity of alloy components is improved.
Furthermore, the vacuum arc melting furnace adopts an argon arc as a heat source, has high energy density, is beneficial to the rapid melting of raw materials, and improves the melting efficiency; the water-cooling copper mold is used for vacuum suction casting to form a temperature gradient with a specific direction, which is beneficial to regulating and controlling the growth orientation of tissues and inhibiting the generation of casting defects such as shrinkage cavity shrinkage porosity and the like.
The invention relates to a nuclear grade ferrite stainless steel with high density nano dispersion particles, the Cr content is 13.78% -14.25%, cr element can be dissolved in Fe crystal lattice to stabilize ferrite and improve the strength of the matrix, the solid solution improves the strength of the ferrite matrix, the corrosion resistance of the steel is improved, the Al content is 4.00% -4.75%, the Al element can improve the lead bismuth corrosion resistance of the matrix and improve the solid solubility of the Cr element in ferrite, the thermal aging embrittlement tendency of ferrite is restrained, the segregation of Cr in the ferrite matrix is avoided while the lead bismuth corrosion resistance of the steel is improved, the Ti content is 0.43% -0.52%, the thermal stability and the lead bismuth corrosion resistance of the ferrite stainless steel are improved while the matrix and oxide dispersion particles are thinned, and Y 2 O 3 The content of (C) is 0.26-1.05%, Y 2 O 3 The nano-scale dispersion particles can be formed by adding the nano-scale dispersion particles, the high-temperature mechanical property and the lead-bismuth corrosion resistance of the material are improved, the optimal toughening effect is realized strictly according to the addition amount of the oxide dispersion strengthening phase, and important performance indexes such as the high-temperature creep resistance, the high-temperature fatigue life, the lead-bismuth corrosion resistance and the like of the material are further improved.
In conclusion, the preparation method can effectively improve the high-temperature mechanical property, the lead-bismuth corrosion resistance and the service safety of the material.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Drawings
FIG. 1 is a process flow diagram of the present invention;
FIG. 2 is a schematic diagram of a high purity argon protected external field auxiliary induction melting apparatus of the present invention;
FIG. 3 is a schematic view of a vacuum arc melting apparatus of the present invention;
FIG. 4 is a photograph of sample OM obtained in example 1;
fig. 5 is a photograph of a FeCrAl alloy OM produced by arc melting.
Detailed Description
The following description of the present invention will be made clearly and fully, and it is apparent that the embodiments described are some, but not all, of the embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the present invention, all embodiments and preferred methods of implementation mentioned herein may be combined with each other to form new solutions, unless otherwise specified.
In the present invention, all technical features mentioned herein and preferred features may be combined with each other to form new technical solutions, unless otherwise specified.
In the present invention, the percentage (%) or parts refer to weight percentage or parts by weight relative to the composition unless otherwise specified.
In the present invention, the components or preferred components thereof may be combined with each other to form a new technical solution, unless otherwise specified.
In the present invention, unless otherwise indicated, the numerical ranges "a-b" represent shorthand representations of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6-22" means that all real numbers between "6-22" have been listed throughout, and "6-22" is only a shorthand representation of a combination of these values.
The "range" disclosed herein may take the form of a lower limit and an upper limit, which may be one or more lower limits and one or more upper limits, respectively.
In the present invention, the term "and/or" as used herein refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
In the present invention, each reaction or operation step may be performed sequentially or sequentially unless otherwise indicated. Preferably, the reaction processes herein are performed sequentially.
Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any method or material similar or equivalent to those described may be used in the present invention.
The invention provides a nuclear grade ferrite stainless steel with high density nano-dispersed particles and a preparation method thereof, wherein the nuclear grade ferrite stainless steel with high density nano-dispersed particles is prepared by combining a high-purity argon shielded external field auxiliary induction smelting process and a vacuum arc smelting process, fine matrix grains are obtained by combining the high-purity argon shielded external field auxiliary induction smelting process and the vacuum arc smelting process, and nano-grade oxide dispersed particles are uniformly distributed on a matrix, so that the high-temperature mechanical property, the lead-bismuth corrosion resistance and the service safety of the material are greatly improved, and compared with the common ferrite stainless steel, the material has better performance; the structure with uniform components, fine grains and uniformly distributed nano-scale oxide dispersion particles is obtained, so that the nuclear grade ferrite stainless steel with fine grain structure, uniformly distributed fine oxide dispersion particles on a matrix and certain strength and high density nano-dispersion particles is obtained, the service corrosion resistance of the nuclear grade ferrite stainless steel in a lead cold fast reactor is improved, and a new thought is provided for the development of the aluminum-containing ferrite stainless steel in the lead cold fast reactor.
Referring to fig. 1, the method for preparing the nuclear grade ferritic stainless steel with high-density nano-dispersed particles comprises the following steps:
s1, weighing 5N-grade pure iron, pure chromium, high-purity titanium, 4N-grade pure aluminum and nano yttrium oxide powder according to the mass fraction ratio, and taking the powder as a raw material for standby;
the ingredients are specifically as follows:
according to the component proportioning requirements, respectively weighing pure iron, pure chromium and pure aluminum, sequentially cleaning with dilute hydrochloric acid and absolute ethyl alcohol in an ultrasonic manner, and placing in a vacuum drying oven for later use after drying.
The nano yttrium oxide powder is weighed by using a ten-thousandth balance and is placed in a vacuum drying oven for standby after drying.
S2, smelting the raw materials 4N-grade pure aluminum and nano yttrium oxide powder configured in the step S1 through a vacuum induction smelting furnace, wherein the smelting process is carried out in a high-purity argon atmosphere, after the raw materials are thoroughly and uniformly mixed, pouring molten metal into a casting mold, and cooling to room temperature to obtain the Al-Y with uniform components, fine grains and uniformly distributed nano-scale dispersed particles 2 O 3 Intermediate alloy;
Al-Y 2 O 3 in the intermediate alloy, the mass fraction of the nano yttrium oxide is 5.00% -20.00%, and the rest is 4N-grade pure aluminum.
Referring to FIG. 2, al-Y is prepared by using high purity argon protected external field auxiliary induction smelting 2 O 3 Intermediate alloy effectively avoids the introduction of impurities in the smelting process, so that Y 2 O 3 The particles are uniformly distributed in the alpha-Al matrix, and the crystal grains are uniform and fine.
The induction smelting furnace is placed in a glove box, vacuum pumping and high-purity argon filling are repeated for 3 times, residual gas in the glove box is discharged, the glove box is filled with high-purity argon (99.99%), a high-frequency ultrasonic generator is arranged in the induction furnace, an alumina crucible for smelting is placed in the ultrasonic generator, and yttrium oxide powder is placed at the bottom of the crucible.
During smelting, pure aluminum is placed into a crucible, induction heating is carried out to 700-720 ℃, an ultrasonic generator is started to apply high-frequency oscillation to molten metal in the smelting process, meanwhile, an aluminum oxide stirring rod is used for mechanical stirring, and after 10min, the molten metal is poured into a casting mould to be cooled to room temperature, so that alloy is obtained.
The method comprises the steps of adopting a glove box, a high-frequency induction smelting furnace, a mechanical vacuum pump, a molecular diffusion pump, an ultrasonic generator and a mechanical stirrer to carry out induction smelting, and adopting a graphite casting mold to carry out molten metal casting.
S3, smelting the raw materials 5N grade pure iron, pure chromium and high purity titanium configured in the step S1 by a vacuum arc smelting furnace, wherein the smelting process is carried out in a high purity argon atmosphere, and after the raw materials are thoroughly and uniformly melted and cut, the raw materials are cooled to room temperature in a protection cavity to prepare Fe-Cr intermediate alloy;
for Fe-Cr intermediate alloy, the mass fraction of pure chromium is 14.50% -15.00%, the mass fraction of high-purity titanium is 0.45% -0.55%, and the balance is 5N grade pure iron.
Referring to fig. 3, the vacuum arc melting furnace adopts a cerium-tungsten electrode to lead out an argon arc, the arc is concentrated, the energy density of a heat source is high, and the melting efficiency is high; the water-cooled copper mold is used as casting mold, has high solidification speed and is beneficial to Y 2 O 3 The particles are uniformly dispersed in the matrix; the mechanical vacuum pump and the molecular diffusion pump are sequentially adopted before alloy smelting to vacuumize and smelt high-purity titanium in the cavity, so that residual oxygen and nitrogen in the cavity are absorbed, the introduction of impurities is avoided, and the purification smelting is realized.
Before smelting, the furnace chamber is cleaned for 3-5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc initiation, the raw materials are placed at the bottom of a water-cooled copper mold in sequence from low melting point to high melting point, the electric arc furnace chamber is vacuumized and continuously filled with high-purity argon, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber.
Each time of smelting is carried out for 2-3 minutes, each sample is turned over and smelted for 4-6 times, and high-purity argon gas and pre-smelted high-purity titanium are pumped in vacuum again after each time of smelting.
Vacuum arc melting is carried out by adopting a vacuum arc melting furnace, an inverter type direct current power supply, a mechanical vacuum pump and a molecular vacuum pump.
S4, smelting the intermediate alloy obtained by smelting in the steps S2 and S3 by a vacuum arc smelting furnace according to a certain mass fraction ratio, wherein the smelting process is carried out in a high-purity argon atmosphere, after the intermediate alloy is thoroughly and uniformly cut, the intermediate alloy is cooled to room temperature in a protective cavity to prepare the ferrite stainless steel with uniform components, fine grains and uniformly distributed nano-scale dispersed particles.
Before smelting, the furnace chamber is cleaned for 3-5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc initiation, the raw materials are placed at the bottom of a water-cooled copper mold in sequence from low melting point to high melting point, the electric arc furnace chamber is vacuumized and continuously filled with high-purity argon, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber.
Each time of smelting is carried out for 2-3 minutes, each sample is turned over and smelted for 4-10 times, and high-purity argon gas and pre-smelted high-purity titanium are pumped in vacuum again after each time of smelting.
Vacuum arc melting is carried out by adopting a vacuum arc melting furnace, an inverter type direct current power supply, a mechanical vacuum pump and a molecular vacuum pump.
Fe-Cr intermediate alloy and Al-Y 2 O 3 The mass ratio of the intermediate alloy is (18.9-19.1): (0.9-1.1).
And after smelting, vacuum suction casting is carried out through a copper mold, and cooling is carried out to room temperature.
The nuclear grade ferrite stainless steel with high density nano dispersion particles prepared by the method comprises a ferrite matrix and dispersion particles distributed on the matrix and a grain boundary, and comprises the following components in percentage by weight: 13.78 to 14.25 percent of Al:4.00% -4.75%, Y 2 O 3 :0.26 to 1.05 percent of Ti: 0.43-0.52%, and the balance of Fe and unavoidable trace impurities.
The results of the XRD and SEM characterization showed that: the metal matrix of the nuclear grade ferrite stainless steel is alpha-Fe, the shape factor and the average grain diameter are respectively 0.66 and 110.63 mu m, and the oxide dispersion particles are Y 2 O 3 The average particle diameter of the dispersed oxide particles is 200nm, and the average distribution density of the dispersed particles is 2.5X10 13 m -3 。
Cr and Al are used as important additive elements in nuclear grade ferrite stainless steel with high-density nano-dispersion particles, and the main functions are to improve the corrosion resistance of the steel and optimize the high-temperature mechanical properties of the steel. In addition, cr is solid-dissolved in the matrix, and hardenability of the alloy can be improved.
According to the previous research results, when Cr and Al contents are respectively 13.78-14.25% and 4.00-4.75%, the obtained tissue performance is the most excellent.
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
Alloy sample preparation
The invention selects pure iron, pure aluminum, nanometer yttrium oxide powder, pure chromium and pure titanium as raw materials. 84.48% of pure iron (the mass fraction of the chemical component of the pure iron is 99.9996% of Fe), 15.00% of pure chromium (the mass fraction of the chemical component of the pure chromium is 99.95% of Cr) and 0.52% of pure titanium (the mass fraction of the chemical component of the pure titanium is 99.996% of Ti) are respectively added into the raw materials of the Fe-Cr intermediate alloy; in Al-Y 2 O 3 90.00% pure aluminum (the mass fraction of the chemical component of the pure aluminum is 99.996% Al) 10.00% nanometer yttrium oxide powder (the mass fraction of the chemical component of the nanometer yttrium oxide powder is 99.9% Y) is respectively added into the raw materials of the intermediate alloy 2 O 3 )。
The specific preparation and smelting process of the invention is as follows:
s1, respectively weighing pure iron, pure chromium and pure aluminum according to the component proportioning requirements, sequentially ultrasonically cleaning with dilute hydrochloric acid and absolute ethyl alcohol, and placing in a vacuum drying oven for later use. The nano yttrium oxide powder is weighed by using a ten-thousandth balance and is placed in a vacuum drying oven for standby after drying.
S2, smelting the raw material 4N-grade pure aluminum and nano yttrium oxide powder prepared in the step S1 through a vacuum induction smelting furnace, placing the induction smelting furnace in a glove box, and repeatedly vacuumizing and filling the glove box with high temperatureAnd 3 times of pure argon, discharging residual gas in a glove box, filling high-purity argon in the glove box, arranging a high-frequency ultrasonic generator in an induction furnace, placing an aluminum oxide crucible for smelting in the ultrasonic generator, and placing yttrium oxide powder at the bottom of the crucible. During smelting, the smelting temperature is 704 ℃, an ultrasonic generator is started in the smelting process to apply 30kHz high-frequency oscillation to molten metal, meanwhile, an alumina stirring rod is used for mechanical stirring at the rotating speed of 120rmp, after 12min, the molten metal is poured into a graphite casting mold to be cooled to room temperature, and Al-Y with uniform components, fine grains and uniformly distributed nano-scale dispersed particles is obtained 2 O 3 And (3) intermediate alloy.
S3, smelting the raw materials of 5N-grade pure iron, pure chromium and high-purity titanium configured in the step S1 by a vacuum arc melting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooled copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00014MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample is turned over and smelted for 150s, and high-purity argon and pre-smelted high-purity titanium are pumped into vacuum again after each smelting. After the molten and thoroughly cut uniformly, the Fe-Cr intermediate alloy is prepared after being cooled to room temperature in a protection cavity, as shown in figure 5.
S4, smelting the Fe-Cr intermediate alloy and the Al-Y obtained in the steps S2 and S3 2 O 3 The mass ratio of the intermediate alloy is 19:1, carrying out smelting treatment by a vacuum arc smelting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooled copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00012MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample is turned over and smelted for 10 times after 170s for each smelting, and high-purity argon gas and pre-smelted high-purity titanium are pumped in vacuum again after each smelting. After the molten copper is thoroughly and uniformly cut, adopting a water-cooling copper mold for vacuumAnd (3) carrying out suction casting, and cooling to room temperature to obtain the ferrite stainless steel with uniform components, fine grains and uniformly distributed nano-scale dispersion particles.
Referring to FIG. 4, Y is prepared 2 O 3 Nuclear grade ferritic stainless steel with high density nano-dispersed particles, Y, content of 1.05 wt% 2 O 3 The addition of (2) can refine the grains and promote the formation of dispersed particles at the grain boundaries and within the grains of the material.
Example 2
Alloy sample preparation
The invention selects pure iron, pure aluminum, nanometer yttrium oxide powder, pure chromium and pure titanium as raw materials. 85.00% pure iron (the mass fraction of the chemical component of the pure iron is 99.9996% Fe), 14.55% pure chromium (the mass fraction of the chemical component of the pure chromium is 99.95% Cr) and 0.45% pure titanium (the mass fraction of the chemical component of the pure titanium is 99.996% Ti) are respectively added into the raw materials of the Fe-Cr intermediate alloy; in Al-Y 2 O 3 94.56% pure aluminum (99.996% Al) 5.44% nanometer yttrium oxide powder (99.9% Y) is added into the raw materials of the intermediate alloy 2 O 3 )。
The specific preparation and smelting process of the invention is as follows:
s1, respectively weighing pure iron, pure chromium and pure aluminum according to the component proportioning requirements, sequentially ultrasonically cleaning with dilute hydrochloric acid and absolute ethyl alcohol, and placing in a vacuum drying oven for later use. The nano yttrium oxide powder is weighed by using a ten-thousandth balance and is placed in a vacuum drying oven for standby after drying.
S2, smelting the raw materials 4N-grade pure aluminum and nano yttrium oxide powder configured in the step S1 through a vacuum induction smelting furnace, placing the induction smelting furnace in a glove box, repeatedly vacuumizing and filling high-purity argon gas for 3 times, discharging residual gas in the glove box, filling high-purity argon gas in the glove box, arranging a high-frequency ultrasonic generator in the induction furnace, placing an aluminum oxide crucible for smelting in the ultrasonic generator, and placing yttrium oxide powder at the bottom of the crucible. During smelting, the smelting temperature is 700 ℃, and during smelting, an ultrasonic generator is started to apply 25kHz high-frequency vibration to molten metalOscillating, mechanically stirring with an alumina stirring rod at 127rmp, pouring the molten metal into a graphite casting mold after 14min, and cooling to room temperature to obtain Al-Y with uniform composition, fine crystal grains and uniformly distributed nano-scale dispersed particles 2 O 3 And (3) intermediate alloy.
S3, smelting the raw materials of 5N-grade pure iron, pure chromium and high-purity titanium configured in the step S1 by a vacuum arc melting furnace. Before smelting, the furnace chamber is cleaned for 3 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooled copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00011MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. 165s are carried out for each smelting, each sample is turned over and smelted for 5 times, and high-purity argon gas and pre-smelted high-purity titanium are pumped into the furnace again after each smelting. And after the alloy is thoroughly and uniformly melted and cut, cooling the alloy in a protection cavity to room temperature to obtain the Fe-Cr intermediate alloy.
S4, smelting the Fe-Cr intermediate alloy and the Al-Y obtained in the steps S2 and S3 2 O 3 The mass ratio of the intermediate alloy is 19:1, carrying out smelting treatment by a vacuum arc smelting furnace. Before smelting, the furnace chamber is cleaned for 3 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooling copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00009MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample is turned over and smelted for 6 times after each smelting for 180 seconds, and high-purity argon gas and pre-smelted high-purity titanium are pumped in vacuum again after each smelting. After the molten ferrite stainless steel is thoroughly and uniformly cut, adopting a water-cooling copper mold for vacuum suction casting, and cooling to room temperature to obtain the ferrite stainless steel with uniform components, fine grains and uniformly distributed nano-scale dispersed particles.
Example 3
Alloy sample preparation
The invention selects pure iron, pure aluminum, nanometer yttrium oxide powder, pure chromium and pure titanium as raw materials. At the position of84.75% pure iron (the mass fraction of the chemical component of the pure iron is 99.9996% Fe), 14.75% pure chromium (the mass fraction of the chemical component of the pure chromium is 99.95% Cr) and 0.50% pure titanium (the mass fraction of the chemical component of the pure titanium is 99.996% Ti) are respectively added into the raw materials of the Fe-Cr intermediate alloy; in Al-Y 2 O 3 80.50% pure aluminum (99.996% Al) 19.50% nanometer yttrium oxide powder (99.9% Y) is added into raw materials of intermediate alloy 2 O 3 )。
The specific preparation and smelting process of the invention is as follows:
s1, respectively weighing pure iron, pure chromium and pure aluminum according to the component proportioning requirements, sequentially ultrasonically cleaning with dilute hydrochloric acid and absolute ethyl alcohol, and placing in a vacuum drying oven for later use. The nano yttrium oxide powder is weighed by using a ten-thousandth balance and is placed in a vacuum drying oven for standby after drying.
S2, smelting the raw materials 4N-grade pure aluminum and nano yttrium oxide powder configured in the step S1 through a vacuum induction smelting furnace, placing the induction smelting furnace in a glove box, repeatedly vacuumizing and filling high-purity argon for 4 times, discharging residual gas in the glove box, filling high-purity argon in the glove box, arranging a high-frequency ultrasonic generator in the induction furnace, placing an aluminum oxide crucible for smelting in the ultrasonic generator, and placing yttrium oxide powder at the bottom of the crucible. During smelting, the smelting temperature is 720 ℃, an ultrasonic generator is started in the smelting process to apply 20kHz high-frequency oscillation to molten metal, meanwhile, an alumina stirring rod is used for mechanical stirring at the rotating speed of 120rmp, after 11min, the molten metal is poured into a graphite casting mold to be cooled to room temperature, and Al-Y with uniform components, fine grains and uniformly distributed nano-scale dispersed particles is obtained 2 O 3 And (3) intermediate alloy.
S3, smelting the raw materials of 5N-grade pure iron, pure chromium and high-purity titanium configured in the step S1 by a vacuum arc melting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooling copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00017MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample is turned over and smelted for 4 times, and high-purity argon and pre-smelted high-purity titanium are pumped into the furnace again after each smelting. And after the alloy is thoroughly and uniformly melted and cut, cooling the alloy in a protection cavity to room temperature to obtain the Fe-Cr intermediate alloy.
S4, smelting the Fe-Cr intermediate alloy and the Al-Y obtained in the steps S2 and S3 2 O 3 The mass ratio of the intermediate alloy is 19:1, carrying out smelting treatment by a vacuum arc smelting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooled copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00016MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample was turned over for 4 times for 130s each time, and high purity argon gas was again introduced and high purity titanium was pre-melted after each time of melting. After the molten ferrite stainless steel is thoroughly and uniformly cut, adopting a water-cooling copper mold for vacuum suction casting, and cooling to room temperature to obtain the ferrite stainless steel with uniform components, fine grains and uniformly distributed nano-scale dispersed particles.
Example 4
Alloy sample preparation
The invention selects pure iron, pure aluminum, nanometer yttrium oxide powder, pure chromium and pure titanium as raw materials. 84.85% pure iron (the mass fraction of the chemical component of the pure iron is 99.9996% Fe), 14.62% pure chromium (the mass fraction of the chemical component of the pure chromium is 99.95% Cr) and 0.53% pure titanium (the mass fraction of the chemical component of the pure titanium is 99.996% Ti) are respectively added into the raw materials of the Fe-Cr intermediate alloy; in Al-Y 2 O 3 The raw materials of the intermediate alloy are respectively added with 85.00 percent of pure aluminum (the mass fraction of the chemical components of the pure aluminum is 99.996 percent of Al) and 5.00 percent of nanometer yttrium oxide powder (the mass fraction of the chemical components of the nanometer yttrium oxide powder is 99.9 percent of Y) 2 O 3 )。
The specific preparation and smelting process of the invention is as follows:
s1, respectively weighing pure iron, pure chromium and pure aluminum according to the component proportioning requirements, sequentially ultrasonically cleaning with dilute hydrochloric acid and absolute ethyl alcohol, and placing in a vacuum drying oven for later use. The nano yttrium oxide powder is weighed by using a ten-thousandth balance and is placed in a vacuum drying oven for standby after drying.
S2, smelting the raw materials 4N-grade pure aluminum and nano yttrium oxide powder configured in the step S1 through a vacuum induction smelting furnace, placing the induction smelting furnace in a glove box, repeatedly vacuumizing and filling high-purity argon gas for 3 times, discharging residual gas in the glove box, filling high-purity argon gas in the glove box, arranging a high-frequency ultrasonic generator in the induction furnace, placing an aluminum oxide crucible for smelting in the ultrasonic generator, and placing yttrium oxide powder at the bottom of the crucible. During smelting, the smelting temperature is 715 ℃, an ultrasonic generator is started in the smelting process to apply 19kHz high-frequency oscillation to molten metal, meanwhile, an alumina stirring rod is used for mechanical stirring at the rotating speed of 117rmp, after 10min, the molten metal is poured into a graphite casting mold to be cooled to room temperature, and Al-Y with uniform components, fine grains and uniformly distributed nano-scale dispersed particles is obtained 2 O 3 And (3) intermediate alloy.
S3, smelting the raw materials of 5N-grade pure iron, pure chromium and high-purity titanium configured in the step S1 by a vacuum arc melting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooled copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00015MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. 140s are carried out for each smelting, each sample is turned over and smelted for 4 times, and high-purity argon gas and pre-smelted high-purity titanium are pumped in vacuum again after each smelting. And after the alloy is thoroughly and uniformly melted and cut, cooling the alloy in a protection cavity to room temperature to obtain the Fe-Cr intermediate alloy.
S4, smelting the Fe-Cr intermediate alloy and the Al-Y obtained in the steps S2 and S3 2 O 3 The mass ratio of the intermediate alloy is 19.1:0.9, smelting treatment is carried out by a vacuum arc smelting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc initiationSequentially placing raw materials at the bottom of a water-cooled copper mold from low melting point to high melting point, sequentially starting a mechanical vacuum pump and a molecular diffusion pump in an electric arc furnace cavity to vacuum to 0.00011MPa, then introducing high-purity argon, and premelting high-purity titanium to remove residual oxygen in the cavity. Each sample was turned over for 155s and smelted 4 times, and after each smelting, high purity argon gas was again pumped in and high purity titanium was pre-smelted. After the molten ferrite stainless steel is thoroughly and uniformly cut, adopting a water-cooling copper mold for vacuum suction casting, and cooling to room temperature to obtain the ferrite stainless steel with uniform components, fine grains and uniformly distributed nano-scale dispersed particles.
Example 5
Alloy sample preparation
The invention selects pure iron, pure aluminum, nanometer yttrium oxide powder, pure chromium and pure titanium as raw materials. 84.65% of pure iron (the mass fraction of the chemical component of the pure iron is 99.9996% of Fe), 14.83% of pure chromium (the mass fraction of the chemical component of the pure chromium is 99.95% of Cr) and 0.52% of pure titanium (the mass fraction of the chemical component of the pure titanium is 99.996% of Ti) are respectively added into the raw materials of the Fe-Cr intermediate alloy; in Al-Y 2 O 3 89.00% pure aluminum (the mass fraction of the chemical component of the pure aluminum is 99.996% Al) 20.00% nanometer yttrium oxide powder (the mass fraction of the chemical component of the nanometer yttrium oxide powder is 99.9% Y) is respectively added into the raw materials of the intermediate alloy 2 O 3 )。
The specific preparation and smelting process of the invention is as follows:
s1, respectively weighing pure iron, pure chromium and pure aluminum according to the component proportioning requirements, sequentially ultrasonically cleaning with dilute hydrochloric acid and absolute ethyl alcohol, and placing in a vacuum drying oven for later use. The nano yttrium oxide powder is weighed by using a ten-thousandth balance and is placed in a vacuum drying oven for standby after drying.
S2, smelting 4N-grade pure aluminum and nano yttrium oxide powder which are raw materials configured in the step S1 through a vacuum induction smelting furnace, placing the induction smelting furnace in a glove box, repeatedly vacuumizing and filling high-purity argon for 3 times, discharging residual gas in the glove box, filling high-purity argon in the glove box, arranging a high-frequency ultrasonic generator in the induction furnace, placing an alumina crucible for smelting in the ultrasonic generator, and placing yttrium oxide powder in the glove boxThe bottom of the crucible. During smelting, the smelting temperature is 705 ℃, an ultrasonic generator is started to apply 19kHz high-frequency oscillation to molten metal in the smelting process, meanwhile, an alumina stirring rod is used for mechanical stirring at the rotating speed of 117rmp, and after 10min, the molten metal is poured into a graphite casting mold to be cooled to room temperature, so that Al-Y with uniform components, fine grains and uniformly distributed nano-scale dispersed particles is obtained 2 O 3 And (3) intermediate alloy.
S3, smelting the raw materials of 5N-grade pure iron, pure chromium and high-purity titanium configured in the step S1 by a vacuum arc melting furnace. Before smelting, the furnace chamber is cleaned for 3 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooled copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00013MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample is turned over and smelted for 145s, and high-purity argon and pre-smelted high-purity titanium are pumped into vacuum again after each smelting. And after the alloy is thoroughly and uniformly melted and cut, cooling the alloy in a protection cavity to room temperature to obtain the Fe-Cr intermediate alloy.
S4, smelting the Fe-Cr intermediate alloy and the Al-Y obtained in the steps S2 and S3 2 O 3 The mass ratio of the intermediate alloy is 18.9:1.1 smelting treatment is carried out by a vacuum arc smelting furnace. Before smelting, the furnace chamber is cleaned for 5 times by adopting high-purity argon atmosphere, and then a cerium tungsten electrode is adopted for arc striking under high current. Before arc drawing, the raw materials are sequentially placed at the bottom of a water-cooling copper mold from low melting point to high melting point, a mechanical vacuum pump and a molecular diffusion pump are sequentially started in an electric arc furnace chamber to be vacuumized to 0.00008MPa, then high-purity argon is introduced, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber. Each sample is turned over and smelted for 4 times after each smelting for 120s, and high-purity argon gas and pre-smelted high-purity titanium are pumped in vacuum again after each smelting. After the molten ferrite stainless steel is thoroughly and uniformly cut, adopting a water-cooling copper mold for vacuum suction casting, and cooling to room temperature to obtain the ferrite stainless steel with uniform components, fine grains and uniformly distributed nano-scale dispersed particles.
In summary, according to the nuclear grade ferrite stainless steel with the high-density nano-dispersion particles and the preparation method thereof, the nuclear grade ferrite stainless steel with the high-density nano-dispersion particles is prepared by combining the high-purity argon protected external field auxiliary induction smelting process and the vacuum arc smelting process, so that the nuclear grade ferrite stainless steel with the high-density nano-dispersion particles has fine grains and fine oxide dispersion particle distribution, various properties of the material are greatly improved, and the material has better properties compared with the common ferrite stainless steel.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.
Claims (10)
1. A method for preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles, comprising the steps of:
Al-Y 2 O 3 And mixing the intermediate alloy and the Fe-Cr intermediate alloy, and then carrying out vacuum arc melting, and cooling to room temperature to prepare the nuclear grade ferrite stainless steel with high-density nano-dispersion particles.
2. The method for preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles according to claim 1, wherein Al-Y 2 O 3 In the intermediate alloy, the nano yttrium oxide accounts for 5.00 to 20.00 mass percent, and the rest is 4N grade pure aluminum.
3. The method for preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles according to claim 2, wherein Al-Y 2 O 3 The intermediate alloy is prepared by adopting an external field auxiliary induction smelting process protected by high-purity argon, and an induction smelting furnace is arranged in a gloveRepeatedly vacuumizing and filling high-purity argon gas for 3 times in a box, discharging residual gas in a glove box, filling high-purity argon gas in the glove box, arranging a high-frequency ultrasonic generator in an induction furnace, placing an alumina crucible for smelting in the high-frequency ultrasonic generator, placing yttrium oxide powder at the bottom of the crucible, placing pure aluminum in the crucible during smelting, heating to 700-720 ℃ in an induction mode, starting the ultrasonic generator to apply high-frequency oscillation to molten metal in the smelting process, simultaneously mechanically stirring by using an alumina stirring rod, pouring the molten metal into a casting mold after 10-15 min, and cooling to room temperature to obtain the alloy.
4. The method for preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles according to claim 1, wherein in the Fe-Cr master alloy, the pure chromium is 14.50% -15.00% by mass, the high purity titanium is 0.45% -0.55% by mass, and the balance is 5N grade pure iron.
5. The method for preparing nuclear grade ferritic stainless steel with high density nano-dispersed particles according to claim 4, wherein the Fe-Cr intermediate alloy is prepared by adopting a vacuum arc melting process, each melting is carried out for 2-3 minutes, each sample is turned over and melted for 4-6 times, high-purity argon and pre-melted high-purity titanium are pumped into vacuum again after each melting, a furnace chamber is cleaned for 3-5 times by adopting high-purity argon atmosphere before melting, and then a cerium-tungsten electrode is adopted for arc striking under high current; before arc initiation, the raw materials are placed at the bottom of a water-cooled copper mold in sequence from low melting point to high melting point, the electric arc furnace chamber is vacuumized and continuously filled with high-purity argon, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber.
6. The method for preparing the nuclear grade ferritic stainless steel with the high-density nano-dispersed particles according to claim 3 or 5, wherein 5N grade pure iron, pure chromium, high-purity titanium, 4N grade pure aluminum and nano yttrium oxide powder are sequentially washed by dilute hydrochloric acid and absolute ethyl alcohol in an ultrasonic manner before smelting, and are dried in vacuum for later use.
7. According to claim 1The preparation method of the nuclear grade ferrite stainless steel with the high-density nano-dispersed particles is characterized in that the preparation method of the nuclear grade ferrite stainless steel is characterized in that 2 O 3 The mass ratio of the intermediate alloy to the Fe-Cr intermediate alloy is 19:1.
8. the method for preparing nuclear grade ferritic stainless steel with high density nano-dispersed particles according to claim 7, wherein each smelting is carried out for 2-3 minutes, each sample is turned over and smelted for 4-10 times, high purity argon gas is pumped into vacuum again after each smelting and high purity titanium is pre-smelted, a furnace chamber is cleaned for 3-5 times by adopting high purity argon gas atmosphere before smelting, and then a cerium tungsten electrode is adopted for arc striking under high current; before arc initiation, the raw materials are placed at the bottom of a water-cooled copper mold in sequence from low melting point to high melting point, the electric arc furnace chamber is vacuumized and continuously filled with high-purity argon, and high-purity titanium is pre-smelted to remove residual oxygen in the chamber.
9. A nuclear grade ferritic stainless steel with high density nano-dispersed particles, characterized in that it is prepared according to the method of preparing a nuclear grade ferritic stainless steel with high density nano-dispersed particles as defined in any one of claims 1 to 8, comprising a metal matrix and nano-oxide dispersed particles, al:3.60 to 5.23, cr:13.70% -14.33%, Y 2 O 3 :0.23 to 1.10 percent of Ti:0.43% -0.53%, and the balance of Fe and unavoidable trace impurities.
10. The nuclear grade ferritic stainless steel with high density nano-dispersed particles of claim 9, wherein the metal matrix is α -Fe, the average particle size is 110 μm, the average particle size of the dispersed oxide particles is 200nm, the average distribution density of the dispersed particles is 2.5x10 13 m -3 。
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| CN117403138A (en) * | 2023-10-24 | 2024-01-16 | 上海交通大学 | Corrosion-resistant oxide dispersion strengthening steel and preparation method thereof |
| CN117403138B (en) * | 2023-10-24 | 2024-05-14 | 上海交通大学 | Corrosion-resistant oxide dispersion strengthening steel and preparation method thereof |
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