Consumable electrode smelting equipment for preparing ODS steel and preparation method of consumable electrode smelting equipment

Abstract

The invention discloses consumable electrode smelting equipment for preparing ODS steel and a preparation method of the consumable electrode smelting equipment, and belongs to the technical field of OSD steel preparation. The equipment comprises a furnace shell, an electrode smelting unit arranged at the lower part of the furnace shell and an atmosphere adjusting device arranged at the upper part of the furnace shell. The atmosphere adjusting device comprises two vent valves, one ends of the two vent valves are connected with an oxygen source and a protective gas source respectively, the other ends of the two vent valves are connected with the gas mixing cavity, and the gas mixing cavity is connected with the mixed gas pressurizing cavity through a gas pressurizing valve. An electrode is placed in the electrode smelting unit, a vent hole penetrating through the upper end face and the lower end face of the electrode is formed in the middle of the electrode, the gas mixing pressurization cavity is connected with the vent hole through a vent pipe, and a gas mixing one-way valve is installed on the vent pipe. According to the method, the equipment is adopted for ODS steel preparation, the atmosphere pressure and the gas content in the cavity can be dynamically adjusted according to the solidification rate of the melt in the smelting process, it is guaranteed that the content of dissolved oxygen elements is stable after the melt is solidified, and the ODS steel uniform in structure and small in segregation is prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of OSD steel preparation, and more specifically, relates to a consumable electrode smelting device for preparing ODS steel and a preparation method thereof. Background Art

[0002] As an important equipment for smelting industrial metal alloys, the consumable electrode melting furnace uses the high temperature generated by the arc discharge between the electrode and the crucible as a heat source to melt the electrode to form an ingot with small segregation and uniform structure. During smelting, it is usually necessary to introduce protective gas into the equipment to protect the electrode melting process.

[0003] For example, the Chinese patent application number is CN201920901234.1, and the patent document with the publication date of February 21, 2020 discloses a protective gas electroslag smelting furnace, including a crystallizer, a bottom water tank, a consumable electrode, a dummy electrode, a clamping arm, a lifting drive mechanism, etc.; there are also two semi-cylindrical protective covers, namely the first protective cover and the second protective cover, and the protective covers are fixed with connecting arms installed on the connecting seat through connecting pieces; the connecting seat includes a supporting seat, which is held on both sides of the vertical slideway by two supporting clamping arms and locked by clamping arm fasteners; the top center of the first protective cover and the second protective cover is provided with a semicircular electrode through hole; the first protective cover or the second protective cover is provided with a gas filling port, which is connected to the protective gas tank. This scheme realizes gas protection during the smelting process by adding an external device to the crystallizer.

[0004] The Chinese patent application number is CN201620928271.8, and the publication date is February 1, 2017. The patent document discloses a gas protection device in the electroslag remelting refining process, including a second gas protection ring arranged in the crystallizer, the second gas protection ring is adjusted by a lifting control rod connected thereto, the inner cavity of the second gas protection ring is filled with protective gas, and the inner side of the second gas protection ring is provided with a plurality of uniformly distributed needle-shaped blowing ports or thin slits. The device can effectively isolate the air in the crystallizer during the electroslag remelting refining process by forming a good gas protection layer.

[0005] The Chinese patent application number is: CN202221512625.2, and the patent document with the publication date of August 2, 2022 discloses a controlled atmosphere melting system. It can maintain the balance of protective gas under different vacuum conditions. It includes a vacuum system and a protective gas filling system connected to the melting system; the vacuum system includes a large Roots pump, a small Roots pump, and a sliding valve pump; the air inlet of the large Roots pump is connected to the vacuum port of the melting system through a pipeline, the exhaust port of the large Roots pump is connected to the air inlet of the small Roots pump through a pipeline, and the exhaust port of the small Roots pump is connected to the air inlet of the sliding valve pump through a pipeline; the protective gas filling system includes a gas cylinder, and the gas cylinder is connected to the air inlet of the melting system through a pipeline; a coaxial valve 1 is arranged on the pipeline between the gas cylinder and the melting system, and the coaxial valve 1 is provided with a parallel branch, and a mass flowmeter and a coaxial valve 2 are arranged on the parallel branch. The system realizes the maintenance of protective gas balance under different vacuum conditions through a vacuum and protective gas filling system connected to the melting system.

[0006] At the same time, there are already some electroslag smelting furnaces with built-in protective gas devices on the market. The air in the crystallizer is continuously blown out through evenly distributed needle-shaped blowing ports, so that the end of the electrode is always in the protective gas layer. For example, the Chinese patent application number is: CN201910846073.5, and the patent document published on November 15, 2019, discloses a high-entropy alloy with good hot working performance, containing Ti, Zr, and at least two of Nb, Ta, Hf, Mo, V, W, and Cr, wherein the molar ratio between any two elements is a, 0.5≤a≤2, and the high-entropy alloy is obtained by smelting in a non-consumable vacuum arc furnace with a mixed gas of H2+Ar as the smelting atmosphere, and the volume fraction of H2 is 0-20% of the mixed gas. The invention realizes the requirement that the smelting process is carried out in a reactive atmosphere by introducing a mixed gas into the smelting furnace after the smelting furnace is vacuumed.

[0007] However, although these devices and methods can provide protective gas and reaction atmosphere to a certain extent, there are the following problems for the preparation process that requires gas to participate in smelting: 1) As the electrode smelting proceeds, the reaction gas content changes uncontrollably, and it is impossible to dynamically adjust the gas content to keep it constant; 2) The reaction gas cannot be evenly filled into the molten pool area, and the prepared tissue has poor uniformity and severe segregation. Summary of the invention

[0008] 1. Problems to be solved

[0009] In view of the problem that the gas content cannot be kept constant and the prepared structure is uneven and easily segregated when the existing consumable electrode smelting equipment prepares metal alloys that require gas to participate in smelting, the present invention provides a consumable electrode smelting equipment for preparing ODS steel and a preparation method thereof. During the smelting process, the atmosphere pressure and gas content in the cavity can be dynamically adjusted according to the solidification rate of the melt, so as to ensure the stability of the dissolved oxygen element content after the melt solidifies, and prepare ODS steel with uniform structure and less segregation.

[0010] 2. Technical solution

[0011] To solve the above problems, the present invention adopts the following technical solutions.

[0012] A consumable electrode smelting device for preparing ODS steel comprises a furnace shell, an electrode smelting unit arranged at the lower part of the furnace shell and an atmosphere regulating device arranged at the upper part of the furnace shell; the atmosphere regulating device comprises two ventilation valves, one end of the two ventilation valves is respectively connected to an oxygen source and a protective gas source, and the other end is connected to a gas mixing chamber; the gas mixing chamber is connected to a gas mixing and boosting chamber through a gas boosting valve; an electrode is placed in the electrode smelting unit, a ventilation hole penetrating the upper and lower end surfaces of the electrode is opened in the middle part of the electrode, the gas mixing and boosting chamber is connected to the ventilation hole through a ventilation pipe, and the ventilation pipe is provided with a gas mixing one-way valve for controlling the gas flow to the electrode.

[0013] As a further improvement of the technical solution, the cavity of the electrode smelting unit is connected to a vacuum device.

[0014] As a further improvement of the technical solution, a one-way pressure control valve for controlling the gas flow to the vacuum device is installed at the connection between the electrode smelting unit and the vacuum device.

[0015] A method for preparing ODS steel, using the above-mentioned consumable electrode smelting equipment to prepare ODS steel, comprises the following steps:

[0016] 1. Prepare raw materials and melt them into cylindrical electrodes;

[0017] 2. Drill an air hole at the center of the end of the electrode along the height direction, and then place the electrode at the electrode melting unit of the consumable electrode melting equipment, so that the air hole is connected to the air pipe at the electrode rod of the electrode melting unit;

[0018] 3. Evacuate the electrode smelting equipment, then adjust the vent valve to pass oxygen and protective gas into the gas mixing chamber. After the gases are fully mixed, they enter the mixed gas boosting chamber through the boosting valve, and finally enter the vent hole 7 through the mixed gas one-way valve 6, and finally prepare the ODS steel ingot.

[0019] As a further improvement of the technical solution, in step 1, the raw materials are prepared according to the following chemical composition and their mass percentages: C: 0.03-0.15%, Cr: 7-20%, W: 1-3%, V: 0.1-0.3%, Ti: 0.05-0.30%, Re: 0.00-0.50%, and the balance is Fe.

[0020] As a further improvement of the technical solution, the step 2 also includes drilling holes in the electrode to add precursor powder, and the chemical composition of the precursor powder and its mass percentage in the entire electrode are: Re: 0.01-0.50%, Cr: 7-20%.

[0021] As a further improvement of the technical solution, when adding precursor powder, the following nested electrode drilling method is adopted: a cylindrical inner nested electrode is dug out from the middle of the electrode along its height direction, a groove is cut on the outer surface of the inner nested electrode and then put back into the electrode, the lower end of the groove is sealed and the inner nested electrode is fixedly connected to the electrode, and then the precursor powder is added to the groove.

[0022] As a further improvement of the technical solution, the number of the grooves is no more than 200, and the hole diameter is 1 to 20 mm.

[0023] As a further improvement of the technical solution, the protective gas is argon.

[0024] As a further improvement of the technical solution, the adjustment range of the partial pressure ratio of oxygen is: 0.1% to 30%.

[0025] 3. Beneficial effects

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention provides a consumable electrode smelting device for preparing ODS steel and a preparation method thereof. By setting the ratio of an atmosphere adjustment device to a one-way pressure control valve, the flow rate of the reaction atmosphere in the molten pool area is controlled, and the excess gas in the furnace is extracted by a vacuum device, so that the atmosphere pressure and gas content in the cavity are dynamically adjusted according to the solidification rate of the melt during the smelting process, the dissolved oxygen element content is ensured to be stable after the melt solidifies, and ODS steel with uniform structure and small segregation is prepared;

[0028] (2) The present invention provides a consumable electrode smelting device for preparing ODS steel and a preparation method thereof. When a large volume electrode is smelted, the problem of deep drilling leading to difficulty in drilling exists. A nested electrode drilling method is designed, which solves this problem well by slotting the outer side of the inner nested electrode. The nested electrode method makes it possible to better adjust the composition of the inner and outer electrodes, further reducing the composition segregation in the preparation process of ODS steel.

[0029] (3) The consumable electrode smelting equipment and preparation method for ODS steel of the present invention can effectively reduce the temperature gradient between the center and edge of the ingot by designing the air vents. The blowing of airflow not only promotes the flow of the molten pool, but also makes the reaction atmosphere further fully contact with the molten pool, while improving the uniformity of the temperature field and composition of the melt. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the consumable electrode smelting equipment of the present invention;

[0031] Figure 2 Schematic diagram of two electrode drilling methods of the present invention;

[0032] In the figure: 1. atmosphere regulating device; 2. ventilation valve; 3. gas mixing chamber; 4. gas boosting valve; 5. gas mixing boosting chamber; 6. gas mixing non-return valve; 7. ventilation pipe; 8. electrode lifting device; 9. electrode rod; 10. non-return pressure control valve; 11. vacuum device; 12. electrode; 13. electric arc; 14. furnace shell; 15. ingot; 16. water-cooled copper crystallizer; 17. ventilation hole; 18. inner nested electrode; 19. groove. DETAILED DESCRIPTION

[0033] Exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention, it should be understood that other embodiments may be implemented and various changes may be made to the present invention without departing from the spirit and scope of the present invention. The more detailed description of the embodiments of the present invention below is not intended to limit the scope of the claimed invention, but is merely for illustration and does not limit the description of the features and characteristics of the present invention, in order to propose the best mode for performing the present invention, and is sufficient to enable those skilled in the art to implement the present invention. Therefore, the scope of the present invention is limited only by the appended claims.

[0034] A consumable electrode smelting device for preparing ODS steel is used for preparing ODS steel by a consumable electrode smelting method. The specific structure and technical effect thereof are described in detail below.

[0035] like Figure 1As shown, the equipment includes a furnace shell 14 and an electrode smelting unit arranged at the lower part of the furnace shell 14, and an atmosphere adjustment device 1 arranged at the upper part of the furnace shell 14. An electrode 12 is placed in the electrode smelting unit, and a vent hole 17 is opened in the middle of the electrode 12 to penetrate the upper and lower end surfaces thereof. A pair of electrode rods 9 are arranged on the upper side of the electrode 12, and a vent pipe 7 is arranged between the pair of electrode rods 9. A water-cooled copper crystallizer 16 is arranged at the bottom of the electrode smelting unit 12. In addition, the electrode smelting unit also includes an electrode lifting device 8 for lifting and lowering the electrode 12. During smelting, an arc 13 is generated at the lower end of the electrode 12, and after the electrode 12 is melted, an ingot 15 is formed at the water-cooled copper crystallizer 16.

[0036] The atmosphere adjustment device includes two vent valves 2, one end of each of the two vent valves 2 is connected to an oxygen source and a protective gas source, respectively, and the other end is connected to a gas mixing chamber 3. The gas mixing chamber 3 is connected to a gas mixing and boosting chamber 5 through a gas boosting valve 4, and the gas mixing and boosting chamber 5 is connected to a vent hole 17 through a vent pipe 7, and a gas mixing one-way valve 6 for controlling the gas flow to the electrode 12 is installed on the vent pipe 7.

[0037] In addition, the cavity of the electrode melting unit is also connected to a vacuum device 11, which can extract excess gas in the cavity. A one-way pressure control valve 10 is installed at the connection between the electrode melting unit and the vacuum device 11 to control the gas flow to the vacuum device 11.

[0038] When the electrode melting equipment is used, the following method is adopted to prepare ODS steel.

[0039] 1. Prepare raw materials and melt them into cylindrical electrodes. In this step, prepare raw materials according to the following chemical composition and their mass percentages: C: 0.03-0.15%, Cr: 7-20%, W: 1-3%, V: 0.1-0.3%, Ti: 0.05-0.30%, Re: 0.00-0.50%, and the balance is Fe.

[0040] Second, a vent hole 17 is made at the center of the end of the electrode 12 along the height direction. The vent hole 17 is located at the center of the electrode and has a diameter of 10 to 200 mm. Then the electrode 12 is placed at the electrode smelting unit of the consumable electrode smelting equipment, and the vent hole 17 is connected to the vent pipe 7 at the electrode rod 9 of the electrode smelting unit. This step also includes drilling a hole in the electrode 12 to add a precursor powder. The chemical composition of the precursor powder and its mass percentage in the entire electrode are: Re: 0.01 to 0.50%, Cr: 7 to 20%. The design of the vent hole 17 can effectively reduce the temperature gradient between the center and edge of the ingot. The blowing of the airflow not only promotes the flow of the molten pool, but also makes the reaction atmosphere further fully contact with the molten pool, while improving the uniformity of the temperature field and composition of the melt.

[0041] It should be noted that if Figure 2As shown on the right, the conventional drilling method is generally to directly drill holes on the surface of the electrode 12 along the height direction. However, when melting large-volume electrodes, there is a problem that drilling holes too deep makes drilling difficult. Therefore, the present invention designs a unique nested electrode drilling method for large-volume electrodes. Figure 2 As shown on the left, a cylindrical inner nested electrode 18 is dug out from the middle of the electrode 12 along its height direction, a semicircular or arc-shaped groove 19 is opened on the outer surface of the inner nested electrode 18 and then put back into the electrode 12, the lower end of the groove 19 is blocked and the inner nested electrode 18 is fixedly connected to the electrode 12, and then the precursor powder is added to the groove 19. This method solves the problem of difficulty in drilling large-volume electrodes, and the nested electrode method makes it possible to better adjust the composition of the inner and outer electrodes, further reducing the composition segregation during the preparation of ODS steel.

[0042] In actual operation, the number of holes or slots 19 is no more than 200, and the hole diameter is 1 to 20 mm.

[0043] 3. The electrode smelting equipment is evacuated, and then the vent valve 2 is adjusted to pass oxygen and protective gas into the gas mixing chamber 3. After the gas is fully mixed, it enters the mixed gas pressurization chamber 5 through the boost valve 4, and finally enters the vent hole 7 through the mixed gas check valve 6, and finally prepares the ODS steel ingot. In this step, the protective gas is argon, the oxygen partial pressure ratio is adjusted in the range of 0.1% to 30%, and the adjustment range of the one-way pressure control valve 10 is set to 0.001MPa to 0.8MPa.

[0044] The present invention controls the flow rate of the reaction atmosphere in the molten pool area by setting the ratio of the atmosphere adjustment device 1 and the one-way pressure control valve 10, and extracts the excess gas in the furnace through the vacuum device 11, so as to dynamically adjust the atmosphere pressure and gas content in the cavity according to the solidification rate of the melt during the smelting process, ensure the stability of the dissolved oxygen element content after the melt solidifies, and prepare ODS steel with uniform structure and small segregation.

[0045] Specific experimental data are given below for further explanation.

[0046] Example 1

[0047] Step 1: Prepare a round rod-shaped cylindrical electrode without rare earth elements by smelting pure elements of Fe, Cr, V, W, C, Ti, and RE in a ratio of mass fraction C: 0.03%, Cr: 7%, W: 1%, V: 0.1%, Ti: 0.05%, RE: 0.00%, and the balance Fe.

[0048] Step 2: punch an air hole 17 along the height direction at the center of the end of the electrode 12, and then place the electrode 12 at the electrode smelting unit of the consumable electrode smelting equipment, so that the air hole 17 is connected to the vent pipe 7 at the electrode rod 9 of the electrode smelting unit. Prepare precursor powders with Re oxide powder and Fe and Cr powders in a ratio of Re: 0.01% and Cr: 7% of the total mass percentage of the electrode. Punch 5 grooves 19 with a diameter of 5 mm evenly distributed on the above electrode in a nested electrode punching manner, place the precursor powder in the groove 19 and seal it, and the inner and outer layers of the nested electrode have the same composition.

[0049] Step 3: Vacuum the electrode melting equipment to 10 -3 Pa, and then adjust the vent valve 2 to dynamically introduce oxygen and protective gas into the gas mixing chamber 3 according to the oxygen partial pressure ratio of 0.1% to 0.3% during the smelting process. After the gases are fully mixed, they enter the mixed gas boosting chamber 5 through the boosting valve 4, and finally enter the vent hole 7 through the mixed gas check valve 6, and finally the ODS steel ingot is prepared.

[0050] Example 2

[0051] Step 1: Prepare a round rod-shaped cylindrical electrode containing rare earth elements by smelting pure elements of Fe, Cr, V, W, C, Ti, and RE in a ratio of mass fraction C: 0.03%, Cr: 9%, W: 1%, V: 0.1%, Ti: 0.05%, RE: 0.02%, and the balance being Fe.

[0052] Step 2: Make an air hole 17 along the height direction at the center of the end of the electrode 12, and then place the electrode 12 at the electrode smelting unit of the consumable electrode smelting equipment, so that the air hole 17 is connected to the air pipe 7 at the electrode rod 9 of the electrode smelting unit. Prepare the precursor powder with the ratio of Re oxide powder and Fe and Cr powder according to the percentage of the total mass of the electrode: Re: 0.02%, Cr: 9%. Figure 2 The integrated electrode drilling method shown on the right side evenly drills three holes with a diameter of 6 mm on the above electrode, places the precursor powder into the holes and seals them.

[0053] Step 3: Vacuum the electrode melting equipment to 10 -3 Pa, and then adjust the vent valve 2 to dynamically introduce oxygen and protective gas into the gas mixing chamber 3 according to the oxygen partial pressure ratio of 0.3% to 0.5% during the smelting process. After the gases are fully mixed, they enter the mixed gas boosting chamber 5 through the boosting valve 4, and finally enter the vent hole 7 through the mixed gas check valve 6, and finally the ODS steel ingot is prepared.

[0054] Example 3

[0055] Step 1: Prepare a round rod-shaped cylindrical electrode containing rare earth elements by smelting pure elements of Fe, Cr, V, W, C, Ti, and RE in a ratio of mass percentage of C: 0.03%, Cr: 11%, W: 1%, V: 0.1%, Ti: 0.05%, RE: 0.05%, and the balance of Fe.

[0056] Step 2: drill an air hole 17 at the center of the end of the electrode 12 along the height direction, and then place the electrode 12 at the electrode smelting unit of the consumable electrode smelting equipment, so that the air hole 17 is connected to the air pipe 7 at the electrode rod 9 of the electrode smelting unit.

[0057] Step 3: Vacuum the electrode melting equipment to 10 -3 Pa, and then adjust the vent valve 2 to dynamically introduce oxygen and protective gas into the gas mixing chamber 3 according to the oxygen partial pressure ratio of 0.9% to 1.5% during the smelting process. After the gases are fully mixed, they enter the mixed gas boosting chamber 5 through the boosting valve 4, and finally enter the vent hole 7 through the mixed gas check valve 6, and finally the ODS steel ingot is prepared.

[0058] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A consumable electrode smelting device for preparing ODS steel, comprising a furnace shell (14) and an electrode smelting unit arranged at the lower part of the furnace shell (14), characterized in that: The invention also comprises an atmosphere regulating device (1) arranged on the upper part of the furnace shell (14); the atmosphere regulating device comprises two ventilation valves (2), one end of the two ventilation valves (2) is respectively connected to the oxygen source and the protective gas source, and the other end is connected to the gas mixing chamber (3); the gas mixing chamber (3) is connected to the gas mixing and boosting chamber (5) through the gas boosting valve (4); an electrode (12) is placed in the electrode smelting unit, a ventilation hole (17) penetrating the upper and lower end surfaces of the electrode (12) is opened in the middle part, and the gas mixing and boosting chamber (5) is connected to the ventilation hole (17) through the ventilation pipe (7), and the ventilation pipe (7) is equipped with a gas mixing check valve (6) for controlling the gas flow to the electrode (12).

2. The consumable electrode smelting equipment for preparing ODS steel according to claim 1, characterized in that: The cavity of the electrode smelting unit is connected to a vacuum device (11).

3. The consumable electrode smelting equipment for preparing ODS steel according to claim 2, characterized in that: A one-way pressure control valve (10) for controlling the flow of gas to the vacuum device (11) is installed at the connection between the electrode smelting unit and the vacuum device (11).

4. A method for preparing ODS steel, characterized in that: The consumable electrode smelting equipment according to any one of claims 1 to 3 is used to prepare ODS steel, comprising the following steps:

1. Prepare raw materials and melt them into cylindrical electrodes; 2. A vent hole (17) is drilled at the center of the end of the electrode (12) along the height direction, and then the electrode (12) is placed at the electrode smelting unit of the consumable electrode smelting equipment, so that the vent hole (17) is connected to the vent pipe (7) at the electrode rod (9) of the electrode smelting unit; 3. The electrode smelting equipment is evacuated, and then the ventilation valve (2) is adjusted to allow oxygen and protective gas to enter the gas mixing chamber (3). After the gases are fully mixed, they enter the mixed gas boosting chamber (5) through the boosting valve (4), and finally enter the ventilation hole 7 through the mixed gas check valve 6, and finally the ODS steel ingot is prepared.

5. The method for preparing ODS steel according to claim 4, characterized in that: In the step 1, raw materials are prepared according to the following chemical composition and its mass percentage: C: 0.03-0.15%, Cr: 7-20%, W: 1-3%, V: 0.1-0.3%, Ti: 0.05-0.30%, Re: 0.00-0.50%, and the balance is Fe.

6. The method for preparing ODS steel according to claim 4, characterized in that: The step 2 also includes drilling holes in the electrode (12) to add precursor powder, wherein the chemical composition of the precursor powder and its mass percentage in the entire electrode are: Re: 0.01-0.50%, Cr: 7-20%.

7. The method for preparing ODS steel according to claim 6, characterized in that: When adding precursor powder, the following nested electrode drilling method is used: a cylindrical inner nested electrode (18) is dug out from the middle of the electrode (12) along its height direction, a groove (19) is cut on the outer surface of the inner nested electrode (18) and then placed back into the electrode (12), the lower end of the groove (19) is sealed and the inner nested electrode (18) is fixedly connected to the electrode (12), and then the precursor powder is added to the groove (19).

8. The method for preparing ODS steel according to claim 7, characterized in that: The number of the grooves (19) is no more than 200, and the hole diameter is 1 to 20 mm.

9. The method for preparing ODS steel according to claim 4, characterized in that: The protective gas is argon.

10. The method for preparing ODS steel according to claim 9, characterized in that: The oxygen partial pressure ratio is adjusted within a range of 0.1% to 30%.

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