A method for preparing a high-strength and high-ductility FeCrAl-based alloy

Abstract

This invention discloses a method for preparing a high-strength and ductile FeCrAl-based alloy. First, a FeCrAl-based alloy ingot is prepared and subjected to high-temperature homogenization treatment. Then, the homogenized alloy ingot is heated and held at that temperature before hot rolling using a cross-rolling method, with a single-pass deformation of 10%–20%. Next, the hot-rolled sheet is directly annealed at the same temperature. Then, the hot-rolled sheet undergoes 60%–90% cold rolling deformation. Finally, the cold-rolled sheet is subjected to short-time annealing at 1130℃–1200℃ for 10–20 seconds, followed by water quenching or gradient cooling. The obtained FeCrAl-based alloy is then pre-deformed by rolling and aged to obtain a FeCrAl-based alloy product with good strength and ductility. This method avoids the formation of surface cracks in the alloy and is simple to operate.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials and relates to a method for preparing a high-strength and ductile FeCrAl-based alloy. Background Technology

[0002] Zirconium alloy is currently the only cladding material used in commercial nuclear reactor fuel elements. However, zirconium alloy has a fatal flaw: it reacts with high-temperature cooling water, releasing a large amount of heat and hydrogen, which could trigger an explosion. Therefore, extensive work has been carried out both domestically and internationally on developing next-generation nuclear cladding materials with excellent high-temperature oxidation resistance and high-temperature strength—that is, accident-resistant cladding materials.

[0003] Among numerous candidate materials, FeCrAl alloy stands out due to the rapid formation of a dense Al2O3 oxide film on the sample surface by the Al element, which prevents the internal alloy matrix from combining with oxygen and corrosive liquids outside the film. Simultaneously, the Cr element also plays a stabilizing role in the Al2O3 oxide film. Therefore, FeCrAl alloy exhibits excellent resistance to high-temperature steam oxidation, corrosion resistance, and good radiation resistance, making it one of the most promising accident-resistant cladding materials. However, the neutron absorption cross-section of FeCrAl alloy is approximately 10 times that of zirconium alloy. To reduce neutron loss within the reactor, the wall thickness of the FeCrAl alloy cladding tube must be reduced to 0.3 mm–0.4 mm, which imposes stringent requirements on the mechanical properties of the FeCrAl alloy cladding tube.

[0004] Defects formed during thermomechanical processing of FeCrAl-based alloys, such as cracks, inclusions, and scratches, can significantly impact the mechanical properties of thin-walled cladding tubes. This is particularly true within nuclear reactors, where harsh environments like high temperatures, high pressures, strong radiation, and corrosion promote further defect development and performance degradation. In FeCrAl-based alloys with high Mo, Nb, Si, and Zr content, the precipitation of Laves precipitates is highly sensitive. While this improves alloy strength and toughness, improper thermomechanical processing can lead to uneven distribution and size of precipitates, consequently affecting the distribution and size of recrystallized grains. Furthermore, inappropriate heat treatment after thermomechanical processing can easily cause cracks at these uneven points due to residual stress on the sample surface.

[0005] Therefore, solving the surface cracking problem of FeCrAl-based alloys is crucial for improving alloy yield, processing efficiency, and even nuclear reactor safety, and remains an urgent problem for scientists and engineers to solve. Summary of the Invention

[0006] To address the problems of existing FeCrAl-based alloy processing technology, this invention provides a method for preparing high-strength and ductile FeCrAl-based alloys, which effectively prevents cracking of FeCrAl-based alloys, and the operation process is simple and convenient.

[0007] This invention is achieved through the following technical solution:

[0008] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0009] Step 1: After heating and holding the FeCrAl-based alloy, hot rolling is performed. The deformation amount of a single rolling pass is 10% to 20%, and the total rolling reduction is 50% to 70%.

[0010] Step 2: After high-temperature annealing, the FeCrAl-based alloy obtained in Step 1 is cooled to room temperature;

[0011] Step 3: The FeCrAl-based alloy obtained in Step 2 is cold-rolled with a deformation of 60% to 90%.

[0012] Step 4: The FeCrAl-based alloy obtained in Step 3 is subjected to short-term annealing at a high temperature of 1130℃~1200℃ for 10s-20s, and then cooled to room temperature;

[0013] Step 5: Roll the FeCrAl-based alloy obtained in Step 4 into a pre-deformed and aged alloy to obtain a high-strength and ductile FeCrAl-based alloy.

[0014] Preferably, the FeCrAl-based alloy described in step 1 is subjected to high-temperature homogenization treatment, cooled to room temperature, and then subjected to high-temperature rolling.

[0015] Preferably, the method for achieving high-temperature homogenization is as follows:

[0016] The FeCrAl-based alloy was held at 1250℃~1300℃ for 0.5h-2h.

[0017] Preferably, the heating temperature of the FeCrAl-based alloy in step 1 is 1200℃~700℃, and the holding time is 5min~20min.

[0018] Preferably, the rolling method in step 1 is cross rolling.

[0019] Preferably, the annealing temperature in step 2 is the same as the rolling temperature, and the annealing holding time is 5 min to 30 min.

[0020] Preferably, the temperature of cold rolling in step 3 is from room temperature to 400°C.

[0021] Preferably, the cold rolling method in step 3 is unidirectional rolling or cross rolling.

[0022] Preferably, in step 4, when the thickness of the FeCrAl-based alloy is less than or equal to 1 mm, it is water-cooled to room temperature.

[0023] Preferably, in step 4, when the thickness of the FeCrAl-based alloy is greater than 1 mm, a gradient cooling method is used to bring the FeCrAl-based alloy to room temperature. The alloy is held at 1000℃~800℃ for 1 min~2 min and then air-cooled to room temperature.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The heat treatment method provided by this invention for preventing thermomechanical cracking in high-strength and high-toughness FeCrAl-based alloys involves homogenization treatment of the ingot at 1250℃~1300℃, which allows the coarse Laves phase formed during solidification to completely dissolve, preventing stress concentration and cracking during subsequent heat treatment cooling. Cross rolling and a single-pass reduction of 10%~20% in the hot rolling process result in more uniform alloy deformation and recrystallized grains. Water cooling or gradient cooling during heat treatment promotes uniform cooling inside and outside the alloy, reducing or avoiding tensile and compressive stresses. This invention does not require changes to the original FeCrAl-based alloy composition or processing equipment, primarily addresses surface cracking, is simple to operate, and is beneficial for further improving the strength and plasticity of FeCrAl-based alloys. Attached Figure Description

[0026] Figure 1 This is a metallographic photograph of the FeCrAl-based alloy microstructure of Example 1 of the present invention.

[0027] Figure 2 This is the engineering stress-strain curve of the FeCrAl-based alloy in Example 1 of this invention.

[0028] Figure 3 This is a metallographic photograph of the FeCrAl-based alloy microstructure of Comparative Example 1 of this invention.

[0029] Figure 4 This is a flowchart of the thermomechanical processing method of the present invention. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings. These descriptions are intended to explain the invention and not to limit it.

[0031] See Figure 4 A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0032] Step 1: Prepare FeCrAl-based alloy ingots by vacuum melting and homogenize them to obtain homogenized FeCrAl-based alloy ingots.

[0033] The method for high-temperature homogenization is as follows: the FeCrAl-based alloy is held at 1250℃~1300℃ for 0.5h-2h.

[0034] Step 2: After heating and holding the FeCrAl-based alloy, hot rolling is performed. The deformation per single pass is 10% to 20%, the total rolling reduction is 50% to 70%, and the rolling method is cross rolling.

[0035] The heating temperature of the FeCrAl-based alloy is 1200℃~700℃, and the holding time is 5min~20min.

[0036] Step 3: After high-temperature annealing, the FeCrAl-based alloy obtained in Step 2 is cooled to room temperature.

[0037] The degradation temperature is the same as the rolling temperature, and the annealing holding time is 5 min to 30 min.

[0038] Step 4: The FeCrAl-based alloy obtained in Step 3 is cold-rolled with a deformation of 60% to 90%. The cold rolling temperature is room temperature to 400°C, and the cold rolling method is unidirectional rolling or cross rolling.

[0039] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to short-term annealing at a high temperature of 1130℃~1200℃ for 10s-20s, and then cooled to room temperature;

[0040] When the thickness of the FeCrAl-based alloy is less than or equal to 1 mm, it is water-cooled to room temperature.

[0041] In step 4, when the thickness of the FeCrAl-based alloy is greater than 1 mm, a gradient cooling method is used to bring the FeCrAl-based alloy to room temperature. The alloy is held at 1000℃~800℃ for 1 min~2 min and then air-cooled to room temperature.

[0042] Step 6: Roll the FeCrAl-based alloy obtained in Step 5 into a pre-deformed and aged alloy to obtain a high-strength and ductile FeCrAl-based alloy.

[0043] Example 1:

[0044] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0045] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 1 hour, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0046] Step 2: The homogenized FeCrAl-based alloy ingot is held at 1100℃ for 5 minutes, and then hot-rolled using a cross-rolling method, with a single-pass rolling deformation of 10% and a total rolling reduction of 50%. After hot rolling, it is annealed at 1100℃ for 5 minutes and then air-cooled to room temperature to obtain a hot-rolled plate.

[0047] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is 350℃, the rolling method is unidirectional rolling, and the cold rolling deformation is 60%.

[0048] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1150℃ for 13 seconds, and then cool it to room temperature by gradient cooling after annealing. That is, after annealing at 1150℃, place the FeCrAl-based alloy at 1000℃ for 1 minute and then air cool it to room temperature.

[0049] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0050] The FeCrAl-based alloy prepared by the above steps exhibits uniform internal deformation, avoiding stress differences throughout the alloy during the annealing and cooling stage. The gradient cooling method used after annealing also helps prevent stress differences between the inside and outside of the alloy, thus preventing the stress difference from exceeding the alloy's strength and causing cracking. Metallographic micrographs of the alloy are shown below. Figure 1 As shown, no cracks were found, which prevents subsequent brittle fracture of the alloy, thus giving the alloy good strength and ductility, such as... Figure 2 As shown.

[0051] Example 2:

[0052] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0053] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1250℃ for 2 hours, and then air-cooled to room temperature.

[0054] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 1100℃ for 5 minutes, then hot roll it using a cross rolling method, with a single-pass rolling deformation of 15% and a total rolling reduction of 50%. After hot rolling, anneal it at 1100℃ for 10 minutes and then air cool it to room temperature.

[0055] Step 3: After hot working, the FeCrAl-based alloy is cold rolled and deformed. The cold rolling temperature is 350℃, the rolling method is unidirectional rolling, and the cold rolling deformation is 60%.

[0056] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1150℃ for 13s, and then cool it by gradient cooling after annealing. That is, after annealing at 1150℃, place the sample at 1000℃ for 1min and then air cool it to room temperature.

[0057] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0058] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks. This prevents the alloy from undergoing brittle fracture, thus giving the alloy good strength and plasticity.

[0059] Example 3:

[0060] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0061] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 1 hour, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0062] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 800℃ for 10 minutes, then hot roll it using cross rolling, with a single-pass deformation of 10% and a total rolling reduction of 50%. After hot rolling, anneal it at 800℃ for 10 minutes and then air cool it to room temperature to obtain a hot-rolled plate.

[0063] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is 350℃, the rolling method is unidirectional rolling, and the cold rolling deformation is 60%.

[0064] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1150℃ for 13 seconds, and then cool it by gradient cooling after annealing. That is, after annealing at 1150℃, place the sample at 900℃ for 1 minute and then air cool it to room temperature.

[0065] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0066] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks. This prevents the alloy from undergoing brittle fracture, thus giving the alloy good strength and plasticity.

[0067] Example 4:

[0068] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0069] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 0.5 h, and then cooled by air.

[0070] Step 2: The homogenized FeCrAl-based alloy ingot is held at 700℃ for 20 minutes, and then hot rolled. The rolling method is cross rolling, and the deformation of a single pass reaches 15%, the total reduction of rolling is 70%, and after hot rolling, it is annealed at 700℃ for 10 minutes. After annealing, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0071] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is room temperature, the rolling method is unidirectional rolling, and the cold rolling deformation is 80%.

[0072] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1200℃ for 13 seconds, and then cool it by water quenching at room temperature.

[0073] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0074] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks, thus giving the alloy good strength and plasticity.

[0075] Example 5:

[0076] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0077] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 0.5 h, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0078] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 1200℃ for 20 minutes, then hot roll it. The rolling method is cross rolling, and the deformation per pass reaches 20%, the total rolling reduction is 50%, and after hot rolling, anneal at 1200℃ for 5 minutes. After annealing, air cool to room temperature to obtain hot rolled plate.

[0079] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is 400℃, the rolling method is unidirectional rolling, and the cold rolling deformation is 90%.

[0080] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1200℃ for 13 seconds, and then cool it to room temperature by water quenching after annealing.

[0081] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0082] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks, thus giving the alloy good strength and plasticity.

[0083] Example 6:

[0084] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0085] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 0.5 h, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0086] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 700℃ for 5 minutes, then hot roll it using cross rolling, with a single-pass deformation of 10% and a total rolling reduction of 50%. After hot rolling, anneal it at 700℃ for 10 minutes and then air cool it to room temperature to obtain a hot-rolled plate.

[0087] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is room temperature, the rolling method is unidirectional rolling, and the cold rolling deformation is 60%.

[0088] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1150℃ for 20 seconds, and then cool it by gradient cooling after annealing. That is, after annealing at 1150℃, place the sample at 800℃ for 2 minutes and then air cool it to room temperature.

[0089] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0090] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks, thus giving the alloy good strength and plasticity.

[0091] Example 7:

[0092] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0093] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 0.5 h, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0094] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 700℃ for 5 minutes, then hot roll it using cross rolling, with a single-pass deformation of 10% and a total rolling reduction of 50%. After hot rolling, anneal it at 700℃ for 10 minutes and then air cool it to room temperature to obtain a hot-rolled plate.

[0095] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is room temperature, the rolling method is unidirectional rolling, and the cold rolling deformation is 60%.

[0096] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1200℃ for 20 seconds, and then cool it by gradient cooling after annealing. That is, after annealing at 1150℃, place the sample at 800℃ for 2 minutes and then air cool it to room temperature.

[0097] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0098] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks, thus giving the alloy good strength and plasticity.

[0099] Example 8:

[0100] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0101] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 2 hours, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0102] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 700℃ for 5 minutes, then hot roll it using cross rolling, with a single-pass deformation of 10% and a total rolling reduction of 50%. After hot rolling, anneal it at 700℃ for 10 minutes and then air cool it to room temperature to obtain a hot-rolled plate.

[0103] Step 3: Cold rolling deformation of FeCrAl-based alloy hot-rolled plate. The cold rolling temperature is room temperature, the rolling method is unidirectional rolling, and the cold rolling deformation is 90%.

[0104] Step 4: Perform short-time annealing of the cold-rolled FeCrAl-based alloy at 1150℃ for 20 seconds, and then cool it by water quenching at 0℃.

[0105] Step 5: The FeCrAl-based alloy obtained in Step 4 is subjected to 15% pre-deformation by rolling, and then aged at 600℃ for 3 hours after pre-deformation.

[0106] The FeCrAl-based alloy prepared by the above steps has a uniform internal stress distribution, which can avoid the formation of cracks, thus giving the alloy good strength and plasticity.

[0107] Comparative Example 1:

[0108] A method for preparing a high-strength, high-ductility FeCrAl-based alloy includes the following steps:

[0109] Step 1: FeCrAl-based alloy ingots were prepared using a vacuum non-consumable arc melting furnace. The FeCrAl-based alloy contained 13 wt.% Cr, 4.5 wt.% Al, 2 wt.% Mo, 2 wt.% Si, and 1 wt.% Nb, with the balance being Fe and trace impurities. The ingots were homogenized at 1300℃ for 1 hour, and then air-cooled to room temperature to obtain homogenized FeCrAl-based alloy ingots.

[0110] Step 2: Hold the homogenized FeCrAl-based alloy ingot at 1100℃ for 20 minutes, and then hot roll it. The rolling method is unidirectional rolling, and the deformation per single pass reaches 5%, and the total rolling reduction is 80%, to obtain a hot-rolled plate.

[0111] Step 4: Anneal the hot-rolled FeCrAl-based alloy at 1100℃ for 30 minutes, and then cool it by air cooling.

[0112] The FeCrAl-based alloy prepared through the above steps suffers from uneven deformation due to the unidirectional rolling method used during hot rolling. Only grains easily deformed in a single rolling direction accumulate deformation energy, resulting in inconsistent deformation of grains with varying orientations within the alloy. Furthermore, the single-pass rolling deformation is relatively small, only 5%, preventing the deformation from being transferred to the interior of the alloy and leading to inconsistent deformation between the surface and core of the alloy plate. Secondly, the strain energy accumulation varies in different parts of the alloy, and the degree of recrystallization during the annealing stage also differs. In addition, the plate thickness is greater than 1 mm during the cooling stage after recrystallization annealing, easily generating strong tensile and compressive stresses between the interior and exterior surfaces of the alloy, as well as between different recrystallized regions. Therefore, noticeable cracks can be observed in the alloy, such as… Figure 3 As shown.

[0113] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a high-strength, high-ductility FeCrAl-based alloy, characterized in that, Includes the following steps: Step 1: After heating and holding the FeCrAl-based alloy, hot rolling is performed. The deformation amount of a single rolling pass is 10% to 20%, and the total rolling reduction is 50% to 70%. The heating temperature of the FeCrAl-based alloy is 1200℃~700℃, and the holding time is 5min~20min; Step 2: After high-temperature annealing, the FeCrAl-based alloy obtained in Step 1 is cooled to room temperature; The annealing temperature is the same as the rolling temperature, and the annealing holding time is 5 min to 30 min. Step 3: The FeCrAl-based alloy obtained in Step 2 is cold-rolled with a deformation of 60% to 90%, and the cold rolling temperature is from room temperature to 400°C. Step 4: The FeCrAl-based alloy obtained in Step 3 is subjected to short-term annealing at a high temperature of 1130℃~1200℃ for 10s-20s, and then cooled to room temperature; When the thickness of the FeCrAl-based alloy is greater than 1 mm, a gradient cooling method is used to bring the FeCrAl-based alloy to room temperature. The alloy is held at 1000℃~800℃ for 1 min~2 min and then air-cooled to room temperature. When the thickness of the FeCrAl-based alloy is less than or equal to 1 mm, it is water-cooled to room temperature; Step 5: Roll the FeCrAl-based alloy obtained in Step 4 into a pre-deformed and aged alloy to obtain a high-strength and ductile FeCrAl-based alloy.

2. The method for preparing a high-strength, high-ductility FeCrAl-based alloy according to claim 1, characterized in that, The FeCrAl-based alloy described in step 1 is subjected to high-temperature homogenization treatment, cooled to room temperature, and then subjected to high-temperature rolling.

3. The method for preparing a high-strength, high-ductility FeCrAl-based alloy according to claim 1, characterized in that, The method for high-temperature homogenization is as follows: The FeCrAl-based alloy was held at 1250℃~1300℃ for 0.5h-2h.

4. The method for preparing a high-strength, high-ductility FeCrAl-based alloy according to claim 1, characterized in that, The rolling method described in step 1 is cross rolling.

5. The method for preparing a high-strength, high-ductility FeCrAl-based alloy according to claim 1, characterized in that, The cold rolling method described in step 3 is unidirectional rolling or cross rolling.

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