WO2021223758A1

WO2021223758A1 - Wrought superalloy capable of forming composite corrosion-resistant layer and preparation process therefor

Info

Publication number: WO2021223758A1
Application number: PCT/CN2021/092490
Authority: WO
Inventors: 严靖博; 谷月峰; 袁勇; 杨征; 张醒兴
Original assignee: 西安热工研究院有限公司
Priority date: 2020-05-08
Filing date: 2021-05-08
Publication date: 2021-11-11
Also published as: CN111394621A

Abstract

A wrought superalloy capable of forming a composite corrosion-resistant layer and a preparation process therefor. The wrought superalloy comprises (in mass percentages): 16-19% of Cr, 10-15% of Co, 0.5-1.5% of Ti, 3.5-4.5% of Al, W: ≤0.5%, Mo: ≤5.0%, Si: ≤0.5%, Mn: ≤0.5%, 0.5-1.0% of Nb, and 0.04-0.07% of C, with the balance being Ni. The process involves smelting, then a homogenization treatment, hot rolling, and finally a heat treatment. The wrought alloy of the present invention has tensile yield strengths at room temperature and 850°C of greater than 820 MPa and 520 Mpa, respectively, and also has excellent processing properties and structural stability, without harmful phase precipitation during heat exposure at 850°C; and after 1350 hours of heat exposure at this temperature, the tensile yield strengths at room temperature and 850°C are respectively greater than 630 MPa and 370 MPa.

Description

Deformed high-temperature alloy capable of forming composite corrosion-resistant layer and preparation process thereof

Technical field

The invention belongs to the field of high-temperature alloys, and specifically relates to a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer and a preparation process thereof, and is particularly suitable for over/reheaters of advanced ultra-supercritical units of thermal power plants, as well as hydrogen-producing converters and high-temperature gas Key components of cold reactor, etc.

Background technique

As my country's electricity demand continues to increase, energy shortages and environmental pollution problems have become increasingly prominent, and the need to develop high-efficiency, energy-saving, and environmentally friendly power generation methods is becoming more and more urgent. Thermal power generation has been the most important power generation technology in my country for a long time. Improving the steam parameters of the unit is considered to be the most effective way to solve the above problems. A large number of past practices have shown that the service performance of materials is the main reason that restricts the improvement of steam parameters of boiler units, and as the most stringent key components of thermal power unit boilers, super/reheaters, main steam pipes, headers, etc. Very high requirements are put forward on the service performance of the material. The above-mentioned components will be affected by multiple factors such as high temperature creep, thermal fatigue, oxidation and high temperature smoke corrosion during service. With the substantial improvement of the main steam parameters of thermal power units, the development of superalloy materials that can meet the performance requirements of key components of high-parameter units has become an urgent issue in the thermal power industry.

In response to the need for material performance of the key components of high-parameter thermal power unit boilers, a lot of research has been carried out abroad, and a series of new alloy materials have been developed, such as Inconel 740H developed by American Special Metals Corporation and Haynes developed by American Hastelloy Company. 282. CCA 617 developed by ThyssenKrupp in Germany, Nimonic 263 developed by Rolls-Royce in the United Kingdom, FENIX700 developed by Hitachi, TOS1X developed by Toshiba, Japan, LTESR700 developed by Mitsubishi, and other nickel-based deformed superalloys . Studies have shown that the continuous improvement of material strength often comes at the expense of alloy processing performance. Since the super/reheater, main steam pipe, header and other parts are mostly pipe materials, the processing and preparation are relatively complicated, which poses new challenges to the selection of superalloys. For example, the common solid solution strengthening element W in superalloys has an obvious tendency to macrosegregate, while the precipitation strengthening element Nb is easy to form a CrNbN phase (Z phase) at the grain boundary, which in turn harms the processing and preparation properties of gold pipes. Therefore, when selecting high-temperature alloys as advanced ultra-supercritical pipe components, it is necessary to ensure the high-temperature performance of the alloy while taking into account its processing performance.

In order to ensure the preparation and processing performance of the material, the content of W element in the alloy composition is strictly controlled to reduce the red hardness and macro segregation of the material, and the Mo element is used to achieve the effect of solid solution strengthening. However, the addition of Mo element is not conducive to the coal ash corrosion resistance of the alloy, so it is necessary to ensure that the alloy has sufficient content of corrosion resistance elements such as Al and Cr at the same time. However, the pure Al ₂ O ₃ layer is unstable in the coal ash corrosive environment, so it is necessary to ensure that the alloy has a sufficient Cr content, but this will also cause problems such as the nucleation of the Z phase at the grain boundary. Therefore, it is necessary to reasonably adjust the amount of Nb element added to improve the _{stability of Ni 3} Al (γ') while avoiding the precipitation of harmful phases at the grain boundary due to excessive addition of it and jeopardizing the processing performance of the alloy.

Summary of the invention

The purpose of the present invention is to develop a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer and its preparation process.

In order to achieve the above objectives of the invention, the technical solutions adopted by the present invention are as follows:

A deformed high-temperature alloy capable of forming a composite corrosion-resistant layer, in terms of mass percentage, includes: Cr: 16-19%, Co: 10-15%, Ti: 0.5-1.5%, Al: 3.5-4.5%, W: ≤0.5%, Mo: ≤5.0%, Si: ≤0.5%, Mn: ≤0.5%, Nb: 0.5-1.0%, C: 0.04-0.07%, and the balance is Ni.

A preparation process of a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer includes the following steps:

1) Alloy smelting: According to mass percentage, Cr: 16-19%, Co: 10-15%, Ti: 0.5-1.5%, Al: 3.5-4.5%, W: ≤0.5%, Mo: ≤5.0% , Si: ≤0.5%, Mn: ≤0.5%, Nb: 0.5-1.0%, C: 0.04-0.07%, the balance is Ni; added to a vacuum induction furnace, alloy smelting under vacuum and argon protection, Refining, and finally obtaining alloy ingots;

2) High-temperature rolling: homogenize the alloy ingot at 1160-1200°C for 24-72 hours, and then roll it at a high temperature of 50-100°C above the _{Ni 3 Alγ' dissolution temperature, and the amount of deformation per pass} Not less than 25%, and the total deformation is not less than 70%;

3) Heat treatment.

A further improvement of the present invention is that in step 1), the mass percentage of N element in the alloy ingot is not more than 0.03%, and the mass percentage of P and S is not more than 0.03%.

A further improvement of the present invention is that before step 2), the alloy ingot is kept at 950-1020°C for 0.5-1.0 hours before step 2) is performed.

A further improvement of the present invention is that the temperature rise rate is not higher than 10°C/min to 950-1020°C.

A further improvement of the present invention is that in step 2), when high temperature rolling is performed, the outside of the alloy ingot is sheathed with 304 stainless steel with a thickness of 0.5-1.0 mm.

A further improvement of the present invention is that in step 2), after each pass of deformation is completed, the furnace is returned to the furnace for 15-20 minutes and then the next rolling is performed.

A further improvement of the present invention is that the specific process of step 3) is: heating the rolled alloy with the furnace to a temperature of 30-70°C above the γ'dissolution temperature for 3-5 hours, and then air cooling to room temperature after completion; The alloy is heated to 300-350°C below the γ'melting temperature for 3-9 hours and then air-cooled, and finally heated to 200-250°C below the γ'melting temperature for 1-3 hours and then air-cooled.

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

As alumina is unstable in coal ash corrosion environment, it is easy to lose its protective matrix effect. Therefore, by controlling the content of Cr and Al in the alloy and their mutual ratio, the present invention can form a composite oxide layer, exert the excellent protective effect of alumina on the matrix under high temperature conditions, and avoid direct contact with the outer coal ash layer at the same time. In addition, in the present invention, the W element content in the alloy composition is controlled to reduce the red hardness and macro segregation of the material, and the Mo element is used to achieve the solid solution strengthening effect, which guarantees the high temperature performance of the alloy while taking into account its processing performance. At the same time, rationally adjust the amount of Nb element added to improve the _{stability of Ni 3} Al(γ') while avoiding excessive addition of harmful phases at the grain boundary and harming the processing performance of the alloy. By adjusting and controlling the content and proportion of anti-corrosion elements such as Al and Cr in the alloy, it promotes the formation of composite anti-corrosion layer in coal ash corrosive environment, and finally obtains a kind of excellent high-temperature strength, anti-corrosion/oxidation performance and good structure stability. A new type of high-temperature alloy with high performance and processing performance.

Description of the drawings

Figure 1 is a photo of the organization of Example 1;

Figure 2 shows the morphology of the γ'enhanced phase in Example 1;

Figure 3 is the test result of the thermal expansion coefficient of Example 1;

Figure 4 shows the impact toughness fracture surface of Example 1;

Figure 5 is a photo of the tissue of Example 2

Figure 6 is a tissue photograph of Example 2 after 1000 hours of heat exposure

Figure 7 is a cross-sectional photo of Example 2 coal ash corrosion after 500 hours

Figure 8 is a photo of the organization of the comparative example;

Figure 9 is a photo of the tissue of the comparative example exposed to heat for 1000 hours.

Figure 10 is a cross-sectional photograph of the coal ash of the comparative example after 500 hours of corrosion.

Detailed ways

The present invention will be further described in detail below in conjunction with the embodiments.

The invention is developed in response to the requirements of advanced ultra-supercritical thermal power units, and can meet the performance requirements of high-temperature components such as superheaters/reheaters. The alloy composition meets the following requirements in terms of mass percentage: Cr: 16-19%, Co: 10-15%, Ti: 0.5-1.5%, Al: 3.5-4.5%, W: ≤0.5%, Mo: ≤5.0%, Si: ≤0.5%, Mn: ≤0.5%, Nb: 0.5-1.0%, C: 0.04-0.07%, the balance is Ni; homogenization treatment after melting, hot rolling, and final heat treatment. The tensile yield strength of the alloy at room temperature and 850°C of the present invention is higher than 820MPa and 520MPa, respectively. At the same time, it has excellent processing performance and structural stability. There is no harmful phase precipitation during heat exposure at 850°C, and it is exposed to heat at this temperature. After 1350 hours, the room temperature and 850°C tensile yield strength were higher than 630MPa and 370MPa, respectively. In addition, after the alloy is _{corroded in a high temperature flue gas environment (N 2} -15% CO ₂ -3.5% O ₂ -0.1% SO ₂ _{) for 500 hours, a composite layer of Cr 2} O ₃ and Al ₂ O ₃ is formed on the surface of the alloy, and its weight changes Less than 0.2mg/cm ² .

The present invention includes the following steps:

1) Alloy smelting: Use vacuum induction furnace for alloy smelting, and make sure that the vacuum degree is lower than 5*10 ^-3 before introducing high-purity argon gas. The electroslag remelting process is then used for refining, and finally an alloy ingot is obtained for processing. Among them, the alloy meets the following requirements: in terms of mass percentage, the alloy in terms of mass percentage, including: Cr: 16-19%, Co: 10-15 %, Ti: 0.5 to 1.5%, Al: 3.5 to 4.5%, W: ≤0.5%, Mo: ≤5.0%, Si: ≤0.5%, Mn: ≤0.5%, Nb: 0.5 to 1.0%, C: 0.04 ～0.07%, the balance is Ni; the N element content of the alloy after electroslag remelting is not more than 300ppm, and the P and S content is not more than 0.03%;

2) High temperature rolling: The alloy is homogenized at 1160-1200℃ for 24-72 hours, and then _{rolled at 50-100℃ above the dissolution temperature of Ni 3} Al(γ'). The total deformation is not Less than 70%, the deformation per pass is not less than 25%; among them, the temperature rise rate is controlled not to be higher than 10℃/min during the homogenization and heating process of the alloy, and after the temperature is raised to 950-1020℃ for 0.5-1.0 hours Continue to heat up to the specified temperature for homogenization; during the rolling process, the outside of the alloy ingot is covered with 304 stainless steel with a thickness of 0.5-1.0mm to slow down the rate of temperature drop after the furnace, and after the deformation is completed, return to the furnace for 15-20min before proceeding to the next step Sub-rolling

3) Heat treatment: heat the rolled alloy with the furnace to a temperature of 30-70°C above the γ'dissolving temperature for 3-5 hours, then air-cool to room temperature after completion; then heat the alloy to 300-350 below the γ'dissolving temperature Keep it in the range of ℃ for 3-9 hours and then air-cool it, and finally heat it to 200-250℃ below the γ'dissolution temperature and then keep it in the air-cooling range for 1-3 hours.

The average grain size of the alloy after heat treatment is 30-50μm, and a large number of dispersed γ'phases are precipitated in the crystal, and the average diameter does not exceed 50nm. The discontinuous carbides are distributed on the grain boundary, and the size of the discontinuous carbide does not exceed 5μm.

The tensile yield strength of the alloy at room temperature and 850°C is higher than 820MPa and 520MPa, respectively. At the same time, it has excellent processing properties and structural stability. No harmful phases are precipitated during heat exposure at 850°C, and after heat exposure at this temperature for 1350 hours The tensile yield strength at room temperature and 850℃ is higher than 630MPa and 370MPa respectively. In addition, after the alloy is _{corroded in a high temperature flue gas environment (N 2} -15% CO ₂ -3.5% O ₂ -0.1% SO ₂ _{) for 500 hours, a composite layer of Cr 2} O ₃ and Al ₂ O ₃ is formed on the surface of the alloy, and its weight changes Less than 0.2mg/cm ² .

Example 1

While ensuring that the alloy meets its strength properties, it limits the addition of elements such as W and Nb to improve its processing properties. The alloy is smelted by a vacuum induction furnace, and the obtained alloy includes Cr: 16%, Co: 15%, Ti: 1.1%, Al: 4.1%, Si: 0.3%, Mn: 0.3%, Nb: 1.0 by mass percentage. %, C: 0.04%, the balance is Ni. Use vacuum induction furnace for alloy smelting, and ensure that the vacuum degree is lower than 5*10 ^-3 before introducing high-purity argon gas. The electroslag remelting process is then used for refining, and finally an alloy ingot is obtained for processing. Ensure that the N element content of the alloy after electroslag remelting is not higher than 300ppm, and the P and S content is not higher than 0.03%.

The alloy is homogenized at 1160°C for 24 hours, and then rolled at a temperature of 100°C above the γ'dissolution temperature. The total deformation is 95%, and the deformation per pass is not less than 30%. During the homogenization and heating process of the alloy, the heating rate is controlled to 10°C/min, and after the temperature is increased to 950 for 0.5 hours, the heating is continued to the specified temperature for homogenization treatment.

The rolled alloy is heated in the furnace to 70°C above the γ'dissolution temperature for 4 hours, and then air-cooled to room temperature after completion. Subsequently, the alloy was heated to 300°C below the γ'dissolution temperature for 8 hours and then air-cooled, and finally heated to 200°C below the γ'dissolution temperature for 2 hours and then air-cooled.

Figure 1 and Figure 2 are photos of the structure and γ'phase morphology after heat treatment in Example 1. It can be seen that after the heat treatment, the average grain size does not exceed 50μm, and a large number of dispersed γ'phases are precipitated in the crystals, and the average diameter is not More than 50nm. The discontinuous carbides are distributed on the grain boundary, and the size of the discontinuous carbide does not exceed 5μm.

Figures 3 and 4 show the thermal expansion coefficient test results and impact toughness fracture surface of Example 1. The thermal expansion coefficients at 800 and 850°C do not exceed 15.49 and 16.48*10 ^-6 K ^-1 , respectively, and the room temperature impact toughness is 74J/cm ² . A large number of dimple features can be observed on the surface of the impact fracture, indicating that it has good fracture toughness.

Example 2

While ensuring that the alloy meets its strength properties, it limits the addition of elements such as W and Nb to improve its processing properties. The alloy is smelted by a vacuum induction furnace, and the obtained alloy includes Cr: 17%, Co: 10%, Ti: 1.5%, Al: 4.0%, Si: 0.2%, Mo: 5.0%, Mn: 0.2 by mass percentage. %, Nb: 1.0%, C: 0.04%, and the balance is Ni. Use vacuum induction furnace for alloy smelting, and ensure that the vacuum degree is lower than 5*10 ^-3 before introducing high-purity argon gas. The electroslag remelting process is then used for refining, and finally an alloy ingot is obtained for processing. Ensure that the N element content of the alloy after electroslag remelting is not higher than 300ppm, and the P and S content is not higher than 0.03%.

The alloy is homogenized at 1200°C for 24 hours, and then rolled at a temperature of 100°C above the γ'dissolution temperature. The total deformation is 70%, and the deformation per pass is not less than 25%. During the homogenization and heating process of the alloy, the heating rate is controlled to 10°C/min, and the temperature is increased to 1020 for 0.5 hours and then the temperature is increased to the specified temperature for homogenization.

The rolled alloy is heated in the furnace to 70°C above the γ'dissolution temperature for 4 hours, and then air-cooled to room temperature after completion. Subsequently, the alloy was heated to 300°C below the γ'dissolution temperature for 8 hours and then air-cooled, and finally heated to 200°C below the γ'dissolution temperature for 2 hours and then air-cooled. After heat treatment, the yield strength of the alloy at room temperature and 850°C is 879MPa and 570MPa, respectively. After heat exposure at 850°C for 1350 hours, the tensile yield strength at room temperature and 850°C is higher than 688MPa and 418MPa, respectively.

Figures 5 and 6 are the structure photos of the heat-treated state and the long-term thermal exposure state of Example 2. It can be seen that no obvious harmful phases are precipitated in the crystal grains during heat exposure at 850°C, which proves that it has excellent structural stability.

Figure 7 is a cross-sectional photo of the alloy of Example 2 after being corroded by coal ash at 850°C high temperature flue gas environment (N ₂ -15% CO ₂ -3.5% O ₂ -0.1% SO ₂ ) for 500 hours. It can be seen that the corrosion layer is from the outer layer. Composed of chromium oxide and inner alumina, its weight gain is only 0.16mg/cm ² .

Example 3

1) Alloy smelting: According to mass percentage, Cr: 16%, Co: 15%, Ti: 1.5%, Al: 3.5%, W: 0.5%, Mo: 3.0%, Si: 0.3%, Mn: 0.1% , Nb: 0.5%, C: 0.04%, the balance is Ni; added to a vacuum induction furnace, alloy smelting and refining under the protection of vacuum and argon gas, and finally an alloy ingot is obtained; the quality of N in the alloy ingot is 100% The content of P and S is not more than 0.03%, and the mass percentage of P and S is not more than 0.03%.

2) High temperature rolling: After raising the alloy ingot to 950°C for 1.0 hour at a heating rate of 10°C/min, the alloy ingot is homogenized at 1160°C for 72 hours, and then the outside thickness is 0.5 -1.0mm 304 stainless steel is sheathed, and _{high temperature rolling is performed at 50℃ above the dissolution temperature of Ni 3} Alγ'. The deformation of each pass is not less than 25%, and the total deformation is not less than 70%; After completion, return to the furnace for 20 minutes and then proceed to the next rolling.

3) Heat treatment: heat the rolled alloy with the furnace to a temperature range of 30°C above the γ'dissolution temperature for 3 hours, then air-cool to room temperature after completion; then heat the alloy to a temperature range of 300°C below the γ'dissolution temperature for 9 hours After air cooling, finally heating to 200 ℃ below the γ'dissolving temperature and holding for 3 hours before air cooling.

Example 4

1) Alloy smelting: In terms of mass percentage, Cr: 17%, Co: 12%, Ti: 1%, Al: 4%, W: 0.1%, Mo: 5.0%, Si: 0.2%, Mn: 0.4% , Nb: 1%, C: 0.04%, the balance is Ni; added to a vacuum induction furnace, alloy smelting and refining under the protection of vacuum and argon gas, and finally an alloy ingot is obtained; the quality of N in the alloy ingot is 100% The content of P and S is not more than 0.03%, and the mass percentage of P and S is not more than 0.03%.

2) High temperature rolling: After raising the alloy ingot to 1020°C at a heating rate of 3°C/min for 0.5 hours, the alloy ingot is homogenized at 1120°C for 24 hours, and then the outside thickness is 0.5 -1.0mm 304 stainless steel is sheathed, and _{high temperature rolling is performed at 70℃ above the dissolution temperature of Ni 3} Alγ', and the deformation of each pass is not less than 25%, and the total deformation is not less than 70%; After completion, return to the furnace for 15 minutes and then proceed to the next rolling.

3) Heat treatment: heat the rolled alloy with the furnace to a temperature range of 40°C above the γ'dissolving temperature for 5 hours, then air-cool to room temperature after completion; then heat the alloy to a temperature range of 350°C below the γ'dissolving temperature for 3 hours After air cooling, finally heating to 250°C below the γ'dissolving temperature for 1 hour and then air cooling.

Example 5

1) Alloy smelting: In terms of mass percentage, Cr: 19%, Co: 10%, Ti: 0.5%, Al: 4.5%, Mo: 1.0%, Si: 0.5%, Mn: 0.5%, Nb: 0.7% , C: 0.05%, the balance is Ni; added to a vacuum induction furnace, alloy smelting and refining under the protection of vacuum and argon gas, and finally an alloy ingot is obtained; the mass percentage of N element in the alloy ingot is not higher than 0.03%, the mass percentage content of P and S is not higher than 0.03%.

2) High temperature rolling: After raising the alloy ingot to 1000°C at a heating rate of 1°C/min for 0.7 hours, then homogenizing the alloy ingot at 1180°C for 50 hours, and then adopting a thickness of 0.5 on the outside. -1.0mm 304 stainless steel is sheathed, and _{high temperature rolling is carried out at 100℃ above the dissolution temperature of Ni 3} Alγ', and the deformation of each pass is not less than 25%, and the total deformation is not less than 70%; After completion, return to the furnace for 17 minutes and perform the next rolling.

3) Heat treatment: heat the rolled alloy with the furnace to a temperature range of 70°C above the γ'dissolving temperature for 4 hours, then air-cool to room temperature; then heat the alloy to a temperature range of 320°C below the γ'dissolving temperature for 5 hours After air cooling, finally heating to 220°C below the γ'dissolving temperature and holding for 2 hours before air cooling.

Comparison

The alloy is smelted by a vacuum induction furnace, and the obtained alloy includes Cr: 21%, Co: 15%, Ti: 1.8%, Al: 4.5%, Si: 0.2%, Mo: 7.0%, Mn: 0.2 by mass percentage. %, Nb: 0.5%, C: 0.04%, the balance is Ni. Use vacuum induction furnace for alloy smelting, and ensure that the vacuum degree is lower than 5*10 ^-3 before introducing high-purity argon gas. The electroslag remelting process is then used for refining, and finally an alloy ingot is obtained for processing. Ensure that the N element content of the alloy after electroslag remelting is not higher than 300ppm, and the P and S content is not higher than 0.03%.

The rolled alloy is heated in the furnace to 70°C above the γ'dissolution temperature for 4 hours, and then air-cooled to room temperature after completion. Subsequently, the alloy was heated to 300°C below the γ'dissolution temperature for 8 hours and then air-cooled, and finally heated to 200°C below the γ'dissolution temperature for 2 hours and then air-cooled. The yield strength of the alloy at room temperature and 850°C after heat treatment is 930MPa and 586MPa, respectively, and the tensile yield strength at room temperature and 850°C after 1000 hours of heat exposure at 850°C is higher than 955MPa and 438MPa, respectively.

Figures 8 and 9 are the microstructure photos of the heat treatment state and the long-term thermal exposure state of the comparative example. It can be seen that a large number of harmful phases appear in the crystal grains during the heat exposure at 850°C, indicating that the microstructure stability is poor.

Figure 10 is a cross-sectional photo of the comparative alloy after being corroded by coal ash in a high temperature flue gas environment (N ₂ -15% CO ₂ -3.5% O ₂ -0.1% SO ₂ ) at 850°C for 500 hours. A complete alumina layer is not formed on the inside. , So the weight loss is as high as 0.96mg/cm ² .

Claims

A deformed high-temperature alloy capable of forming a composite corrosion-resistant layer, characterized in that, in terms of mass percentage, it includes: Cr: 16-19%, Co: 10-15%, Ti: 0.5-1.5%, Al: 3.5-4.5 %, W: ≤0.5%, Mo: ≤5.0%, Si: ≤0.5%, Mn: ≤0.5%, Nb: 0.5-1.0%, C: 0.04-0.07%, and the balance is Ni.
A preparation process of a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer is characterized in that it comprises the following steps:

1) Alloy smelting: According to mass percentage, Cr: 16-19%, Co: 10-15%, Ti: 0.5-1.5%, Al: 3.5-4.5%, W: ≤0.5%, Mo: ≤5.0% , Si: ≤0.5%, Mn: ≤0.5%, Nb: 0.5-1.0%, C: 0.04-0.07%, the balance is Ni; added to a vacuum induction furnace, alloy smelting under vacuum and argon protection, Refining, and finally obtaining alloy ingots;

2) High-temperature rolling: homogenize the alloy ingot at 1160-1200°C for 24-72 hours, and then roll it at a high temperature of 50-100°C above the Ni 3 Alγ' dissolution temperature, and the amount of deformation per pass Not less than 25%, and the total deformation is not less than 70%;

3) Heat treatment.
A process for preparing a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer according to claim 2, characterized in that, in step 1), the mass percentage of N element in the alloy ingot is not more than 0.03%, and P and The mass percentage of S is not higher than 0.03%.
The preparation process of a wrought high-temperature alloy capable of forming a composite corrosion-resistant layer according to claim 2, characterized in that, before step 2), the alloy ingot is kept at 950-1020°C for 0.5-1.0 hours before proceeding. Step 2).
The preparation process of a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer according to claim 4, characterized in that the temperature rise rate is not higher than 10°C/min to 950-1020°C.
The preparation process of a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer according to claim 2, characterized in that, in step 2), during high-temperature rolling, the outside of the alloy ingot is made of 304 with a thickness of 0.5-1.0 mm. Stainless steel cladding.
The preparation process of a deformed superalloy capable of forming a composite corrosion-resistant layer according to claim 2, characterized in that, in step 2), after each pass of deformation is completed, the heat is returned to the furnace for 15-20 minutes, and then the next rolling is performed. system.
A process for preparing a deformed high-temperature alloy capable of forming a composite corrosion-resistant layer according to claim 2, wherein the specific process of step 3) is: heating the rolled alloy with the furnace to above the γ'dissolution temperature Keep the temperature in the range of 30-70℃ for 3-5 hours, and then air-cool to room temperature after completion; then heat the alloy to below the γ'dissolving temperature and keep it in the range of 300-350℃ for 3-9 hours and then air-cool, and finally heat to below the γ'dissolving temperature Keep the temperature in the range of 200-250℃ for 1-3 hours and then air cool.