Ultra-high-strength and high-plasticity nickel-based corrosion-resistant alloy and bar, and preparation methods therefor

Abstract

An ultra-high-strength and high-plasticity nickel-based corrosion-resistant alloy and bar, and preparation methods therefor. The alloy bar comprises, in percentage by weight, 50.0-57.0% of Ni, 20.0-22.0% of Cr, 6.0-7.5% of Nb, 2.0-3.0% of Mo, 0.8-1.2% of Ti, 0.4-0.9% of Al, and trace elements including C ≤ 0.03%, V ≤ 0.1%, B ≤ 0.003%, Zr ≤ 0.1%, and Mg ≤ 0.03%, with the balance being Fe and impurities normally present in metal smelting. The contents of the impurities, in percentage by mass, are controlled to P ≤ 0.030%, S ≤ 0.035%, O ≤ 0.005%, and N ≤ 0.012%. The nickel-based corrosion-resistant alloy bar is obtained by means of steps such as vacuum induction melting (VIM) plus electroslag remelting (ESR) duplex smelting, homogenization diffusion annealing, forging, and heat treatment. By means of multiple approaches such as composition control, hot deformation, and heat treatment, the content and distribution of strengthening phases in the alloy are controlled, ensuring that the bar exhibits a yield strength that can reach 1300 MPa or more, a tensile strength that can reach 1450 MPa or more, an elongation that can reach 18% or more, and a percentage reduction of area that can reach 40% or more, thereby achieving the technical improvement of ultra-high strength and high plasticity of the nickel-based corrosion-resistant alloy.

Description

A high-strength, high-ductility nickel-based corrosion-resistant alloy, rods and their preparation method Technical Field

[0001] This invention relates to the field of metal materials and processing technology, and in particular to an ultra-high strength, high plasticity nickel-based corrosion-resistant alloy, a bar, and a method for preparing the same. Background Technology

[0002] In recent years, my country's dependence on foreign oil and gas resources has been increasing year by year. Building an oil and gas security system under fully open conditions has become an urgent task. Vigorously developing deep and unconventional oil and gas resources, represented by deep water (1500-3000 m) and deep earth (>10000 m), has become an inevitable strategic choice for my country's oil and gas industry. Rotary steerable systems are a shining example of directional drilling technology and a crucial technical means to achieve low-cost, high-efficiency development of oil and gas resources. One type of rotary steerable instrument is used in the final landing section of directional well operations, where the drilling depth is large and the loads are complex, placing extremely stringent requirements on material strength.

[0003] Traditional age-hardening precipitation-strengthened nickel-based corrosion-resistant alloys, according to the latest API 6ACRA technical specifications, have yield strengths ranging from 758 to 965 MPa (N09925), 1034 to 1207 MPa (N07718), and 1103 to 1241 MPa (N09946), with a maximum tensile strength of 1241 MPa (N09946). However, under high-strength conditions, the alloy elongation is only 18% and the reduction of area is only 25% (N09946), which is insufficient to meet the ultra-high strength and high plasticity requirements of nickel-based corrosion-resistant alloys in offshore oil and gas drilling and production.

[0004] Currently, improving the strength grade of nickel-based corrosion-resistant alloys is generally achieved by controlling the alloy composition or adopting cold deformation. However, the addition of a large number of strengthening elements not only aggravates the tendency of element segregation during melting and solidification, but also increases the deformation resistance, making it difficult to form bars. Furthermore, the alloy bars are too small under cold deformation, which makes it difficult to meet the size restrictions of rotary guide instruments.

[0005] Therefore, those skilled in the art are dedicated to developing a nickel-based corrosion-resistant alloy, rods, and preparation methods that can effectively solve the problem of ultra-high strength and high plasticity that existing precipitation-strengthened nickel-based corrosion-resistant alloys cannot achieve. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a nickel-based corrosion-resistant alloy, rods and their preparation methods that effectively solve the problem of ultra-high strength and high plasticity that existing precipitation-strengthened nickel-based corrosion-resistant alloys cannot achieve.

[0007] To achieve the aforementioned objective, this invention provides an ultra-high strength, high ductility, nickel-based corrosion-resistant alloy, which, by weight percentage, comprises 50.0~57.0% Ni, 20.0~22.0% Cr, 6.0~7.5% Nb, 2.0~3.0% Mo, 0.8~1.2% Ti, 0.4~0.9% Al, and trace elements C≤0.03%, V≤0.1%, B≤0.003%, Zr≤0.1%, and Mg≤0.03%, with the balance being Fe and unavoidable impurities.

[0008] Furthermore, by weight percentage, it includes 55.9–56.1% Ni, 20.52–20.98% Cr, 6.18–7.32% Nb, 2.80–2.96% Mo, 0.93–1.07% Ti, 0.48–0.86% Al, and trace elements 0.019–0.023% C, 0.075–0.096% V, 0.0022–0.003% B, 0.028–0.054% Zr, and 0.027–0.031% Mg, with unavoidable impurities ≤0.082%, and the balance being Fe.

[0009] Furthermore, by weight percentage, the impurities are P≤0.030%, S≤0.035%, O≤0.005% and N≤0.012%.

[0010] The present invention also provides a method for manufacturing the above-mentioned ultra-high strength and high ductility nickel-based corrosion-resistant alloy, comprising the following steps:

[0011] S1. Material preparation: Weigh the raw materials according to the alloy element batching table, where V, B and Mg are weighed as intermediate alloys Fe-V, Fe-B and Mg-Ni respectively, and other elements are weighed as elemental substances.

[0012] S2. Vacuum induction melting: A vacuum induction melting furnace is used for melting. First, Ni, Cr, Fe, Nb and Mo are melted. After melting, C, Ti and Al are added first. After melting, Fe-V, Fe-B and Zr are added. After melting, Mg-Ni is added last.

[0013] S3. Electroslag remelting: The surface of the vacuum ingot is sand-milled, and slag suitable for the alloy is selected for electroslag remelting to obtain a nickel-based alloy ingot.

[0014] S4. Annealing: The nickel-based alloy ingot is annealed to obtain the ultra-high strength and high plasticity nickel-based corrosion-resistant alloy.

[0015] Furthermore, in step S2, vacuum melting is enhanced by high temperature (1500~1550℃) and high vacuum (1~3Pa), and the mixture is thoroughly stirred and vibrated to ensure uniformity of composition.

[0016] Furthermore, in step S3, the slag material is a quaternary slag system of CaO-Al2O3-MgO-CaF2, wherein the weight percentage of each component is 55~75% CaO, 10~20% Al2O3, 0.5~5% MgO and 10~20% CaF2, which effectively controls the burning loss of Ti and Al and the problem of heavy scale on the surface of electroslag ingots.

[0017] Furthermore, in step S4, the annealing is carried out using a two-stage homogenization diffusion annealing process. In the first stage, the temperature is held at 1160°C to eliminate the brittle phase, and in the second stage, the temperature is held at 1190°C to eliminate elemental segregation.

[0018] The present invention also provides an ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy rod, which is made of the above-mentioned ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy.

[0019] This invention also provides a method for preparing the above-mentioned ultra-high strength, high ductility, nickel-based corrosion-resistant alloy rod, comprising the following steps:

[0020] S5. Forging and forming: Forging the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy into a forging bar;

[0021] S6. Heat treatment: The forged bar is heat treated by solution aging process to obtain ultra-high strength and high plasticity nickel-based corrosion-resistant alloy bar.

[0022] Furthermore, in step S5, the billet is forged by upsetting and drawing at a temperature range of 1100~1170℃ for 90 minutes, with a deformation of ≥30%; then, it is drawn in multiple heats at a temperature range of 1050~1150℃, and finally rolled to obtain a forged bar.

[0023] Furthermore, in step S6, the solution aging process is as follows: solution treatment at 1010~1080℃ for 0.5~2h, followed by water quenching to room temperature, holding at 700~780℃ for 8~10h, followed by furnace cooling to 600~650℃ for 8~12h for two-stage aging, followed by air cooling, thus obtaining ultra-high strength and high plasticity nickel-based corrosion-resistant alloy rods.

[0024] The main roles of various elements in the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy rods described in this invention are as follows:

[0025] Nickel: A matrix element; a high nickel content ensures resistance to stress corrosion.

[0026] Chromium: Solid solution strengthening; in high-temperature environments, it forms a dense oxide film, improving oxidation resistance; in corrosive environments, it forms a dense passivation film, improving corrosion resistance and pitting resistance in strongly oxidizing acidic environments.

[0027] Iron: Reduces the tendency to carburize at high temperatures, thus reducing alloy costs.

[0028] Carbon: Deoxidation during vacuum smelting; forming highly stable carbides such as titanium carbide and niobium carbide, which hinder grain growth at high temperatures, pin grain boundaries, and improve strength; however, if the carbon content is too high, the carbides will lead to chromium-depleted areas, reducing corrosion resistance, so it is necessary to control the carbon content within a reasonable range.

[0029] Aluminum and titanium: During aging, dispersed strengthening phases such as Ni3Al, Ni3Ti, and Ni3 (Ti, Al) are precipitated, which improves strength; deoxidation and denitrification improve the purity of the alloy; and carbon fixation improves resistance to intergranular corrosion.

[0030] Niobium: During aging, dispersed Ni3Nb is precipitated, which improves strength; adding a higher content of niobium forms Ni3 (Ti, Al, Nb), which enhances the strengthening effect; carbon fixation improves resistance to intergranular corrosion.

[0031] Vanadium: It forms fine and dispersed VC and VN, which become nucleation sites in solidification, dynamic recrystallization, and other processes, resulting in less segregation and a refined microstructure. When heated at high temperatures, the fine and dispersed VC and VN pin grain boundaries, hindering grain growth. It also forms vanadium carbide, which consumes carbon and nitrogen in the alloy, reduces Ti (C, N) and Nb (C, N), and improves resistance to intergranular corrosion.

[0032] Boron, zirconium, and magnesium: purify grain boundaries; improve high-temperature mechanical properties; reduce low-melting-point phases and improve processing performance.

[0033] Compared with the prior art, the advantages of the present invention include:

[0034] (1) The alloy of the present invention has added a large number of strengthening elements Nb, Ti and Al to increase the content of strengthening phase, which can effectively improve the strength of the alloy. At the same time, beneficial trace elements such as V, B, Zr and Mg are added to pin and purify the grain boundaries, ensuring the plasticity of the alloy.

[0035] (2) By adding intermediate alloys such as Fe-B, Fe-V, and Mg-Ni during the smelting of the alloy of the present invention, the loss of beneficial trace elements V, B and Mg in the alloy can be effectively controlled.

[0036] (3) The ultra-high strength and high plasticity nickel-based corrosion-resistant alloy rod of the present invention controls the content and distribution of the strengthening phase in the alloy through multiple means such as composition regulation, hot deformation and heat treatment. The yield strength can reach more than 1300MPa, the tensile strength can reach more than 1450MPa, the elongation can reach more than 18%, and the reduction of area can reach 40% or more, which meets the requirements of ultra-high strength and high plasticity of nickel-based corrosion-resistant alloys in marine oil and gas drilling and production, and realizes the technical improvement of ultra-high strength and high plasticity of nickel-based corrosion-resistant alloys. Attached Figure Description

[0037] Figure 1 is a flowchart of the preparation method of the ultra-high strength and high plasticity nickel-based corrosion-resistant alloy of the present invention;

[0038] Figure 2 is a flowchart of the preparation method of the ultra-high strength and high plasticity nickel-based corrosion-resistant alloy rod of the present invention;

[0039] Figure 3 shows the macroscopic low-magnification microstructure of the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy bar of Embodiment 1 of the present invention;

[0040] Figure 4 shows the microstructure of the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy bar of Example 1 of the present invention;

[0041] Figure 5 shows the tensile stress-strain curve of the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy bar of Embodiment 1 of the present invention. Detailed Implementation

[0042] To enable those skilled in the art to understand the features and effects of this application, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art in this application, and in case of conflict, the definitions in this specification shall prevail.

[0043] The theories or mechanisms described and disclosed herein, whether right or wrong, shall not in any way limit the scope of this application, that is, the content of this application may be implemented without being limited by any particular theory or mechanism.

[0044] In this document, "this application" means "this invention" or "this disclosure".

[0045] The terms “a,” “an,” “a,” or similar expressions are used herein to describe the components and technical features described in this application. Such descriptions are merely for convenience and to provide a general meaning for the scope of this application. Therefore, such descriptions should be understood to include one or at least one, and the singular includes the plural, unless clearly otherwise indicated.

[0046] In this article, "or a combination thereof" means "or any combination thereof", and "any one", "any kind", "any one" means "any one", "any kind", "any one".

[0047] In this document, the terms “comprising,” “including,” “having,” “containing,” or any similar terms are open-ended transitional phrases intended to encompass non-exclusive inclusions. For example, a composition or article thereof containing multiple elements is not limited to the elements listed herein, but may also include other elements not explicitly listed but typically inherent to the composition or article thereof. Furthermore, unless explicitly stated otherwise, the term “or” is an inclusive “or,” not an exclusive “or.” For example, the condition “A or B” is satisfied in any of the following cases: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); A and B are both true (or exist). Moreover, in this document, the terms “comprising,” “including,” “having,” and “containing” are interpreted as specifically disclosed and simultaneously encompassing closed conjunctions such as “composed of,” “consisting of,” “balance of,” and conjunctions such as “substantially composed of,” “mainly composed of,” “mainly composed of,” “essentially containing,” “basically composed of,” “essentially composed of,” “essentially composed of,” and “essentially containing.”

[0048] In this document, all features or conditions defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible subranges and individual numerical values ​​(including integers and fractions) within the ranges, especially integer values. For example, range descriptions such as "1.0 to 8.0," "between 1.0 and 8.0," or "between 1.0 and 8.0" should be considered as specifically disclosing all subranges such as 1.0 to 8.0, 1.0 to 7.0, 2.0 to 8.0, 2.0 to 6.0, 3.0 to 6.0, 4.0 to 8.0, 3.0 to 8.0, etc., and should be considered as covering endpoint values, especially subranges defined by integer values, and should be considered as specifically disclosing individual numerical values ​​within the ranges such as 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, etc. Unless otherwise specified, the foregoing interpretation applies to all contents of this application, whether extensive or not.

[0049] If a quantity, concentration, or other numerical value or parameter is expressed as a range, preferred range (or better range), or a series of upper and lower limits, it should be understood that this document has specifically disclosed all ranges consisting of any pair of upper or preferred values ​​(or better values) and lower or preferred values ​​(or better values) of that range, regardless of whether such ranges are disclosed separately. Furthermore, when a range of numerical values ​​is mentioned herein, unless otherwise stated, the range should include its endpoints and all integers and fractions within the range.

[0050] In this document, numerical values ​​are to be understood as having a precision with significant digits, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range of 39.50 to 40.49.

[0051] It should be understood that the features disclosed in the various embodiments herein can be arbitrarily combined to form the technical solution of this application, as long as there is no contradiction in the combination of these features.

[0052] The present application will be described below with reference to specific embodiments and examples. It should be understood that these specific embodiments and examples are merely illustrative and are not intended to limit the scope or use of the present application.

[0053] Unless otherwise stated, the methods, reagents, and conditions used in the preparation examples, comparative examples, and embodiments described below are conventional methods, reagents, and conditions in the art.

[0054] The technical solution of the present invention will be illustrated below through three embodiments and two comparative examples.

[0055] Example 1

[0056] A high-strength, high-ductility, nickel-based corrosion-resistant alloy rod, as shown in Figures 1 and 2, is prepared by the following method:

[0057] S1. Material preparation: Weigh the raw materials according to the alloy element batching table. V, B and Mg are weighed as master alloys Fe-V, Fe-B and Mg-Ni respectively. Other elements are weighed as elemental substances. The weight percentage of their chemical composition is shown in Table 1.

[0058] S2. Vacuum Induction Melting: A vacuum induction melting furnace is used for melting. First, Ni, Cr, Fe, Nb and Mo are melted. After melting, C, Ti and Al are added first. After melting, Fe-V, Fe-B and Zr are added. After melting, Mg-Ni is added last. Vacuum melting is carried out at high temperature (1500~1550℃) and high vacuum (1~3Pa) to strengthen refining. Electromagnetic and / or mechanical stirring and vibration are fully employed (electromagnetic and / or mechanical stirring and vibration are common techniques in the metallurgical field and will not be elaborated here) to ensure the uniformity of composition.

[0059] S3. Electroslag Remelting: The surface of the vacuum ingot is sand-milled, and a suitable slag is selected for electroslag remelting to obtain a nickel-based alloy ingot. In this step, the slag is a quaternary slag system of CaO-Al2O3-MgO-CaF2, with each component having a weight percentage of 55-75% CaO, 10-20% Al2O3, 0.5-5% MgO, and 10-20% CaF2, effectively controlling Ti and Al burn-off and the problem of surface scale on the electroslag ingot. Chips are drilled from the top and bottom of the cooled electroslag ingot for chemical composition analysis to ensure uniform and controllable alloy composition.

[0060] S4. Annealing: The nickel-based alloy ingot is annealed to obtain the ultra-high strength and high plasticity nickel-based corrosion-resistant alloy. The annealing is carried out by a two-stage homogenization diffusion annealing process. In the first stage, the temperature is held at 1160℃ to eliminate brittle phases, and in the second stage, the temperature is held at 1190℃ to eliminate element segregation.

[0061] S5. Forging: The ultra-high strength and high plasticity nickel-based corrosion-resistant alloy is forged into a forging bar, and then subjected to upsetting and drawing forging in the temperature range of 1100~1170℃ for 90 minutes, with a deformation of ≥30%; then subjected to multiple drawing in the temperature range of 1050~1150℃, and finally rolled to obtain the forging bar.

[0062] S6. Heat treatment: The forged bar is heat-treated by solution aging process to obtain ultra-high strength and high plasticity nickel-based corrosion-resistant alloy bar. The solution aging process is as follows: solution treatment at 1010~1080℃ for 0.5~2h, followed by water quenching to room temperature, holding at 700~780℃ for 8~10h, furnace cooling to 600~650℃ for 8~12h, double-stage aging, followed by air cooling to obtain ultra-high strength and high plasticity nickel-based corrosion-resistant alloy bar.

[0063] Example 2

[0064] Except for the ingredient list of raw materials, which differs from that of Example 1, all other steps are the same, and the weight percentage of their chemical components is shown in Table 1.

[0065] Example 3

[0066] Except for the ingredient list of raw materials, which differs from that of Example 1, all other steps are the same, and the weight percentage of their chemical components is shown in Table 1.

[0067] Example 4

[0068] Except for the ingredient list of raw materials, which differs from that of Example 1, all other steps are the same, and the weight percentage of their chemical components is shown in Table 1.

[0069] Example 5

[0070] Except for the ingredient list of raw materials, which differs from that of Example 1, all other steps are the same, and the weight percentage of their chemical components is shown in Table 1.

[0071] Comparative Example 1

[0072] The raw material formulation for this comparative example is shown in Table 1. The preparation method for comparative example 1 is the same as that for example 1, except for step S6.

[0073] Comparative Example 2

[0074] Zr and Mg were removed from the raw material formulation of this comparative example. The raw material formulation of this comparative example is shown in Table 1, and its preparation method is the same as that of the example.

[0075] Table 1. Chemical composition (wt.%) of different embodiments of ultra-high strength, high ductility, nickel-based corrosion-resistant alloy bars.

[0076] Elemental Examples 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Ni 56 .1056 .1055 .9050 .0057 .0056 .1052 .10 Cr 20 .9820 .9820 .5222 .0020 .0020 .9819 .07 Nb 6 .286 .187 .326 .007 .506 .185 .03 Mo 2 .852 .962 .802 .003 .002 .962 .92 Ti 1 .070 .960 .931 .200 .800 .960 .95 Al 0 .860 .720 .480 .400 .900 .720 .47C0 .0210 .0190 .0230 .0190 .0200 .0190 .020V0 .0950 .0960 .0750 .0800 .1000 .0950 .047B0 .00280 .00220 .00300 .00280 .00300 .00280 .0011Zr0 .0540 .0460 .0280 .0620 .1000 .054 / Mg0 .0270 .0280 .0310 .0280 .0300 .027 / P0 .0260 .0240 .0190 .0300 .0230 .0260 .006S0 .0320 .0310 .0230 .0350 .0300 .0320 .001O0 .00340 .00440 .00320 .00410 .00350 .0034 / N0 .01200 .01000 .00870 .01200 .00910 .0120 / Fe remainder ...

[0077] To further illustrate the unexpected positive technical effects achieved by the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy rods in the various embodiments of the present invention, the mechanical properties of the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy rods prepared in Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 2. The mechanical property testing method is based on the tensile testing standard ASTM A370 established by the American Committee on Testing Standards and Specifications for Materials. The low-magnification microstructure of Example 1 is shown in Figure 3, which is based on the low-magnification testing standard ASTM A604. The high-magnification microstructure of Example 1 is shown in Figure 4, which is based on ASTM E2. The tensile stress-strain curve is shown in Figure 5.

[0078] Table 2 Mechanical properties of ultra-high strength, high ductility, nickel-based corrosion-resistant alloy bars in different embodiments

[0079] Rm / MPaRp0.2 / MPaA / %Z / % Example 1: 1454132118.541.0 Example 2: 1510138018.540.0 Example 3: 1560141022.040.0 Example 4: 1540139021.040.0 Example 5: 1520140020.040.0 Comparative Example 1: 1357113325.045.0 Comparative Example 2: 1310115027.551.0

[0080] As can be seen from Table 2 and Figure 3, the tensile properties of Examples 1 to 5 are better than those of the comparative examples, and the yield strength can reach more than 1300 MPa, the tensile strength can reach more than 1450 MPa, the elongation can reach more than 18%, and the reduction of area can reach 40% or more. These properties meet the requirements for ultra-high strength and high plasticity of nickel-based corrosion-resistant alloys in marine oil and gas drilling and production, and realize the technical improvement of ultra-high strength and high plasticity of nickel-based corrosion-resistant alloys.

[0081] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-strength, high-ductility, nickel-based corrosion-resistant alloy, characterized in that: The alloy, by weight percentage, comprises 50.0–57.0% Ni, 20.0–22.0% Cr, 6.0–7.5% Nb, 2.0–3.0% Mo, 0.8–1.2% Ti, 0.4–0.9% Al, and trace elements C≤0.03%, V≤0.1%, B≤0.003%, Zr≤0.1%, and Mg≤0.03%, with the balance being Fe and unavoidable impurities.

2. The ultra-high strength, high ductility, nickel-based corrosion-resistant alloy according to claim 1, characterized in that: By weight percentage, it includes 55.9–56.1% Ni, 20.52–20.98% Cr, 6.18–7.32% Nb, 2.80–2.96% Mo, 0.93–1.07% Ti, 0.48–0.86% Al, and trace elements 0.019–0.023% C, 0.075–0.096% V, 0.0022–0.003% B, 0.028–0.054% Zr, and 0.027–0.031% Mg, with unavoidable impurities ≤0.082%, and the balance being Fe.

3. A method for manufacturing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy as described in claim 1 or 2, characterized in that: Includes the following steps: S1. Material Preparation: Weigh the raw materials according to the alloy element batching table, where V, B, and Mg are weighed as master alloys Fe-V, Fe-B, and Mg-Ni, respectively, and other elements are weighed as elemental substances; S2. Vacuum Induction Melting: Melt using a vacuum induction melting furnace. First, melt Ni, Cr, Fe, Nb, and Mo. After melting, add C, Ti, and Al first, and after melting, add Fe-V, Fe-B, and Zr. After melting, add Mg-Ni last; S3. Electroslag Remelting: Sand-mill the surface of the vacuum ingot, select slag suitable for this alloy, and perform electroslag remelting to obtain a nickel-based alloy ingot; S4. Annealing: The nickel-based alloy ingot is annealed to obtain the ultra-high strength and high plasticity nickel-based corrosion-resistant alloy.

4. The method for preparing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy according to claim 3, characterized in that: In step S2, vacuum melting is carried out by strengthening refining at high temperature (1500~1550℃) and high vacuum (1~3Pa), and the mixture is thoroughly stirred and vibrated.

5. The method for preparing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy according to claim 3, characterized in that: In step S3, the slag material is a quaternary slag system of CaO-Al2O3-MgO-CaF2, wherein the weight percentage of each component is 55~75% CaO, 10~20% Al2O3, 0.5~5% MgO and 10~20% CaF2.

6. The method for preparing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy according to claim 3, characterized in that: In step S4, the annealing is carried out using a two-stage homogenization diffusion annealing process, with the temperature held at 1160°C in the first stage and at 1190°C in the second stage.

7. A high-strength, high-ductility, nickel-based corrosion-resistant alloy rod, characterized in that: Made from the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy as described in claim 1 or 2.

8. A method for preparing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy rod as described in claim 7, characterized in that: The process includes the following steps: S5. Forging: Forging the ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy into a forging bar; S6. Heat treatment: Heat treating the forging bar using a solution aging process to obtain an ultra-high strength, high plasticity, nickel-based corrosion-resistant alloy bar.

9. The method for preparing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy rod according to claim 8, characterized in that: In step S5, the billet is forged by upsetting and drawing at a temperature range of 1100~1170℃ for 90 minutes, with a deformation of ≥30%; then, it is drawn in multiple heats at a temperature range of 1050~1150℃, and finally rolled to obtain a forged bar.

10. The method for preparing the ultra-high strength, high ductility, nickel-based corrosion-resistant alloy rod according to claim 8, characterized in that: In step S6, the solution aging process is as follows: solution treatment at 1010~1080℃ for 0.5~2h, followed by water quenching to room temperature, holding at 700~780℃ for 8~10h, furnace cooling to 600~650℃ for 8~12h, followed by two-stage aging and air cooling, thus obtaining ultra-high strength and high plasticity nickel-based corrosion-resistant alloy rods.

Images