A high-strength C276 corrosion-resistant alloy strip and preparation method thereof

Abstract

The invention relates to the field of low-temperature superconductivity, and in particular to a high-strength C276 corrosion-resistant alloy strip and a manufacturing method thereof. The components of the high-strength C276 corrosion-resistant alloy strip are as follows: C<0.008%, Mn<0.50%, S<0.010%, Co<0.90%, 15.00%≤Mo≤19.00%, 14.50%≤Cr≤18.00%, V<0.35%, 4.70%≤Fe≤7.00%, P<0.025, 3.00%≤W≤4.50%, the remainder is Ni and unavoidable impurities, and the sum of Cr, Fe, Ni, Mo and W components is required to be greater than 99.0%. The performance requirements of the high-strength C276 corrosion-resistant alloy strip are as follows: tensile strength Rm=1655±83MPa, yield strength Rp 0.2 1517±76MPa, elongation after fracture is 2±0.2%. The high-strength C276 corrosion-resistant alloy strip provided by the present invention is a pure C276 corrosion-resistant alloy strengthened by a special processing method, and its strength far exceeds that of the alloy produced by other processing techniques of the material, and can be applied to the field of high-end precision electronic equipment and domestic application promotion, solving the current situation of long-term dependence on imports in the domestic market, and has broad market prospects and influence in the technical field.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion-resistant alloy preparation, and in particular to a high-strength C276 corrosion-resistant alloy strip and a preparation method thereof. Background Art

[0002] Corrosion-resistant alloy materials are an important guarantee for industrial development and equipment operation. Due to their excellent corrosion resistance, they are widely used in pharmaceutical, chemical, hydrometallurgical, marine engineering, flue gas desulfurization equipment for pollution control, and oil and gas production. In the above applications, the performance of corrosion-resistant alloys plays a decisive role in the stability and service life of equipment, especially in extreme corrosive environments, where the quality of their corrosion resistance and mechanical properties directly affects the reliability of industrial systems.

[0003] In these fields, C-276 alloy has become one of the commonly used materials due to its excellent corrosion resistance. C-276 alloy has good resistance to pitting, crevice corrosion and oxidation, and is widely used in the treatment of highly corrosive chemical media and mechanical parts in harsh environments. However, C-276 alloy in the prior art still has some obvious technical deficiencies, especially in the field of low-temperature superconducting materials, its mechanical properties and processability are difficult to meet the stringent requirements of special applications.

[0004] First, the insufficient strength of the existing C-276 alloy has become an important factor limiting its application. The tensile strength and yield strength of the existing C-276 alloy are relatively low. For example, the tensile strength at room temperature is usually around 780MPa, and the yield strength is only around 337MPa, which makes it difficult to perform at its best in complex environments that require high strength and high corrosion resistance. In addition, the plasticity of the C-276 alloy is relatively high (the elongation after fracture is about 66%), which is helpful for processing and forming, but it also makes its disadvantage of insufficient strength in some fields more prominent; and the existing C-276 alloy preparation process has limited improvement on the mechanical properties of the material. Traditional hot rolling and cold rolling processes are usually difficult to achieve effective control of the strength and plasticity of the alloy. For example, the strength of the C-276 alloy strengthened by cold rolling deformation is improved to a certain extent, but the improper coordination of its deformation amount and solid solution softening process can easily lead to a decrease in the plasticity and uniformity of the alloy. In addition, the temperature and time control of the heat treatment process in the existing process is relatively rough, the precipitation of the strengthening phase and the work hardening have not been effectively optimized, and the mechanical properties of the material are difficult to meet the high strength requirements; in addition, the application of the existing C-276 alloy in the field of low-temperature superconducting materials still relies on imports, and the technology for domestic substitution is not yet mature. Due to the shortcomings of the manufacturing process, the domestically produced C-276 alloy has a gap compared with imported products in terms of strength, processing accuracy and stability, and also makes domestic users face high import costs and long delivery cycles. In the field of low-temperature superconductivity, the demand for high-strength and ultra-thin strips is particularly prominent, but the existing technology has not yet formed high-performance C-276 corrosion-resistant alloy strips suitable for this field in China.

[0005] In summary, the existing C-276 alloy has obvious deficiencies in strength, corrosion resistance, preparation process and performance in low-temperature superconducting applications. These problems need to be solved by optimizing alloy composition, improving preparation process and improving processing technology to meet the urgent demand for high-strength corrosion-resistant alloy materials in high-end application fields, while breaking the dependence on imported products and achieving domestic substitution. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a high-strength C276 corrosion-resistant alloy strip to solve the problems of insufficient strength, poor corrosion resistance and unstable performance caused by high impurity content in conventional corrosion-resistant alloy strips in the prior art.

[0007] In order to overcome the defects of the above-mentioned prior art, the present invention provides a high-strength C276 corrosion-resistant alloy strip, whose components include by weight percentage: Mo: 15.00-19.00%, Cr: 14.50-18.00%, Fe: 4.70-7.00%, W: 3.00-4.50%, C: <0.008%, Mn: <0.50%, S: <0.010%, Co: <0.90%, V: <0.35%, P: <0.025%, the remainder is Ni and unavoidable impurities, and the sum of Cr, Fe, Ni, Mo and W components is greater than 99.0%.

[0008] Compared with the prior art, the high-strength C276 corrosion-resistant alloy strip of the present application has the following advantages:

[0009] Mo and W: As the main contributing elements to corrosion resistance and strength, Mo (15.00-19.00%) and W (3.00-4.50%) work synergistically in the alloy to significantly improve the pitting and crevice corrosion resistance, while also playing a solid solution strengthening role on the alloy matrix.

[0010] Cr: The precise control of Cr content (14.50-18.00%) enables the alloy to form a dense Cr2O3 passivation film on the surface in a corrosive environment, effectively resisting oxidation and chemical corrosion, and enhancing the overall stability of the alloy.

[0011] Fe: The addition of Fe (4.70-7.00%) reduces the cost of raw materials while ensuring the strength of the material, and effectively inhibits the precipitation of harmful phases such as Ni4Mo, thereby improving the processing performance and durability.

[0012] Strict control of C, Mn, S and P: The extremely low contents of C (<0.008%), Mn (<0.50%), S (<0.010%) and P (<0.025%) greatly reduce the inclusion content of the material during processing, further improving the purity and corrosion resistance of the alloy, while significantly improving intergranular corrosion and brittleness problems.

[0013] Optimization of Ni matrix: Ni, as a matrix element, forms a stable austenite structure with elements such as Cr and Mo, ensuring the mechanical properties and fatigue resistance of the alloy in low temperature and highly corrosive environments.

[0014] Control of V: ​​The appropriate addition of V (<0.35%) has a significant effect on the grain refinement of the alloy, further improving the comprehensive mechanical properties of the alloy.

[0015] Ultra-low control of impurities: By limiting the content of impurities such as Co (<0.90%), the negative impact of impurities on the corrosion resistance and mechanical properties of the alloy is avoided, ensuring the long-term stability of the material.

[0016] The alloy of the present invention has higher tensile strength and yield strength while maintaining high corrosion resistance through precise design and ratio optimization of the above-mentioned components, which solves the technical bottleneck of existing corrosion-resistant alloy strips that are difficult to strike a balance between strength and corrosion resistance. The alloy is suitable for key application areas such as low-temperature superconductivity, high-end precision electronic equipment and corrosive environments.

[0017] In a possible implementation, the tensile strength Rm of the high-strength C276 corrosion-resistant alloy strip is 1655±83MPa, and the yield strength Rp 0.2 It is 1517±76MPa, and the elongation at break is 2±0.2%.

[0018] Compared with the prior art, the alloy strip of the present invention improves the solid solution strengthening effect and corrosion resistance of the alloy by adopting the above technical solution through precise control of elements such as Mo, Cr, Fe and W. Mo and W can effectively improve the corrosion resistance and mechanical strength of the alloy, while Cr and Fe work together to enhance the structural stability of the alloy and form a strong passivation film, thereby enabling the high-strength C276 corrosion-resistant alloy strip of the present invention to meet the application requirements of low-temperature superconductivity and other fields with extremely high requirements for mechanical properties and corrosion resistance.

[0019] Another technical problem to be solved by the present invention is to provide a method for preparing a high-strength C276 corrosion-resistant alloy strip, so as to solve the problems of lax purity control, insufficient mechanical properties and inclusions in the corrosion-resistant alloy strip prepared by the conventional corrosion-resistant alloy strip preparation method in the prior art.

[0020] In order to overcome the above defects of the prior art, the present invention also provides a method for preparing the above high-strength C276 corrosion-resistant alloy strip, comprising the following steps:

[0021] S1: Take the C276 corrosion-resistant alloy slab with the chemical composition requirements of the high-strength C276 corrosion-resistant alloy strip, and process it through multiple hot rolling processes to obtain a hot-rolled coil, and the conditions of the hot rolling process are: heat the C276 corrosion-resistant alloy slab to 1150±10℃;

[0022] S2: subjecting the hot-rolled coil obtained in step S1 to high-temperature solution heat treatment to obtain a softened corrosion-resistant alloy hot-rolled coil;

[0023] S3: The softened corrosion-resistant alloy hot-rolled coil obtained in step S2 is subjected to multiple cold rolling treatments and high-temperature solution heat treatments to obtain a high-strength C276 corrosion-resistant alloy strip.

[0024] Compared with the prior art, the preparation method of a high-strength C276 corrosion-resistant alloy strip in the present application has the following advantages: the traditional hot rolling and cold rolling processes and simple solution treatment in the prior art are replaced by strictly controlled multiple hot rolling and cold rolling deformation treatments combined with precise high-temperature solution heat treatment processes. This process combination effectively improves the microstructural uniformity and purity of the material, thereby significantly improving the mechanical properties and corrosion resistance of the alloy strip. Through the process connection between hot rolling, solution treatment, and cold rolling, an efficient synergistic mechanism is formed, which not only optimizes the internal organizational structure of the material, but also ensures the high consistency of the alloy performance. The organic combination of hot rolling to refine grains, solution stress relief and precipitation phases, and cold rolling strengthening balances the strength and toughness of the strip. Specifically, in each step:

[0025] Optimizing the hot rolling process (S1): The preparation method of the present invention controls the multiple hot rolling deformation of the C276 corrosion-resistant alloy slab at 1150±10°C to refine the grain structure and effectively disperse the strengthening phase in the alloy, so that the microstructure uniformity of the alloy is significantly improved, providing an excellent processing foundation for subsequent solution and cold rolling treatments. Compared with the simple hot rolling in the prior art, the hot rolling step of the present invention ensures that the alloy strip has both initial strength and toughness.

[0026] High-temperature solution heat treatment (S2): In the preparation method of the present invention, in S2, precise high-temperature solution treatment is used to eliminate the work hardening and residual internal stress generated during the hot rolling process, so that the strengthening phase in the alloy is effectively dissolved, and the formation of harmful precipitation phases is suppressed by cooling, thereby maintaining the good corrosion resistance and structural stability of the alloy. Compared with the wide range of heat treatment conditions in the prior art, the present invention accurately controls the temperature and cooling time to ensure that the strip performance reaches the optimal state.

[0027] Multiple cold rolling and solution treatment (S3): The preparation method of the present invention combines cold rolling deformation with high-temperature solution heat treatment, which is the key link of the present invention. By controlling the deformation amount of single cold rolling and the total deformation amount, and combining high-temperature solution treatment, each round of cold rolling can repair the work hardening and defects in the alloy, while strengthening the uniformity and density of the organization. This combination of cyclic deformation treatment and solution technology significantly improves the tensile strength (1655±83MPa), yield strength (1517±76MPa) and ductility (elongation after fracture 2±0.2%) of the strip.

[0028] In a possible implementation, in step S1, the thickness of the C276 corrosion-resistant alloy slab is 50-70 mm, and the thickness of the hot-rolled coil is 4-6 mm.

[0029] Compared with the existing technology, the above technical scheme is adopted to control the thickness of C276 corrosion-resistant alloy slab within the range of 50-70 mm, and the coil thickness is controlled within 4-6 mm through hot rolling. This optimization reduces the formation of coarse grains and promotes the uniformity of alloy structure through effective deformation and heat treatment. Compared with the traditional method, proper thickness control and multiple hot rolling can more fully eliminate the stress concentration and grain unevenness that may exist in the alloy, thereby improving the corrosion resistance and mechanical properties of the strip.

[0030] In a possible implementation, in step S1, the conditions for the multiple hot rolling treatments are: the C276 corrosion-resistant alloy slab is processed by one-hot multi-pass rolling, and the deformation amount of each pass is controlled at 20-30%.

[0031] Compared with the prior art, the above technical solution controls the deformation of each pass to 20-30%, which can ensure the uniformity of deformation during hot rolling and prevent uneven grains or insufficient recrystallization caused by excessive or insufficient deformation. Such deformation control can not only promote the refinement of alloy grains, but also avoid excessive deformation stress from damaging the internal microstructure of the material. The thickness of the slab is gradually reduced through multiple rolling. Under the condition of one-hot rolling, the accumulated deformation can significantly reduce the grain size, reduce grain boundary sliding, and improve the microstructure of the alloy, thereby enhancing the mechanical properties and corrosion resistance of the material. Reasonable control of the deformation of each pass can also reduce the risk of cracks during processing and optimize the hot rolling processing performance of the alloy.

[0032] In a possible embodiment, in step S2, the conditions of the high-temperature solution heat treatment are: after the hot-rolled coil is unfolded, it passes through an inert gas protection heating furnace, and by controlling the speed of passing through the inert gas protection heating furnace, each part of the hot-rolled coil is heated to 1180±10°C in the inert gas protection heating furnace, and the temperature is kept, and then the hot-rolled coil is taken out of the furnace and cooled.

[0033] Compared with the prior art, the above-mentioned technical solution is adopted to heat the hot-rolled coil to a high temperature of 1180±10°C and keep it warm, so that the strengthening phase and the second phase particles in the alloy can be fully dissolved into the matrix, the stress and work hardening generated during the rolling process are eliminated, the plasticity of the material is restored, and stable organizational conditions are provided for subsequent cold processing. During the high-temperature treatment process, the elements such as Cr and Mo in the alloy are redistributed to avoid the precipitation of harmful phases (such as σ phase), thereby improving the corrosion resistance of the alloy; and through inert gas protection (such as argon or nitrogen), oxidation can be effectively avoided during the high-temperature treatment process, the formation of surface oxide scale and inclusions can be reduced, and the smoothness and purity of the alloy surface can be maintained. The inert gas environment can also inhibit the absorption of harmful gases (such as O, N, H), further improve the purity of the material, optimize the corrosion resistance and mechanical properties of the alloy, and ultimately improve the stability and service life of the high-strength C276 corrosion-resistant alloy, meeting the use requirements of extreme environments such as low-temperature superconductors and high-end electronic equipment.

[0034] In a possible implementation manner, in step S2, the heat preservation time is 8-10 minutes, and the cooling method is water cooling treatment after the furnace is removed.

[0035] Compared with the prior art, the above technical solution is adopted to keep the alloy at a high temperature of 1180±10°C for 8-10 minutes, which can ensure that the strengthening elements (such as Cr, Mo, W, etc.) in the C276 corrosion-resistant alloy are fully diffused and redistributed, which is helpful to eliminate work hardening and local stress concentration. The holding time also avoids staying in the high temperature range for too long, prevents abnormal grain growth (overheating) and precipitation of harmful phases (such as σ phase), and ensures grain refinement and organizational stability. After the high-temperature alloy is taken out of the furnace, water cooling is used to quickly reduce the material temperature to room temperature, effectively shortening the material's residence time in the strengthening phase precipitation temperature range (600-800°C) and inhibiting the formation of harmful precipitation phases (such as carbides, σ phases, etc.).

[0036] In a possible embodiment, in step S3, the conditions of the multiple cold rolling treatments and high-temperature solution heat treatments are as follows: the softened high-strength C276 corrosion-resistant alloy hot-rolled coil is cold-rolled and deformed in a 20-roll 650mm rolling mill, and the single cold rolling deformation is controlled to be ≤10%. After the total deformation reaches 30%, a high-temperature solution heat treatment is performed to soften it, and then the cold rolling and high-temperature solution heat treatment are repeated until the high-strength C276 corrosion-resistant alloy coil is cold-rolled to a thickness of 0.1-0.12mm, that is, the high-strength C276 corrosion-resistant alloy strip.

[0037] Compared with the prior art, by adopting the above technical scheme, during the cold rolling process, the deformation of a single pass is controlled at ≤10%, which can effectively avoid excessive stress concentration, reduce the generation of microcracks, and improve the processing uniformity of the strip. The total deformation is controlled at 30% and then softened, which can significantly improve the strength of the material while avoiding a significant reduction in plasticity, thereby ensuring the machinability of the material in subsequent cold rolling. In the high-temperature solution heat treatment process after cold rolling, the processing stress inside the alloy is fully released. At the same time, the structural distortion caused by cold rolling deformation is eliminated through high-temperature heating and rapid cooling (such as water cooling). The high-temperature solution treatment can also make strengthening elements such as Cr and Mo fully dissolved in the matrix to form a uniform austenite structure, further improving the corrosion resistance and mechanical properties. The cyclic synergistic effect of the above-mentioned cold rolling and solution heat treatment, through the alternation of multiple cold rolling and high-temperature solution heat treatment, gradually realizes the refinement of grains and the homogenization of the structure. The increase in dislocation density caused by cold rolling deformation provides a mechanistic basis for improving strength, while solution heat treatment eliminates the stress accumulated during cold rolling and restores the plasticity of the material. Ultimately, the thickness of the C276 corrosion-resistant alloy strip is controlled at 0.1-0.12mm. The thickness is gradually reduced through multiple cycles to ensure that the material maintains excellent strength and toughness in thin specifications while avoiding cracks or structural defects caused by excessive processing.

[0038] In a possible implementation, in step S3, the thickness of the high-strength C276 corrosion-resistant alloy strip is 0.010-0.015 mm.

[0039] Compared with the prior art, the present invention adopts the above technical scheme, and gradually reduces the thickness of the strip through multiple hot rolling, cold rolling, high-temperature solid solution heat treatment and other processes. In each processing process, the deformation amount and processing temperature are strictly controlled to avoid cracks or defects caused by excessive processing, so that the thickness of the strip is gradually reduced and uniform, and the initial slab thickness is 50-70mm, which is thinned to 4-6mm through one-fire multi-pass hot rolling, and then through multiple cold rolling and solid solution heat treatment cycle processes, the strip thickness is gradually reduced to 0.010-0.015mm. During the cold rolling process, the deformation of a single pass is controlled to be ≤10% to avoid internal defects caused by excessive deformation. The stress is released in time in combination with high-temperature solution heat treatment to ensure the controllability of dimensional thinning and structural uniformity. After each cold rolling, high-temperature solution heat treatment is performed to restore the plasticity of the material, eliminate work hardening and internal residual stress, and inhibit the precipitation of harmful phases (such as σ phase) through high-temperature rapid cooling to ensure that the material still has high strength and excellent corrosion resistance in an extremely thin state. When the final thickness of 0.010-0.015mm of the above implementation scheme is reached, the uniform distribution of grains can be ensured, while avoiding uneven thickness or surface cracks caused by excessive processing, thereby obtaining high strength and stability of the thin strip. DETAILED DESCRIPTION

[0040] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0041] The invention provides a high-strength C276 corrosion-resistant alloy strip, which comprises, by weight percentage, the following components: Mo: 15.00-19.00%, Cr: 14.50-18.00%, Fe: 4.70-7.00%, W: 3.00-4.50%, C: <0.008%, Mn: <0.50%, S: <0.010%, Co: <0.90%, V: <0.35%, P: <0.025%, the remainder being Ni and unavoidable impurities, and the sum of Cr, Fe, Ni, Mo and W components is greater than 99.0%.

[0042] As a preferred solution, the tensile strength Rm of the high-strength C276 corrosion-resistant alloy strip is 1655±83MPa, and the yield strength Rp 0.2 It is 1517±76MPa, and the elongation at break is 2±0.2%.

[0043] The present invention also provides a method for preparing the above-mentioned high-strength C276 corrosion-resistant alloy strip, comprising the following steps:

[0044] S1: Take the C276 corrosion-resistant alloy slab with the chemical composition requirements of the high-strength C276 corrosion-resistant alloy strip, and process it through multiple hot rolling processes to obtain a hot-rolled coil, and the conditions of the hot rolling process are: heat the C276 corrosion-resistant alloy slab to 1150±10℃;

[0045] S2: subjecting the hot-rolled coil obtained in step S1 to high-temperature solution heat treatment to obtain a softened corrosion-resistant alloy hot-rolled coil;

[0046] S3: The softened corrosion-resistant alloy hot-rolled coil obtained in step S2 is subjected to multiple cold rolling treatments and high-temperature solution heat treatments to obtain a high-strength C276 corrosion-resistant alloy strip.

[0047] As a preferred solution, in step S1, the thickness of the C276 corrosion-resistant alloy slab is 50-70 mm, and the thickness of the hot-rolled coil is 4-6 mm.

[0048] As a preferred solution, in step S1, the conditions for the multiple hot rolling treatments are: the C276 corrosion-resistant alloy slab is processed by one-hot multi-pass rolling, and the deformation amount of each pass is controlled at 20-30%.

[0049] As a preferred solution, in step S2, the conditions for the high-temperature solution heat treatment are as follows: after the hot-rolled coil is unfolded, it is passed through an inert gas protection heating furnace, and the speed of passing through the inert gas protection heating furnace is controlled so that each part of the hot-rolled coil is heated to 1180±10°C in the inert gas protection heating furnace, and the temperature is kept, and then the hot-rolled coil is taken out of the furnace and cooled.

[0050] As a preferred solution, in step S2, the heat preservation time is 8-10 minutes, and the cooling method is water cooling treatment after being taken out of the furnace.

[0051] As a preferred scheme, in step S3, the conditions of the multiple cold rolling treatments and high-temperature solution heat treatments are as follows: the softened high-strength C276 corrosion-resistant alloy hot-rolled coil is cold-rolled and deformed in a 20-roll 650mm rolling mill, and the single cold rolling deformation is controlled to be ≤10%. After the total deformation reaches 30%, a high-temperature solution heat treatment is performed to soften it, and then the cold rolling and high-temperature solution heat treatment are repeated until the high-strength C276 corrosion-resistant alloy coil is cold-rolled to a thickness of 0.1-0.12mm, that is, the high-strength C276 corrosion-resistant alloy strip.

[0052] As a preferred solution, in step S3, the thickness of the high-strength C276 corrosion-resistant alloy strip is 0.010-0.015 mm.

[0053] Now, for the prior art, the key influencing factors of the mechanical properties of the high-strength C276 corrosion-resistant alloy strip provided by the present invention are analyzed as follows: as for the high-temperature solution heat treatment in steps S2 and S3, the temperature requirement is 1180±10°C, the purpose of which is to harden the work caused by the previous cold and hot working, and the water cooling is required to allow the material to cool quickly, reduce the residence time of the material in the temperature range of the precipitation of the strengthening phase, thereby avoiding the precipitation of the strengthening phase, providing suitable material strength for subsequent deformation processing, and ensuring that the deformation amount of subsequent deformation processing meets the design requirements; the specification of the material before the final finished product processing in step c as described in claim 1 is controlled to 0.1-0.12mm, the purpose of which is to control the cold working deformation amount of the final finished product within the range of 50% to 60%, to ensure that the final finished product ultra-high strength C276 corrosion-resistant alloy strip meets the design requirements, and exceeding this deformation control range will cause the strength of the final finished product ultra-high strength C276 corrosion-resistant alloy strip to fail to reach the lower limit of the design requirements or exceed the upper limit.

[0054] In combination with the above technical solution, an embodiment combined with specific data is provided below to further expand the content of the invention of the present invention:

[0055] Embodiment 1:

[0056] The present embodiment provides a high-strength C276 corrosion-resistant alloy strip and a preparation method thereof. The raw material slab chemical composition of the high-strength C276 corrosion-resistant alloy strip is C: 0.006%, Mn: 0.24%, Si: 0.060%, P: 0.002%, S: 0.0013%, Cr: 17.27%, W: 4.16%, Mo: 16.92%, Fe: 6.12%, Al: 0.034%, Co: 0.072%, V: 0.017%, H: 0.00012%, O: 0.0008%, N: 0.0011%, and the remainder is Ni and unavoidable impurities.

[0057] The preparation steps of the high-strength C276 corrosion-resistant alloy strip are as follows:

[0058] S1: The high purity C276 corrosion resistant alloy slab is heated to 1150±10°C and rolled into a hot rolled coil with a thickness of 5 mm through multiple passes.

[0059] S2: The hot-rolled coil described in S1 is heated to 1180±10° C. in an inert gas protection furnace and kept at this temperature for 9 minutes for high-temperature solution heat treatment, and then water-cooled to obtain a softened high-strength C276 corrosion-resistant alloy hot-rolled coil.

[0060] S3: The softened C276 corrosion-resistant alloy hot-rolled coil obtained in S2 is subjected to multiple cold rolling and high-temperature solution heat treatment, and the single-pass deformation of the cold-rolled semi-finished product is controlled to be ≤10%, and the total deformation is controlled to be ≤30%. The high-temperature solution temperature is controlled to be 1180±10℃ and kept warm for 5 minutes. The final product is rolled from 0.110mm through multiple passes with a deformation of 10%, thereby obtaining a high-strength C276 corrosion-resistant alloy strip as described in claim 1.

[0061] Example 2

[0062] The present embodiment provides a high-strength C276 corrosion-resistant alloy strip and a preparation method thereof. The raw material slab chemical composition of the high-strength C276 corrosion-resistant alloy strip is C: 0.0065%, Mn: 0.25%, Si: 0.065%, P: 0.0025%, S: 0.0016%, Cr: 17.14%, W: 4.14%, Mo: 16.85%, Fe: 6.21%, Al: 0.039%, Co: 0.064%, V: 0.015%, H: 0.00014%, O: 0.00095%, N: 0.0009%, and the remainder is Ni and unavoidable impurities.

[0063] The preparation steps of the above-mentioned high-strength C276 corrosion-resistant alloy strip are as follows:

[0064] S1: The high purity C276 corrosion resistant alloy slab is heated to 1150±10°C and rolled into a hot rolled coil with a thickness of 5 mm through multiple passes.

[0065] S2: The hot-rolled coil described in step S1 is heated to 1180±10° C. in an inert gas protection furnace and kept at that temperature for 9 minutes for high-temperature solution heat treatment, and then water-cooled to obtain a softened high-strength C276 corrosion-resistant alloy hot-rolled coil.

[0066] S3: The softened C276 corrosion-resistant alloy hot-rolled coil obtained in step S2 is subjected to multiple cold rolling and high-temperature solution heat treatment. The single-pass deformation of the cold-rolled semi-finished product is controlled to be ≤10%, and the total deformation is controlled to be ≤30%. The high-temperature solution temperature is controlled to be 1180±10℃ and kept warm for 5 minutes. The final product is rolled from 0.105mm through multiple passes with a deformation of 10%, thereby obtaining the high-strength C276 corrosion-resistant alloy strip.

[0067] Example 3

[0068] The present embodiment provides a high-strength C276 corrosion-resistant alloy strip and a preparation method thereof. The raw material slab chemical composition of the high-strength C276 corrosion-resistant alloy strip is C: 0.006%, Mn: 0.23%, Si: 0.058%, P: 0.0024%, S: 0.0015%, Cr: 17.33%, W: 4.17%, Mo: 17.13%, Fe: 6.15%, Al: 0.0375%, Co: 0.068%, V: 0.0165%, H: 0.00013%, O: 0.00076%, N: 0.0008%, and the remainder is Ni and unavoidable impurities.

[0069] The preparation steps of the above-mentioned high-strength C276 corrosion-resistant alloy strip are as follows:

[0070] S1: The high purity C276 corrosion resistant alloy slab is heated to 1150±10°C and rolled into a hot rolled coil with a thickness of 5 mm through multiple passes.

[0071] S2: The hot-rolled coil described in step S1 is heated to 1180±10° C. in an inert gas protection furnace and kept at that temperature for 9 minutes for high-temperature solution heat treatment, and then water-cooled to obtain a softened high-strength C276 corrosion-resistant alloy hot-rolled coil.

[0072] S3: The softened C276 corrosion-resistant alloy hot-rolled coil obtained in step S2 is subjected to multiple cold rolling and high-temperature solution heat treatment, and the single-pass deformation of the cold-rolled semi-finished product is controlled to be ≤10%, and the total deformation is controlled to be ≤30%. The high-temperature solution temperature is controlled to be 1180±10℃ and kept warm for 5 minutes. The final product is rolled from 0.115mm through multiple passes with a deformation of 10%, thereby obtaining a high-strength C276 corrosion-resistant alloy strip as described in claim 1.

[0073] Comparative Example:

[0074] Preparation method of C-276 alloy:

[0075] Step a, heating the existing C-276 alloy slab to 1120±10°C, and hot rolling it into a 5mm thick hot-rolled plate through multiple passes; the chemical composition of the existing C-276 alloy slab is as follows: C: 0.008%, Mn: 0.46%, Si: 0.068%, P: 0.018%, S: 0.008%, Cr: 16.08%, W: 3.56%, Mo: 15.65%, Fe: 6.25%, Al: 0.225%, Co: 0.115%, V: 0.034%, H: 0.00021%, O: 0.0015%, N: 0.0024%, and the remainder is Ni and unavoidable impurities.

[0076] Step b, keeping the hot-rolled plate in step a at 1180±10° C. for 9 minutes, water cooling, high-temperature solution heat treatment, pickling and polishing to remove surface defects.

[0077] Step c, subjecting the hot-rolled plate after high-temperature solution heat treatment and pickling in step b to multiple cold rolling and heat treatment to obtain a 0.5-2.0 mm thick cold-rolled plate, wherein the cold rolling controls the deformation of the semi-finished product to 20%-30%, the maximum deformation per pass is ≤10%, and the deformation of the finished product is ≥30%; the heat treatment temperature of the semi-finished product is controlled at 1180±10°C, and the holding time is t=(1.5*d+3~5)min, and the heat treatment temperature of the finished product is controlled at 1120±10°C, and the holding time is t=(1.5*d+3~5)min.

[0078] Table 1: Mechanical properties test data of C-276 thin strips prepared in Examples 1-3 and Comparative Example C-276 thin plates

[0079]

[0080]

[0081] It can be seen from the above table that compared with the existing C-276 alloy, the room temperature tensile strength and yield strength of the C-276 corrosion-resistant alloy strips prepared in Examples 1-3 of the present invention are higher, far exceeding the strength of the existing C-276 thin plates, and the elongation after fracture is lower than that of the existing C-276 thin plates, indicating that the plasticity thereof is significantly reduced. The reason is that after cold working deformation strengthening, the plasticity of the strip material is reduced to improve the strength of the material to meet the design requirements.

[0082] In summary, the high-strength C276 corrosion-resistant alloy strip of the present invention has excellent strength and meets the requirements for replacing imported high-strength C-276 corrosion-resistant alloy strips in the field of low-temperature superconductivity (the present invention accurately controls the proportions of key elements such as Mo, Cr, Fe, and W in the material composition design, so that the alloy significantly improves the tensile strength and yield strength while maintaining excellent corrosion resistance. At the same time, through the synergy of multi-stage processing technology, including high-temperature solution treatment and multiple cold rolling deformation strengthening, the grain structure of the material is further optimized, and the grain boundary defects and inclusion content are reduced, thereby improving the uniformity and strength performance of the material. Finally, through reasonable control of cold rolling deformation amount, combined with solution treatment softening, the optimal balance between the strength and toughness of the thin strip material is ensured, meeting the strict requirements of high strength, low plasticity and high corrosion resistance in the field of superconductivity.) It has broad market prospects and technological advancement; and the high-strength C276 corrosion-resistant alloy strip of the present invention has excellent strength, meets the requirements for replacing imported high-strength C-276 corrosion-resistant alloy strips in the field of low-temperature superconductivity, and has broad market prospects and technological advancement.

[0083] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0084] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A high-strength C276 corrosion-resistant alloy strip, characterized in that: Its components include by weight percentage: Mo: 15.00-19.00%, Cr: 14.50-18.00%, Fe: 4.70-7.00%, W: 3.00-4.50%, C: <0.008%, Mn: <0.50%, S: <0.010%, Co: <0.90%, V: <0.35%, P: <0.025%, the remainder is Ni and unavoidable impurities, and the sum of Cr, Fe, Ni, Mo and W components is greater than 99.0%.

2. The high-strength C276 corrosion-resistant alloy strip according to claim 1, characterized in that: The tensile strength Rm of the high-strength C276 corrosion-resistant alloy strip is 1655±83MPa, and the yield strength Rp 0.2 It is 1517±76MPa, and the elongation at break is 2±0.2%.

3. A method for preparing a high-strength C276 corrosion-resistant alloy strip according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1: Take the C276 corrosion-resistant alloy slab with the chemical composition requirements of the high-strength C276 corrosion-resistant alloy strip, and process it through multiple hot rolling processes to obtain a hot-rolled coil, and the conditions of the hot rolling process are: heat the C276 corrosion-resistant alloy slab to 1150±10℃; S2: subjecting the hot-rolled coil obtained in step S1 to high-temperature solid solution heat treatment to obtain a softened corrosion-resistant alloy hot-rolled coil; S3: The softened corrosion-resistant alloy hot-rolled coil obtained in step S2 is subjected to multiple cold rolling treatments and high-temperature solution heat treatments to obtain a high-strength C276 corrosion-resistant alloy strip.

4. The method for preparing the high-strength C276 corrosion-resistant alloy strip according to claim 3, characterized in that: In the step S1, the thickness of the C276 corrosion-resistant alloy slab is 50-70 mm, and the thickness of the hot-rolled coil is 4-6 mm.

5. The method for preparing the high-strength C276 corrosion-resistant alloy strip according to claim 3, characterized in that: In the step S1, the conditions of the multiple hot rolling treatments are: the C276 corrosion-resistant alloy slab is processed by one-hot multi-pass rolling, and the deformation amount of each pass is controlled at 20-30%.

6. The method for preparing the high-strength C276 corrosion-resistant alloy strip according to claim 3, characterized in that: In step S2, the conditions of the high-temperature solution heat treatment are as follows: after the hot-rolled coil is unrolled, it is passed through an inert gas protection heating furnace, and the speed of passing through the inert gas protection heating furnace is controlled so that each part of the hot-rolled coil is heated to 1180±10°C in the inert gas protection heating furnace, and the temperature is kept, and then the hot-rolled coil is taken out of the furnace and cooled.

7. The method for preparing the high-strength C276 corrosion-resistant alloy strip according to claim 6, characterized in that: In step S2, the heat preservation time is 8-10 minutes, and the cooling method is water cooling after it is taken out of the furnace.

8. The method for preparing the high-strength C276 corrosion-resistant alloy strip according to claim 3, characterized in that: In step S3, the conditions of the multiple cold rolling treatments and high-temperature solution heat treatments are as follows: the softened high-strength C276 corrosion-resistant alloy hot-rolled coil is cold-rolled and deformed in a 20-roll 650mm rolling mill, and the single cold rolling deformation is controlled to be ≤10%. After the total deformation reaches 30%, a high-temperature solution heat treatment is performed to soften it, and then the cold rolling and high-temperature solution heat treatment are repeated until the high-strength C276 corrosion-resistant alloy coil is cold-rolled to a thickness of 0.1-0.12mm, that is, the high-strength C276 corrosion-resistant alloy strip.

9. The method for preparing the high-strength C276 corrosion-resistant alloy strip according to claim 8, characterized in that: In the step S3, the thickness of the high-strength C276 corrosion-resistant alloy strip is 0.010-0.015 mm.

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