Nickel-based alloy plate rolling process and nickel-based alloy plate

Abstract

This invention relates to a rolling process for nickel-based alloy plates and the nickel-based alloy plates themselves. The rolling process includes: obtaining a continuously cast slab using a continuous casting process; homogenizing the obtained continuously cast slab by controlling the homogenization temperature at 1230-1260℃ and the homogenization time at 8-12 hours; controlling the rolling deformation of the first three passes to ≤3% and the rolling deformation of all subsequent passes to ≤5%; performing a single-pass rolling on the homogenized slab to obtain an intermediate billet; and performing a second-pass rolling on the intermediate billet obtained after the single-pass rolling to obtain the target slab. This invention uses a continuous casting process for billet preparation, thus effectively suppressing the segregation of elements such as molybdenum and tungsten and shortening the homogenization time. The finished plates obtained by this invention have no defects such as scale, cracks, burrs, or pits on the surface and exhibit excellent overall performance.

Description

Technical Field

[0001] This invention belongs to the field of sheet metal rolling technology, specifically relating to a nickel-based alloy sheet metal rolling process and nickel-based alloy sheet metal. Background Technology

[0002] Nickel-based alloys possess high room temperature and high temperature strength, good oxidation and corrosion resistance, excellent creep and fatigue resistance, good microstructural stability, and reliable performance. Based on these properties, nickel-based alloys are widely used in industries such as petrochemicals, energy, machinery, and environmental protection. However, nickel-based alloy sheets are characterized by long production processes, high quality requirements, and complex process control. This is especially true for Hastelloy alloys with high molybdenum and tungsten content, which suffer from problems such as easy cracking during rolling, high mill load, numerous surface defects, low yield, and difficulty in controlling microstructure and properties. These problems severely restrict the application of nickel-based alloy sheets. Therefore, achieving high-quality rolling production of nickel-based alloy sheets is an urgent problem to be solved. Summary of the Invention

[0003] In order to solve all or part of the above problems, the present invention aims to provide a nickel-based alloy sheet rolling process and a nickel-based alloy sheet. The finished sheet obtained by using the nickel-based alloy sheet rolling process of the present invention has no defects such as scale, cracks, burrs, and pits on its surface and has excellent comprehensive performance.

[0004] According to one aspect of the present invention, a rolling process for nickel-based alloy plates is provided, comprising: Continuous casting process is used to obtain continuously cast slabs; The obtained continuous casting slab was subjected to homogenization treatment, with the homogenization temperature controlled at 1230-1260℃ and the homogenization time at 8-12h. The rolling deformation in the first three passes is controlled to be ≤3%, and the rolling deformation in all subsequent passes is controlled to be ≤5%. The homogenized slab is rolled in one pass to obtain intermediate billet. The intermediate billet obtained after the first rolling is subjected to a second rolling process to obtain the target slab.

[0005] Furthermore, after controlling the rolling deformation of the first three passes to ≤3% and the rolling deformation of all subsequent passes to ≤5%, and performing a single-fire rolling process on the homogenized slab to obtain an intermediate billet, the method further includes... The intermediate billet obtained after one-fire rolling is subjected to surface grinding treatment.

[0006] Furthermore, the process of performing a second rolling process on the intermediate billet obtained after the first rolling to obtain the target slab specifically involves: The refurbished billet is subjected to a second rolling process to obtain the target slab.

[0007] Furthermore, the process of performing a second-heat rolling on the ground billet to obtain the target slab specifically involves: The heating temperature is controlled at 1250-1280℃, the holding time is 2-4h, the rolling compression ratio is ≥5, and the final rolling temperature is greater than or equal to 980℃. The refurbished billet is then subjected to a second rolling process to obtain the target slab.

[0008] Furthermore, after performing a second rolling process on the intermediate billet obtained after the first rolling to obtain the target slab, the method further includes: The target slab obtained after the second rolling process is subjected to water cooling treatment to cool it to room temperature.

[0009] Furthermore, by mass fractions, the target slab is composed of the following components: C≤0.010, Si≤0.08, Mn≤1.00, P≤0.040, S≤0.030, 14.50≤Cr≤16.50, 15.00≤Mo≤17.00, 3.00≤W≤4.50, 4.00≤Fe≤7.00, Co≤2.50, V≤0.35, with the balance being Ni and unavoidable impurities.

[0010] This invention also provides a nickel-based alloy sheet, which is prepared using any of the rolling processes described above.

[0011] As can be seen from the above technical solution, the nickel-based alloy sheet rolling process and nickel-based alloy sheet provided by the present invention have the following beneficial effects: This invention employs continuous casting for billet preparation, thus effectively suppressing the segregation of elements such as molybdenum and tungsten and shortening the homogenization time. The plasticity of the continuously cast billet obtained by this invention is approximately 50-80%, while the optimal plasticity obtained by existing technologies is approximately 40-60%. Therefore, the embodiments of this invention significantly improve the plasticity of the billet. The rolling process of this invention is divided into single-fire rolling and double-fire rolling. After single-fire rolling, the hot plasticity of the billet is greatly improved. Double-fire rolling is mainly characterized by large deformation. As long as the rolling load can be met, rapid large deformation rolling is performed. The finished plate obtained by this invention has no defects such as scale, cracks, burrs, or pits on its surface and exhibits excellent overall performance. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a nickel-based alloy sheet rolling process according to an embodiment of the present invention. Detailed Implementation

[0013] To better understand the purpose, structure, and function of this invention, the following detailed description, in conjunction with the accompanying drawings, provides an example of a nickel-based alloy sheet rolling process and the nickel-based alloy sheet itself.

[0014] This invention provides a plate rolling process for N10276 high-end nickel-based alloy, which can effectively improve the surface quality and overall performance of nickel-based alloy plates.

[0015] Specifically, such as Figure 1 As shown, it illustrates a nickel-based alloy sheet rolling process according to an embodiment of the present invention, including the following steps: Step S001: Obtain a continuously cast slab using a continuous casting process; Step S002: The obtained continuous casting slab is subjected to homogenization treatment, and the temperature of homogenization treatment is controlled at 1230-1260℃, and the time of homogenization treatment is 8-12h. Step S003: Control the rolling deformation of the first three passes to ≤3%, and the rolling deformation of all subsequent passes to ≤5%. Perform one-fire rolling on the homogenized slab to obtain intermediate billet. Step S004: Perform a second rolling process on the intermediate billet obtained after the first rolling to obtain the target slab.

[0016] Regarding step S001: In this embodiment of the invention, the continuous casting process used to obtain continuously cast slabs can effectively suppress the segregation of elements such as molybdenum and tungsten in the alloy. Specifically, for example, by using a water-cooled slab crystallizer for continuous casting, continuous cast slabs can be obtained. In the specific implementation of this embodiment, attention should be paid to the effective coordination of cooling water and special protective slag to prevent the formation of cracks in the cast slab.

[0017] Regarding step S002: Since the segregation of the continuously cast slab obtained by the continuous casting process is reduced compared to traditional processes such as the combination of vacuum induction smelting and electroslag remelting (VIM+ESR) or the combination of vacuum induction smelting and vacuum arc remelting (VIM+VAR), homogenization can be completed in a shorter time. In this embodiment of the invention, the temperature is set to 1230-1260℃ and the time to 8-12h. In specific implementation, for example, the homogenization temperature is set to 1230℃, 1240℃, 1250℃, or 1260℃; and the homogenization time is set to 8h, 9h, 10h, 11h, or 12h.

[0018] Regarding step S003: This single-pass rolling is used to break down the as-cast structure to obtain an intermediate billet of suitable size. Taking a continuously cast slab with a thickness of 160-180mm and a width of 1000-1250mm as an example, this embodiment obtains an intermediate billet with a thickness of 80-120mm through single-pass rolling. During the single-pass rolling process, the rolling deformation in the first three passes is ≤3%, and the rolling deformation in all subsequent passes is ≤5%.

[0019] After controlling the rolling deformation amount of the first three passes to ≤3% and the rolling deformation amount of all subsequent passes to ≤5% in step S003, and performing a single-pass rolling process on the homogenized slab to obtain an intermediate billet, the method of this embodiment of the invention further includes surface grinding of the intermediate billet obtained after the single-pass rolling. The purpose of performing surface grinding on the intermediate billet here is to ensure that the billet entering the second-pass rolling process is free of any defects.

[0020] The corresponding step S004 involves performing a second rolling process on the intermediate billet obtained after the first rolling process to obtain the target slab. Specifically, this involves performing a second rolling process on the ground billet to obtain the target slab.

[0021] Specifically, the process of performing a second-heat rolling on the ground billet to obtain the target slab involves controlling the heating temperature to 1250-1280℃, the holding time to 2-4h, the rolling compression ratio to ≥5, and the final rolling temperature to ≥980℃.

[0022] Specifically, for the billet after grinding, the second rolling is the finished plate rolling. The heating temperature of the second rolling is 1250-1280℃, and the holding time is 2-4h. In order to ensure the final rolling temperature, the billet of the second rolling is directly and quickly rolled to the bottom, with a rolling compression ratio ≥5. The final rolling temperature is controlled above 980℃. As the temperature decreases during the rolling process, the final rolling temperature is lower than the heating temperature of the second rolling.

[0023] For two-stage rolling, the specific implementation may involve heating temperatures of 1250℃, 1260℃, 1270℃, or 1280℃, holding times of 2h, 2.5h, 3h, 3.5h, or 4h, rolling compression ratios of 5, 5.5, 6, 6.5, or 7, and final rolling temperatures of 980℃, 990℃, or 1000℃.

[0024] The nickel-based alloys targeted in this embodiment of the invention, such as N10276 nickel-based alloy, have their composition control standards based on ASME SB575. ASME SB575 is the standard for Hastelloy C276, Hastelloy C-4, and Hastelloy C-22 plates. Specifically, by mass fraction, the target slab consists of the following components: C≤0.010, Si≤0.08, Mn≤1.00, P≤0.040, S≤0.030, 14.50≤Cr≤16.50, 15.00≤Mo≤17.00, 3.00≤W≤4.50, 4.00≤Fe≤7.00, Co≤2.50, V≤0.35, with the balance being Ni and unavoidable impurities.

[0025] Regarding the rolling process of this invention: Since the billet is prepared by continuous casting, the segregation of elements such as molybdenum and tungsten is effectively suppressed, and the homogenization time is shortened; the plasticity of the continuous casting billet obtained by this invention is about 50-80%, while the best plasticity obtained by the prior art is about 40-60%. Therefore, this invention significantly improves the plasticity of the billet; the rolling process of this invention is divided into single-fire rolling and double-fire rolling. After the single-fire rolling, the hot plasticity of the billet is greatly improved. The double-fire rolling is mainly large deformation rolling. As long as the rolling load can be met, rapid large deformation rolling is carried out. The finished plate obtained by this invention has no defects such as heavy scale, cracks, burrs, and pits on the surface, and has excellent comprehensive performance.

[0026] This invention also provides a nickel-based alloy sheet, which is prepared using any of the rolling processes described above.

[0027] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of these embodiments. Experimental methods not specifically described in the following embodiments are performed according to conventional methods and conditions.

[0028] First, the composition of the existing N10276 nickel-based alloy and the composition of the alloys in Examples 1-4 are shown in Table 1 below: Table 1: Composition of existing N10276 nickel-based alloys and the composition of alloys in Examples 1-4 below.

[0029] Example 1: The slab was obtained by continuous casting, and its actual composition is shown in Table 1. The slab was rolled in one heat to obtain an intermediate billet. The surface of the intermediate billet was completely ground to eliminate visible defects. After grinding, the thickness of the intermediate billet was 110 mm.

[0030] In the second rolling process, the billet is heated to 1260℃ for 3 hours. After the second rolling, the final rolling temperature is 1010℃, resulting in a finished plate with a thickness of 22mm and a width of 2500mm.

[0031] The finished board has no defects such as blister packing, cracks, burrs, or pits on its surface, and its performance is excellent.

[0032] Example 2: The slab was obtained by continuous casting, and its actual composition is shown in Table 1. The slab was rolled in one heat to obtain an intermediate billet. The surface of the intermediate billet was completely ground to eliminate visible defects. After grinding, the thickness of the intermediate billet was 90 mm.

[0033] In the second rolling process, the billet is heated to 1280℃ for 2 hours. After the second rolling, the final rolling temperature is 1000℃, resulting in a finished plate with a thickness of 12mm and a width of 2800mm.

[0034] The finished board has no defects such as blister packing, cracks, burrs, or pits on its surface, and its performance is excellent.

[0035] Implementation 3: The slab was obtained by continuous casting, and its actual composition is shown in Table 1. The slab was rolled in one heat to obtain an intermediate billet. The surface of the intermediate billet was completely ground to eliminate visible defects. After grinding, the thickness of the intermediate billet was 95 mm.

[0036] In the second rolling process, the billet is heated to 1280℃ for 2.5 hours. After the second rolling, the final rolling temperature is 1020℃, resulting in a finished plate with a thickness of 10mm and a width of 3150mm.

[0037] The finished board has no defects such as blister packing, cracks, burrs, or pits on its surface, and its performance is excellent.

[0038] Example 4 The slab was obtained by continuous casting, and its actual composition is shown in Table 1. The slab was rolled in one heat to obtain an intermediate billet. The surface of the intermediate billet was completely ground to eliminate visible defects. After grinding, the thickness of the intermediate billet was 110 mm.

[0039] In the second rolling process, the billet is heated to 1270℃ for 3.5 hours. After the second rolling, the final rolling temperature is 1030℃, resulting in a finished plate with a thickness of 12mm and a width of 2990mm.

[0040] The finished board has no defects such as blister packing, cracks, burrs, or pits on its surface, and its performance is excellent.

[0041] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by those skilled in the art to which this invention pertains.

[0042] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0043] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A rolling process for nickel-based alloy plates, characterized in that, include: Continuous casting process is used to obtain continuously cast slabs; The obtained continuous casting slab was subjected to homogenization treatment, with the homogenization temperature controlled at 1230-1260℃ and the homogenization time at 8-12h. The rolling deformation in the first three passes is controlled to be ≤3%, and the rolling deformation in all subsequent passes is controlled to be ≤5%. The homogenized slab is rolled in one pass to obtain intermediate billet. The intermediate billet obtained after the first rolling is subjected to a second rolling process to obtain the target slab.

2. The rolling process according to claim 1, characterized in that, After controlling the rolling deformation amount of the first three passes to ≤3% and the rolling deformation amount of all subsequent passes to ≤5%, and performing a single-fire rolling process on the homogenized slab to obtain an intermediate billet, the method further includes... The intermediate billet obtained after one-fire rolling is subjected to surface grinding treatment.

3. The rolling process according to claim 2, characterized in that, The process of performing a second rolling process on the intermediate billet obtained after the first rolling to obtain the target slab specifically involves: The refurbished billet is subjected to a second rolling process to obtain the target slab.

4. The rolling process according to claim 3, characterized in that, The process of performing a second-heat rolling on the ground billet to obtain the target slab specifically involves: The heating temperature is controlled at 1250-1280℃, the holding time is 2-4h, the rolling compression ratio is ≥5, and the final rolling temperature is greater than or equal to 980℃. The refurbished billet is then subjected to a second rolling process to obtain the target slab.

5. The rolling process according to claim 1, characterized in that, After performing a second rolling process on the intermediate billet obtained after the first rolling to obtain the target slab, the method further includes: The target slab obtained after the second rolling process is subjected to water cooling treatment to cool it to room temperature.

6. The rolling process according to claim 1, characterized in that, The target slab, by mass fraction, consists of the following components: C≤0.010, Si≤0.08, Mn≤1.00, P≤0.040, S≤0.030, 14.50≤Cr≤16.50, 15.00≤Mo≤17.00, 3.00≤W≤4.50, 4.00≤Fe≤7.00, Co≤2.50, V≤0.35, with the balance being Ni and unavoidable impurities.

7. A nickel-based alloy sheet, characterized in that, It is prepared by the rolling process described in any one of claims 1-6.

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