Preparation method of high-uniform super-wide and super-long nickel-based high-temperature alloy plate
By employing a process of widening through single-rolling and lengthening through double-rolling, combined with roll preheating and solution quenching, the problems of edge cracking and uneven microstructure in ultra-wide and ultra-long nickel-based high-temperature alloy plates have been solved, achieving efficient and stable production and reducing production costs and cycle time.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU XIANGYUN TITANIUM ALLOY NEW MATERIALS CO LTD
- Filing Date
- 2026-05-19
- Publication Date
- 2026-07-31
AI Technical Summary
Existing technologies are insufficient for efficiently preparing ultra-wide and ultra-long nickel-based superalloy plates, and suffer from problems such as edge cracking during rolling, uneven microstructure, narrow processing window, high production cost, and long production cycle.
The process strategy of widening by rolling in one heat and increasing by rolling in two heats is adopted. Combined with roll preheating, solution quenching and strict control of furnace exit time, the rolling speed and reduction are optimized, and reasonable slab specifications are designed to ensure that the plate deforms in multiple directions and has uniform microstructure.
It has achieved efficient and stable production of highly uniform ultra-wide and ultra-long nickel-based high-temperature alloy plates with thicknesses of 10mm to 30mm, widths of 1300mm to 2300mm, and lengths of 6000mm to 8000mm, reducing production costs and time, and improving yield and microstructure uniformity.
Smart Images
Figure CN122480101A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal material processing technology, and in particular to a method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based high-temperature alloy plate. Background Technology
[0002] Nickel-based superalloys, with their excellent high-temperature strength, oxidation resistance, corrosion resistance, fatigue resistance, and fracture toughness, have become irreplaceable key materials in fields such as hot-end components of aerospace engines, gas turbine blades, and critical components of nuclear power plants. As related equipment develops towards larger sizes and higher performance, the market demand for ultra-wide and ultra-long nickel-based superalloy plates is increasing daily.
[0003] However, these alloys face significant challenges during hot working: First, as the deformation temperature decreases, the deformation resistance of high-temperature alloys increases sharply, easily leading to edge cracking during rolling, severely reducing yield and prolonging production cycles; second, their excellent thermal conductivity causes rapid heat dissipation during rolling, resulting in a very narrow effective processing window (i.e., the suitable temperature range for rolling). This narrow processing window forces production to employ multi-pass rolling, which not only increases costs but also causes fluctuations in microstructure and properties due to repeated heating and cooling.
[0004] Furthermore, unidirectional rolling deformation easily induces anisotropy in the microstructure and properties of the sheet metal, while frequent reversing rolling exacerbates temperature drop, further compressing the processing window. Excessively low rolling temperatures also lead to increased mill bounce, severely affecting the dimensional accuracy of the sheet metal thickness. These factors collectively restrict the efficient and stable preparation of large-size, highly uniform nickel-based superalloy sheets. Summary of the Invention
[0005] Therefore, this invention provides a method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate. By optimizing the slab design, rolling process, and solution treatment process, a large-size nickel-based alloy plate with ultra-wide and ultra-long dimensions is prepared and the uniformity of the plate's microstructure is improved.
[0006] To solve the above-mentioned technical problems, the present invention provides a method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate, comprising: A nickel-based high-temperature alloy slab is provided, the nickel-based high-temperature alloy slab is heated in one heat, and the rolls are hot-rolled before the one heat rolling. One-fire rolling is performed, in which the nickel-based high-temperature alloy slab heated in one fire is rolled along the first direction, which is the width direction of the original slab, so that the size of the plate after one-fire rolling in the first direction reaches the target width, and a semi-finished nickel-based high-temperature alloy plate is obtained. The semi-finished nickel-based high-temperature alloy sheet is subjected to a second heating process, and the rolls are hot-rolled before the second heating rolling. The semi-finished nickel-based high-temperature alloy sheet is rolled in a second direction, which is the length direction of the original slab, so that the thickness of the sheet after the second rolling reaches the target thickness, and the finished nickel-based high-temperature alloy sheet is obtained.
[0007] In one embodiment of the present invention, during the first and second rolling processes, the rolling speed is controlled by first slowing down the feed, then increasing the rolling speed, and then gradually decreasing the rolling speed, so as to reduce the ejection time of the slab or plate during the rolling process.
[0008] In one embodiment of the present invention, when performing first-pass rolling and second-pass rolling, the time from exiting the furnace to transferring the rolls is less than 40 seconds, and the rolling time per pass of the first-pass rolling is controlled to not exceed 15 seconds and the rolling time per pass of the second-pass rolling is controlled to not exceed 18 seconds.
[0009] In one embodiment of the present invention, the volume of the nickel-based superalloy slab is 1.1 to 1.4 times the volume of the finished nickel-based superalloy sheet, and the thickness of the semi-finished nickel-based superalloy sheet after the first rolling is 2 to 5 times the volume thickness of the finished nickel-based superalloy sheet, so as to ensure that the second rolling still has sufficient deformation and promotes grain refinement.
[0010] In one embodiment of the present invention, the finished nickel-based high-temperature alloy plate has a thickness of 10mm to 30mm, a width of 1300mm to 2300mm, and a length of 6000mm to 8000mm. The nickel-based high-temperature alloy slab has a thickness of 100mm~170mm, a width of 850mm~1500mm, and a length of 2000mm~2500mm.
[0011] In one embodiment of the present invention, when performing single-pass rolling, the reduction per pass is 8-12 mm when the slab thickness is 100-170 mm; the reduction per pass is 5-10 mm when the slab thickness is 50-100 mm; and the reduction per pass is 1-5 mm when the slab thickness is less than 50 mm. When performing two-pass rolling, the reduction per pass is 5-10mm when the plate thickness is 50-100mm; and the reduction per pass is 1-8mm when the plate thickness is less than 50mm.
[0012] In one embodiment of the present invention, the width of the semi-finished nickel-based high-temperature alloy sheet after the first rolling is (y+a1) mm, where y is the finished width, a1 is the width machining allowance, and a1 ranges from 50 mm to 150 mm; the thickness of the semi-finished nickel-based high-temperature alloy sheet after the second rolling is (x+a2) mm, where x is the finished thickness, a2 is the thickness machining allowance, and a2 ranges from 0.5 mm to 2 mm.
[0013] In one embodiment of the present invention, the rolls are subjected to a hot rolling treatment before the first rolling, so that the roll temperature reaches above 30°C before the first rolling of the nickel-based high-temperature alloy slab; the rolls are subjected to a hot rolling treatment before the second rolling, so that the roll temperature reaches above 30°C before the second rolling of the semi-finished nickel-based high-temperature alloy sheet.
[0014] In one embodiment of the present invention, it further includes: When hot-rolling the rolls before the first and second rolling processes, arrange 3 to 5 production billets for hot-rolling, and after rolling, oscillate the production billets on the roller table for 10 to 15 minutes, with the rolling temperature not lower than 900℃.
[0015] In one embodiment of the present invention, the finished nickel-based high-temperature alloy sheet rolled by two heat treatment is further subjected to solution quenching. During solution quenching, the finished nickel-based high-temperature alloy sheet rolled by two heat treatment is heated to 1000℃~1200℃ with a holding coefficient of 0.5min / mm~1.2min / mm. Then, it is taken out of the furnace for quenching. The transfer time after taking it out of the furnace does not exceed 3 minutes, and the quenching time is 5 minutes~30 minutes. After taking it out of the water, the surface temperature of the sheet is below 100℃.
[0016] The technical solution of the present invention has the following advantages compared with the prior art: The present invention discloses a method for preparing highly uniform, ultra-wide, and ultra-long nickel-based superalloy plates. Addressing the challenges of low final rolling temperature, narrow processing window, deformation and cracking, multiple rolling passes, unidirectional microstructural deformation, unqualified grain size, and small reduction per pass in highly uniform, ultra-wide, and ultra-long nickel-based superalloy plates, the method solves these problems through systematic process design, including billet design, furnace exit time control, hot roll design, rolling pass reduction design, rolling speed control, and time control for each pass.
[0017] This invention adopts a process strategy of "one-pass rolling for widening + two-pass rolling for lengthening". While ensuring that the plate obtains multi-directional deformation and improves the uniformity of the structure, it avoids frequent reversal operations within a single pass and the rolling interruption and temperature drop that may be caused by intermediate measurements. This significantly shortens the single pass and total rolling time and effectively improves the final rolling temperature.
[0018] This invention optimizes the rolling speed curve (low-speed bite, high-speed rolling, and final deceleration speed control curve) by strictly controlling the transfer time from slab exiting the furnace to rolling (<40s) and reducing the slab ejection distance between passes, thereby minimizing non-deformation time and reducing workpiece temperature drop. Higher rolling temperatures not only reduce the risk of edge cracking but also facilitate the use of larger pass reductions. Larger deformation promotes dynamic recrystallization, contributing to finer and more homogenized microstructure, while simultaneously reducing the required number of rolling passes, creating a virtuous cycle of increased rolling temperature and increased deformation.
[0019] This invention uses a specific specification of hot-roll material for rolling before rolling, and combines this with roller table oscillation to preheat the rolls (hot-rolls) to above 30°C. The preheated rolls can effectively reduce the drastic temperature drop when the workpiece comes into contact with the cold rolls, which is beneficial for stabilizing the rolling force, suppressing the thickness bounce of the sheet, and improving the dimensional accuracy of the final product.
[0020] In this invention, the plate after solution treatment is subjected to strict control of the furnace transfer time (≤3min) and quenching cooling rate / time to ensure that the high-temperature microstructure is rapidly frozen, effectively suppressing the precipitation of harmful second phases and excessive growth or coarsening of grains, thereby obtaining the desired uniform microstructure and excellent comprehensive properties.
[0021] Compared to traditional multi-pass or tempering processes for ultra-wide and ultra-long nickel-based superalloy sheets, the process of this invention can mitigate the adverse effects of anisotropy in ultra-wide and ultra-long sheets, significantly reduce rolling time, and, with the addition of hot-rolling technology, effectively increase the sheet temperature during and after rolling, thereby increasing the reduction per pass and resulting in greater deformation and a more uniform sheet microstructure. Higher rolling temperatures reduce edge cracking and decrease the number of passes or tempering, thus lowering production costs and cycle time. Furthermore, time control during solution treatment can further improve the microstructure uniformity and mechanical properties of the sheet.
[0022] This invention, through systematic optimization of slab design, rolling process (reversal, timing, hot rolling, and pressing), and solution quenching regime, successfully solves the core problems in the preparation of large-size nickel-based high-temperature alloy plates, such as rapid temperature drop, easy cracking, uneven microstructure, and difficulty in dimensional control. It achieves efficient and stable production of ultra-wide and ultra-long plates with high uniformity, a thickness of 10mm~30mm, a width of 1300mm~2300mm, and a length of 6000mm~8000mm, significantly improving the yield and reducing production costs. Attached Figure Description
[0023] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0024] Figure 1This is a flowchart of the preparation method of the highly uniform, ultra-wide and ultra-long nickel-based high-temperature alloy plate of the present invention.
[0025] Figure 2 This is a schematic diagram of the first-fire rolling widening and the second-fire rolling growth of the present invention.
[0026] Figure 3 This is a metallographic structure (level 5) diagram of Embodiment 1 of the present invention.
[0027] Figure 4 This is a metallographic structure (grade 3.5, locally coarse-grained) diagram of Comparative Example 1 of the present invention. Detailed Implementation
[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.
[0029] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.
[0030] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0031] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.
[0032] Reference Figure 1 As shown, a method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate includes: Step S1: Provide a nickel-based high-temperature alloy slab, heat the nickel-based high-temperature alloy slab in one heat, and perform a hot rolling treatment on the rolls before the one heat rolling.
[0033] In this embodiment, the finished thickness of the nickel-based superalloy sheet is x, the finished width is y, and the finished length is z. The nickel-based superalloy slab is designed with a thickness of X, a width of Y, and a length of Z.
[0034] The finished nickel-based high-temperature alloy plate has a thickness x of 10mm~30mm, a width y of 1300mm~2300mm, and a length z of 6000mm~8000mm. The thickness (X) of the nickel-based superalloy slab is 100mm~170mm, the width (Y) is 850mm~1500mm, and the length (Z) is 2000mm~2500mm. Furthermore, considering the losses during machining and finished product cutting, the slab volume needs to be calculated during design. The volume of the nickel-based superalloy slab is 1.1~1.4 times the volume of the finished nickel-based superalloy sheet. The slab thickness design needs to consider the width that can be achieved after the first rolling process, including the allowance for width extension. The thickness after the first rolling process should also be 2~5 times the thickness of the finished product, because sufficient deformation is required during the second rolling process to refine the grains.
[0035] In this embodiment, a triple melting process is employed to obtain ingots with high purity and uniform composition, wherein the chemical composition of the ingots meets the requirements of the relevant grade of ingots. The triple melting process involves vacuum induction melting (VIM), electroslag remelting (ESR), and vacuum arc remelting (VAR).
[0036] Nickel-based high-temperature alloy slabs were prepared by high-temperature homogenization of ingots, forging, re-forging and forming, and the surface oxide scale was removed by machining.
[0037] Specifically, the high-temperature homogenization treatment of the ingot involves heating the ingot to 1150℃~1250℃ using a three-stage heating method and holding it at that temperature for 30~80 hours. Forging, reforging, and forming refer to heating the ingot after the high-temperature homogenization treatment and preparing the designed slab with uniform microstructure through billet preparation, reforging, and slab forming.
[0038] Specifically, single-heating refers to heating a nickel-based high-temperature alloy slab at a temperature of 1100℃~1200℃ with a holding coefficient of 1.5min / mm~2.0min / mm.
[0039] Specifically, the hot roll treatment refers to the need to plan and arrange 3 to 5 production billets to be hot rolled before the slab is rolled out of the furnace. The thickness of the production billet is 50mm to 300mm, the length is 1000mm to 3000mm, the width is 1000mm to 2000mm, the rolling temperature is not lower than 900℃, and after the production billet is rolled, it is oscillated on the roller table for 10min to 15min to make the roll temperature reach above 30℃ before the nickel-based high-temperature alloy slab is rolled in one heat.
[0040] One-fire rolling is performed, in which the nickel-based high-temperature alloy slab heated in one fire is rolled along the first direction, which is the width direction of the original slab, so that the size of the plate after one-fire rolling in the first direction reaches the target width, and a semi-finished nickel-based high-temperature alloy plate is obtained. Step S2: Perform single-heat rolling, rolling the nickel-based superalloy slab after single-heat heating along the first direction, referring to... Figure 2 As shown, the first direction is the width direction of the original slab, so that the size of the plate after one-fire rolling reaches the target width in the first direction, and a semi-finished nickel-based high-temperature alloy plate is obtained.
[0041] Furthermore, during single-heat rolling, the transfer time from the first-heated nickel-based superalloy slab to the rolls is less than 40 seconds, and the single-heat rolling speed is 3 m / s to 5 m / s. During the single-heat rolling process, the rolling speed is controlled by first slowing down the feed, then increasing the rolling speed, and then gradually decreasing the rolling speed to reduce the ejection time of the slab or sheet during the rolling process (referring to the time from when the slab leaves the rolls at the end of the rolling process to when it stops on the roll table). In this embodiment, during single-heat rolling, the slab feed speed is 1.5 m / s to 3 m / s, the rolling speed is increased to 3 m / s to 5 m / s after the slab feeds, and the rolling speed is reduced when the rolling is about to end so that the slab ejection speed is no more than 2 m / s.
[0042] Specifically, during single-pass rolling, when the slab thickness is 100~170mm, the reduction per pass is 8~12mm; when the slab thickness is 50~100mm, the reduction per pass is 5~10mm; when the slab thickness is below 50mm, the reduction per pass is 1~5mm; the rolling time for each pass does not exceed 15s; the final rolling temperature is ≥900℃; the width of the plate after single-pass rolling is (y+a1)mm, and the single-pass rolling is completed, where y is the finished width, a1 is the width machining allowance, and a1 ranges from 50mm to 150mm.
[0043] Specifically, this also includes grinding the semi-finished nickel-based superalloy sheet obtained in step S2. Grinding involves removing defects from the surface of the semi-finished nickel-based superalloy sheet to prevent further expansion of defects during the second rolling process, which could affect the surface quality of the finished sheet.
[0044] Step S3: The semi-finished nickel-based high-temperature alloy sheet is subjected to a second heating process, and the rolls are hot-rolled before the second heating process.
[0045] Specifically, the second heating refers to heating the semi-finished nickel-based high-temperature alloy plate at a temperature of 1050℃~1180℃ with a holding coefficient of 1.2min / mm~1.8min / mm.
[0046] Furthermore, "hot rolling" refers to the process of arranging 3 to 5 production billets to be hot rolled before the billets are rolled out of the furnace. The production billets have a thickness of 50mm to 300mm, a length of 1000mm to 3000mm, and a width of 1000mm to 2000mm. The rolling temperature is not lower than 900℃. After the production billets are rolled, they are oscillated on the roller table for 10 to 15 minutes to allow the roller temperature to reach above 30℃ before the semi-finished sheet is rolled again.
[0047] Step S4: Perform secondary heating rolling. Roll the semi-finished nickel-based superalloy sheet after secondary heating along the second direction, referring to... Figure 2 As shown, the second direction is the length direction of the original slab, so that the thickness of the plate after the second rolling reaches the target thickness, and the finished nickel-based high-temperature alloy plate is obtained.
[0048] Furthermore, during the second-heat rolling process, the transfer time from the semi-finished nickel-based superalloy sheet heated in the second heat to the rolls is less than 40 seconds. The second-heat rolling speed is 3 m / s to 5 m / s. During the second-heat rolling process, the rolling speed is controlled by first slowing down the feed, then increasing the rolling speed, and then gradually decreasing the rolling speed to reduce the ejection time of the slab or sheet during the rolling process (referring to the time from when the sheet leaves the rolls at the end of the rolling process to when it stops on the roller table). In this embodiment, during the second-heat rolling process, the feed speed of the sheet is 1.5 m / s to 3 m / s. After the sheet is fed in, the rolling speed is increased to 3 m / s to 5 m / s. The rolling speed is reduced when the rolling is about to end so that the ejection speed of the sheet is no more than 2 m / s.
[0049] Furthermore, during the rolling process, when the billet thickness is 50~100mm, the reduction per pass is 5~10mm; when the thickness is below 50mm, the reduction per pass is 1~8mm; the rolling time for each pass does not exceed 18s; the final rolling temperature is ≥850℃, and the thickness of the plate after two-fire rolling is (x+a2)mm, where x is the finished thickness, a2 is the thickness machining allowance, and a2 ranges from 0.5mm to 2mm.
[0050] Furthermore, after rolling, the finished nickel-based superalloy sheet is subjected to solution treatment, straightening, surface treatment, and finished product cutting.
[0051] Furthermore, it also includes solution quenching of the finished nickel-based high-temperature alloy sheet rolled by two heat treatments, including heating the sheet after two heat treatments to 1000~1200℃ with a holding coefficient of 0.5~1.2min / mm, then taking it out of the furnace for quenching, with the transfer time after taking it out of the furnace not exceeding 3min, the quenching time being 5~30min, and the surface temperature after taking it out of the water being below 100℃, thus completing the solution treatment.
[0052] Furthermore, after the plate has undergone solution hardening and quenching, it is straightened, and then subjected to surface treatments such as water grinding, re-grinding, and whole-plate polishing to remove oxide scale and defects. Finally, the finished plate is cut to the specifications of the finished plate using a water jet cutter, namely the finished thickness x, the finished width y, and the finished length z.
[0053] Using the above method, a reasonable slab specification is first designed, and a process of widening by rolling in one pass and lengthening by rolling in two passes is adopted to obtain large-size finished plates. Before rolling, the rolls are preheated using hot rollers, and then the furnace exit time and the rolling time for each pass are precisely controlled. The intermediate reversal process is eliminated by reversing the direction of the rolling passes. Since the slab temperature is high immediately after exiting the furnace, a high-reduction rolling process is adopted during rolling, with the rolling speed gradually decreasing to reduce the ejection time during rolling. This significantly reduces the plate rolling time, thereby increasing the final rolling temperature. After rolling, the plate undergoes solution heat treatment, and the furnace transfer time and water cooling time are controlled to allow for rapid cooling, resulting in nickel-based alloy plates with a highly uniform microstructure. This method can produce highly uniform, ultra-wide, and ultra-long nickel-based high-temperature alloy plates with a thickness of 10mm–30mm, a width of 1300mm–2300mm, and a length of 6000mm–8000mm.
[0054] Example 1 A method for preparing highly uniform, ultra-wide, and ultra-long nickel-based superalloy plates includes the following steps: S1: Slab design.
[0055] The target dimensions for an N06617 nickel-based high-temperature alloy sheet are a thickness of 15 mm, a width of 2000 mm, and a length of 7000 mm. The slab dimensions can be designed to be a thickness of 110 mm, a width of 1000 mm, and a length of 2260 mm.
[0056] S2: Based on the slab designed in S1, calculate the weight of the cast ingot, mix the raw materials required for the nickel-based high-temperature alloy ingot, press them into several electrode blocks, weld them into a whole round electrode, and then prepare a high-temperature alloy ingot with high purity and uniform composition through VIM+ESR+VAR (vacuum induction + electroslag remelting + vacuum self-consumption) triple melting. The chemical composition of the ingot meets the requirements of the chemical composition of grade N06617 ingot. S3: The high-temperature alloy ingot obtained in step S2 is subjected to multi-fire forging, including high-temperature homogenization treatment of the ingot, and forging of blank, modified forging and slab forming to obtain the alloy slab designed in S1. The oxide scale on the surface of the slab is removed by machining to obtain the final slab with a thickness of 110mm, a width of 1000mm and a length of 2260mm.
[0057] S4: The shaped alloy slab obtained in step S3 is heated and rolled in one pass. The heating regime for the one-pass rolling of the slab is to hold at 1190℃ for 180 minutes; before rolling, three production slabs are arranged to be rolled on rolling rollers. The thickness of the production slab is 200mm, the length is 2000mm, and the width is 1800mm. The rolling temperature of the production slab is 920℃. After rolling the production slab and oscillating it on the roller table for 15 minutes, the temperature of the rollers is measured to be 38℃, and then the nickel-based high-temperature alloy slab is rolled out of the furnace. 35 seconds after the slab exits the furnace, the rolling speed is 3.3 m / s. Rolling begins at the mill opening, with the long side of the slab (2260 mm) as the width direction. The slab is then laterally widened during rolling, with reductions of 10 mm, 10 mm, 10 mm, 10 mm, 10 mm, and 8 mm per pass. The rolling times for each pass are 8 seconds, 8 seconds, 9 seconds, 12 seconds, 14 seconds, and 14 seconds, respectively. After one pass, the final rolling temperature is 1032℃, and the resulting sheet has the following dimensions: thickness: 53 mm; width: 2075 mm; length: 2260 mm. It should be noted that during actual rolling, due to the high deformation resistance of high-temperature alloy sheets, sheet springback occurs, meaning the actual thickness after rolling may exceed the set roll gap value. Therefore, depending on the high-temperature alloy and the final rolled thickness, the thickness springback value is approximately 0.5 to 2 mm.
[0058] S5: The semi-finished board obtained in step S4 is cut and the cracks are polished. The specifications of the board after cutting and polishing the cracks are: thickness: 52.5mm, width: 2075mm, length: 2260mm.
[0059] S6: The semi-finished sheet obtained in step S5 is heated and rolled twice to obtain the finished sheet. The sheet is heated to 1170℃ during the second rolling process and held at that temperature for 80 minutes. Before rolling, three production sheet blanks are prepared for rolling on hot rollers. The thickness of the production blank is 200mm, the length is 2000mm, and the width is 1800mm. The rolling temperature of the production blank is 920℃. After rolling the production blank, it is oscillated on the roller table for 15 minutes. The roller temperature is measured to be 37℃, and then the nickel-based high-temperature alloy slab is rolled out of the furnace. Thirty-one seconds after the slab exits the furnace, at a rolling speed of 3.3 m / s, rolling begins at the mill mouth. The slab is rolled longitudinally with a width of 2075 mm as the guide width. The reduction per pass is 10 mm, 8 mm, 6 mm, 6 mm, 4 mm, and 3.5 mm; the rolling time per pass is 13 s, 14 s, 14 s, 15 s, 16 s, and 17 s. After the second rolling process, the final rolling temperature is 923℃. The resulting sheet has a thickness of 16.1 mm, a width of 2102 mm, and a length of 7274 mm.
[0060] S7: After rolling, the sheet material obtained in step S6 is heated to 1170℃ in an annealing furnace. Once the furnace is warmed, timing begins, and the material is held at that temperature for 15 minutes. Before removing it from the furnace, the quenching mechanism is activated with the flow rate at maximum. After removal, the sheet material enters the quenching zone for cooling at the highest speed of the furnace rollers. The sheet material transfer time is 0.5 minutes, the quenching time is 10 minutes, and the surface temperature after quenching is 9℃. After surface treatments such as water grinding and finishing to remove oxide scale, the finished sheet material is finally cut to the specified dimensions using a water jet cutter: thickness 15mm, width 2000mm, and length 7000mm.
[0061] The microstructure of finished boards is as follows Figure 3 As shown in Table 1, the properties of the sheet material are as follows.
[0062] Example 2 A method for preparing an ultra-wide and ultra-long nickel-based superalloy plate with high microstructure uniformity includes the following steps: S1: Slab design.
[0063] A GH3625 nickel-based high-temperature alloy sheet has a target size of 20 mm in thickness, 1450 mm in width, and 6800 mm in length. Based on the formula, the slab dimensions are designed to be 140 mm in thickness, 850 mm in width, and 2000 mm in length.
[0064] S2: Based on the slab size specifications designed in S1, calculate the weight of the cast ingot, mix the raw materials required for the nickel-based high-temperature alloy ingot, press them into several electrode blocks, weld them into a whole round electrode, and then prepare a high-temperature alloy ingot with high purity and uniform composition through VIM+ESR+VAR (vacuum induction + electroslag remelting + vacuum self-consumption) triple melting. The chemical composition of the ingot meets the requirements of the chemical composition of GH3625 grade ingot. S3: The GH3625 high-temperature alloy ingot obtained in step S2 is subjected to multi-fire forging, including high-temperature homogenization treatment of the ingot, and forging of blank, modified forging and slab forming to obtain the alloy slab designed in S1. The oxide scale on the surface of the slab is removed by machining to obtain the final slab with a thickness of 140mm, a width of 850mm and a length of 2000mm.
[0065] S4: After surface treatment, the shaped alloy slab obtained in step S3 is heated and rolled in one heat. The heating regime for the slab during one heat rolling is to hold at 1150℃ for 210 minutes. Before rolling, three slabs of production sheet are arranged to be rolled with hot rollers. The production billet has a thickness of 200mm, a length of 2000mm, and a width of 1400mm. The rolling temperature of the production billet is 960℃. After the production billet is rolled and oscillated on the roller table for 15 minutes, the roll temperature is measured at 35℃. Then, the billet is rolled from the furnace to form a nickel-based high-temperature alloy slab. The slab reaches the mill mouth 30 seconds after exiting the furnace and begins rolling at a speed of 3.3m / s. The slab is laterally widened with the long side of 2000mm as the width direction. The reduction per pass is: 10mm, 10mm, 10mm, 10mm, 9mm, 9mm, 7mm; the rolling time per pass is 7s, 8s, 8s, 10s, 10s, 13s, 13s. After one pass, the final rolling temperature is 927℃. The specifications of the rolled plate are: thickness: 76.5mm, width: 1560mm, length: 2000mm.
[0066] S5: Grind the semi-finished board obtained in step S4. The specifications of the board after grinding the cracks are: thickness: 75.5mm, width: 1560mm, length: 2000mm.
[0067] S6: The semi-finished sheet obtained in step S5 is heated and rolled twice to obtain the finished sheet. The sheet is heated to 1150℃ during the second rolling process and held at that temperature for 90 minutes. Before rolling, three production sheet blanks are prepared for rolling on hot rollers. The thickness of the production blank is 180mm, the length is 2300mm, and the width is 1600mm. The rolling temperature of the production blank is 980℃. After rolling the production blank, it is oscillated on the roller table for 15 minutes. The roller temperature is measured to be 39℃, and then the nickel-based high-temperature alloy slab is rolled out of the furnace. Thirty-one seconds after the slab exits the furnace, at a rolling speed of 3.3 m / s, rolling begins at the mill mouth. Following exiting the furnace, the slab is longitudinally rolled with a width of 1560 mm. The reduction per pass is 10 mm, 8 mm, 8 mm, 8 mm, 6 mm, 6 mm, 5 mm, and 4 mm, with rolling times of 10 s, 10 s, 11 s, 12 s, 12 s, 15 s, 15 s, and 16 s respectively. The second rolling process is completed at a final rolling temperature of 907℃. The resulting sheet metal after the second rolling process has a thickness of 21.3 mm, a width of 1583 mm, and a length of 7068 mm.
[0068] S7: After rolling, the sheet material obtained in step S6 is heated to 1120℃ in an annealing furnace and then loaded into the furnace. Timing begins after reaching the heating temperature, and the material is held at that temperature for 22 minutes. Before exiting the furnace, the quenching mechanism is activated with the flow rate at maximum. After exiting the furnace, the sheet material enters the quenching zone for cooling at the highest speed of the furnace rollers. The sheet material transfer time is 2 minutes, the quenching time is 15 minutes, and the surface temperature after quenching is 19℃. Afterwards, surface treatments such as straightening and water grinding are performed to remove the oxide scale. Finally, the finished sheet material is cut to the specified dimensions using a water jet cutter: thickness 20mm, width 1450mm, and length 6800mm.
[0069] The properties of the finished boards are shown in Table 1.
[0070] Example 3 A method for preparing an ultra-wide and ultra-long nickel-based superalloy plate with high microstructure uniformity includes the following steps: S1: Slab design.
[0071] A target size for a GH3536 nickel-based high-temperature alloy sheet is 27mm thick, 1500mm wide, and 6100mm long. According to the formula, the slab dimensions can be designed to be 155mm thick, 900mm wide, and 2100mm long.
[0072] S2: Based on the slab designed in S1, calculate the weight of the cast ingot, mix the raw materials required for the nickel-based high-temperature alloy ingot, press them into several electrode blocks, weld them into a whole round electrode, and then prepare a high-temperature alloy ingot with high purity and uniform composition through VIM+ESR+VAR (vacuum induction + electroslag remelting + vacuum self-consumption) triple melting. The chemical composition of the ingot meets the requirements of the chemical composition of GH3536 grade ingot. S3: The GH3536 high-temperature alloy ingot obtained in step S2 is subjected to multi-fire forging, including high-temperature homogenization treatment of the ingot, and forging of blank, modified forging and slab forming to obtain the alloy slab designed in S1. The oxide scale on the surface of the slab is removed by machining to obtain the final slab with a thickness of 155mm, a width of 900mm and a length of 2100mm.
[0073] S4: After surface treatment, the shaped alloy slab obtained in step S3 is heated and rolled in one heat. The heating regime for the slab during one heat rolling is to hold at 1150℃ for 240 minutes. Before rolling, three slabs of production sheet are arranged to be rolled with hot rollers. The production billet has a thickness of 240mm, a length of 2300mm, and a width of 1740mm. The rolling temperature of the production billet is 940℃. After the production billet is rolled and oscillated on the roller table for 15 minutes, the roll temperature is measured to be 39℃. Then, the billet is rolled into a nickel-based high-temperature alloy slab. 32 seconds after exiting the furnace, the rolling speed is 3.3m / s, and rolling begins at the mill mouth. The slab is laterally widened with the long side of 2100mm as the width direction. The reduction per pass is: 10mm, 10mm, 10mm, 9mm, 9mm, 8mm, 7mm, 5mm. The rolling time per pass is 8s, 8s, 10s, 10s, 11s, 11s, 12s, 14s. After the first rolling process, the final rolling temperature was 912℃. The rolled plate specifications were: thickness: 87.6mm, width: 1592mm, length: 2100mm.
[0074] S5: The semi-finished board obtained in step S4 is cut and the cracks are polished. The specifications of the board after cutting and polishing the cracks are: thickness: 87mm, width: 1592mm, length: 2100mm.
[0075] S6: The semi-finished sheet obtained in step S5 is heated and rolled twice to obtain the finished sheet. The sheet is heated to 1110℃ during the second rolling process and held at that temperature for 130 minutes. Before rolling, three production sheet blanks are prepared for rolling and heating on the rollers. The thickness of the production blank is 280mm, the length is 1600mm, and the width is 1500mm. The rolling temperature of the production blank is 960℃. After rolling the production blank, it is oscillated on the roller table for 15 minutes. The roller temperature is measured to be 46℃, and then the nickel-based high-temperature alloy slab is rolled out of the furnace. Thirty-four seconds after exiting the furnace, the slab is rolled at a speed of 3.3 m / s until it reaches the mill mouth. After exiting the furnace, the slab is longitudinally rolled with a width of 1592 mm. The reduction per pass is 10 mm, 10 mm, 8 mm, 7 mm, 7 mm, 6 mm, 6 mm, and 5.5 mm; the rolling time per pass is 10 s, 10 s, 12 s, 13 s, 13 s, 15 s, 15 s, and 17 s. The second rolling process is completed at a final rolling temperature of 914℃. The dimensions of the plate after the second rolling process are: thickness 28.2 mm, width 1630 mm, and length 6327 mm.
[0076] S7: After rolling, the sheet material obtained in step S6 is heated to 1120℃ in an annealing furnace. Once the furnace is warmed, timing begins, and the material is held at that temperature for 28 minutes. Before removing it from the furnace, the quenching mechanism is activated with the flow rate at maximum. After removal, the sheet material enters the quenching zone for cooling at the highest speed of the furnace rollers. The sheet material transfer time is 2 minutes, the quenching time is 20 minutes, and the surface temperature after quenching is 16℃. Following this, surface treatments such as straightening and water grinding are performed to remove the oxide scale. Finally, the finished sheet material is cut to the specified dimensions using a water jet cutter: thickness 27mm, width 1500mm, and length 6100mm.
[0077] Comparative Example 1 The target dimensions of the sheet metal required for a N06617 nickel-based superalloy are 15mm thick, 2000mm wide, and 7000mm long. A slab with the same dimensions of 110mm thick, 1000mm wide, and 2260mm long is used. Based on the designed slab, the weight of the ingot to be cast is calculated. The raw materials required for the nickel-based superalloy ingot are mixed and pressed into several electrode blocks, then welded into a complete round electrode. The ingot is then prepared by a triple melting process of VIM+ESR+VAR (vacuum induction remelting + electroslag remelting + vacuum arc remelting). The slab is then forged using the same process as in Example 1 to obtain the slab. The resulting shaped alloy slab is then surface-treated, heated, and rolled in one heat. The resulting one-heat rolled semi-finished sheet is then polished to remove cracks. The polished semi-finished sheet is then heated and rolled in a second heat to obtain the finished sheet. The sheet is annealed in an annealing furnace. After surface treatments such as water grinding and polishing to remove the oxide scale, the finished boards are finally cut to the specified dimensions using a water jet cutter: 15mm thickness, 2000mm width, and 7000mm length. The microstructure is as follows: Figure 4 As shown in Table 1, the properties of the sheet material are as follows.
[0078] Table 1 Mechanical properties of the solution-treated high-temperature alloy sheets in the examples and comparative examples
[0079] As can be seen from Table 1, compared with the plate of Comparative Example 1 with the conventional process, the plate of Example 1, after being rolled with a larger reduction, has improved tensile strength and yield strength at both room temperature and high temperature, and Example 1 has better plasticity. Figure 3 This is the microstructure of the nickel-based superalloy sheet after solution treatment in Example 1. Figure 4 The microstructure of the nickel-based superalloy sheet after solution treatment in Example 1 is similar to that in Comparative Example 1, both exhibiting equiaxed grain structures. However, Example 1 clearly shows a more uniform grain structure with no localized coarse grains and a grain size rating of 5, while Comparative Example 1 has a grain size rating of only 3.5 and contains a large number of coarse grains. Example 1, due to the use of reversible rolling and controlled final rolling temperature, allows for a greater reduction, resulting in complete grain breakage and a more uniform microstructure.
[0080] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate, characterized in that, include: A nickel-based high-temperature alloy slab is provided, the nickel-based high-temperature alloy slab is heated in one heat, and the rolls are hot-rolled before the one heat rolling. One-fire rolling is performed, in which the nickel-based high-temperature alloy slab heated in one fire is rolled along the first direction, which is the width direction of the original slab, so that the size of the plate after one-fire rolling in the first direction reaches the target width, and a semi-finished nickel-based high-temperature alloy plate is obtained. The semi-finished nickel-based high-temperature alloy sheet is subjected to a second heating process, and the rolls are hot-rolled before the second heating rolling. The semi-finished nickel-based high-temperature alloy sheet is rolled in a second direction, which is the length direction of the original slab, so that the thickness of the sheet after the second rolling reaches the target thickness, and the finished nickel-based high-temperature alloy sheet is obtained.
2. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based high-temperature alloy plate according to claim 1, characterized in that, During the first and second rolling processes, the rolling speed is controlled by first slowing down the feed, then increasing the rolling speed, and then gradually decreasing the rolling speed, in order to reduce the ejection time of the slab or plate during the rolling process.
3. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to claim 1, characterized in that, When performing first-pass rolling and second-pass rolling, the time from exiting the furnace to transferring the rolls should be less than 40 seconds, and the rolling time for each pass of first-pass rolling should not exceed 15 seconds and the rolling time for each pass of second-pass rolling should not exceed 18 seconds.
4. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based high-temperature alloy plate according to claim 1, characterized in that, The volume of the nickel-based superalloy slab is 1.1 to 1.4 times the volume of the finished nickel-based superalloy sheet, and the thickness of the semi-finished nickel-based superalloy sheet after the first rolling is 2 to 5 times the thickness of the finished nickel-based superalloy sheet, so as to ensure that the second rolling still has sufficient deformation and promotes grain refinement.
5. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to claim 4, characterized in that, The finished nickel-based high-temperature alloy plate has a thickness of 10mm~30mm, a width of 1300mm~2300mm, and a length of 6000mm~8000mm; The nickel-based high-temperature alloy slab has a thickness of 100mm~170mm, a width of 850mm~1500mm, and a length of 2000mm~2500mm.
6. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to claim 4 or 5, characterized in that, When performing single-pass rolling, the reduction per pass is 8-12mm when the slab thickness is 100-170mm; the reduction per pass is 5-10mm when the slab thickness is 50-100mm; and the reduction per pass is 1-5mm when the slab thickness is below 50mm. When performing two-pass rolling, the reduction per pass is 5-10mm when the plate thickness is 50-100mm; and the reduction per pass is 1-8mm when the plate thickness is less than 50mm.
7. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to any one of claims 4-6, characterized in that, The width of the semi-finished nickel-based high-temperature alloy plate after one-fire rolling is (y+a1) mm, where y is the finished width and a1 is the width machining allowance, and a1 ranges from 50 mm to 150 mm. The thickness of the semi-finished nickel-based high-temperature alloy plate after the second rolling is (x+a2) mm, where x is the finished thickness and a2 is the machining allowance, which ranges from 0.5 mm to 2 mm.
8. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to claim 1, characterized in that, Before the first rolling, the rolls are heated to a temperature of 30°C or higher before the nickel-based high-temperature alloy slab is rolled. Before the second rolling process, the rolls are heated to a temperature of 30°C or higher before the semi-finished nickel-based high-temperature alloy sheet is rolled again.
9. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to claim 8, characterized in that, Also includes: When hot-rolling the rolls before the first and second rolling processes, arrange 3 to 5 production billets for hot-rolling, and after rolling, oscillate the production billets on the roller table for 10 to 15 minutes, with the rolling temperature not lower than 900℃.
10. The method for preparing a highly uniform, ultra-wide, and ultra-long nickel-based superalloy plate according to claim 1, characterized in that, It also includes solution quenching of the finished nickel-based high-temperature alloy sheet rolled by two heat treatments. During solution quenching, the finished nickel-based high-temperature alloy sheet rolled by two heat treatments is heated to 1000℃~1200℃ with a holding coefficient of 0.5min / mm~1.2min / mm. Then it is taken out of the furnace for quenching. The transfer time after taking it out of the furnace shall not exceed 3 minutes, and the quenching time shall be 5 minutes~30 minutes. After taking it out of the water, the surface temperature of the sheet is below 100℃.