Preparation method of super-thin and super-wide nickel-based N10276 coiled sheet for cold deep drawing

Abstract

The application discloses a preparation method of an ultra-thin and ultra-wide nickel-based N10276 coiled plate for cold deep drawing, which comprises the following steps: ingredients of raw materials and smelting additives are prepared according to a weight ratio; vacuum induction smelting and electroslag remelting are sequentially performed on the raw materials and the smelting additives to obtain finished nickel-based N10276 ingots; the finished nickel-based N10276 ingots are forged for 2-3 times to become slabs, and then the slabs are subjected to hot continuous rolling, cold rolling and annealing to obtain finished nickel-based N10276 coiled plates with a thickness of 0.5-0.7 mm and a width of 1000-1219 mm. The method can completely produce the nickel-based N10276 coiled plates reaching the level of imported materials, and fills the domestic technical blank.

Description

Technical Field

[0001] This invention belongs to the field of metal material smelting and rolling technology, specifically relating to a method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing. Background Technology

[0002] Hastelloy N10276 (Hastelloy C-276) is a tungsten-containing nickel-chromium-molybdenum alloy, often referred to as "super stainless steel" among corrosion-resistant materials. This batch has extremely low silicon and carbon content; its chemical composition primarily consists of 15% Cr, 15% Mo, and 60% Ni, with small amounts of Fe (4%-7%), W (3%-4.5%), and Co (≤2.5%). The nickel in the alloy can dissolve large amounts of Fe, Cr, Mo, Cu, and W to form solid solutions, and it can also form stable austenite with Fe and Cr, serving as the matrix for the corrosion-resistant alloy. Furthermore, this alloy exhibits stronger corrosion resistance than iron in media containing halogens, caustic alkalis, and reducing acids, and it maintains a stable austenitic structure at both room temperature and high temperatures. This alloy is mainly used in equipment, containers, and pipelines used in strongly reducing and strongly oxidizing-reducing corrosive media, as well as in seawater environments. In highly corrosive media, its surface forms a dense, stable, and extremely corrosion-resistant protective film, resisting the erosion of the metal by the corrosive media. It is suitable for various chemical process industries containing oxidizing and reducing media. The high molybdenum and chromium content in the alloy enables it to resist chloride ion corrosion, while tungsten further enhances its corrosion resistance. Furthermore, Hastelloy is one of the few materials capable of resisting corrosion from moist chlorine gas, hypochlorites, and chlorine dioxide solutions, and exhibits significant resistance to high concentrations of chloride salt solutions (such as ferric chloride and copper chloride). In addition, the alloy also possesses excellent resistance to pitting corrosion, crevice corrosion, and stress corrosion cracking.

[0003] Nickel-based N10276 for cold deep drawing is a special-purpose material. It requires pressing sheets (typically 0.6mm thick) into various shapes such as corrugations, corner holes, and sealing grooves. The stamping depth is generally between 4 and 6mm, resulting in dense stamping patterns. Therefore, nickel-based N10276 coils for this application have extremely high requirements for dimensional accuracy, cold bending, and cold stamping performance.

[0004] According to research and feedback from leading domestic heat exchange companies such as Lanzhou Petrochemical Heat Exchanger and Siping Juyuan, the current demand for Hastelloy N10276 cold deep-drawing coils in my country is 50-60 tons per year. However, my country currently lacks the production technology for this product and all products are purchased from Hastelloy, ATI, VDM, and Nippon Yakin, etc., resulting in high prices (ranging from RMB 380,000 to RMB 420,000 per ton) and long delivery times (August to October). Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing. The technical problem to be solved by this invention is achieved through the following technical solution:

[0006] A method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing includes:

[0007] Step 1: Mix the raw materials according to the following weight ratio: metallic chromium 15.5~16.2%; pure iron 4.5~6.5%; nickel-molybdenum alloy 15.5~16.3%; nickel-tungsten alloy 3.4~4.0%; nickel-manganese alloy 0.5~0.8%; the remainder is electrolytic nickel;

[0008] Based on the total weight of the raw materials, smelting additives are added in the following weight ratios: nickel-magnesium alloy 0.5~0.6%; borax 0.005~0.1%; sponge titanium 0.1~0.15%; pure aluminum 0.05~0.1%; lanthanum-cerium rare earth alloy 0.015~0.02%, wherein the lanthanum content accounts for 60~66% and the cerium content accounts for 34~40%.

[0009] Step 2: Add the raw materials and smelting additives described in Step 1 to a vacuum induction furnace for vacuum induction smelting to obtain the first semi-finished product, nickel-based N10276 ingot.

[0010] Step 3: After sawing off the head and tail of the first semi-finished nickel-based N10276 ingot, place it in an electric resistance furnace for baking to obtain the second semi-finished nickel-based N10276 ingot; wherein, the baking temperature is 400~500℃ and the baking time is ≥7h.

[0011] Step 4: Electroslag remelting the second semi-finished nickel-based N10276 ingot, cooling it, and then cutting off the riser and bottom to obtain the finished nickel-based N10276 ingot;

[0012] Step 5: Heat the finished nickel-based N10276 ingot to 950~1000℃, hold for 4.5~5.5h, and then continue heating to 1200~1260℃ at a heating rate ≤100℃ / 60min, hold for 6~8h, and then remove from the furnace for multi-fire forging to obtain a nickel-based N10276 slab with a thickness of 110~120mm, a width of 1050~1260mm, and a length ≥4000mm;

[0013] Step 6: Heat the nickel-based N10276 slab to 1250~1330℃, hold for 130~170min, then dephosphorize under high pressure, and then perform rough rolling to roll the thickness of the nickel-based N10276 slab to 33~37mm. Then heat it to 1180~1220℃. After the slab temperature drops to 1140~1160℃, immediately perform hot continuous rolling. After hot rolling, perform continuous annealing to obtain a nickel-based N10276 hot coil with a thickness of 4.0~4.5mm and a width of 1040~1250mm.

[0014] Step 7: Cold roll the nickel-based N10276 hot roll to obtain a semi-finished nickel-based N10276 coil with a thickness of 0.5~0.7mm and a width of 1000~1219mm;

[0015] Step 8: After continuous annealing of the semi-finished nickel-based N10276 coil under inert atmosphere protection, it is rapidly air-cooled to obtain the finished nickel-based N10276 coil.

[0016] Further, step 2 includes:

[0017] Step 2.1: Electrolytic nickel, metallic chromium, pure iron, nickel-molybdenum alloy, nickel-tungsten alloy, and nickel-manganese alloy are sequentially added into the vacuum induction furnace and heated until they are completely melted to obtain liquid metal.

[0018] Step 2.2: Refine the liquid metal for 60-90 minutes. After refining, add nickel-magnesium alloy, borax, sponge titanium, pure aluminum, and lanthanum-cerium rare earth alloy to the liquid metal. When the furnace temperature reaches 1400-1430℃, pour the liquid metal to obtain the first semi-finished nickel-based N10276 ingot.

[0019] Further, in step 4, the slag material from the electroslag remelting comprises the following raw materials in the following mass ratios: calcium fluoride 64~66%; alumina: 14~16%; calcium oxide 14~16%; magnesium oxide 2.4~2.6%; titanium monoxide: 1.9~2.1%; lanthanum-cerium rare earth alloy: 0.4~0.6%.

[0020] Further, in step 5, the multi-fire forging process is as follows: after the billet from the first fire is put into the furnace and covered with a heat-insulating sleeve, it is put back into the furnace and kept warm for 1 to 1.5 hours before being forged into a square billet; then the square billet is returned to the furnace for reheating for 1 to 1.5 hours before being put into the furnace again and covered with a heat-insulating sleeve. After a pad preheated to 1170 to 1230°C is laid on its upper surface, it is subjected to 1 to 2 fires of constant temperature forging to obtain the nickel-based N10276 slab.

[0021] Furthermore, in step 6, the continuous annealing temperature is 1160~1200℃, and the annealing rate is 5.3~5.7m / min.

[0022] Furthermore, in step 7, when the deformation of the nickel-based N10276 hot-rolled coil is 50-60%, intermediate continuous annealing is performed at a temperature of 1080-1120℃ and an annealing speed of 0.8-1.2m / min.

[0023] Furthermore, in step 8, the continuous annealing temperature is 1130~1160℃, the annealing rate is 2.0~2.5m / min, and the entire annealing process is carried out under an argon protective atmosphere.

[0024] The beneficial effects of this invention are:

[0025] 1. A composite additive consisting of nickel-magnesium alloy, borax, sponge titanium, pure aluminum, and lanthanum-cerium rare earth alloy is used as an alloy ingot for degassing, impurity removal, grain refinement, and reduction of microstructure segregation. The ingot is then prepared through a two-step smelting process to improve dendritic segregation and produce a high-purity alloy ingot with interstitial element O≤20ppm, N≤50ppm, and impurity elements such as S, P, and H ≤10ppm, exhibiting excellent forgeability.

[0026] 2. By using constant temperature forging, heat loss during the forging process is reduced, and the temperature of the billet remains basically constant during the forging process, thereby reducing the original 6-7 forging passes to 2-3 passes.

[0027] 3. Through the process technology of this patented series, nickel-based N10276 coils and sheets that meet the level of imported materials can be produced, pointing the way for the localization of this type of product. Attached Figure Description

[0028] Figure 1 Photograph of nickel-based N10276 ingot obtained by electroslag remelting in an embodiment of the present invention;

[0029] Figures 2-5 Elemental composition test report of the finished nickel-based N10276 ingot prepared according to an embodiment of the present invention;

[0030] Figure 6 This is a photograph of the alloy slab after mechanical processing according to an embodiment of the present invention;

[0031] Figure 7 A photograph of a nickel-based N10276 hot roll prepared for an embodiment of the present invention;

[0032] Figures 8-10 Test report of nickel-based N10276 hot rolls prepared for embodiments of the present invention;

[0033] Figure 11 This is a photograph of the cold rolling process of nickel-based N10276 hot-rolled coil in an embodiment of the present invention;

[0034] Figures 12-13 A photograph of the finished nickel-based N10276 coil prepared for an embodiment of the present invention;

[0035] Figures 14-16 The test report for the finished nickel-based N10276 coil prepared according to the embodiments of the present invention;

[0036] Figure 17 Photograph of a plate heat exchanger manufactured using the nickel-based N10276 coil prepared according to the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0038] Example 1

[0039] This invention provides a method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing. The prepared nickel-based N10276 coils have a thickness of 0.6 mm and a width of 1219 mm.

[0040] Specifically, the preparation method includes:

[0041] Step 1: Prepare the raw materials according to the following weight ratio: 15.8% metallic chromium; 5.5% pure iron; 15.8% nickel-molybdenum alloy; 3.7% nickel-tungsten alloy; 0.8% nickel-manganese alloy; the remainder is electrolytic nickel; wherein, the electrolytic nickel is Ni9996, the pure iron is YF01, the nickel-molybdenum alloy is Ni45Mo, the nickel-tungsten alloy is Ni42W, and the nickel-manganese alloy is Ni50Mn.

[0042] Based on the total weight of the raw materials, the following smelting additives are added in the following weight ratios: 0.5% nickel-magnesium alloy; 0.01% borax; 0.15% sponge titanium; 0.1% pure aluminum; 0.015% lanthanum-cerium rare earth alloy, wherein the lanthanum-cerium rare earth alloy is La35Ce; and the nickel-magnesium alloy is Ni20Mg.

[0043] Step 2: Add the raw materials and smelting additives described in Step 1 to a vacuum induction furnace for vacuum induction smelting to obtain the first semi-finished product, nickel-based N10276 ingot.

[0044] The mold used in vacuum induction melting is a steel mold with a diameter of Ф540×2300mm. The total amount of material fed is 5200kg. All billets must be kept clean and dry before being loaded into the furnace for melting. The steel is then fully refined and degassed in the high vacuum furnace. Finally, N10276 primary ingots with a single weight of about 5 tons are cast, which are electroslag remelting electrodes.

[0045] Step 2 specifically includes the following steps:

[0046] Step 2.1: Electrolytic nickel, metallic chromium, pure iron, nickel-molybdenum alloy, nickel-tungsten alloy, and nickel-manganese alloy are sequentially added to the vacuum induction furnace and heated until they are completely melted to obtain liquid metal.

[0047] After loading the furnace, the vacuum induction furnace is evacuated. Once the vacuum level is ≤5Pa, the temperature is increased. Depending on the furnace type, the power of the vacuum induction furnace is slowly increased to the optimal melting power according to different heating regimes. For furnaces below 25kW, the power is increased to 25kW at a rate of 5kW / 5min. For furnaces above 35kW, the power is increased to 35kW at a rate of 5kW / 10min. During the melting process, the billet is melted under a high vacuum before it turns into liquid. The maximum vacuum level can reach 0.5Pa to fully degas the vacuum induction furnace. Once the billet begins to turn into liquid, the vacuum is maintained between 5 and 10Pa until all the billet turns into liquid metal.

[0048] Step 2.2: Close the main valve and refine the liquid metal for 75 minutes. If visibility inside the furnace is poor during refining, the main valve can be opened to remove volatiles. After refining, once the liquid surface is calm, heat the vacuum induction furnace. When the furnace temperature reaches 1400~1430℃, pour the liquid metal into the furnace. Complete the pouring within 3 minutes with a pouring power of 350~400kw. After pouring, open the ingot mold into the ingot mold chamber and allow it to cool for 30~40 minutes before removing it from the furnace to obtain the first semi-finished nickel-based N10276 ingot.

[0049] Step 3: After sawing off the head and tail of the first semi-finished nickel-based N10276 ingot and cleaning off the surface oxide layer, place it in an electric resistance furnace for baking to obtain the second semi-finished nickel-based N10276 ingot; wherein, the baking temperature is 400~500℃ and the baking time is ≥7h, thereby eliminating the coolant that seeps into the ingot during sawing and ensuring that there are no porosity inclusions in the subsequent finished product.

[0050] Step 4: Electroslag remelting the second semi-finished nickel-based N10276 ingot, cooling it, and then cutting off the riser and bottom to obtain the finished nickel-based N10276 ingot.

[0051] Specifically, the crystallizer used for remelting has a specification of Φ580 / Φ620×2300mm. During furnace loading, ensure electrode alignment, seal the upper fume hood, and then introduce high-purity argon gas into the furnace. When the oxygen content in the furnace is ≤0.01%, initiate the arc ignition, slag removal, transition section, stabilization remelting, and smelting filling processes. After remelting, cool the furnace for 100 minutes before removing the ingot. A photograph of the resulting nickel-based N10276 ingot is shown below. Figure 1 As stated above.

[0052] Specifically, the slag material during electroslag remelting includes: calcium fluoride, alumina, calcium oxide, magnesium oxide, titanium monoxide, and lanthanum-cerium rare earth alloy; the mass ratio of the slag material is: calcium fluoride 65%; alumina 15%; calcium oxide 15%; magnesium oxide 2.5%; titanium monoxide 2.0%; lanthanum-cerium rare earth alloy 0.5%.

[0053] Samples were taken from the finished nickel-based N10276 ingot, and the elemental compositions were obtained as shown in Table 1 and Table 2. Figures 2-5 As shown:

[0054] By using quenching and tempering agents such as borax, lanthanum-cerium rare earth alloy La35Ce, nickel-magnesium alloy, and sponge titanium, the purity of the alloy can be significantly improved, the segregation of carbides and other metallic compounds can be eliminated, and the oxygen content can be controlled below 20 ppm. During the atmosphere-protected electroslag remelting process, the constant melting rate and control of the alternating current in electroslag remelting are utilized to achieve the directional migration of impurity elements such as sulfur (S) and phosphorus (P), ensuring that the content of interstitial element O and other impurity elements such as S, P, and H are all ≤10 ppm. Ultimately, the purity of the alloy ingot reaches Class 1 level in the ASTM B574 standard, exhibiting excellent forgeability.

[0055] Step 5: Heat the finished nickel-based N10276 ingot to 980℃, hold it for 5 hours, and then continue heating it to 1220℃ at a heating rate of ≤100℃ / 60min. Hold it for 36 hours and then remove it from the furnace for two forging cycles to obtain a nickel-based N10276 slab with a thickness of 110mm, a width of 1260mm, and a length of ≥4000mm.

[0056] Before forging, the riser and bottom pad of the finished nickel-based N10276 ingot are thoroughly removed. The ingot is forged in a 100MN free forging press and heated in a 480KW box-type resistance furnace.

[0057] Specifically, the two-stage forging process is as follows: The finished nickel-based N10276 ingot is first heated to 1220℃, held at that temperature for 6.5 hours, then removed from the furnace and fitted with an insulating sleeve. It is then placed back into the furnace and held at that temperature for another hour before being forged. Through upsetting and drawing, it is squared to a thickness of 300mm and a width of 1250mm. This square billet is then returned to the furnace for reheating for 1 hour before being fitted with an insulating sleeve again. A preheated 1200℃ pad is placed on its upper surface before constant-temperature forging to obtain a nickel-based N10276 slab with a thickness of 110mm, a width of 1260mm, and a length ≥4000mm. By using a high-temperature protective pad and an insulating sleeve on the billet, heat loss during the process is reduced, ensuring that the billet temperature remains essentially constant during forging, thus reducing the original number of forging stages.

[0058] Then, the head, tail, and tongue portions of the alloy slab are mechanically cut off, the sides are machined and milled, and the surface is mechanically polished to obtain a smooth, flat, and regularly shaped billet. Figure 6 As shown, the strip undergoes 100% PT inspection to ensure it meets the requirements for continuous rolling. The specifications of the strip are: thickness 104mm, width 1250mm, and length ≥4000mm.

[0059] Step 6: Using a walking beam furnace, the nickel-based N10276 slab is heated to 1280℃, held for 150 minutes, and then subjected to high-pressure descaling. It is then rapidly fed into a 1780mm roughing mill for rough rolling, reducing the thickness of the nickel-based N10276 slab to 35mm. It is then sent to an induction heating chamber for further heating to 1200℃. Once the temperature display shows the slab temperature has dropped to 1150℃, it is immediately fed into the F1~F8 continuous rolling mills for hot rolling. After hot rolling, it is continuously annealed in an annealing line to soften and whiten the slab, resulting in a nickel-based N10276 hot-rolled coil with a thickness of 4.1mm and a width of 1260mm. Figure 7 As shown.

[0060] Specifically, the continuous annealing temperature is 1180℃ and the annealing rate is 5.5m / min.

[0061] Samples of the nickel-based N10276 hot-rolled coil were tested, and the results are shown in Table 2 and... Figures 8-10 As shown:

[0062] The test results show that all test results of the nickel-based N10276 hot-rolled coil meet the industry requirements and the standard requirements of Hastelloy.

[0063] Step 7: Cold roll the nickel-based N10276 hot roll to obtain a nickel-based N10276 coil with a thickness of 0.6 mm and a width of 1219 mm.

[0064] By utilizing the equipment capabilities of BaoTi's 1370mm twenty-roll reversible cold rolling mill and combining it with the inherent properties of the alloy, a semi-finished nickel-based N10276 coil with a thickness of 0.6mm and a width of 1219mm was successfully produced.

[0065] When the deformation of the nickel-based N10276 hot-rolled coil reaches 55%, intermediate continuous annealing is performed to relieve stress. The continuous annealing temperature is 1100℃ and the annealing speed is 1.0 m / min. A photograph of the cold rolling process of this nickel-based N10276 hot-rolled coil is shown below. Figure 11 As shown.

[0066] Step 8: After continuous annealing of the semi-finished nickel-based N10276 coil under inert atmosphere protection, it is rapidly air-cooled to obtain the finished nickel-based N10276 coil.

[0067] After degreasing and cleaning the semi-finished nickel-based N10276 coil, it undergoes heat treatment on a continuous annealing line. The heat treatment regime is as follows: temperature 1150℃, annealing rate 2.3 m / min. The entire annealing process is carried out under an argon protective atmosphere, followed by rapid air cooling to achieve solution strengthening. After tensioning, slitting, and rewinding, the finished nickel-based N10276 coil is obtained. Figure 12 and 13 As shown.

[0068] After sampling and testing, the room temperature tensile strength, hardness, cupping properties of the finished coil fully meet the requirements for cold deep drawing. Its microstructure is uniform single-phase austenite with no obvious second precipitate. Specific test results are shown in Table 3 and... Figures 14-16 As shown.

[0069]

[0070] As shown in Table 3, after sampling and testing, the chemical composition and room temperature tensile strength of the finished strip meet the requirements of ASME SB575. Its hardness, grain size, and cupping value meet the requirements for use in the cold deep-drawing field. Its microstructure is uniform single-phase austenite with no obvious second precipitate. The ultra-thin and ultra-wide nickel-based N10276 coil prepared by the process of this invention fills a domestic technological gap. The comprehensive performance of the prepared product reaches the quality level of equivalent imported materials, fully meeting the requirements of the plate heat exchanger industry and enabling the substitution of imported materials. Plate heat exchangers prepared using this ultra-thin and ultra-wide nickel-based N10276 coil are as follows: Figure 17 As shown.

[0071] Example 2

[0072] This invention provides a method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing. The prepared nickel-based N10276 coils have a thickness of 0.7 mm and a width of 1180 mm.

[0073] Specifically, the preparation method includes:

[0074] Step 1: Prepare the raw materials according to the following weight ratio: metallic chromium 16.2%; pure iron 6.0%; nickel-molybdenum alloy 15.5%; nickel-tungsten alloy 4.0%; nickel-manganese alloy 0.6%; the remainder is electrolytic nickel; wherein, the electrolytic nickel is Ni9996, the pure iron is YF01, the nickel-molybdenum alloy is Ni45Mo, the nickel-tungsten alloy is Ni42W, and the nickel-manganese alloy is Ni50Mn;

[0075] Based on the total weight of the raw materials, smelting additives are added in the following weight ratios: 0.5% nickel-magnesium alloy; 0.05% borax; 0.1% sponge titanium; 0.05% pure aluminum; 0.02% lanthanum-cerium rare earth alloy, wherein the lanthanum-cerium rare earth alloy is La35Ce; and the nickel-magnesium alloy is Ni20Mg.

[0076] Step 2: Add the raw materials and smelting additives described in Step 1 to a vacuum induction furnace for vacuum induction smelting to obtain the first semi-finished product, nickel-based N10276 ingot.

[0077] The mold used in vacuum induction melting is a steel mold with a diameter of Ф540×2300mm. The total amount of material fed is 5200kg. All billets must be kept clean and dry before being loaded into the furnace for melting. The steel is then fully refined and degassed in the high vacuum furnace. Finally, N10276 primary ingots with a single weight of about 5 tons are cast, which are electroslag remelting electrodes.

[0078] Step 2 specifically includes the following steps:

[0079] Step 2.1: Electrolytic nickel, metallic chromium, pure iron, nickel-molybdenum alloy, nickel-tungsten alloy, and nickel-manganese alloy are sequentially added to the vacuum induction furnace and heated until they are completely melted to obtain liquid metal.

[0080] After loading the furnace, the vacuum induction furnace is evacuated. Once the vacuum level is ≤5Pa, the temperature is increased. Depending on the furnace type, the power of the vacuum induction furnace is slowly increased to the optimal melting power according to different heating regimes. For furnaces below 25kW, the power is increased to 25kW at a rate of 5kW / 5min. For furnaces above 35kW, the power is increased to 35kW at a rate of 5kW / 10min. During the melting process, the billet is melted under a high vacuum before it turns into liquid. The maximum vacuum level can reach 0.5Pa to fully degas the vacuum induction furnace. Once the billet begins to turn into liquid, the vacuum is maintained between 5 and 10Pa until all the billet turns into liquid metal.

[0081] Step 2.2: Close the main valve and refine the liquid metal for 60 minutes. If visibility inside the furnace is poor during refining, the main valve can be opened to remove volatiles. After refining, once the liquid surface is calm, heat the vacuum induction furnace. When the furnace temperature reaches 1400~1430℃, pour the liquid metal into the furnace. Complete the pouring within 3 minutes with a pouring power of 350~400kw. After pouring, open the mold into the mold chamber and cool for 30~40 minutes before removing it from the furnace to obtain the first semi-finished nickel-based N10276 ingot.

[0082] Step 3: After sawing off the head and tail of the first semi-finished nickel-based N10276 ingot and cleaning off the surface oxide layer, place it in an electric resistance furnace for baking to obtain the second semi-finished nickel-based N10276 ingot; wherein, the baking temperature is 400~500℃ and the baking time is ≥7h, thereby eliminating the coolant that seeps into the ingot during sawing and ensuring that there are no porosity inclusions in the subsequent finished product.

[0083] Step 4: Electroslag remelting the second semi-finished nickel-based N10276 ingot, cooling it, and then cutting off the riser and bottom to obtain the finished nickel-based N10276 ingot.

[0084] Specifically, the crystallizer used for remelting has a specification of Φ580 / Φ620×2300mm. When loading the furnace, ensure that the electrodes are aligned. After sealing the upper hood, fill the furnace with high-purity argon gas. When the O content in the furnace is ≤0.01%, start the arc ignition, slag formation, transition section, stabilization remelting, smelting and filling, etc. After the remelting is completed, cool the furnace for 100 minutes before unloading.

[0085] Specifically, the slag material during electroslag remelting includes: calcium fluoride, alumina, calcium oxide, magnesium oxide, titanium monoxide, and lanthanum-cerium rare earth alloy; the mass ratio of the slag material is: calcium fluoride 66%; alumina 14%; calcium oxide 15%; magnesium oxide 2.4%; titanium monoxide 2.1%; lanthanum-cerium rare earth alloy 0.5%.

[0086] By using quenching and tempering agents such as borax, lanthanum-cerium rare earth alloy La35Ce, nickel-magnesium alloy, and sponge titanium, the purity of the alloy can be significantly improved, the segregation of carbides and other metallic compounds can be eliminated, and the oxygen content can be controlled below 20 ppm. During the atmosphere-protected electroslag remelting process, the constant melting rate and control of the alternating current in electroslag remelting are utilized to achieve the directional migration of impurity elements such as sulfur (S) and phosphorus (P), ensuring that the content of interstitial element O and other impurity elements such as S, P, and H are all ≤10 ppm. Ultimately, the purity of the alloy ingot reaches Class 1 level in the ASTM B574 standard, exhibiting excellent forgeability.

[0087] Step 5: Heat the finished nickel-based N10276 ingot to 1000℃, hold it at that temperature for 5.5 hours, and then continue heating it to 1260℃ at a heating rate of ≤100℃ / 60min. Hold it at that temperature for 6~7 hours and then remove it from the furnace for three forging cycles to obtain a nickel-based N10276 slab with a thickness of 120mm, a width of 1200mm, and a length of ≥4000mm.

[0088] Before forging, the riser and bottom pad of the finished nickel-based N10276 ingot are thoroughly removed. The ingot is forged in a 100MN free forging press and heated in a 480KW box-type resistance furnace.

[0089] Specifically, the three-stage forging process is as follows: The finished nickel-based N10276 ingot is first heated to 1260℃, held at that temperature for 6.5 hours, then removed from the furnace and fitted with an insulating sleeve. It is then placed back into the furnace and held at that temperature for another 1.5 hours before being forged. Through upsetting and drawing, it is then squared to a thickness of 300mm and a width of 1190mm. This square billet is then returned to the furnace for reheating for 1.5 hours, removed from the furnace, fitted with an insulating sleeve again, and a preheated 1230℃ pad is placed on its upper surface. Two more constant-temperature forging stages are then performed. After each stage, a 1230℃ pad is placed on top, ultimately resulting in a nickel-based N10276 slab with a thickness of 120mm, a width of 1200mm, and a length ≥4000mm. By using high-temperature protective pads and insulating sleeves on the billet, heat loss during the process is reduced, ensuring that the billet temperature remains essentially constant throughout the forging process, thus reducing the original number of forging stages.

[0090] Then, the head, tail, and tongue portions of the alloy slab are mechanically cut off, the sides are machined and milled, and the surface is mechanically polished to obtain a smooth, flat, and regularly shaped billet. It then undergoes 100% PT inspection to ensure the strip meets the requirements for continuous rolling. The billet specifications are: thickness 113mm, width 1190mm, and length ≥4000mm.

[0091] Step 6: Using a walking beam furnace, the nickel-based N10276 slab is heated to 1330℃, held for 170 minutes, and then descaled under high pressure. It is then quickly fed into a 1780mm roughing mill for rough rolling to reduce the thickness of the nickel-based N10276 slab to 37mm. It is then sent to an induction heating chamber for heating to 1220℃. Once the temperature display shows that the slab temperature has dropped to 1160℃, it is immediately fed into the F1~F8 continuous rolling mill for hot continuous rolling. After hot rolling, it is fed into an annealing line for continuous annealing to soften and whiten the slab, resulting in a nickel-based N10276 hot coil with a thickness of 4.5mm and a width of 1190mm.

[0092] Specifically, the continuous annealing temperature is 1200℃ and the annealing rate is 5.3m / min.

[0093] Step 7: Cold roll the nickel-based N10276 hot roll to obtain a nickel-based N10276 coil with a thickness of 0.7 mm and a width of 1180 mm.

[0094] By utilizing the equipment capabilities of BaoTi's 1370mm twenty-roll reversible cold rolling mill and combining it with the inherent properties of the alloy, a semi-finished nickel-based N10276 coil with a thickness of 0.7mm and a width of 1180mm was successfully produced.

[0095] When the deformation of the cold-rolled nickel-based N10276 hot-rolled coil reaches 60%, intermediate continuous annealing is performed to relieve stress. The continuous annealing temperature is 1120℃ and the annealing speed is 0.8m / min.

[0096] Step 8: After continuous annealing of the semi-finished nickel-based N10276 coil under inert atmosphere protection, it is rapidly air-cooled to obtain the finished nickel-based N10276 coil.

[0097] After degreasing and cleaning the semi-finished nickel-based N10276 coil, the finished product heat treatment was completed on a continuous annealing line. The heat treatment regime was 1160℃ and the annealing speed was 2m / min. The entire annealing process was carried out under an argon protective atmosphere and was rapidly air-cooled to achieve solid solution strengthening. After stretching, slitting, and rewinding, the finished nickel-based N10276 coil was obtained.

[0098] Example 3

[0099] This invention provides a method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing. The prepared nickel-based N10276 coils have a thickness of 0.5 mm and a width of 1000 mm.

[0100] Specifically, the preparation method includes:

[0101] Step 1: Mix the raw materials according to the following weight ratio: metallic chromium 15.5%; pure iron 4.5%; nickel-molybdenum alloy 16.3%; nickel-tungsten alloy 3.4%; nickel-manganese alloy 0.8%; the remainder is electrolytic nickel; wherein, the electrolytic nickel is Ni9996, the pure iron is YF01, the nickel-molybdenum alloy is Ni45Mo, the nickel-tungsten alloy is Ni42W, and the nickel-manganese alloy is Ni50Mn;

[0102] Based on the total weight of the raw materials, smelting additives are added in the following weight ratios: 0.6% nickel-magnesium alloy; 0.1% borax; 0.13% sponge titanium; 0.03% pure aluminum; 0.018% lanthanum-cerium rare earth alloy, wherein the lanthanum-cerium rare earth alloy is La35Ce; and the nickel-magnesium alloy is Ni20Mg.

[0103] Step 2: Add the raw materials and smelting additives described in Step 1 to a vacuum induction furnace for vacuum induction smelting to obtain the first semi-finished product, nickel-based N10276 ingot.

[0104] The mold used in vacuum induction melting is a steel mold with a diameter of Ф540×2300mm. The total amount of material fed is 5200kg. All billets must be kept clean and dry before being loaded into the furnace for melting. The steel is then fully refined and degassed in the high vacuum furnace. Finally, N10276 primary ingots with a single weight of about 5 tons are cast, which are electroslag remelting electrodes.

[0105] Step 2 specifically includes the following steps:

[0106] Step 2.1: Electrolytic nickel, metallic chromium, pure iron, nickel-molybdenum alloy, nickel-tungsten alloy, and nickel-manganese alloy are sequentially added to the vacuum induction furnace and heated until they are completely melted to obtain liquid metal.

[0107] After loading the furnace, the vacuum induction furnace is evacuated. Once the vacuum level is ≤5Pa, the temperature is increased. Depending on the furnace type, the power of the vacuum induction furnace is slowly increased to the optimal melting power according to different heating regimes. For furnaces below 25kW, the power is increased to 25kW at a rate of 5kW / 5min. For furnaces above 35kW, the power is increased to 35kW at a rate of 5kW / 10min. During the melting process, the billet is melted under a high vacuum before it turns into liquid. The maximum vacuum level can reach 0.5Pa to fully degas the vacuum induction furnace. Once the billet begins to turn into liquid, the vacuum is maintained between 5 and 10Pa until all the billet turns into liquid metal.

[0108] Step 2.2: Close the main valve and refine the liquid metal for 90 minutes. If visibility inside the furnace is poor during refining, the main valve can be opened to remove volatiles. After refining, once the liquid surface is calm, heat the vacuum induction furnace. When the furnace temperature reaches 1400~1430℃, pour the liquid metal into the furnace. Complete the pouring within 3 minutes with a pouring power of 350~400kw. After pouring, open the ingot mold into the ingot mold chamber and allow it to cool for 30~40 minutes before removing it from the furnace to obtain the first semi-finished nickel-based N10276 ingot.

[0109] Step 3: After sawing off the head and tail of the first semi-finished nickel-based N10276 ingot and cleaning off the surface oxide layer, place it in an electric resistance furnace for baking to obtain the second semi-finished nickel-based N10276 ingot; wherein, the baking temperature is 400~500℃ and the baking time is ≥7h, thereby eliminating the coolant that seeps into the ingot during sawing and ensuring that there are no porosity inclusions in the subsequent finished product.

[0110] Step 4: Electroslag remelting the second semi-finished nickel-based N10276 ingot, cooling it, and then cutting off the riser and bottom to obtain the finished nickel-based N10276 ingot.

[0111] Specifically, the crystallizer used for remelting has a specification of Φ580 / Φ620×2300mm. When loading the furnace, ensure that the electrodes are aligned. After sealing the upper hood, fill the furnace with high-purity argon gas. When the O content in the furnace is ≤0.01%, start the arc ignition, slag formation, transition section, stabilization remelting, smelting and filling, etc. After the remelting is completed, cool the furnace for 100 minutes before unloading.

[0112] Specifically, the slag material during electroslag remelting includes: calcium fluoride, alumina, calcium oxide, magnesium oxide, titanium monoxide, and lanthanum-cerium rare earth alloy; the mass ratio of the slag material is: calcium fluoride 64%; alumina 15%; calcium oxide 16%; magnesium oxide 2.4%; titanium monoxide 2.0%; lanthanum-cerium rare earth alloy 0.6%.

[0113] By using quenching and tempering agents such as borax, lanthanum-cerium rare earth alloy La35Ce, nickel-magnesium alloy, and sponge titanium, the purity of the alloy can be significantly improved, the segregation of carbides and other metallic compounds can be eliminated, and the oxygen content can be controlled below 20 ppm. During the atmosphere-protected electroslag remelting process, the constant melting rate and control of the alternating current in electroslag remelting are utilized to achieve the directional migration of impurity elements such as sulfur (S) and phosphorus (P), ensuring that the content of interstitial element O and other impurity elements such as S, P, and H are all ≤10 ppm. Ultimately, the purity of the alloy ingot reaches Class 1 level in the ASTM B574 standard, exhibiting excellent forgeability.

[0114] Step 5: Heat the finished nickel-based N10276 ingot to 950℃, hold it at that temperature for 4.5 hours, and then continue heating it to 1200℃ at a heating rate of ≤100℃ / 60min. Hold it at that temperature for 7 hours and then remove it from the furnace for three forging cycles to obtain a nickel-based N10276 slab with a thickness of 110mm, a width of 1050mm, and a length of ≥4000mm.

[0115] Before forging, the riser and bottom pad of the finished nickel-based N10276 ingot are thoroughly removed. The ingot is forged in a 100MN free forging press and heated in a 480KW box-type resistance furnace.

[0116] Specifically, the three-stage forging process is as follows: The finished nickel-based N10276 ingot is first heated to 1200℃, held at that temperature for 6 hours, then removed from the furnace and fitted with an insulating sleeve. It is then placed back into the furnace and held at that temperature for another 1.3 hours before being forged. Through upsetting and drawing, it is then squared to a thickness of 300mm and a width of 1040mm. This square billet is then returned to the furnace for reheating for 1.3 hours before being fitted with an insulating sleeve again. A preheated 1170℃ pad is placed on its upper surface, followed by two more constant-temperature forging stages. After each stage, a 1170℃ pad is placed on top, ultimately resulting in a nickel-based N10276 slab with a thickness of 110mm, a width of 1050mm, and a length ≥4000mm. By using high-temperature protective pads and insulating sleeves on the billet, heat loss during the process is reduced, ensuring that the billet temperature remains essentially constant throughout the forging process, thus reducing the original number of forging stages.

[0117] Then, the head, tail, and tongue portions of the alloy slab are mechanically cut off, the sides are machined and milled, and the surface is mechanically polished to obtain a smooth, flat, and regularly shaped billet. It then undergoes 100% PT inspection to ensure the strip meets the requirements for continuous rolling. The billet specifications are: thickness 104mm, width 1040mm, and length ≥4000mm.

[0118] Step 6: Using a walking beam furnace, the nickel-based N10276 slab is heated to 1250℃, held for 130 minutes, and then descaled under high pressure. It is then quickly fed into a 1780mm roughing mill for rough rolling to reduce the thickness of the nickel-based N10276 slab to 33mm. It is then sent to an induction heating chamber for heating to 1180℃. Once the temperature display shows that the slab temperature has dropped to 1140℃, it is immediately fed into the F1~F8 continuous rolling mill for hot continuous rolling. After hot rolling, it is fed into an annealing line for continuous annealing to soften and whiten the slab, resulting in a nickel-based N10276 hot coil with a thickness of 4.1mm and a width of 1050mm.

[0119] Specifically, the continuous annealing temperature was 1160℃ and the annealing rate was 5.7m / min.

[0120] Step 7: Cold roll the nickel-based N10276 hot roll to obtain a nickel-based N10276 coil with a thickness of 0.5 mm and a width of 1000 mm.

[0121] By utilizing the equipment capabilities of BaoTi's 1370mm twenty-roll reversible cold rolling mill and combining it with the inherent properties of the alloy, a semi-finished nickel-based N10276 coil with a thickness of 0.5mm and a width of 1000mm was successfully produced.

[0122] When the deformation of the cold-rolled nickel-based N10276 hot-rolled coil reaches 50%, intermediate continuous annealing is performed to relieve stress. The continuous annealing temperature is 1080℃ and the annealing speed is 1.2m / min.

[0123] Step 8: After continuous annealing of the semi-finished nickel-based N10276 coil under inert atmosphere protection, it is rapidly air-cooled to obtain the finished nickel-based N10276 coil.

[0124] After degreasing and cleaning the semi-finished nickel-based N10276 coil, the finished product heat treatment is completed on a continuous annealing line. The heat treatment regime is as follows: heating temperature 1130℃, annealing speed 2.5m / min. The entire annealing process is carried out under an argon protective atmosphere and rapid air cooling is performed to achieve solid solution strengthening. After stretching, slitting, and rewinding, the finished nickel-based N10276 coil is obtained.

[0125] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0126] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing, characterized in that, include: Step 1: Mix the raw materials according to the following weight ratio: metallic chromium 15.5~16.2%; pure iron 4.5~6.5%; Nickel-molybdenum alloy 15.5~16.3%; nickel-tungsten alloy 3.4~4.0%; nickel-manganese alloy 0.5~0.8%; the remainder is electrolytic nickel; Based on the total weight of the raw materials, smelting additives are added in the following weight ratios: nickel-magnesium alloy 0.5~0.6%; borax 0.005~0.1%; sponge titanium 0.1~0.15%; pure aluminum 0.05~0.1%; lanthanum-cerium rare earth alloy 0.015~0.02%, wherein the lanthanum content accounts for 60~66% and the cerium content accounts for 34~40%. Step 2: Add the raw materials and smelting additives described in Step 1 to a vacuum induction furnace for vacuum induction smelting to obtain the first semi-finished product, nickel-based N10276 ingot. Step 3: After sawing off the head and tail of the first semi-finished nickel-based N10276 ingot, place it in an electric resistance furnace for baking to obtain the second semi-finished nickel-based N10276 ingot; wherein, the baking temperature is 400~500℃ and the baking time is ≥7h. Step 4: Electroslag remelting the second semi-finished nickel-based N10276 ingot, cooling it, and then cutting off the riser and bottom to obtain the finished nickel-based N10276 ingot; Step 5: Heat the finished nickel-based N10276 ingot to 950~1000℃, hold for 4.5~5.5h, and then continue heating to 1200~1260℃ at a heating rate ≤100℃ / 60min, hold for 6~8h, and then remove from the furnace for multi-fire forging to obtain a nickel-based N10276 slab with a thickness of 110~120mm, a width of 1050~1260mm, and a length ≥4000mm; Step 6: Heat the nickel-based N10276 slab to 1250~1330℃, hold for 130~170min, then dephosphorize under high pressure, and then perform rough rolling to roll the thickness of the nickel-based N10276 slab to 33~37mm. Then heat it to 1180~1220℃. After the slab temperature drops to 1140~1160℃, immediately perform hot continuous rolling. After hot rolling, perform continuous annealing to obtain a nickel-based N10276 hot coil with a thickness of 4.0~4.5mm and a width of 1040~1250mm. Step 7: Cold roll the nickel-based N10276 hot roll to obtain a semi-finished nickel-based N10276 coil with a thickness of 0.5~0.7mm and a width of 1000~1219mm; Step 8: After continuous annealing of the semi-finished nickel-based N10276 coil under inert atmosphere protection, it is rapidly air-cooled to obtain the finished nickel-based N10276 coil.

2. The method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing according to claim 1, characterized in that, Step 2 includes: Step 2.1: Electrolytic nickel, metallic chromium, pure iron, nickel-molybdenum alloy, nickel-tungsten alloy, and nickel-manganese alloy are sequentially added into the vacuum induction furnace and heated until they are completely melted to obtain liquid metal. Step 2.2: Refine the liquid metal for 60-90 minutes. After refining, add nickel-magnesium alloy, borax, sponge titanium, pure aluminum, and lanthanum-cerium rare earth alloy to the liquid metal. When the furnace temperature reaches 1400-1430℃, pour the liquid metal to obtain the first semi-finished nickel-based N10276 ingot.

3. The method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing according to claim 1, characterized in that, In step 4, the slag material from the electroslag remelting comprises the following raw materials in the following mass ratios: calcium fluoride 64~66%; alumina 14~16%; calcium oxide 14~16%; magnesium oxide 2.4~2.6%; titanium monoxide 1.9~2.1%; lanthanum-cerium rare earth alloy 0.4~0.6%.

4. The method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing according to claim 1, characterized in that, In step 5, the multi-fire forging process is as follows: after the billet from the first fire is taken out of the furnace and fitted with a heat-insulating sleeve, it is put back into the furnace and kept warm for 1 to 1.5 hours before being forged into a square billet; then the square billet is returned to the furnace for reheating for 1 to 1.5 hours before being taken out of the furnace and fitted with a heat-insulating sleeve again. After a pad preheated to 1170 to 1230°C is laid on its upper surface, it is subjected to 1 to 2 fires of constant temperature forging to obtain the nickel-based N10276 slab.

5. The method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing according to claim 1, characterized in that, In step 6, the continuous annealing temperature is 1160~1200℃, and the annealing rate is 5.3~5.7m / min.

6. The method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing according to claim 1, characterized in that, In step 7, when the deformation of the nickel-based N10276 hot-rolled coil is 50-60%, intermediate continuous annealing is performed at a temperature of 1080-1120℃ and an annealing speed of 0.8-1.2m / min.

7. The method for preparing ultra-thin and ultra-wide nickel-based N10276 coils for cold deep drawing according to claim 1, characterized in that, In step 8, the continuous annealing temperature is 1130~1160℃, the annealing rate is 2.0~2.5m / min, and the entire annealing process is carried out under an argon protective atmosphere.

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