High-corrosion-resistance nickel-chromium-based alloy foil and preparation method thereof

Abstract

The invention relates to the technical field of nickel-chromium alloy materials, in particular to a high-corrosion-resistance nickel-chromium-based alloy foil and a preparation method thereof.The preparation method comprises the following steps that S1, raw materials are weighed, cleaned and dried; s2, the raw materials are smelted and cast after being treated, and an alloy cast ingot is obtained; s3, the alloy cast ingot is subjected to homogenization treatment and hot rolling cogging, and a hot-rolled plate blank is obtained; s4, the hot-rolled plate blank is subjected to multi-pass cold rolling and intermediate annealing treatment, and a primary foil is prepared; and S5, the preliminary foil is subjected to finished product passivation treatment, rolling and packaging are conducted after detection is qualified, and the high-corrosion-resistance nickel-chromium-based alloy foil is obtained. According to the nickel-chromium-based alloy foil, a compact physical barrier is formed through zirconium phosphate to block permeation of a corrosive medium, the additive A and the additive B inhibit corrosion, and the corrosion resistance of the nickel-chromium-based alloy foil in a corrosive environment is effectively improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nickel-chromium alloy materials, in particular to a high-corrosion-resistance nickel-chromium-based alloy foil and a preparation method thereof. BACKGROUND

[0002] The nickel-chromium-based alloy foil is a kind of thin sheet metal material made of nickel and chromium as main elements through precise rolling, and the core functions include high-temperature structural protection parts such as an aero-engine sealing foil, corrosion environment barriers such as a chemical corrosion foil, electronic precision components such as a thin film resistor, and sensitive sealing parts of precision instruments such as a sensor strain foil, and the nickel-chromium-based alloy foil is widely used in high-end manufacturing key scenes.

[0003] In the prior art, the passivation film has poor compactness, and the chromium-based oxide film is easily locally damaged, so that the corrosion resistance of the nickel-chromium-based alloy foil is insufficient. Based on this, the application provides a high-corrosion-resistance nickel-chromium-based alloy foil and a preparation method thereof. SUMMARY

[0004] The application aims to provide a high-corrosion-resistance nickel-chromium-based alloy foil and a preparation method thereof, and the high-corrosion-resistance nickel-chromium-based alloy foil prepared by the application has good corrosion resistance performance, and the use performance of the nickel-chromium-based alloy foil is effectively improved.

[0005] To achieve the above-mentioned purpose, the application provides the following technical scheme. In a first aspect, the application provides a high-corrosion-resistance nickel-chromium-based alloy foil and a preparation method thereof, which comprises the following steps. S1: weighing raw materials and cleaning and drying the raw materials; S2: after the raw materials are treated, melting and casting are performed to obtain an alloy ingot; S3: homogenizing treatment and hot rolling are performed on the alloy ingot to obtain a hot-rolled slab; S4: multi-pass cold rolling and intermediate annealing treatment are performed on the hot-rolled slab to prepare a preliminary foil; S5: finish passivation treatment is performed on the preliminary foil, and after detection, the foil is wound and packaged to obtain a high-corrosion-resistance nickel-chromium-based alloy foil.

[0006] Further, the raw materials comprise, by weight percentage, 24-26% chromium, 5-7% molybdenum, 2-4% tungsten, 1-2% niobium, 0.8-1.5% composite additive, 0.4-0.8% silicon, 0.08-0.12% carbon and 0.5-1% iron, and the balance is nickel.

[0007] Further, the composite additive is obtained by compounding an additive A, an additive B, zirconium phosphate and a corrosion inhibitor, and the zirconium phosphate is pretreated before the composite additive is prepared.

[0008] Further, the preparation method of the composite additive is as follows: Additive A and Additive B are mixed at a mass ratio of (2-4):(1-3), and zirconium phosphate and corrosion inhibitor are added. The mixture is then vacuum dried at 100°C for 2-3 hours to obtain the composite additive. The mass of zirconium phosphate is 8-12% of the total mass of Additive A and Additive B, and the mass of corrosion inhibitor is 2-3% of the total mass of Additive A and Additive B. The corrosion inhibitor is benzotriazole.

[0009] Further, the preparation method of additive A is as follows: nano-titanium nitride is slowly added to tetrabutyl titanate ethanol solution at a mass ratio of 1:(6-8), stirred at 40-50℃ and 300-400rpm for 30-40min to form a suspension, coupling agent KH-550 is added to the suspension, and the reaction is kept at 60-70℃ for 2-3h. Then, it is transferred to a vacuum drying oven and dried at 80℃ for 4-6h. The mixture is then ground to a particle size of 100-200nm to obtain additive A, wherein the nano-titanium nitride particle size is 50-80nm, the mass fraction of tetrabutyl titanate ethanol solution is 10-15%, and the mass of coupling agent KH-550 accounts for 3-5% of the mass of the suspension.

[0010] Further, the preparation method of additive B is as follows: cerium oxide powder is added to aluminum sol at a mass ratio of 1:(4-6), stirred at 500-600 rpm for 20-30 min, and the pH is adjusted to 4.5-5.5 with dilute nitric acid to obtain a mixture. Then, sodium borohydride is added at a mass of 2-4% of the mixture, and ultrasonically dispersed at a power of 500W and a frequency of 25kHz for 20-30 min. Subsequently, it is freeze-dried at -40℃ for 12-16 h and pulverized to a particle size of 80-150 nm to obtain additive B, wherein the particle size of cerium oxide powder is 30-50 nm and the mass fraction of aluminum sol is 8-12%.

[0011] Further, the pretreatment method of zirconium phosphate is as follows: zirconium phosphate is placed in a low-temperature plasma reactor, evacuated to 3-5 Pa, and argon gas is introduced at a flow rate of 20-30 mL / min. The plasma is treated with 100 W for 10-20 min. The treated zirconium phosphate is added to a hexadecyltrimethylammonium bromide ethanol solution at a solid-liquid ratio of 1:(8-12). The mixture is stirred at 50-60℃ and 200-300 rpm for 1-2 h. After vacuum filtration, the filter residue is vacuum dried at 90-100℃ for 4-5 h and ground to a particle size of 15-25 nm to obtain pretreated zirconium phosphate. The mass fraction of the hexadecyltrimethylammonium bromide ethanol solution is 3-5%.

[0012] Furthermore, the melting and casting steps and parameters are as follows: First, add nickel blocks into the furnace, evacuate to below 0.005 Pa, heat to 1500-1550℃ to melt, add chromium, molybdenum, tungsten, and niobium in sequence, keep warm and stir for 30-40 minutes, cool to 1450-1500℃, add ferrosilicon alloy and graphite powder, keep warm and stir for 20-25 minutes, finally add composite additives, keep warm and stir for 10-20 minutes, the stirring rate throughout is 55-65 rpm, the argon flow rate is 20-30 mL / min, the alloy liquid is allowed to stand at 1400-1450℃ for 10-20 minutes, and then cast into a water-cooled copper mold at a cooling rate of 5-8℃ / s, with an ingot size of 100mm×400mm.

[0013] Further, the homogenization treatment and hot rolling slab steps and parameters are as follows: In the homogenization treatment, the alloy ingot is first placed in a vacuum annealing furnace, vacuumed to below 0.01 Pa, and then heated to 1150-1200℃ and held for 8-12 hours. During the holding process, it is stirred at a rate of 30 rpm for 5 minutes every 2 hours and then cooled to room temperature at a rate of 3-5℃ / min. In the hot rolling slab, it is first preheated in a heating furnace at 1100-1150℃ for 2-3 hours. During the preheating, nitrogen gas with a flow rate of 15-20 mL / min is introduced for protection. Then, it is rolled using a two-roll hot rolling mill with an initial rolling temperature of 1050-1100℃, a final rolling temperature greater than 850℃, a reduction per pass of 8-12%, and a total reduction of 70-80%. During the rolling process, it is cooled with water mist at a rate of 10-15℃ / s, and finally, a hot-rolled slab with a thickness of 8-12 mm is obtained.

[0014] Furthermore, the steps and parameters of the cold rolling and intermediate annealing are as follows: after the hot-rolled slab is mechanically ground to remove the oxide scale, it is soaked in 5% dilute hydrochloric acid for 10-15 minutes, rinsed with deionized water until neutral, dried at 80°C for 1 hour, and then rolled in multiple passes using a four-roll cold rolling mill, with a reduction of 5-10% per pass and a rolling speed of 30-50 m / min, until the final thickness is 0.01-0.1 mm, thus obtaining the preliminary foil material.

[0015] Further, the passivation treatment method is as follows: the preliminary foil is placed in the passivation solution and soaked at 50-60℃ for 1-5 minutes. After passivation, it is rinsed with deionized water until neutral and then vacuum dried at 60℃ for 20-40 minutes. The passivation solution is prepared by compounding sodium hydroxide, sodium silicate, potassium molybdate, sodium citrate and distilled water in a mass ratio of (1-7):(3-6):(18-22):(5-10):1000 and adjusting the pH to 9-10.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, pretreated zirconium phosphate is activated by plasma and modified with hydrophobicity to form a dense physical barrier to block the penetration of corrosive media. Additive A, nano-titanium nitride, inhibits corrosion due to its high aspect ratio. Additive B, cerium oxide, can quickly repair the damaged passivation film. Combined with the chemical adsorption protection of benzotriazole, the corrosion resistance of nickel-chromium alloy foil in corrosive environments is effectively improved.

[0017] 2. In this invention, additives A and B form a multidimensional reinforcing phase with pretreated zirconium phosphate, which improves the interfacial bonding force and load transfer efficiency. At the same time, the bridging effect of the coupling agent further optimizes the dispersion of the additives in the matrix, reduces interfacial defects and stress concentration, and improves the tensile strength of the foil. Attached Figure Description

[0018] Figure 1 The present invention provides a flowchart of a highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0021] Example 1: (1) Preparation of additive A: Nano titanium nitride was slowly added to tetrabutyl titanate ethanol solution at a mass ratio of 1:6. The mixture was stirred at 40°C and 300 rpm for 30 min to form a suspension. Coupling agent KH-550 was added to the suspension and the mixture was kept at 60°C for 2 h. Then it was transferred to a vacuum drying oven and dried at 80°C for 4 h. The mixture was then ground to a particle size of 100 nm to obtain additive A. The nano titanium nitride had a particle size of 50 nm, the tetrabutyl titanate ethanol solution had a mass fraction of 10%, and the coupling agent KH-550 accounted for 3% of the mass of the suspension.

[0022] (2) Preparation of additive B: Cerium oxide powder was added to aluminum sol at a mass ratio of 1:4, stirred at 500 rpm for 20 min, and the pH was adjusted to 4.5 with dilute nitric acid to obtain a mixture. Then, sodium borohydride was added at a mass of 2% of the mixture, and ultrasonically dispersed at a power of 500 W and a frequency of 25 kHz for 20 min. Subsequently, it was freeze-dried at -40℃ for 12 h and pulverized to a particle size of 80 nm to obtain additive B, wherein the particle size of cerium oxide powder was 30 nm and the mass fraction of aluminum sol was 8%.

[0023] (3) Pretreated zirconium phosphate: Zirconium phosphate was placed in a low-temperature plasma reactor, evacuated to 3 Pa, and argon gas was introduced at a flow rate of 20 mL / min. The plasma was treated with 100 W for 10 min. The treated zirconium phosphate was added to a hexadecyltrimethylammonium bromide ethanol solution at a solid-liquid ratio of 1:8. The mixture was stirred at 50 °C and 200 rpm for 1 h. After vacuum filtration, the filter residue was dried under vacuum at 90 °C for 4 h and ground to a particle size of 15 nm to obtain pretreated zirconium phosphate. The mass fraction of the hexadecyltrimethylammonium bromide ethanol solution was 3%.

[0024] (4) Preparation of composite additive: Mix additive A and additive B at a mass ratio of 2:1, add zirconium phosphate and corrosion inhibitor, and vacuum dry at 100°C for 2 hours to obtain composite additive. The mass of zirconium phosphate is 8% of the total mass of additive A and additive B, the mass of corrosion inhibitor is 2% of the total mass of additive A and additive B, and the corrosion inhibitor is benzotriazole.

[0025] (5) Weigh the raw materials by weight percentage: 24-26% chromium, 5-7% molybdenum, 2-4% tungsten, 1-2% niobium, 0.8-1.5% composite additives, 0.4-0.8% silicon, 0.08-0.12% carbon and 0.5-1% iron, with the balance being nickel.

[0026] (6) The raw materials are cleaned and dried. After treatment, the raw materials are smelted and cast. First, the nickel block is added into the furnace, the vacuum is drawn to below 0.005Pa, the temperature is raised to 1500℃ to melt, chromium, molybdenum, tungsten and niobium are added in sequence, the temperature is kept and stirred for 30min, the temperature is lowered to 1450℃, ferrosilicon alloy and graphite powder are added, the temperature is kept and stirred for 20min, the composite additive is added, the temperature is kept and stirred for 10min, the stirring rate is 55rpm throughout the process, the argon flow rate is 20mL / min, the alloy liquid is kept at 1400℃ for 10min, and the alloy is cast into a water-cooled copper mold at a cooling rate of 5℃ / s to obtain an alloy ingot with an ingot size of 100mm×400mm.

[0027] (7) Homogenization treatment and hot rolling of alloy ingots: Homogenization treatment: First, put the alloy ingot into a vacuum annealing furnace, evacuate it to below 0.01 Pa, then heat it to 1150℃ and hold it for 8 hours. During the holding process, stir it at a rate of 30 rpm for 5 minutes every 2 hours and cool it down to room temperature at a rate of 3℃ / min. Hot rolling: First, preheat it in a heating furnace at 1100℃ for 2 hours. During the preheating, nitrogen gas with a flow rate of 15 mL / min is introduced for protection. Then, it is rolled by a two-roll hot rolling mill with an initial rolling temperature of 1050℃ and a final rolling temperature greater than 850℃. The reduction per pass is 8% and the total reduction is 70%. During the rolling process, water mist is used for cooling at a rate of 10℃ / s. Finally, a hot-rolled slab with a thickness of 8 mm is obtained.

[0028] (8) The hot-rolled slab is subjected to multiple cold rolling and intermediate annealing treatment: After the oxide scale is removed by mechanical grinding, the hot-rolled slab is soaked in 5% dilute hydrochloric acid for 10 min, rinsed with deionized water until neutral, dried at 80℃ for 1 h, and then rolled in multiple passes using a four-roll cold rolling mill. The reduction in each pass is 5%, the rolling speed is 30 m / min, and finally rolled to a thickness of 0.1 mm to obtain the preliminary foil.

[0029] (9) The initial foil is placed in the passivation solution and soaked at 50°C for 1 min. After passivation, it is rinsed with deionized water until neutral and vacuum dried at 60°C for 20 min. After passing the test, it is rolled up and packaged to obtain a high corrosion resistant nickel-chromium alloy foil. The passivation solution is prepared by mixing sodium hydroxide, sodium silicate, potassium molybdate, sodium citrate and distilled water in a mass ratio of 1:3:18:5:1000 and adjusting the pH to 9.

[0030] Example 2: (1) Preparation of additive A: Nano titanium nitride was slowly added to tetrabutyl titanate ethanol solution at a mass ratio of 1:7. The mixture was stirred at 45°C and 350 rpm for 35 min to form a suspension. Coupling agent KH-550 was added to the suspension and the mixture was kept at 65°C for 2.5 h. Then it was transferred to a vacuum drying oven and dried at 80°C for 5 h. The mixture was then ground to a particle size of 150 nm to obtain additive A. The nano titanium nitride had a particle size of 75 nm, the mass fraction of tetrabutyl titanate ethanol solution was 12%, and the mass of coupling agent KH-550 accounted for 4% of the mass of the suspension.

[0031] (2) Preparation of additive B: Cerium oxide powder was added to aluminum sol at a mass ratio of 1:5, stirred at 550 rpm for 25 min, and the pH was adjusted to 5 with dilute nitric acid to obtain a mixture. Then, sodium borohydride was added at a mass of 3% of the mixture, and ultrasonically dispersed at a power of 500 W and a frequency of 25 kHz for 25 min. Subsequently, it was freeze-dried at -40℃ for 14 h and pulverized to a particle size of 100 nm to obtain additive B, wherein the particle size of cerium oxide powder was 40 nm and the mass fraction of aluminum sol was 10%.

[0032] (3) Pretreated zirconium phosphate: Zirconium phosphate was placed in a low-temperature plasma reactor, evacuated to 4 Pa, and argon gas was introduced at a flow rate of 25 mL / min. The plasma was treated with 100 W for 15 min. The treated zirconium phosphate was added to a hexadecyltrimethylammonium bromide ethanol solution at a solid-liquid ratio of 1:10. The mixture was stirred at 55 °C and 250 rpm for 1.5 h. After vacuum filtration, the filter residue was dried under vacuum at 95 °C for 4.5 h and ground to a particle size of 20 nm to obtain pretreated zirconium phosphate. The mass fraction of the hexadecyltrimethylammonium bromide ethanol solution was 4%.

[0033] (4) Preparation of composite additive: Mix additive A and additive B at a mass ratio of 3:2, add zirconium phosphate and corrosion inhibitor, and vacuum dry at 100°C for 2.5 h to obtain composite additive. The mass of zirconium phosphate is 10% of the total mass of additive A and additive B, the mass of corrosion inhibitor is 2.5% of the total mass of additive A and additive B, and the corrosion inhibitor is benzotriazole.

[0034] (5) Weigh the raw materials by weight percentage: 24-26% chromium, 5-7% molybdenum, 2-4% tungsten, 1-2% niobium, 0.8-1.5% composite additives, 0.4-0.8% silicon, 0.08-0.12% carbon and 0.5-1% iron, with the balance being nickel.

[0035] (6) The raw materials are cleaned and dried. After treatment, the raw materials are smelted and cast. First, the nickel block is added into the furnace, the vacuum is drawn to below 0.005Pa, the temperature is raised to 1520℃ to melt, chromium, molybdenum, tungsten and niobium are added in sequence, the temperature is kept and stirred for 35min, the temperature is lowered to 1480℃, ferrosilicon alloy and graphite powder are added, the temperature is kept and stirred for 25min, the composite additive is added, the temperature is kept and stirred for 15min, the stirring rate is 60rpm throughout the process, the argon flow rate is 25mL / min, the alloy liquid is kept at 1420℃ for 15min, and the alloy is cast into a water-cooled copper mold at a cooling rate of 6℃ / s to obtain an alloy ingot with an ingot size of 100mm×400mm.

[0036] (7) Homogenization treatment and hot rolling of alloy ingots: Homogenization treatment: First, put the alloy ingot into a vacuum annealing furnace, evacuate it to below 0.01 Pa, then heat it to 1180℃ and hold it for 10 hours. During the holding process, stir it at 30 rpm for 5 minutes every 2 hours and cool it down to room temperature at 4℃ / min. Hot rolling: First, preheat it in a 1120℃ heating furnace for 2.5 hours. During the preheating, nitrogen gas with a flow rate of 18 mL / min is introduced for protection. Then, it is rolled by a two-roll hot rolling mill with an initial rolling temperature of 1080℃ and a final rolling temperature greater than 850℃. The reduction per pass is 10% and the total reduction is 75%. During the rolling process, water mist is used for cooling at a rate of 12℃ / s. Finally, a hot-rolled slab with a thickness of 10 mm is obtained.

[0037] (8) The hot-rolled slab is subjected to multiple cold rolling and intermediate annealing treatment: After the oxide scale is removed by mechanical grinding, the hot-rolled slab is soaked in 5% dilute hydrochloric acid for 12 minutes, rinsed with deionized water until neutral, dried at 80°C for 1 hour, and then rolled in multiple passes using a four-roll cold rolling mill with a reduction of 8% per pass and a rolling speed of 40 m / min. Finally, it is rolled to a thickness of 0.05 mm to obtain the preliminary foil material.

[0038] (9) The initial foil is placed in the passivation solution and soaked at 55°C for 3 minutes. After passivation, it is rinsed with deionized water until neutral and vacuum dried at 60°C for 30 minutes. After passing the test, it is rolled up and packaged to obtain a highly corrosion-resistant nickel-chromium alloy foil. The passivation solution is prepared by mixing sodium hydroxide, sodium silicate, potassium molybdate, sodium citrate and distilled water in a mass ratio of 4:5:20:8:1000 and adjusting the pH to 9.5.

[0039] Example 3: (1) Preparation of additive A: Nano titanium nitride was slowly added to tetrabutyl titanate ethanol solution at a mass ratio of 1:8. The mixture was stirred at 50°C and 400 rpm for 40 min to form a suspension. Coupling agent KH-550 was added to the suspension and the mixture was kept at 70°C for 2.5 h. Then it was transferred to a vacuum drying oven and dried at 80°C for 5 h. The mixture was then ground to a particle size of 150 nm to obtain additive A. The nano titanium nitride had a particle size of 80 nm, the mass fraction of tetrabutyl titanate ethanol solution was 15%, and the mass of coupling agent KH-550 accounted for 5% of the mass of the suspension.

[0040] (2) Preparation of additive B: Cerium oxide powder was added to aluminum sol at a mass ratio of 1:6, stirred at 600 rpm for 30 min, and the pH was adjusted to 5.5 with dilute nitric acid to obtain a mixture. Then, sodium borohydride was added at a mass of 4% of the mixture, and ultrasonically dispersed at a power of 500 W and a frequency of 25 kHz for 30 min. Subsequently, it was freeze-dried at -40℃ for 16 h and pulverized to a particle size of 150 nm to obtain additive B, wherein the particle size of cerium oxide powder was 50 nm and the mass fraction of aluminum sol was 12%.

[0041] (3) Pretreated zirconium phosphate: Zirconium phosphate was placed in a low-temperature plasma reactor, evacuated to 5 Pa, and argon gas was introduced at a flow rate of 30 mL / min. The plasma was treated with 100 W for 20 min. The treated zirconium phosphate was added to a hexadecyltrimethylammonium bromide ethanol solution at a solid-liquid ratio of 1:12. The mixture was stirred at 60 °C and 300 rpm for 2 h. After vacuum filtration, the filter residue was dried under vacuum at 100 °C for 5 h and ground to a particle size of 25 nm to obtain pretreated zirconium phosphate. The mass fraction of the hexadecyltrimethylammonium bromide ethanol solution was 5%.

[0042] (4) Preparation of composite additive: Mix additive A and additive B at a mass ratio of 4:3, add zirconium phosphate and corrosion inhibitor, and vacuum dry at 100°C for 3 hours to obtain composite additive. The mass of zirconium phosphate is 12% of the total mass of additive A and additive B, the mass of corrosion inhibitor is 3% of the total mass of additive A and additive B, and the corrosion inhibitor is benzotriazole.

[0043] (5) Weigh the raw materials by weight percentage: 24-26% chromium, 5-7% molybdenum, 2-4% tungsten, 1-2% niobium, 0.8-1.5% composite additives, 0.4-0.8% silicon, 0.08-0.12% carbon and 0.5-1% iron, with the balance being nickel.

[0044] (6) The raw materials are cleaned and dried. After treatment, the raw materials are smelted and cast. First, the nickel block is added into the furnace, the vacuum is drawn to below 0.005Pa, the temperature is raised to 1550℃ to melt, chromium, molybdenum, tungsten and niobium are added in sequence, the temperature is kept and stirred for 40min, the temperature is lowered to 1500℃, ferrosilicon alloy and graphite powder are added, the temperature is kept and stirred for 30min, the composite additive is added, the temperature is kept and stirred for 20min, the stirring rate is 65rpm throughout the process, the argon flow rate is 30mL / min, the alloy liquid is kept at 1450℃ for 20min, and the alloy is cast into a water-cooled copper mold at a cooling rate of 8℃ / s to obtain an alloy ingot with an ingot size of 100mm×400mm.

[0045] (7) Homogenization treatment and hot rolling of alloy ingots: Homogenization treatment: First, put the alloy ingot into a vacuum annealing furnace, evacuate it to below 0.01 Pa, then heat it to 1200℃ and hold it for 12 hours. During the holding process, stir it at 30 rpm for 5 minutes every 2 hours and cool it down to room temperature at 5℃ / min. Hot rolling: First, preheat it in a 1150℃ heating furnace for 3 hours. During the preheating, nitrogen gas with a flow rate of 20 mL / min is introduced for protection. Then, it is rolled by a two-roll hot rolling mill with an initial rolling temperature of 1100℃ and a final rolling temperature greater than 850℃. The reduction per pass is 12% and the total reduction is 80%. During the rolling process, water mist is used for cooling at a rate of 15℃ / s. Finally, a hot-rolled slab with a thickness of 12 mm is obtained.

[0046] (8) The hot-rolled slab is subjected to multiple cold rolling and intermediate annealing: After the oxide scale is removed by mechanical grinding, the hot-rolled slab is soaked in 5% dilute hydrochloric acid for 15 min, rinsed with deionized water until neutral, dried at 80℃ for 1 h, and then rolled in multiple passes using a four-roll cold rolling mill. The reduction in each pass is 10%, the rolling speed is 50 m / min, and finally rolled to a thickness of 0.01 mm to obtain the preliminary foil.

[0047] (9) The initial foil is placed in the passivation solution and soaked at 60°C for 5 minutes. After passivation, it is rinsed with deionized water until neutral and vacuum dried at 60°C for 40 minutes. After passing the test, it is rolled up and packaged to obtain a high corrosion resistant nickel-chromium alloy foil. The passivation solution is prepared by mixing sodium hydroxide, sodium silicate, potassium molybdate, sodium citrate and distilled water in a mass ratio of 7:6:22:10:1000 and adjusting the pH to 10.

[0048] Comparative Example 1: The difference between this comparative example and Example 1 is that this comparative example does not contain composite additives.

[0049] Comparative Example 2 differs from Example 1 in that additive A was not added during the preparation of the composite additive in this comparative example.

[0050] Comparative Example 3 differs from Example 1 in that zirconium phosphate in this comparative example is not pretreated.

[0051] Performance testing: The high corrosion-resistant nickel-chromium-based alloy foils prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing, and the test data are recorded in the table below: Table 1

[0052] In performance testing, corrosion resistance is expressed by salt spray test life, and the test is conducted in accordance with GB / T 10125-2021. The longer the salt spray test life, the better the corrosion resistance. The tensile strength test shall be conducted in accordance with GB / T 228.1-2021.

[0053] The salt spray test life results of the highly corrosion-resistant nickel-chromium-based alloy foils prepared in Examples 1-3 and Comparative Examples 1-3 were 1050h, 1150h, 1100h, 700h, 800h, and 900h, respectively.

[0054] The tensile strength test results of the highly corrosion-resistant nickel-chromium-based alloy foils prepared in Examples 1-3 and Comparative Examples 1-3 were 782 MPa, 803 MPa, 795 MPa, 552 MPa, 630 MPa, and 694 MPa, respectively.

[0055] It is evident that the corrosion resistance and tensile strength of the nickel-chromium based alloy foils prepared in Comparative Examples 1-3 are lower than those in Examples 1-3. This indicates that in the composite additives, the pretreated zirconium phosphate forms a rough surface through plasma etching, and the refined particle size can extend the penetration path of the corrosive medium, constructing physical barriers and interfacial anchoring. The nano-titanium nitride in additive A forms continuous corrosion inhibition channels with its high aspect ratio and high hardness, which can hinder dislocation movement. The dispersed distribution of cerium oxide can refine the matrix grains. The two, together with the pretreated zirconium phosphate, enhance the mechanical properties of the matrix while improving corrosion resistance. The cerium oxide in additive B can repair the damaged passivation film, and benzotriazole enhances the stability of the passivation film through chemical adsorption. The components in additives A and B synergistically enhance the anti-corrosion effect. At the same time, the bridging effect of the coupling agent KH-550 promotes the formation of a stable chemical bond between the additives and the nickel-chromium matrix, inhibits the agglomeration of the additives, and achieves a simultaneous improvement in dispersion uniformity and interfacial bonding force. In Comparative Example 1, no composite additives were used, and the protection relied solely on the passivation film of the matrix itself. There was neither a physical barrier layer nor corrosion repair and chemical adsorption, resulting in an incomplete anti-corrosion system. Furthermore, the lack of the dispersion strengthening effect of the additives led to a significant decrease in salt spray test life and tensile strength. In Comparative Example 2, no additive A was used, and the lack of nano-titanium nitride to inhibit corrosion and the dispersion distribution of cerium oxide to strengthen the interfacial bonding of the matrix affected the corrosion resistance and tensile strength of the foil. In Comparative Example 3, zirconium phosphate was not pretreated, resulting in a large particle size and poor dispersion, making it difficult to construct a dense physical barrier and a stable interfacial bonding, which slightly reduced the salt spray test life and tensile strength.

[0056] By comparing and analyzing the relevant data in the table, it can be seen that the highly corrosion-resistant nickel-chromium-based alloy foil prepared by this invention not only has excellent corrosion resistance but also good tensile strength. This indicates that the highly corrosion-resistant nickel-chromium-based alloy foil provided by this invention has a broader market prospect and is more suitable for widespread application.

[0057] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method, characterized in that, Includes the following steps: S1: Weigh the raw materials and clean and dry them; S2: After processing, the raw materials are smelted and cast to obtain alloy ingots; S3: Homogenize the alloy ingot and hot-roll it to obtain a hot-rolled slab. S4: The hot-rolled slab is subjected to multiple cold rolling and intermediate annealing processes to prepare preliminary foil materials; S5: The initial foil material undergoes passivation treatment, and after passing inspection, it is wound up and packaged to obtain a highly corrosion-resistant nickel-chromium-based alloy foil material; The raw materials, by weight percentage, comprise: 24-26% chromium, 5-7% molybdenum, 2-4% tungsten, 1-2% niobium, 0.8-1.5% composite additives, 0.4-0.8% silicon, 0.08-0.12% carbon, and 0.5-1% iron, with the balance being nickel; The composite additive is prepared by compounding additive A, additive B, zirconium phosphate and corrosion inhibitor, wherein the zirconium phosphate is pretreated before the preparation of the composite additive.

2. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The method for preparing the composite additive is as follows: Additive A and Additive B are mixed at a mass ratio of (2-4):(1-3), and zirconium phosphate and corrosion inhibitor are added. The mixture is then vacuum dried at 100°C for 2-3 hours to obtain the composite additive. The mass of zirconium phosphate is 8-12% of the total mass of Additive A and Additive B, and the mass of corrosion inhibitor is 2-3% of the total mass of Additive A and Additive B. The corrosion inhibitor is benzotriazole.

3. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The preparation method of additive A is as follows: nano-titanium nitride is slowly added to tetrabutyl titanate ethanol solution at a mass ratio of 1:(6-8), stirred at 300-400 rpm for 30-40 min at 40-50℃ to form a suspension, coupling agent KH-550 is added to the suspension, and the reaction is carried out at 60-70℃ for 2-3 h, then transferred to a vacuum drying oven and dried at 80℃ for 4-6 h, and ground to a particle size of 100-200 nm to obtain additive A, wherein the nano-titanium nitride particle size is 50-80 nm, the mass fraction of tetrabutyl titanate ethanol solution is 10-15%, and the mass of coupling agent KH-550 accounts for 3-5% of the mass of the suspension.

4. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The preparation method of additive B is as follows: Cerium oxide powder is added to aluminum sol at a mass ratio of 1:(4-6), stirred at 500-600 rpm for 20-30 min, and the pH is adjusted to 4.5-5.5 with dilute nitric acid to obtain a mixture. Then, sodium borohydride is added at a mass of 2-4% of the mixture, and ultrasonically dispersed at a power of 500W and a frequency of 25kHz for 20-30 min. Subsequently, it is freeze-dried at -40℃ for 12-16 h and pulverized to a particle size of 80-150 nm to obtain additive B, wherein the particle size of cerium oxide powder is 30-50 nm and the mass fraction of aluminum sol is 8-12%.

5. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The pretreatment method for zirconium phosphate is as follows: zirconium phosphate is placed in a low-temperature plasma reactor, evacuated to 3-5 Pa, and argon gas is introduced at a flow rate of 20-30 mL / min. The plasma is treated with 100 W for 10-20 min. The treated zirconium phosphate is added to a hexadecyltrimethylammonium bromide ethanol solution at a solid-liquid ratio of 1:(8-12). The mixture is stirred at 50-60℃ and 200-300 rpm for 1-2 h. After vacuum filtration, the filter residue is vacuum dried at 90-100℃ for 4-5 h and ground to a particle size of 15-25 nm to obtain pretreated zirconium phosphate. The mass fraction of the hexadecyltrimethylammonium bromide ethanol solution is 3-5%.

6. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The melting and casting steps and parameters are as follows: First, add nickel blocks into the furnace, evacuate to below 0.005 Pa, heat to 1500-1550℃ to melt, add chromium, molybdenum, tungsten, and niobium in sequence, keep warm and stir for 30-40 minutes, cool to 1450-1500℃, add ferrosilicon alloy and graphite powder, keep warm and stir for 20-25 minutes, finally add composite additives, keep warm and stir for 10-20 minutes, the stirring rate throughout is 55-65 rpm, the argon flow rate is 20-30 mL / min, the alloy liquid is allowed to stand at 1400-1450℃ for 10-20 minutes, and then cast into a water-cooled copper mold at a cooling rate of 5-8℃ / s. The ingot size is 100mm×400mm.

7. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The homogenization process and hot rolling process are as follows: For homogenization, the alloy ingot is first placed in a vacuum annealing furnace and evacuated to below 0.01 Pa. Then, the temperature is raised to 1150-1200℃ and held for 8-12 hours. During the holding process, the ingot is stirred at 30 rpm for 5 minutes every 2 hours and then cooled to room temperature at 3-5℃ / min. For hot rolling, the ingot is first preheated in a heating furnace at 1100-1150℃ for 2-3 hours. During preheating, nitrogen gas is introduced at a flow rate of 15-20 mL / min for protection. Then, the ingot is rolled using a two-roll hot rolling mill with an initial rolling temperature of 1050-1100℃ and a final rolling temperature greater than 850℃. The reduction per pass is 8-12%, and the total reduction is 70-80%. During the rolling process, the ingot is cooled with water mist at a rate of 10-15℃ / s. Finally, a hot-rolled slab with a thickness of 8-12 mm is obtained.

8. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The steps and parameters for cold rolling and intermediate annealing are as follows: After the hot-rolled slab is mechanically ground to remove the oxide scale, it is soaked in 5% dilute hydrochloric acid for 10-15 minutes, rinsed with deionized water until neutral, dried at 80°C for 1 hour, and then rolled in multiple passes using a four-roll cold rolling mill, with a reduction of 5-10% per pass and a rolling speed of 30-50 m / min, until the final thickness is 0.01-0.1 mm, thus obtaining the preliminary foil material.

9. The highly corrosion-resistant nickel-chromium-based alloy foil and its preparation method according to claim 1, characterized in that, The passivation treatment method is as follows: the preliminary foil is placed in the passivation solution and soaked at 50-60℃ for 1-5 minutes. After passivation, it is rinsed with deionized water until neutral and vacuum dried at 60℃ for 20-40 minutes. The passivation solution is prepared by compounding sodium hydroxide, sodium silicate, potassium molybdate, sodium citrate and distilled water in a mass ratio of (1-7):(3-6):(18-22):(5-10):1000 and adjusting the pH to 9-10.

10. A highly corrosion-resistant nickel-chromium-based alloy foil, characterized in that, It is prepared by the method for preparing highly corrosion-resistant nickel-chromium-based alloy foil according to any one of claims 1-9.

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