Corrosion-resistant high-toughness environment-friendly composite crystal film slurry for thin steel plate

Abstract

The invention discloses corrosion-resistant high-toughness environment-friendly composite crystal film slurry for a thin steel plate. The kyanite toughened glass ceramic is prepared by mixing the following components in parts by weight: 30-45 parts of kyanite toughened glass ceramic micro powder, 25-40 parts of polysilazane, 6-10 parts of zirconium oxychloride, 3-6 parts of blast furnace slag, 2-5 parts of vanadium dioxide, 1-4 parts of sodium carbonate, 3-7 parts of modified soft kaolin, 3-7 parts of barium titanate, 0.5-2 parts of a stabilizer and 1-3 parts of a toughening agent A, 3-6 parts by weight of a curing agent and 3-6 parts by weight of a solvent. The composite crystal film slurry is applied to the surface of a thin steel plate, the steel plate is effectively protected against corrosion of corrosive gas and liquid, and when the steel plate is distorted due to vibration, the composite crystal film material does not crack or peel off, does not generate creases and does not weaken the protection effect.

Description

Technical Field

[0001] The invention belongs to the field of functional coating films, and more specifically relates to a corrosion-resistant, high-toughness, and environmentally friendly composite crystal film slurry for thin steel plates. Background Art

[0002] Packing towers are widely used in chemical, petroleum, metallurgy, environmental protection and other fields. They are an important gas-liquid mass transfer equipment. In order to alleviate the wall flow effect and increase the mass transfer surface area, packing is arranged in the packed tower. Packing is the basic component for contact mass transfer between gas and liquid phases in the tower. Metal packing is widely used due to its thin processing wall, large porosity, large flux, small resistance, heat resistance, and high separation efficiency. Metal packing is generally made into regular packing or ball rings, Raschig rings and other shapes. Regardless of the shape, it is made of thin steel plates with a thickness of about 0.1-2mm. Thin steel plates are easily oxidized in high temperature and corrosive environments, leading to problems such as clogging and damage of packing. High temperature corrosion protection of thin steel plates is an important means to improve the life of packing and application effect.

[0003] The 0.1-2mm alloy steel in the tube bundle of tubular heat exchangers, plate heat exchanger plates and other heat exchange and heating devices also have the problems of corrosion damage and unreliable anti-corrosion measures. The existing technical means include metal surface passivation film anti-corrosion, but it is not enough to deal with the erosion of various corrosive elements. In the environment of small molecules and gaseous corrosive elements, the passivation film effect is not ideal. There is also metal surface enamel, which can resist high temperature and corrosion, but the substrate is in a vibrating working condition during the application process, and the enamel material has poor toughness and is easy to break. Therefore, a surface material with high toughness and resistance to multi-element corrosion is needed to protect thin steel plates. Summary of the invention

[0004] In order to solve some or certain problems existing in the above-mentioned prior art, the object of the present invention is to provide a corrosion-resistant, high-toughness, and environmentally friendly composite crystal membrane slurry for thin steel plates.

[0005] The present invention uses blast furnace slag, soft kaolin, diopside, magnesite, and calcium chrome garnet that are obtained naturally or through rough processing as part of the raw materials, replacing high-purity alumina powder, ultrafine silica powder and other high-energy consumption and pollution-prone industrial raw materials, and successfully develops an environmentally friendly composite crystal membrane slurry.

[0006] The present invention designs an environmentally friendly composite crystallization film slurry with high corrosion resistance and high toughness for thin steel plates by studying the toughening mechanism of glass-ceramics, the toughening mechanism of composite crystallization films, and the thermal stability of kyanite, and verifying through various corrosion element experiments. Corrosion prevention is achieved in two aspects. Firstly, the material itself does not react with corrosion elements and has chemical inertness. Secondly, the density of the crystallization film material is increased so that corrosion elements cannot penetrate the composite crystallization film material. The high toughness of the material is achieved by applying phase transformation toughening, whisker toughening, and grid microcrack toughening and other techniques to the composite crystallization film.

[0007] An environmentally friendly composite crystallization film slurry with high corrosion resistance and high toughness for thin steel plates according to the present invention is formed by mixing the following components: 30 - 45 parts by weight of kyanite toughened glass-ceramic micro-powder, 25 - 40 parts by weight of polysilazane, 6 - 10 parts by weight of zirconium oxychloride, 3 - 6 parts by weight of blast furnace slag, 2 - 5 parts by weight of vanadium dioxide, 1 - 4 parts by weight of sodium carbonate, 3 - 7 parts by weight of modified soft kaolin, 3 - 7 parts by weight of barium titanate, 0.5 - 2 parts by weight of stabilizer, 1 - 3 parts by weight of toughening agent A, 3 - 6 parts by weight of curing agent, and 3 - 6 parts by weight of solvent.

[0008] In a specific case, the raw material components of the kyanite toughened glass-ceramic micro-powder are: 20 - 25 parts by weight of boron oxide, 15 - 25 parts by weight of diopside, 5 - 10 parts by weight of aluminum hydroxide, 8 - 15 parts by weight of magnesite, 8 - 12 parts by weight of uvarovite, 5 - 8 parts by weight of vanadium dioxide, 3 - 6 parts by weight of aluminum fluoride, 4 - 8 parts by weight of titanium oxide, 2 - 5 parts by weight of crystallization agent, 0.5 - 3 parts by weight of flux, 1 - 3 parts by weight of toughening agent B, and 0.2 - 0.8 parts by weight of defoaming agent.

[0009] In a preferred case, the crystallization agent is calcium fluoride, the flux is a composition of sodium oxide and vanadium pentoxide, and the weight ratio of the two is 1:1. The toughening agent B is a composition of ytterbium oxide and samarium oxide, and the weight ratio of the two is 1:2. The defoaming agent is stearic acid.

[0010] In a specific case, the preparation process of the kyanite toughened glass-ceramic micro-powder is as follows:

[0011] (1) Mixing and melting: Mix all components, heat up to 1550°C - 1650°C, and the mixture becomes a homogenized molten state, clear and with bubbles discharged; cool down to 1180°C to 1200°C at a rate of 8 - 10°C / min and keep warm for 4 - 6 hours; continue to cool down to 770°C to 800°C at a rate of 4 - 6°C / min and keep warm for 8 - 10 hours; continue to cool down to room temperature at a rate of 10 - 15°C / min;

[0012] (2) Nucleation treatment: Heat the glassy mixture to 650°C to 700°C at a rate of 2 - 3°C / min and keep warm for 15 - 16 hours;

[0013] (3) Crystallization treatment: Continue to raise the temperature to 1250°C to 1300°C at a rate of 2 - 3°C / min, and hold for 10 - 12 hours; then continue to cool to room temperature at a rate of 1 - 2°C / min to obtain toughened glass-ceramics.

[0014] (4) Crushing and powder making: Crush the obtained kyanite toughened glass-ceramics and use a high-energy ball mill to make kyanite toughened glass-ceramics micro-powder with a particle size of 6 - 10μm.

[0015] Preferably, the stabilizer is neodymium oxide with a particle size of 200 - 500nm.

[0016] Preferably, the toughening agent A is nanocrystalline zirconia with a particle size of 10 - 50nm.

[0017] Preferably, the curing agent is acrylic acid, maleic acid or methacrylic acid.

[0018] Preferably, the solvent is one or more of n-octane, xylene, and acetone.

[0019] The production of the composite crystalline film slurry of the present invention is to put the raw materials into a high-speed disperser according to the designed ratio, disperse them evenly, then grind, filter and package to obtain the composite crystalline film slurry for use in the heating furnace tubes. The implementation steps of the application of the composite crystalline film are as follows:

[0020] (1) Pickle the surface of the thin steel plate to remove the oxide layer and impurities.

[0021] (2) At room temperature, evenly spray or dip the composite crystalline film slurry on the surface of the thin steel plate with a thickness of 20 - 60 microns.

[0022] (3) Remove moisture by natural drying.

[0023] (4) Bake to form a film and then it can be put into use, and the formed film will further undergo high-temperature reaction sintering during the operation of the heating furnace.

[0024] Performance tests show that the composite crystalline film applied to the thin steel plate has the properties of corrosion resistance and high toughness, and the realization of these properties is based on the following technical principles:

[0025] (1) The main structures of blast furnace slag and soft kaolin are stable silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons, which have a dense polymer network structure of amorphous and quasi-crystalline states. With this characteristic as the matrix structure of the crystalline film coating, alkali metal ions can be solid-soluted into the gaps of the network structure to form covalent bonds and ionic bonds, and the composite crystalline film can obtain higher toughness.

[0026] (2) During the heating process of the composite crystalline film slurry, polysilazane thermally decomposes to generate SiO2, SiCN, and a small amount of Si3N4. These phases all contribute to improving the high-temperature oxidation resistance, high-temperature creep resistance, hardness, thermal stability, and wear resistance of the composite crystalline film.

[0027] (3) The toughened glass-ceramic micro-powder is a near-zero porosity glass-ceramic with borosilicate glass as the matrix, kyanite as the main crystal phase, and fine mullite whiskers. Borosilicate glass has better thermal stability than single-component silica glass, and kyanite has high strength and excellent thermal shock performance. By adding rare-earth compounds ytterbium oxide and samarium oxide, the growth of kyanite grains can be inhibited. The kyanite in the glass-ceramic is fine and uniform, and the overall toughness of the material is improved. In addition, during the preparation of the glass-ceramic, aluminum hydroxide and diopside generate mullite whiskers at 1300°C under the action of a flux. Mullite whiskers are fine needle-like structures, which play the role of whisker reinforcement and toughening. When the composite crystalline film material is added with kyanite toughened glass-ceramic micro-powder as the skeleton structure, it cooperates with polysilazane to fill the micro-pores and large cracks in the material, making the composite crystalline film form a dense and highly tough coating material.

[0028] (4) During the heating process of the composite crystalline film slurry, barium titanate, soft kaolin, and blast furnace slag in it in situ generate aluminum titanate and sodium aluminum titanate needle-like crystals under the action of sodium carbonate, and the continuous growth of the needle-like crystals is inhibited under the action of rare-earth neodymium oxide. Eventually, a fine needle-like crystal structure is formed in the material, which plays a pinning effect. Aluminum titanate and sodium aluminum titanate further improve the toughness and strength of the composite crystalline film material. In addition, rare-earth elements promote the formation of a network of micro-cracks in the material, which can also improve the toughness of the material.

[0029] The composite crystalline film material of the present invention is applied to the surface of thin steel plates, which can significantly improve its corrosion resistance. Under the condition of vibration and distortion of thin steel plates, the composite crystalline film can still not generate cracks and fall off, protecting the base material. Specific Embodiments

[0030] The present invention will be described in detail below through specific embodiments. However, the uses and purposes of these exemplary embodiments are only used to illustrate the present invention, and do not constitute any form of limitation to the actual protection scope of the present invention, nor will the protection scope of the present invention be limited thereto.

[0031] The raw materials used in the specific embodiments of the present invention can all be obtained through the commercial market, and some of the raw materials can also be prepared by oneself through the following preparation methods.

[0032] Preparation Example 1: Kyanite Toughened Glass-Ceramic Micro-Powder

[0033] (1) Mixing and melting: Mix all components, heat up to 1550°C - 1650°C, and the mixture becomes a homogenized molten state, clear and free of bubbles; cool it down to 1180°C to 1200°C at a rate of 8 - 10°C / min and hold for 4 - 6 hours; continue to cool it down to 770°C to 800°C at a rate of 4 - 6°C / min and hold for 8 - 10 hours; continue to cool it down to room temperature at a rate of 10 - 15°C / min;

[0034] (2) Nucleation treatment: Heat the glassy mixture to 650°C to 700°C at a rate of 2 - 3°C / min and hold for 15 - 16 hours;

[0035] (3) Crystallization treatment: Continue to heat it to 1250°C to 1300°C at a rate of 2 - 3°C / min and hold for 10 - 12 hours; continue to cool it down to room temperature at a rate of 1 - 2°C / min to obtain kyanite toughened glass-ceramics;

[0036] (4) Crushing and powder making: Crush the obtained kyanite toughened glass-ceramics and use a high-energy ball mill to make kyanite toughened glass-ceramics micro-powder with a particle size of about 6 - 10μm.

[0037] Preparation Example 2: Nanocrystalline zirconia

[0038] Raw materials: ZrOCl2, NH3·H2O, CaCl2, NaOH, ammonia water, absolute ethanol

[0039] Process: Mix the aqueous solution of ZrOCl2 with the aqueous solutions of NH3·H2O, CaCl2, and NaOH in a certain proportion, then drop them into ammonia water under sufficient stirring for co-precipitation, then filter, wash away the residual Cl ions, wash and dry with absolute ethanol, and finally calcine at 650°C to prepare nanocrystalline zirconia.

[0040] Preparation Example 3: Modified soft kaolin

[0041] (1) Remove the structural water of soft kaolin by calcining at 550°C.

[0042] (2) Mix white clay with NaOH solution (2 - 5mol / L) and carry out hydrothermal reaction (100 - 120°C) for 5 hours.

[0043] (3) After washing and drying the mixture, obtain modified soft kaolin.

[0044] (4) Make the modified soft kaolin into raw materials with a particle size of 1 - 20μm.

[0045] Example 1

[0046] 30 parts by weight of kyanite toughened glass-ceramics powder, 40 parts by weight of polysilazane, 6 parts by weight of zirconium oxychloride, 3 parts by weight of blast furnace slag, 5 parts by weight of vanadium dioxide, 4 parts by weight of sodium carbonate, 3 parts by weight of modified soft kaolin, 3 parts by weight of barium titanate, 0.5 parts by weight of stabilizer, 1 part by weight of toughening agent A, 3 parts by weight of curing agent, 3 parts by weight of solvent.

[0047] Put the above raw materials into a high-speed dispersant, disperse evenly, then grind, filter and package to obtain the composite crystalline film slurry SEF1 of the present invention.

[0048] Among them, the raw material components of the kyanite toughened glass-ceramics powder are: 25 parts by weight of boron oxide, 20 parts by weight of diopside, 10 parts by weight of aluminum hydroxide, 15 parts by weight of magnesite, 8 parts by weight of uvarovite, 5 parts by weight of vanadium dioxide, 3 parts by weight of aluminum fluoride, 4 parts by weight of titanium oxide, 2 parts by weight of calcium fluoride, 0.25 parts by weight of sodium oxide, 0.25 parts by weight of vanadium pentoxide, 1 part by weight of ytterbium oxide, 2 parts by weight of samarium oxide, 0.2 parts by weight of stearic acid.

[0049] Among them, the stabilizer is neodymium oxide with a particle size of 200 - 500 nanometers.

[0050] Among them, the toughening agent A is nanocrystalline zirconia with a particle size of 10 - 50 nanometers.

[0051] Among them, the curing agent is acrylic acid and the solvent is n-octane.

[0052] Example 2

[0053] 30 parts by weight of kyanite toughened glass-ceramics powder, 30 parts by weight of polysilazane, 7 parts by weight of zirconium oxychloride, 4 parts by weight of blast furnace slag, 3 parts by weight of vanadium dioxide, 2 parts by weight of sodium carbonate, 7 parts by weight of modified soft kaolin, 7 parts by weight of barium titanate, 1 part by weight of stabilizer, 1.5 parts by weight of toughening agent A, 4 parts by weight of curing agent, 6 parts by weight of solvent.

[0054] Put the above raw materials into a high-speed dispersant, disperse evenly, then grind, filter and package to obtain the composite crystalline film slurry SEF2 of the present invention.

[0055] Among them, the raw material components of the kyanite toughened glass-ceramics powder are: 27 parts by weight of boron oxide, 18 parts by weight of diopside, 8 parts by weight of aluminum hydroxide, 13 parts by weight of magnesite, 10 parts by weight of uvarovite, 6 parts by weight of vanadium dioxide, 3 parts by weight of aluminum fluoride, 7 parts by weight of titanium oxide, 4 parts by weight of calcium fluoride, 1 part by weight of sodium oxide, 1 part by weight of vanadium pentoxide, 1 part by weight of ytterbium oxide, 2 parts by weight of samarium oxide, 0.4 parts by weight of stearic acid.

[0056] Among them, the stabilizer is neodymium oxide with a particle size of 200 - 500 nanometers.

[0057] Among them, toughening agent A is nanocrystalline zirconia with a particle size of 10 - 50 nanometers.

[0058] Among them, the curing agent is methacrylic acid, and the solvent is acetone and n - octane, with a ratio of 1:1.

[0059] Example 3

[0060] 45 parts by weight of kyanite - toughened glass - ceramic powder, 25 parts by weight of polysilazane, 6 parts by weight of zirconium oxychloride, 5 parts by weight of blast furnace slag, 2 parts by weight of vanadium dioxide, 1 part by weight of sodium carbonate, 5 parts by weight of modified soft kaolin, 4 parts by weight of barium titanate, 2 parts by weight of stabilizer, 3 parts by weight of toughening agent A, 3 parts by weight of curing agent, 3 parts by weight of solvent.

[0061] Put the above - mentioned raw materials into a high - speed dispersant, disperse them evenly, then grind, filter, and package to obtain the composite crystalline film slurry SEF3 of the present invention.

[0062] Among them, the raw material components of the kyanite - toughened glass - ceramic powder are: 30 parts by weight of boron oxide, 16 parts by weight of diopside, 8 parts by weight of aluminum hydroxide, 8 parts by weight of magnesite, 12 parts by weight of uvarovite, 8 parts by weight of vanadium dioxide, 6 parts by weight of aluminum fluoride, 8 parts by weight of titanium oxide, 3 parts by weight of calcium fluoride, 0.5 part by weight of sodium oxide, 0.5 part by weight of vanadium pentoxide, 0.5 part by weight of ytterbium oxide, 1 part by weight of samarium oxide, 0.2 part by weight of stearic acid.

[0063] Among them, the stabilizer is neodymium oxide with a particle size of 200 - 500 nanometers.

[0064] Among them, toughening agent A is nanocrystalline zirconia with a particle size of 10 - 50 nanometers.

[0065] Among them, the curing agent is maleic acid, and the solvent is n - octane, xylene, and acetone, with a ratio of 1:1:1.

[0066] Example 4

[0067] 40 parts by weight of kyanite - toughened glass - ceramic powder, 35 parts by weight of polysilazane, 6 parts by weight of zirconium oxychloride, 3 parts by weight of blast furnace slag, 2 parts by weight of vanadium dioxide, 1 part by weight of sodium carbonate, 3 parts by weight of modified soft kaolin, 3 parts by weight of barium titanate, 0.5 part by weight of stabilizer, 1 part by weight of toughening agent A, 3 parts by weight of curing agent, 3 parts by weight of solvent.

[0068] Put the above - mentioned raw materials into a high - speed dispersant, disperse them evenly, then grind, filter, and package to obtain the composite crystalline film slurry SEF4 of the present invention.

[0069] Among them, the raw material components of the kyanite toughened glass-ceramics powder are: 25 parts by weight of boron oxide, 12 parts by weight of diopside, 5 parts by weight of aluminum hydroxide, 14 parts by weight of magnesite, 12 parts by weight of uvarovite, 7 parts by weight of vanadium dioxide, 5 parts by weight of aluminum fluoride, 7 parts by weight of titanium oxide, 4 parts by weight of calcium fluoride, 1 part by weight of sodium oxide, 1 part by weight of vanadium pentoxide, 1 part by weight of ytterbium oxide, 2 parts by weight of samarium oxide, and 0.6 parts by weight of stearic acid.

[0070] Among them, the stabilizer is neodymium oxide, and the particle size is 200 - 500 nanometers.

[0071] Among them, toughening agent A is nanocrystalline zirconia, and the particle size is 10 - 50 nanometers.

[0072] Among them, the curing agent is acrylic acid, the solvent is xylene and acetone, and the ratio of the two is 1:1.

[0073] Comparative Example 1

[0074] Compared with Example 1, in Comparative Example 1, polysiloxazane is used instead of polysilazane in the formula, and other components and preparation processes are the same, and the composite crystalline film slurry SEF5 of the present invention is prepared.

[0075] Comparative Example 2

[0076] Compared with Example 1, in Comparative Example 2, barium titanate is not added in the formula, and other components and preparation processes are the same, and the composite crystalline film slurry SEF6 of the present invention is prepared.

[0077] Comparative Example 3

[0078] Compared with Example 1, in Comparative Example 3, aluminum hydroxide is not added in the kyanite toughened glass-ceramics formula, and other components and preparation processes are the same, and the composite crystalline film slurry SEF7 of the present invention is prepared.

[0079] Comparative Example 4

[0080] Compared with Example 1, in Comparative Example 4, toughening agent A (nanocrystalline zirconia) is not added in the formula, and other components and preparation processes are the same, and the composite crystalline film slurry SEF8 of the present invention is prepared.

[0081] Comparative Example 5

[0082] Compared with Example 1, in Comparative Example 5, toughening agent B (ytterbium oxide and samarium oxide) is not added in the kyanite toughened glass-ceramics formula, and other components and preparation processes are the same, and the composite crystalline film slurry SEF9 of the present invention is prepared.

[0083] Comparative Example 6

[0084] According to the sample SEC7 ratio in Chinese Patent CN109401387B "A Slurry Capable of Forming a Composite Crystalline Film", the composite crystalline film slurry SEF10 is prepared;

[0085] Performance test

[0086] Preparation of composite crystalline film / coating: Spraying was carried out using an air spray gun with a gun pressure of 0.25 MPa. The slurries prepared in the examples and comparative example SEF1-10 were respectively sprayed onto a thin steel plate substrate with a thickness of 40 μm. After pre-drying at 70 °C for 30 min, it was baked and cured in an oven at 150 °C according to the heating curve. After cooling, composite crystalline film / coating specimens were obtained. The specific heating regime is as follows: The total baking time is 26 hours. First, start to slowly heat up at room temperature, and the temperature is raised to 110 °C within 8 hours and kept at 110 °C for 4 hours. Then heat up again, and the temperature is raised to 350 °C within 4 hours and kept at 350 °C for 2 hours. Then heat up again, and the temperature is raised to 450 °C within 4 hours and kept at 450 °C for 4 hours to end the baking of the crystalline film / coating at this time.

[0087] To accurately test the performance of the composite crystalline film, the specimens were treated by simulating the heating furnace working conditions: The specimens were placed in a laboratory heating furnace and slowly heated to 230 °C and kept at this temperature for 24 hours. At this time, the composite crystalline film was exactly the same as that under the actual application working conditions. After natural cooling, the following test was started:

[0088] 1. Corrosion resistance test

[0089] Salt spray corrosion test was carried out in accordance with GB / T 2423.17-2024 "Environmental testing - Test Ka: Salt spray". The SEF1-10 composite crystalline film slurries prepared on thin steel plates were used for comparative testing in accordance with the national standard.

[0090] 2. Toughness test

[0091] The toughness test of the composite crystalline film was carried out in accordance with GB / T 30791-2014 "Paints and varnishes - T-bend test". The SEF1-10 composite crystalline film slurries prepared on thin steel plates were used for comparative testing in accordance with the national standard.

[0092] 3. Thermal shock performance test

[0093] The SEF1-10 composite crystalline film slurries were prepared on the same metal substrate. In an air atmosphere, they were respectively heated to 230 °C and kept at this temperature for 10 minutes and then water-cooled, and the cycle was repeated 20 times. The appearance damage of the composite crystalline film was compared, including cracking, peeling, falling off, and discoloration.

[0094] The results of the above tests are shown in Table 1.

[0095] Table 1 Comparison of performance test results of composite crystalline film

[0096]

[0097]

[0098] Conclusion:

[0099] 1. When comparing the embodiments of SEF1, SEF2, SEF3, and SEF4, when each component is within the preferred weight part range, the performance differences of the materials are very small and do not affect the performance of the composite crystalline film.

[0100] 2. Comparison between Example 1 and Comparative Example 1: When polysiloxonitride in Comparative Example 1 replaces polysilazane, the micro pores of the material cannot be filled. In the corrosion experiment, the material is prone to micro pitting corrosion. While the film layer formed by polysilazane is denser and can isolate the penetration of corrosive elements. In terms of toughness, since the strength and toughness of the SiO2, SiCN, and Si3N4 composite structure formed by polysilazane are higher than those of the simple SiO2 structure, there are tiny cracks in the toughness test of Comparative Example 1.

[0101] 3. Comparison between Example 1 and Comparative Example 2: Barium titanate is not added to the formulation of Comparative Example 2, so aluminotitanate and sodium aluminotitanate acicular crystals cannot be formed in the composite crystalline film material, losing the pinning effect, resulting in the failure to enhance the strength and toughness of the material, with an unsatisfactory toughness test effect and a slight decrease in thermal shock resistance.

[0102] 4. Comparison between Example 1 and Comparative Example 3: Aluminum hydroxide is not added to the toughened glass-ceramics formulation of Comparative Example 3, resulting in a significant reduction in the amount of mullite whiskers formed in the glass-ceramics. The whisker toughening effect is not ideal, and the "skeleton" strength and toughness of the material become poor, leading to the fracture of glass-ceramics particles during the toughness test. In the thermal shock experiment, due to the fracture of glass-ceramics particles, the overall strength of the material decreases, resulting in punctate spalling of the material.

[0103] 5. Comparison between Example 1 and Comparative Examples 4 and 5: Removing the toughening agent from the composite crystalline film formulation and the toughened glass-ceramics formulation. First, the composite crystalline film loses the toughening effect of nanocrystalline zirconia phase transformation. Second, the crystals in the glass-ceramics grow too large and unevenly. Both lead to a significant reduction in the overall toughness and strength of the material, and the corrosion test, toughness test, and thermal shock test effects all become worse.

[0104] 6. Compared with Comparative Example 6, the new invention uses a variety of toughening technologies, and its toughness is greatly improved. The new formulation is more suitable for application on the surface of thin steel plates and can resist material failure caused by substrate vibration.

[0105] It should be understood that the uses of these embodiments are only for illustrating the present invention and are not intended to limit the protection scope of the present invention. In addition, it should also be understood that after reading the technical content of the present invention, those skilled in the art can make various changes, modifications, and / or variations to the present invention, and all these equivalent forms also fall within the protection scope defined by the appended claims of this application.

Claims

1. A corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates, characterized in that: It is prepared by mixing the following components: 30-45 parts by weight of kyanite toughened microcrystalline glass powder, 25-40 parts by weight of polysilazane, 6-10 parts by weight of zirconium oxychloride, 3-6 parts by weight of blast furnace slag, 2-5 parts by weight of vanadium dioxide, 1-4 parts by weight of sodium carbonate, 3-7 parts by weight of modified soft kaolin, 3-7 parts by weight of barium titanate, 0.5-2 parts by weight of stabilizer, 1-3 parts by weight of toughening agent A, 3-6 parts by weight of curing agent and 3-6 parts by weight of solvent.

2. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The raw material components of the kyanite toughened microcrystalline glass powder are: 20-25 weight parts of boron oxide, 15-25 weight parts of diopside, 5-10 weight parts of aluminum hydroxide, 8-15 weight parts of dolomite, 8-12 weight parts of calcium chrome garnet, 5-8 weight parts of vanadium dioxide, 3-6 weight parts of aluminum fluoride, 4-8 weight parts of titanium oxide, 2-5 weight parts of crystallizer, 0.5-3 weight parts of flux, 1-3 weight parts of toughening agent B, and 0.2-0.8 weight parts of defoaming agent.

3. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 2, characterized in that: in, The crystallizing agent is calcium fluoride, the solvent is a combination of sodium oxide and vanadium pentoxide, the weight ratio of the two is 1:1, the toughening agent B is a combination of ytterbium oxide and samarium oxide, the weight ratio of the two is 1:2, and the defoaming agent is stearic acid.

4. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 2, characterized in that: The preparation process of the kyanite toughened glass-ceramic powder is as follows: (1) Mixing and melting: Mix all components, heat to 1550°C-1650°C, the mixture becomes a homogenized molten state, clarified and bubbles are discharged; reduce the temperature to 1180°C-1200°C at a rate of 8-10°C / min, and keep it at that temperature for 4-6 hours; continue to reduce the temperature to 770°C-800°C at a rate of 4-6°C / min, and keep it at that temperature for 8-10 hours; continue to reduce the temperature to room temperature at a rate of 10-15°C / min; (2) Nucleation treatment: The glass mixture is heated to 650°C to 700°C at a rate of 2-3°C / min and kept at this temperature for 15-16 hours; (3) Crystallization treatment: Continue to raise the temperature to 1250°C to 1300°C at a rate of 2-3°C / min, and keep it warm for 10-12 hours; continue to reduce the temperature to room temperature at a rate of 1-2°C / min, aluminum hydroxide, diopside and calcite generate kyanite crystals during the crystallization process, and finally obtain kyanite toughened micro-ceramics glass; (4) Crushing and powdering: The obtained kyanite toughened glass-ceramics are crushed and made into 6-10 μm kyanite toughened glass-ceramics powder using a high-energy ball mill.

5. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The blast furnace slag has a particle size of 1-50 μm.

6. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The modified soft kaolin has a particle size of 1-20 μm.

7. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The stabilizer is neodymium oxide with a particle size of 200-500nm.

8. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The toughening agent A is nanocrystalline zirconium oxide with a particle size of 10-50 nm.

9. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The curing agent is acrylic acid, maleic acid or methacrylic acid.

10. The corrosion-resistant, high-toughness, environmentally friendly composite crystal membrane slurry for thin steel plates according to claim 1, characterized in that: The solvent is one or more of n-octane, xylene and acetone.

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