High-temperature-resistant composite coating for induction coil of intermediate frequency furnace

Abstract

The invention discloses a high-temperature-resistant composite coating for an induction coil of an intermediate frequency furnace in the field of intermediate frequency furnaces. The high-temperature-resistant coating for the induction coil of the intermediate frequency furnace is prepared by preparing a modified fluorosilicone solvent, preparing coating powder and mixing the modified fluorosilicone solvent and the coating powder. The process flow is simple, and the prepared high-temperature-resistant coating for the induction coil of the intermediate frequency furnace can form a layer of compact glaze surface in a high-temperature environment, and has the characteristics of molten steel scouring resistance, water resistance, moisture resistance and good acid and alkali corrosion resistance. The device can bear the erosion of molten steel under the molten steel leakage condition of the intermediate frequency furnace, has an excellent protection effect on the induction coil of the intermediate frequency furnace, reduces the damage rate of the induction coil, prolongs the service life of the induction coil, improves the safety of the induction coil, and saves the cost.

Description

Technical Field

[0001] The invention relates to the technical field of medium frequency furnaces, in particular to a high-temperature resistant composite coating for an induction coil of a medium frequency furnace. Background Art

[0002] At present, most of the high-temperature resistant coatings for medium-frequency furnace induction coils sold on the market are organic insulating coatings, and there are also a small number of inorganic high-temperature resistant coatings. Overall, the temperature resistance of organic insulating coatings for medium-frequency furnace induction coils is mostly below 200°C, and a small number of inorganic high-temperature resistant coatings are below 300°C. There are problems such as insufficient heat resistance and easy peeling of the paint layer under high temperature conditions. Especially under special circumstances, the leakage of molten steel in the medium-frequency furnace directly corrodes the induction coil, which will cause serious consequences such as burning of the copper tube of the induction coil.

[0003] In view of the above problems existing in commonly used high-temperature resistant paints, it is necessary to develop a high-temperature resistant composite coating for medium-frequency furnace induction coils to solve the problems existing in the original coatings. Summary of the Invention

[0004] In order to overcome the deficiencies in the background technology, the present invention discloses a high-temperature resistant composite coating for an induction coil of a medium-frequency furnace.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: A high-temperature resistant composite coating for an induction coil of a medium-frequency furnace is characterized by comprising a modified fluorosilicone solvent and coating powder, wherein the modified fluorosilicone solvent contains 15-30wt% of trimethylsilane and perfluorooctene by weight and 70-85wt% of xylene; the coating powder is composed of 1-4wt% of yttrium oxide micropowder, 0.5-2wt% of cobalt oxide micropowder, 20-25wt% of aluminum oxide micropowder, 8-16wt% of chromium oxide micropowder, 8-15% of silicon carbide whiskers, and the remainder is silicon nitride micropowder.

[0006] The preparation method is as follows: (1) Preparation of modified fluorosilicone solvent: trimethylsilane and perfluorooctene are added to xylene at a weight ratio of 1:1 to 1.2, and 0.02% to 0.1% of the total mass of the reactants as a catalyst of chloroplatinic acid is added. The mixture is heated and stirred in a reactor for 60 to 100 minutes at a heating temperature of 60 to 100°C and a stirring rate of 450 to 800 r / min to obtain a modified fluorosilane compound. (2) Preparation of coating powder: Yttrium oxide micropowder, cobalt oxide micropowder, silicon nitride micropowder, aluminum oxide micropowder, chromium oxide micropowder, and silicon carbide whiskers are mixed and calcined in an argon atmosphere for 110 to 120 minutes at a calcination temperature of 1650 to 1750°C to obtain coating powder; (3) Coating preparation: The modified fluorosilicone solvent and coating powder are mixed evenly in a weight ratio of 1:1.2 to 1.5 to obtain a high-temperature resistant composite coating for the induction coil of a medium-frequency furnace.

[0007] Preferably, the purity of the yttrium oxide micropowder, cobalt oxide micropowder, silicon nitride micropowder, aluminum oxide micropowder, and chromium oxide micropowder is above 99.8%.

[0008] Preferably, the silicon carbide whisker has a diameter of 0.1 to 2 μm and a length of 30 to 80 μm.

[0009] Preferably, the stirring in step (3) is vigorous stirring at 450-800 r / min for 60-90 min.

[0010] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects: The process flow of the high-temperature resistant composite coating for the induction coil of the medium-frequency furnace disclosed by the present invention is simple. The prepared high-temperature resistant coating for the induction coil of the medium-frequency furnace will form a dense glaze under a high-temperature environment, and has the characteristics of being waterproof, moisture-proof, and resistant to acid and alkali corrosion. For the situation of molten steel leakage in the medium-frequency furnace, the present invention can withstand the erosion of the molten steel, has an excellent protective effect on the induction coil of the medium-frequency furnace, reduces the damage rate of the induction coil, improves the service life and safety of the induction coil, and saves costs. DETAILED DESCRIPTION Example 1

[0011] (1) Preparation of modified fluorosilicone solvent: trimethylsilane and perfluorooctene were added to xylene in a weight ratio of 1:1, with the sum of the mass of trimethylsilane and perfluorooctene being 15 wt% and the mass of xylene being 85 wt%. 0.02% of the total mass of the reactants in the form of chloroplatinic acid was added as a catalyst. The mixture was heated and stirred in a reactor for 60 min at a heating temperature of 90°C and a stirring rate of 450-800 r / min to obtain a modified fluorosilane compound. (2) Preparation of coating powder: 1 wt% yttrium oxide micropowder, 0.5 wt% cobalt oxide micropowder, 62.5 wt% silicon nitride micropowder, 20 wt% aluminum oxide micropowder, 8 wt% chromium oxide micropowder, and 8 wt% silicon carbide whiskers were mixed and calcined for 120 min under an argon atmosphere at a calcination temperature of 1650°C to obtain coating powder; (3) Coating preparation: The modified fluorosilicone solvent and coating powder were mixed evenly in a weight ratio of 1:1.2, and vigorously stirred at 450-800 r / min for 60 min to obtain a high-temperature resistant composite coating for the induction coil of a medium-frequency furnace. Example 2

[0012] (1) Preparation of modified fluorosilicone solvent: trimethylsilane and perfluorooctene were added to xylene at a weight ratio of 1:1.2, with the sum of the mass of trimethylsilane and perfluorooctene being 20 wt% and the mass of xylene being 80 wt%. 0.05% of the total mass of the reactants as catalyst chloroplatinic acid was added, and the mixture was heated and stirred in a reactor for 80 min at a heating temperature of 100°C and a stirring rate of 450-800 r / min to obtain a modified fluorosilane compound. (2) Preparation of coating powder: 2 wt% of yttrium oxide micropowder, 1 wt% of cobalt oxide micropowder, 53 wt% of silicon nitride micropowder, 22 wt% of aluminum oxide micropowder, 12 wt% of chromium oxide micropowder, and 10 wt% of silicon carbide whiskers were mixed and calcined for 120 min under an argon atmosphere at a calcination temperature of 1700°C to obtain coating powder; (3) Coating preparation: The modified fluorosilicone solvent and coating powder were mixed evenly in a weight ratio of 1:1.3, and vigorously stirred at 450-800 r / min for 70 min to obtain a high-temperature resistant composite coating for the induction coil of a medium-frequency furnace. Example 3

[0013] (1) Preparation of modified fluorosilicone solvent: trimethylsilane and perfluorooctene were added to xylene in a weight ratio of 1:1.1, with the sum of the mass of trimethylsilane and perfluorooctene being 25 wt% and the mass of xylene being 75 wt%. A catalyst of chloroplatinic acid was added at 0.07% of the total mass of the reactants, and the mixture was heated and stirred in a reactor for 100 min at a heating temperature of 60°C and a stirring rate of 450-800 r / min to obtain a modified fluorosilane compound. (2) Preparation of coating powder: 3 wt% yttrium oxide micropowder, 1.5 wt% cobalt oxide micropowder, 45 wt% silicon nitride micropowder, 24 wt% aluminum oxide micropowder, 14 wt% chromium oxide micropowder, and 12.5 wt% silicon carbide whiskers were mixed and calcined for 120 min under an argon atmosphere at a calcination temperature of 1725°C to obtain coating powder; (3) Coating preparation: The modified fluorosilicone solvent and coating powder were mixed evenly at a weight ratio of 1:1.45, and vigorously stirred at 450-800 r / min for 80 min to obtain a high-temperature resistant composite coating for the induction coil of a medium-frequency furnace. Example 4

[0014] (1) Preparation of modified fluorosilicone solvent: trimethylsilane and perfluorooctene were added to xylene at a weight ratio of 1:1.2, with the sum of the mass of trimethylsilane and perfluorooctene being 30 wt% and the mass of xylene being 70 wt%. 0.1% of the total mass of the reactants as catalyst chloroplatinic acid was added, and the mixture was heated and stirred in a reactor for 60 min at a heating temperature of 100°C and a stirring rate of 450-800 r / min to obtain a modified fluorosilane compound. (2) Preparation of coating powder: 4 wt% of yttrium oxide micropowder, 2 wt% of cobalt oxide micropowder, 44 wt% of silicon nitride micropowder, 25 wt% of aluminum oxide micropowder, 15 wt% of chromium oxide micropowder, and 10 wt% of silicon carbide whiskers were mixed and calcined for 120 min under an argon atmosphere at a calcination temperature of 1750°C to obtain coating powder; (3) Coating preparation: The modified fluorosilicone solvent and coating powder were mixed evenly at a weight ratio of 1:1.5, and vigorously stirred at 450-800 r / min for 90 min to obtain a high-temperature resistant composite coating for the induction coil of a medium-frequency furnace.

[0015] Comparative Example 1, existing medium frequency furnace induction coil insulating coating.

[0016] Table 1 Performance comparison of Examples 1-4 and Comparative Example 1

[0017] From the performance comparison of Examples 1 to 4 and Comparative Example 1 in Table 1, it can be seen that compared with the existing insulating coating for the induction coil of a medium frequency furnace, the present invention has higher temperature resistance and resistance to molten steel scouring.

[0018] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A high temperature resistant composite coating for an induction coil of a medium frequency furnace, characterized by: The invention comprises a modified fluorosilicone solvent and coating powder. The modified fluorosilicone solvent contains 15-30wt% of trimethylsilane and perfluorooctene by weight and 70-85wt% of xylene by weight. The coating powder comprises 1-4wt% of yttrium oxide micropowder, 0.5-2wt% of cobalt oxide micropowder, 20-25wt% of aluminum oxide micropowder, 8-16wt% of chromium oxide micropowder, 8-15% of silicon carbide whiskers, and the rest is silicon nitride micropowder.

2. The high-temperature resistant composite coating for the induction coil of a medium-frequency furnace according to claim 1, characterized in that: The preparation method is as follows: (1) Preparation of modified fluorosilicone solvent: trimethylsilane and perfluorooctene are added to xylene at a weight ratio of 1:1 to 1.2, and 0.02% to 0.1% of the total mass of the reactants as a catalyst of chloroplatinic acid is added. The mixture is heated and stirred in a reactor for 60 to 100 minutes at a heating temperature of 60 to 100°C and a stirring rate of 450 to 800 r / min to obtain a modified fluorosilane compound. (2) Preparation of coating powder: Yttrium oxide micropowder, cobalt oxide micropowder, silicon nitride micropowder, aluminum oxide micropowder, chromium oxide micropowder, and silicon carbide whiskers are mixed and calcined in an argon atmosphere for 110 to 120 minutes at a calcination temperature of 1650 to 1750°C to obtain coating powder; (3) Coating preparation: The modified fluorosilicone solvent and coating powder are mixed evenly in a weight ratio of 1:1.2 to 1.5, and stirred to obtain a high-temperature resistant composite coating for the induction coil of a medium-frequency furnace.

3. The high temperature resistant composite coating for the induction coil of a medium frequency furnace according to claim 1, characterized in that: The purity of the yttrium oxide micropowder, cobalt oxide micropowder, silicon nitride micropowder, aluminum oxide micropowder and chromium oxide micropowder is above 99.8%.

4. The high-temperature resistant composite coating for the induction coil of a medium-frequency furnace according to claim 1, characterized in that: The diameter of silicon carbide whiskers is 0.1 to 2 μm and the length is 30 to 80 μm.

5. The high temperature resistant composite coating for the induction coil of a medium frequency furnace according to claim 2, characterized in that: The stirring in step (3) is vigorous stirring at 450-800 r / min for 60-90 min.

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