Silicon carbide castable

Abstract

The invention relates to the technical field of castable, and discloses a silicon carbide castable which comprises main materials and auxiliary materials, the main materials comprise 30-70 parts of silicon carbide particles, 5-20 parts of micro powder which is silicon carbide micro powder, 5-20 parts of nano aluminum oxide, 5-20 parts of a phase change material and 5-20 parts of reinforced fibers, and the auxiliary materials comprise a binding agent, an additive, a heat stabilizer, a high-heat-conductivity additive and an antioxidant. The phase-change material is a metal alloy phase-change material, and the reinforcing fiber is 5-20 parts of steel fiber. The binding agent is 10-15 parts of pure calcium aluminate cement, and the additive is 3-5 parts. In the preparation process of the silicon carbide castable, the steel fiber, the metal alloy phase change material and the graphite are added, the overall performance of the silicon carbide castable can be remarkably improved, the steel fiber can remarkably improve the toughness and mechanical strength of the silicon carbide castable, the castable can be effectively prevented from being heated to deform at a high temperature, shrinkage is inhibited, and a good prevention and treatment effect on microcracks is achieved; therefore, the overall stability and durability of the pouring material are improved.

Description

Technical Field

[0001] The invention relates to the technical field of castables, in particular to a silicon carbide castable. Background Art

[0002] Silicon carbide castable is a high-performance amorphous refractory material. Silicon carbide has excellent wear resistance, oxidation resistance and corrosion resistance. These characteristics make silicon carbide castable have excellent stability and durability in high temperature, high pressure and corrosive environment. Therefore, silicon carbide castable is widely used in various high-temperature industrial kilns and heat treatment equipment. Existing silicon carbide castables are easily corroded in environments with oxidizing gases (such as oxygen, water vapor, carbon monoxide, carbon dioxide) and iron oxide. At the same time, due to the poor water solubility of silicon carbide, the fluidity of silicon carbide castables in water-based amorphous refractory materials sometimes deteriorates. The reduction in fluidity will affect the density of the castable, which may affect its overall performance and life. In addition, silicon carbide castables are difficult to obtain high strength in the absence of sintering. In high-pressure vessels and pipelines, since the material needs to withstand huge internal pressure, it is difficult for traditional silicon carbide castables to obtain high strength. Summary of the invention

[0003] The purpose of the present invention is to provide a silicon carbide castable which can effectively solve the problems in the background technology.

[0004] To achieve the above object, the technical solution adopted by the present invention is: A silicon carbide casting material comprises a main material and auxiliary materials, wherein the main material comprises silicon carbide particles, micropowder, nano-alumina, a phase change material and reinforcing fibers, and the auxiliary materials comprise a binder, an additive, a heat stabilizer, a high thermal conductivity additive and an antioxidant. The silicon carbide particles comprise 30-70 parts, the micropowder comprises 5-20 parts of silicon carbide micropowder, the nano-alumina comprises 5-15 parts, the phase change material comprises 5-10 parts of a metal alloy phase change material, and the reinforcing fibers comprise 5-20 parts of steel fibers; the binder comprises 10-15 parts of pure calcium aluminate cement, the additive comprises 3-5 parts, the heat stabilizer comprises 2-4 parts, the high thermal conductivity additive comprises 3-8 parts of graphite, and the antioxidant comprises 2-4 parts.

[0005] As a further preferred embodiment of the present invention, the silicon carbide particle size is 0.063 mm (ie 240 mesh) to 0.015 mm (ie 1200 mesh).

[0006] As a further preferred embodiment of the present invention, the nano-alumina has a purity greater than 95% and a particle size of 10nm-100nm.

[0007] As a further preferred embodiment of the present invention, the additive further comprises a water reducer, a retarder and a plasticizer, wherein the water reducer is 2-4 parts, the retarder is 1-3 parts and the plasticizer is 3-6 parts.

[0008] As a further preferred embodiment of the present invention, the graphite purity is above 99%, the graphite particle size is required to be 5 μm-150 μm, and the graphite thermal conductivity is required to be 80 w / (m·k)-151 w / (m·k).

[0009] As a further preferred embodiment of the present invention, the metal alloy phase change material is an aluminum alloy, and the thermal expansion coefficient of the aluminum alloy is selected as (25°C （100℃）的平均线膨胀系数介于（6.7） 8.4) × 10^-6 / K, the density of the aluminum alloy is required to be between 2.5 and 2.9 g / cm³.

[0010] As a further preferred embodiment of the present invention, the steel fiber has a diameter of 0.2 mm to 1.2 mm, an aspect ratio of 30:1 to 80:1, a specific surface area of ​​50 m² / kg to 75 m² / kg, and a curvature of 30 mm to 40 mm.

[0011] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, during the preparation process of silicon carbide casting material, steel fiber, metal alloy phase change material and graphite are added, which can significantly improve its overall performance. Steel fiber can significantly improve the toughness and mechanical strength of silicon carbide casting material, can effectively prevent the casting material from being deformed by heat at high temperature, inhibit shrinkage, and has a good preventive effect on micro cracks, thereby improving the overall stability and durability of the casting material. The addition of metal alloy phase change materials can further improve the thermal stability and thermal shock resistance of silicon carbide castables. It can undergo phase change when the temperature changes, absorb or release heat, thereby adjusting the temperature of the castable and improving its thermal shock resistance. The addition of graphite can increase the electrical conductivity, thermal conductivity and oxidation resistance of silicon carbide, thereby improving the comprehensive performance of silicon carbide castables. At the same time, it can play a lubricating role in the preparation process and improve the fluidity of the castables. DETAILED DESCRIPTION

[0012] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods. Example

[0013] The present invention provides a silicon carbide casting material, comprising a main material and auxiliary materials, wherein the main material comprises silicon carbide particles, micropowder, nano-alumina, phase change material and reinforcing fiber, and the auxiliary materials comprise a binder, an additive, a heat stabilizer, a high thermal conductivity additive and an antioxidant; Silicon carbide particles are 30-70 parts, micropowder is 5-20 parts of silicon carbide micropowder, nano alumina is 5-15 parts, phase change material is metal alloy phase change material 5-10 parts, and reinforcing fiber is 5-20 parts of steel fiber; the binder is pure calcium aluminate cement 10-15 parts, the additive is 3-5 parts, the heat stabilizer is 2-4 parts, the high thermal conductivity additive is graphite 3-8 parts, and the antioxidant is 2-4 parts.

[0014] The particle size of silicon carbide is 0.063mm (i.e. 240 mesh) to 0.015mm (i.e. 1200 mesh), the purity of nano alumina is greater than 95%, and the particle size is 10nm-100nm. The additives also include water reducer, retarder, and plasticizer. The water reducer is 2-4 parts, the retarder is 1-3 parts, and the plasticizer is 3-6 parts. The purity of graphite is more than 99%, the graphite particle size is required to be 5μm-150μm, and the thermal conductivity of graphite is required to be 80w / (m·k) -151w / (m·k). The metal alloy phase change material is aluminum alloy, and the thermal expansion coefficient of aluminum alloy is selected as (25℃ （100℃）的平均线膨胀系数介于（6.7） 8.4) × 10^-6 / K, the density of the aluminum alloy is required to be between 2.5 and 2.9 g / cm³, the diameter of the steel fiber is between 0.2 mm and 1.2 mm, the aspect ratio is between 30:1 and 80:1, the specific surface area is between 50 m² / kg and 75 m² / kg, and the curvature is between 30 mm and 40 mm. Example

[0015] It includes main materials and auxiliary materials. The main materials include silicon carbide particles, micro powder, nano-alumina, phase change materials and reinforcing fibers. The auxiliary materials include binders, additives, thermal stabilizers, high thermal conductivity additives and antioxidants. Silicon carbide particles are 40-80 parts, micropowder is silicon carbide micropowder 7-22 parts, nano alumina is 7-17 parts, phase change material is metal alloy phase change material 7-12 parts, and reinforcing fiber is steel fiber 7-22 parts; the binder is pure calcium aluminate cement 12-17 parts, the additive is 5-8 parts, the heat stabilizer is 4-6 parts, the high thermal conductivity additive is graphite 5-10 parts, and the antioxidant is 4-6 parts.

[0016] The particle size of silicon carbide is 0.063mm (i.e. 240 mesh) to 0.015mm (i.e. 1200 mesh), the purity of nano alumina is greater than 95%, and the particle size is 10nm-100nm. The additives also include water reducer, retarder, and plasticizer. The water reducer is 2-4 parts, the retarder is 1-3 parts, and the plasticizer is 3-6 parts. The purity of graphite is more than 99%, the graphite particle size is required to be 5μm-150μm, and the thermal conductivity of graphite is required to be 80w / (m·k) -151w / (m·k). The metal alloy phase change material is aluminum alloy, and the thermal expansion coefficient of aluminum alloy is selected as (25℃ （100℃）的平均线膨胀系数介于（6.7） 8.4) × 10^-6 / K, the density of the aluminum alloy is required to be between 2.5 and 2.9 g / cm³, the diameter of the steel fiber is between 0.2 mm and 1.2 mm, the aspect ratio is between 30:1 and 80:1, the specific surface area is between 50 m² / kg and 75 m² / kg, and the curvature is between 30 mm and 40 mm. Example

[0017] It includes main materials and auxiliary materials. The main materials include silicon carbide particles, micro powder, nano-alumina, phase change materials and reinforcing fibers. The auxiliary materials include binders, additives, thermal stabilizers, high thermal conductivity additives and antioxidants. Silicon carbide particles are 45-83 parts, micropowder is 8-23 parts of silicon carbide micropowder, nano alumina is 8-118 parts, phase change material is metal alloy phase change material 8-13 parts, and reinforcing fiber is 8-23 parts of steel fiber; the binder is pure calcium aluminate cement 13-18 parts, the additive is 6-9 parts, the heat stabilizer is 5-7 parts, the high thermal conductivity additive is graphite 6-11 parts, and the antioxidant is 5-7 parts.

[0018] The particle size of silicon carbide is 0.063mm (i.e. 240 mesh) to 0.015mm (i.e. 1200 mesh), the purity of nano alumina is greater than 95%, and the particle size is 10nm-100nm. The additives also include water reducer, retarder, and plasticizer. The water reducer is 2-4 parts, the retarder is 1-3 parts, and the plasticizer is 3-6 parts. The purity of graphite is more than 99%, the graphite particle size is required to be 5μm-150μm, and the thermal conductivity of graphite is required to be 80w / (m·k) -151w / (m·k). The metal alloy phase change material is aluminum alloy, and the thermal expansion coefficient of aluminum alloy is selected as (25℃ （100℃）的平均线膨胀系数介于（6.7） 8.4) × 10^-6 / K, the density of the aluminum alloy is required to be between 2.5 and 2.9 g / cm³, the diameter of the steel fiber is between 0.2 mm and 1.2 mm, the aspect ratio is between 30:1 and 80:1, the specific surface area is between 50 m² / kg and 75 m² / kg, and the curvature is between 30 mm and 40 mm.

[0019] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A silicon carbide castable, characterized in that: The invention comprises main materials and auxiliary materials, wherein the main materials include silicon carbide particles, micropowder, nano-aluminum oxide, phase change material and reinforcing fiber, and the auxiliary materials include binder, additive, heat stabilizer, high thermal conductivity additive and antioxidant; The silicon carbide particles are 30-70 parts, the micropowder is 5-20 parts of silicon carbide micropowder, the nano alumina is 5-15 parts, the phase change material is 5-10 parts of metal alloy phase change material, and the reinforcing fiber is 5-20 parts of steel fiber; the binder is 10-15 parts of pure calcium aluminate cement, the additive is 3-5 parts, the heat stabilizer is 2-4 parts, the high thermal conductivity additive is 3-8 parts of graphite, and the antioxidant is 2-4 parts.

2. A silicon carbide castable according to claim 1, characterized in that: The silicon carbide particle size is 0.063 mm (ie 240 mesh) to 0.015 mm (ie 1200 mesh).

3. A silicon carbide castable according to claim 1, characterized in that: The nano-alumina has a purity greater than 95% and a particle size of 10nm-100nm.

4. A silicon carbide castable according to claim 1, characterized in that: The additives also include a water reducer, a retarder, and a plasticizer. The water reducer is 2-4 parts, the retarder is 1-3 parts, and the plasticizer is 3-6 parts.

5. The silicon carbide castable according to claim 1, characterized in that: The graphite purity is above 99%, the graphite particle size is required to be between 5 μm and 150 μm, and the graphite thermal conductivity is required to be between 80 w / (m·k) and 151 w / (m·k).

6. A silicon carbide castable according to claim 1, characterized in that: The metal alloy phase change material is an aluminum alloy, and the thermal expansion coefficient of the aluminum alloy is selected as (25°C （100℃）的平均线膨胀系数介于（6.7） 8.4) × 10^-6 / K, the density of the aluminum alloy is required to be between 2.5 and 2.9 g / cm³.

7. The silicon carbide castable according to claim 1, characterized in that: The steel fiber has a diameter of 0.2 mm to 1.2 mm, an aspect ratio of 30:1 to 80:1, a specific surface area of ​​50 m² / kg to 75 m² / kg, and a curvature of 30 mm to 40 mm.