CN111348905A

CN111348905A - Magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate and preparation method thereof

Info

Publication number: CN111348905A
Application number: CN201910612116.3A
Authority: CN
Inventors: 马北越; 任鑫明; 石明东; 高陟
Original assignee: Yingkou Shixing Refractory Technology Co ltd
Current assignee: Yingkou Shixing Refractory Technology Co ltd
Priority date: 2019-07-08
Filing date: 2019-07-08
Publication date: 2020-06-30

Abstract

A magnesia micropowder reinforced aluminum zirconium carbon slide plate and a preparation method thereof are disclosed, wherein the main raw materials comprise fused corundum, zirconium mullite, aluminum powder, carbon, a bonding agent and magnesia micropowder, and the magnesium oxide micropowder is prepared by mixing, molding and heat treatment. According to the invention, high-activity magnesium oxide fine powder is introduced, and partial reaction can be carried out to form spinel during high-temperature treatment, so that the apparent porosity of the material is reduced, and ceramic bonding is formed. In addition, in the high-temperature service process, the spinel can also be used for dissolving manganese and iron in the slag, increasing the viscosity of the slag and improving the slag resistance. The invention has simple process design and obvious enhancement effect, and can be popularized to practical application in industry.

Description

Magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate and preparation method thereof

Technical Field

The invention belongs to the technical field of refractory materials for continuous casting, and mainly relates to a magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate and a preparation method thereof.

Background

A certain amount of carbon is added into the traditional oxide refractory material, so that two key performances of slag resistance and thermal shock resistance of the refractory material can be obviously improved, and the service life of the refractory material is effectively prolonged. The development and application of the carbon-containing refractory material greatly improve the metallurgical industry, in particular the development of ferrous metallurgy. However, carbon-containing refractory materials also have their own insurmountable drawbacks. One is poor oxidation resistance. Carbon, although poorly compatible with slag, is very easily oxidized. Upon oxidation, pores are formed, resulting in a decrease in slag resistance. Secondly, the recarburizing effect on the molten steel. In the refining and continuous casting stages, the content of inclusions in molten steel needs to be strictly controlled, otherwise, the tapping quality is seriously influenced. Particularly, for special steel such as low carbon steel and ultra-low carbon steel, the recarburization behavior of the high carbon refractory material can seriously affect the quality of the steel.

The continuous casting process is an important process after blast furnace iron making and converter (electric furnace) steel making. Consists of a steel ladle, a tundish, a crystallizer, a secondary cooling section and the like. The devices are connected by water gaps (long water gaps and submerged nozzles) and transmit molten steel. The slide plate brick is used for controlling the flow rate of molten steel. Since the slide plate brick needs to slide to control the flow rate of molten steel according to working conditions, high wear resistance is also required. Zirconia is commonly used to enhance the wear resistance and thermal shock resistance of slider materials. Because zirconia has low expansion and excellent wear resistance. Even so, higher performance skateboard materials are still needed.

Disclosure of Invention

The invention provides an aluminum zirconium carbon sliding plate material with relatively simple process and better performance on the basis of the prior art, and discloses a magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate and a preparation method thereof. . The sliding plate material prepared by the method has the advantages that magnesium aluminate spinel is formed by high-temperature in-situ reaction, and the apparent porosity, the mechanical property, the thermal shock resistance and the wear resistance are enhanced to a certain degree.

In order to achieve the purpose, the invention adopts the following technical scheme:

the magnesium oxide micro powder reinforced aluminum zirconium carbon slide plate is characterized in that the raw materials comprise fused corundum, zirconium mullite, aluminum powder, carbon, a bonding agent and magnesium oxide micro powder.

The purity of the fused corundum is more than or equal to 99.5%, the granularity of the fused corundum is 3-1 mm (25% -35%), and the granularity of the fused corundum is less than or equal to 1 mm (15% -20%).

The zirconium mullite has the purity of more than or equal to 99.5 percent, the granularity of 1-0.088 mm (15-20 percent) and the granularity of less than or equal to 0.088 mm (15-20 percent).

The purity of the aluminum powder is more than or equal to 99.5 percent, and the granularity is less than or equal to 0.044 mm (1-3 percent).

The carbon is high-purity graphite with the purity more than or equal to 98.5 percent and the granularity less than or equal to 0.044 mm (8-12 percent).

The binding agent is liquid phenolic resin, and the industrial purity is 2-5%.

The purity of the magnesium oxide micro powder is more than or equal to 99.5 percent, the granularity is less than or equal to 10 mu m (0.5-2.5 percent), and the magnesium oxide micro powder is added in the total mass of the raw materials.

The magnesium oxide micro powder reinforced aluminum zirconium carbon slide plate is characterized by comprising the following specific steps of mixing, molding and heat treatment.

The pressing and forming instrument is a hydraulic press and adopts single pressure maintaining forming. Keeping the pressure at 250-300 MPa for 1-3 min.

The heat treatment temperature is 1500-1700 ℃, and the heat preservation time is 5-8 h.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the magnesium oxide micro powder is introduced, so that the porosity, strength, thermal shock resistance and slag resistance of the aluminum-zirconium-carbon sliding plate material can be improved. The enhancement mechanism is in situ enhancement. Because the magnesia micropowder has high activity, the magnesia micropowder can react with alumina fine powder to form magnesia-alumina spinel (MgO + Al)₂O₃=MgA_l2O₄). The spinel has excellent strength and thermal shock resistance, and simultaneously, because the spinel is synthesized by in-situ chemistry, the spinel can form ceramic bonding on a matrix, and the integral strength of the material is improved. Further, the reaction expands by about 8% in volume, and pores (pores formed by oxidation of carbon) in the material can be made fine. Avoiding serious slag penetration and even damage caused by the increase of air holes. Secondly, the spinel formed in situ can also absorb part of manganese and iron in the slag to form a solid solution, so that the viscosity of the slag is increased. This is very advantageous for casting manganese killed steel.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1

The magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate is characterized by comprising 25% of fused corundum with the diameter of 3-1 mm and the diameter of less than or equal to 1 mm in a ratio of 20%, 20% of zirconium mullite with the diameter of 1-0.088 mm and the diameter of less than or equal to 0.088 mm in a ratio of 20%, 2% of aluminum powder, 8% of high-purity graphite, 5% of liquid phenolic resin and 1.5% of magnesium oxide micro powder. The method comprises the specific steps of mixing, molding and heat treatment.

Wherein the pressing pressure is 250 MPa, and the pressure is maintained for 3 min. And keeping the temperature at 1600 ℃ for 5 h under the protection of argon.

The implementation of the detection result of the related performance:

the normal temperature compressive strength is 104.75 MPa, the high temperature rupture strength is 21.55 MPa, and the retention rate of the thermal shock resistance (4 times of thermal shock at 1000 ℃) is 72.99 percent. The sliding plate is simulated to be industrially cast in a laboratory, and the wear rate and the damage rate of the sliding plate are obviously reduced compared with those of the sliding plate without adding the magnesium oxide micro powder.

Example 2

The magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate is characterized in that raw materials comprise 30% of 3-1 mm fused corundum with the thickness being less than or equal to 1 mm and 18%, 18% of 1-0.088 mm zirconium mullite with the thickness being less than or equal to 0.088 mm and 20%, 3% of aluminum powder, 9% of high-purity graphite, 2% of liquid phenolic resin and 2.5% of magnesium oxide micro powder. The method comprises the specific steps of mixing, molding and heat treatment.

Wherein the pressing pressure is 280 MPa, and the pressure is maintained for 3 min. And preserving the temperature for 5 hours at 1700 ℃ under the protection of argon.

The implementation of the detection result of the related performance:

the normal temperature compressive strength is 114.52 MPa, the high temperature rupture strength is 27.61 MPa, and the thermal shock resistance (4 thermal shock at 1000 ℃) has the strength retention rate of 81.34%. The sliding plate is simulated to be industrially cast in a laboratory, and the wear rate and the damage rate of the sliding plate are obviously reduced compared with those of the sliding plate without adding the magnesium oxide micro powder.

Example 3

The magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate is characterized in that the raw materials comprise 35% of 3-1 mm fused corundum with the thickness not more than 1 mm and 18%, 15% of 1-0.088 mm zirconium mullite with the thickness not more than 0.088 mm and 16%, 1% of aluminum powder, 12% of high-purity graphite, 3% of liquid phenolic resin and 2.0% of magnesium oxide micro powder. The method comprises the specific steps of mixing, molding and heat treatment.

Wherein the pressing pressure is 300 MPa, and the pressure is maintained for 1 min. And keeping the temperature at 1600 ℃ for 8 h under the protection of argon.

The implementation of the detection result of the related performance:

the normal temperature compressive strength is 98.57 MPa, the high temperature rupture strength is 31.94 MPa, and the thermal shock resistance (4 thermal shock at 1000 ℃) has the strength retention rate of 84.24%. The sliding plate is simulated to be industrially cast in a laboratory, and the wear rate and the damage rate of the sliding plate are obviously reduced compared with those of the sliding plate without adding the magnesium oxide micro powder.

Example 4

The magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate is characterized by comprising 34% of fused corundum with the diameter of 3-1 mm and the diameter of 15% of fused corundum with the diameter of less than or equal to 1 mm, 19% of zirconium mullite with the diameter of 1-0.088 mm and the diameter of 15% of zirconium mullite with the diameter of less than or equal to 0.088 mm, 2% of aluminum powder, 12% of high-purity graphite, 3% of liquid phenolic resin and 0.9% of magnesium oxide micro powder. The method comprises the specific steps of mixing, molding and heat treatment.

Wherein the pressing pressure is 300 MPa, and the pressure is maintained for 2 min. And preserving the temperature for 8 h at 1500 ℃ under the protection of argon.

The implementation of the detection result of the related performance:

the normal temperature compressive strength is 89.76 MPa, the high temperature rupture strength is 23.59MPa, and the thermal shock resistance (4 thermal shock at 1000 ℃) has the strength retention rate of 79.18%. The sliding plate is simulated to be industrially cast in a laboratory, and the wear rate and the damage rate of the sliding plate are obviously reduced compared with those of the sliding plate without adding the magnesium oxide micro powder.

Example 5

The magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate is characterized in that the raw materials comprise 31% of fused corundum with the diameter of 3-1 mm and the diameter of 17% of fused corundum with the diameter of less than or equal to 1 mm, 19% of zirconium mullite with the diameter of 1-0.088 mm and the diameter of 17% of zirconium mullite with the diameter of less than or equal to 0.088 mm, 3% of aluminum powder, 9% of high-purity graphite, 4% of liquid phenolic resin and 0.5% of magnesium oxide micro powder. The method comprises the specific steps of mixing, molding and heat treatment.

Wherein the pressing pressure is 260 MPa, and the pressure is maintained for 3 min. And preserving the heat at 1700 ℃ for 6 h under the protection of argon.

The implementation of the detection result of the related performance:

the normal temperature compressive strength is 103.72 MPa, the high temperature rupture strength is 25.12 MPa, and the thermal shock resistance (4 thermal shock at 1000 ℃) has the strength retention rate of 80.58%. The sliding plate is simulated to be industrially cast in a laboratory, and the wear rate and the damage rate of the sliding plate are obviously reduced compared with those of the sliding plate without adding the magnesium oxide micro powder.

Claims

1. The magnesium oxide micro powder reinforced aluminum zirconium carbon slide plate is characterized in that the raw materials comprise fused corundum, zirconium mullite, aluminum powder, carbon, magnesium oxide micro powder and a bonding agent.

2. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof according to claim 1, wherein the purity of the electro-fused corundum is more than or equal to 99.5%, the granularity is 3-1 mm (25-35%), and the granularity is less than or equal to 1 mm (15-20%).

3. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof according to claim 1, wherein the zirconium mullite has a purity of not less than 99.5%, a particle size of 1-0.088 mm (15-20%), and not more than 0.088 mm (15-20%).

4. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof as claimed in claim 1, wherein the purity of the aluminum powder is more than or equal to 99.5%, and the particle size is less than or equal to 0.044 mm (1% -3%).

5. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof as claimed in claim 1, wherein the carbon is high purity graphite with purity more than or equal to 98.5% and particle size less than or equal to 0.044 mm (8% -12%).

6. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof as claimed in claim 1, wherein the purity of the magnesia micropowder is not less than 99.5%, and the particle size is not more than 10 μm (0.5% -2.5%).

7. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof as claimed in claim 1, wherein the binder is liquid phenolic resin with industrial purity (2% -5%).

8. The magnesium oxide micro powder reinforced aluminum zirconium carbon sliding plate and the preparation method thereof according to claim 8, wherein the press forming apparatus is a hydraulic press, and single pressure maintaining forming is adopted, wherein the pressure is 250-300 MPa, and the pressure is maintained for 1-3 min.

9. The magnesia micropowder reinforced aluminum zirconium carbon slide plate and the preparation method thereof according to claim 8, characterized in that the heat treatment temperature is 1500-1700 ℃, and the heat preservation time is 5-8 h.