阅读说明：本技术 一种钢水定氢探头用透气陶瓷头及其制备方法 (Breathable ceramic head for molten steel hydrogen determination probe and preparation method thereof ) 是由 杨明江 杨德帆 杨德顺 宋道举 于 2019-09-06 设计创作，主要内容包括：一种钢水定氢探头用透气陶瓷头的制备方法,其特征在于,包括步骤：a)将镁稳定氧化锆粉体、镁铝尖晶石粉体及石墨粉以一定比例混合后,再加入总质量适量的粘结剂,经混匀、造粒后,经双面模压成型,得透气陶瓷头生坯；b)将透气陶瓷头生坯于90～120℃下进行干燥,再缓慢升温至500～700℃下进行排胶,然后缓慢升温至1500～1600℃后烧结1～2小时,再快速降温至800℃后自然冷却至室温,得透气陶瓷头成品。由本方法制得的钢水定氢探头用透气陶瓷头,其烧结后能够形成大量开口气孔,其气孔中位径为250μm左右,开气孔率可达30％,表观密度1.6g/cm<Sup>3</Sup>。其能够在良好透气的基础上不透钢水；其在保持良好透气性的基础上,还能够在正常测量状态下坚持70秒以上。(A preparation method of a breathable ceramic head for a molten steel hydrogen determination probe is characterized by comprising the following steps: a) mixing magnesium-stabilized zirconia powder, magnesia-alumina spinel powder and graphite powder in a certain proportion, adding a proper amount of binder in the total mass, uniformly mixing, granulating, and performing double-sided compression molding to obtain a gas-permeable ceramic head green body; b) drying the air-permeable ceramic head green body at 90-120 ℃, slowly heating to 500-700 ℃ for glue removal, slowly heating to 1500-1600 ℃, sintering for 1-2 hours, rapidly cooling to 800 ℃, and naturally cooling to room temperature to obtain the air-permeable ceramic head finished product. The air-permeable ceramic head for the molten steel hydrogen determination probe prepared by the method can form a large number of open pores after being sinteredThe median diameter of the pores is about 250 μm, the open pore rate can reach 30%, and the apparent density is 1.6g/cm 3 . The air-permeable steel sheet can not be penetrated by molten steel on the basis of good air permeability; on the basis of keeping good air permeability, the air permeability can be kept for more than 70 seconds under a normal measuring state.)

1. A preparation method of a breathable ceramic head for a molten steel hydrogen determination probe is characterized by comprising the following steps:

a) mixing magnesium-stabilized zirconia powder, magnesia-alumina spinel powder and graphite powder in a certain proportion, adding a proper amount of binder in the total mass, uniformly mixing, granulating, and performing double-sided compression molding to obtain a gas-permeable ceramic head green body;

b) drying the air-permeable ceramic head green body at 90-120 ℃, slowly heating to 500-700 ℃ for glue removal, slowly heating to 1500-1600 ℃, sintering for 1-2 hours, rapidly cooling to 800 ℃, and naturally cooling to room temperature to obtain the air-permeable ceramic head finished product.

2. The preparation method of the gas-permeable ceramic head for the molten steel hydrogen-determining probe according to claim 1, wherein the magnesium-stabilized zirconia powder is prepared by adding 0.1-5% by mass of a sintering promoter to a base powder, uniformly mixing, and sieving;

wherein the base powder comprises the following components in percentage by mole of 80% -99%: 0.1% -10%: 0.1% -5%: 0.1 to 5 percent of ZrO₂、MgO、Y₂O₃Mixing CaO to obtain the final product; the sintering accelerant consists of the following components in percentage by mole 10% -40%, 30% -60%: 20% -50%: 0.5 to 20 percent of Al₂O₃、SiO₂、TiO₂、Fe₂O₃Mixing to obtain the final product.

3. The method for preparing the gas-permeable ceramic head for the molten steel hydrogen determination probe according to claim 1, wherein the magnesia alumina spinel powder is composed of MgCO₃、Al₂O₃In a molar ratio of 1: 0.85-1.15, pre-sintering at 1000-1200 ℃ for 1.5-3 hours, grinding and sieving to obtain the product.

4. The method for preparing the gas-permeable ceramic head for the molten steel hydrogen determination probe according to claim 1, wherein the mixing ratio of the magnesium-stabilized zirconia powder, the magnesium aluminate spinel powder and the graphite powder is 10-30% by mass: 60% -75%: 5 to 20 percent.

5. The method for preparing the gas-permeable ceramic head for the molten steel hydrogen-determining probe according to claim 1, wherein the binder is PVA, and the addition amount of the PVA is 0.2-0.6% of the total mass of the magnesium-stabilized zirconia powder, the magnesia-alumina spinel powder and the graphite powder.

6. The method of manufacturing a porous ceramic head for a molten steel hydrogen probe according to claim 1, wherein the moisture content of the porous ceramic head green body is controlled to 3% to 5% after drying.

7. The method of manufacturing a porous ceramic head for a molten steel hydrogen probe according to claim 1, wherein the pressure at the time of double-sided press molding is controlled to 35 to 70 MPa.

8. The gas permeable ceramic head for a molten steel hydrogen probe according to claim 1, which is produced by the production method according to any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of material preparation, in particular to a breathable ceramic head for a molten steel hydrogen determination probe and a preparation method thereof.

Background

The hydrogen content in steel is an important performance index of steel, and online real-time measurement of the hydrogen content in the molten steel becomes an important means for improving the process control precision. Currently, an on-line hydrogen analyzer is widely used in the market, and a Hydris hydrogen determination system is adopted. The Hydris Hydrogen determination System measures the amount of hydrogen carried in the carrier gas (nitrogen) and then calculates the partial pressure of hydrogen in the molten steel based on Western Watt. Wherein, the nitrogen carrying hydrogen needs to be collected through the ventilating ceramic head on the hydrogen-determining probe. Because the system needs a certain time for balancing, the longer the time is, the closer the system state is to the balanced state, and the closer the measured data is to the real data.

Because the use environment is severe, the measurement environment is usually about 1600 ℃, and in the actual use process, the air holes of the air-permeable ceramic head can be gradually blocked by molten steel. When the existing hydrogen determination probe is used, the air-permeable ceramic head can only stand in molten steel for 30-70 seconds.

Disclosure of Invention

The technical problem to be solved is to provide a preparation method of the breathable ceramic head for the molten steel hydrogen determination probe, so that the prepared breathable ceramic head can be persisted for a longer time in a measurement state.

The technical scheme adopted for solving the technical problem is as follows:

a preparation method of a breathable ceramic head for a molten steel hydrogen determination probe comprises the following steps: a) mixing magnesium-stabilized zirconia powder, magnesia-alumina spinel powder and graphite powder in a certain proportion, adding a proper amount of binder in the total mass, uniformly mixing, granulating, and performing double-sided compression molding to obtain a gas-permeable ceramic head green body; b) drying the air-permeable ceramic head green body at 90-120 ℃, slowly heating to 500-700 ℃ for glue removal, slowly heating to 1500-1600 ℃, sintering for 1-2 hours, rapidly cooling to 800 ℃, and naturally cooling to room temperature to obtain the air-permeable ceramic head finished product.

Preferably, the magnesium-stabilized zirconia powder is prepared by adding 0.1-5% by mass of a sintering promoter into base powder, uniformly mixing and sieving;

wherein, theThe base powder comprises the following components in percentage by mole 80-99%: 0.1% -10%: 0.1% -5%: 0.1 to 5 percent of ZrO₂、MgO、Y₂O₃Mixing CaO to obtain the final product; the sintering accelerant consists of the following components in percentage by mole 10% -40%, 30% -60%: 20% -50%: 0.5 to 20 percent of Al₂O₃、SiO₂、TiO₂、Fe₂O₃Mixing to obtain the final product.

Preferably, the magnesia-alumina spinel powder consists of MgCO₃、Al₂O₃In a molar ratio of 1: 0.85-1.15, pre-sintering at 1000-1200 ℃ for 1.5-3 hours, grinding and sieving to obtain the product.

Preferably, the mixing ratio of the magnesium-stabilized zirconia powder, the magnesia-alumina spinel powder and the graphite powder is 10 to 30 mass percent: 60% -75%: 5 to 20 percent.

Preferably, the binder is PVA, and the addition amount thereof is 0.2-0.6% of the total mass of the magnesium-stabilized zirconia powder, the magnesia-alumina spinel powder and the graphite powder.

Preferably, after the air-permeable ceramic head green body is dried, the water content of the air-permeable ceramic head green body is controlled to be 3% -5%.

Preferably, the pressure at the time of double-sided press molding is controlled to be 35MPa to 70 MPa.

The invention also claims the breathable ceramic head for the molten steel hydrogen determination probe prepared by the preparation method.

The invention has the following advantages: the air-permeable ceramic head for the molten steel hydrogen determination probe prepared by the method can form a large number of open pores after sintering, the median diameter of the pores is about 250 mu m, the open pore rate can reach 30 percent, and the apparent density is 1.6g/cm³. The air-permeable steel sheet can not be penetrated by molten steel on the basis of good air permeability; on the basis of keeping good air permeability, the air permeability can be kept for more than 70 seconds under a normal measuring state.

Detailed Description