CN104211411A - ZrO2-BN ceramic material submerged nozzle and its preparation method - Google Patents

Abstract

The invention provides a ZrO2-BN ceramic material submerged nozzle and its preparation method. The submerged nozzle comprises, by mass, 70-95% of ZrO2, 5-35% of BN, 0-5% of an antioxidant and 1-5% of ZrBr2. The preparation method comprises the following steps: putting above materials in a ball mill, carrying out ball milling, granulating and mixing, putting the ball-milled raw materials in a die, carrying out cold isostatic compaction under a molding pressure of 80-160MPa, carrying out nitridation sintering in a nitridation furnace under a heating rate of 1-2DEG C/min, and carrying out heat insulation for 5-7 after the sintering. BN with strong oxidation resistance and with same structure with graphite is adopted to substitute a graphite material with low oxidation resistance in traditional materials. High temperature treatment makes the above material have a high high-temperature thermal shock stability and substantially improved oxidation resistance, so the service life is improved.

Description

ZrO 2-BN stupalith submerged nozzle and preparation method thereof

Technical field

The present invention relates to refractory material for immersed sprue field, specifically a kind of ZrO ₂-BN stupalith submerged nozzle and preparation method thereof.

Background technology

Along with scientific-technical progress, era development, after entering 21 century, in order to adapt to the development of sequence casting, many stoves continuous casting.Be developed the intrusive mood mouth of a river of multiple reinforcement.Provide high-quality, efficient, multi-functional continuous casting intrusive mood nozzle material.

Continuous casting aluminum-carbon refractory material is commonly called as continuous-casting three-main-product, primarily of long nozzle, integral stopper rod, submerged nozzle composition.Submerged nozzle is as one of continuous-casting three-main-product product, and the effect such as play flow control in casting process, dam, its importance is self-evident, can be described as the critical function element ensureing that casting process carries out smoothly.

All the time, the anti-oxidation matter of utmost importance being carbonaceous material always and needing to solve.From use experience in the past, metal powder coordinates the anti-oxidation measure of non-oxidized substance always in occupation of the dominant position of this respect.BN has the structure same with graphite-phase, so not only have good thermostability, and its antioxidant property is obviously better than graphite material.A certain amount of ZrBr is added in this ₂, its antioxidant property is significantly improved.

Existing submerged nozzle material is greatly mainly with Al-SiC-C matter, ZrO ₂-C material is main, wherein ZrO ₂the method that-BN material is used for submerged nozzle is not also reported, relevant use properties also has no its report.

Summary of the invention

The present invention, in order to solve the problem of prior art, provides a kind of ZrO ₂-BN stupalith submerged nozzle and preparation method thereof, makes the antioxidant property at the intrusive mood mouth of a river and work-ing life greatly improve.

ZrO provided by the invention ₂-BN stupalith submerged nozzle comprises the material composition of following mass percent: zirconium white (ZrO ₂) 70%-95%, boron nitride (BN) 10%-35%, antioxidant 0%-5% and bonding agent 1%-5%.BN is utilized to substitute traditional material ZrO ₂the material of C in-C.

Described ZrO ₂granularity be 1000 order ~ 1500 orders.

Described antioxidant is ZrBr ₂.

Present invention also offers a kind of ZrO ₂the preparation method of-BN stupalith submerged nozzle, comprises the following steps:

1) raw material is put into ball mill, carry out ball milling granulation batch mixing, ball-milling technology Ball-milling Time is positive and negative each 1-2 hour;

2) raw material that ball milling is good is put into mold cold isostatic pressing, forming pressure is 80-160MPa;

3) nitridation sintered in nitriding furnace, heat-up rate is 1-2 DEG C/min, at 0 DEG C ~ 900 DEG C, sinter 1-2 hour, at 900 DEG C ~ 1200 DEG C, sinter 2-3 hour, insulation 5-7 hour.

Beneficial effect of the present invention is:

1, adopt oxidation-resistance comparatively strong and there is the isostructural boron nitride of graphite-phase and replace the graphite material that in traditional material, antioxidant property is lower.

2, by pyroprocessing, make material not only have relatively high high temperature thermal shock resistance and be greater than 5 times, antioxidant property improves greatly simultaneously, and under equal conditions, its work-ing life can reach 8-10 times.

Embodiment

Below in conjunction with embodiment, the invention will be further described.

Embodiment one:

Novel ZrO ₂-BN material and preparation process as follows:

The first step is by ZrO ₂, BN, ZrBr ₂and corresponding bonding agent is by total mass 70%ZrO ₂, 25%BN, 5%ZrBr ₂and the bonding agent of 5% mixes;

Second step adopts isostatic cool pressing by material forming, and pressure forming pressure is 80MPa, 200 DEG C of dryings 1 hour, and room temperature leaves standstill 48 hours;

Big for step 2 gained body is placed in nitriding furnace nitridation sintered by the 3rd step, with the speed of 1 DEG C/min, sinters 2 hours, between 900 DEG C ~ 1200 DEG C 2 hours, be incubated 5 hours between 0 DEG C ~ 900 DEG C.Obtain the performance at the mouth of a river in table one.

Embodiment two

Novel ZrO ₂-BN material and preparation process as follows:

The first step is by ZrO ₂, BN, ZrBr ₂and corresponding bonding agent is by total mass 85%ZrO ₂, 13%BN, 1%ZrBr ₂and the bonding agent of 1% mixes;

Second step adopts isostatic cool pressing by material forming, and pressure forming pressure is 120MPa, 200 DEG C of dryings 1 hour, and room temperature leaves standstill 48 hours;

Big for step 2 gained body is placed in nitriding furnace nitridation sintered by the 3rd step, with the speed of 1.5 DEG C/min, sinters 1 hour, between 900 DEG C ~ 1200 DEG C 2.5 hours, be incubated 6 hours between 0 DEG C ~ 900 DEG C.Obtain the performance at the mouth of a river in table one.

Embodiment three

Novel ZrO ₂-BN material and preparation process as follows:

The first step is by ZrO ₂, BN, ZrBr ₂and corresponding bonding agent is by total mass 93%ZrO ₂, 5%BN, 1%ZrBr ₂and the bonding agent of 1% mixes;

Second step adopts isostatic cool pressing by material forming, and pressure forming pressure is 120MPa, 200 DEG C of dryings 1 hour, and room temperature leaves standstill 48 hours;

Big for step 2 gained body is placed in nitriding furnace nitridation sintered by the 3rd step, with the speed of 2 DEG C/min, sinters 2 hours, between 900 DEG C ~ 1200 DEG C 3 hours, be incubated 7 hours between 0 DEG C ~ 900 DEG C.Obtain the performance at the mouth of a river in table one.

Comparative example is conventional ZrO ₂submerged nozzle prepared by-C material.

Example	Apparent porosity/%	Volume density/g/cm 3	Folding strength Mpa	Compressive strength Mpa	Heat-shock resistance (secondary)
						1	16	2.4	7	23	9
2	14.7	2.35	6.6	22	8
						3	15.4	2.43	6.7	24	8
Contrast	16.2	2.3	6.5	23	8

Embody rule approach of the present invention is a lot, and the above is only the preferred embodiment of the present invention, should be understood that; for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvement, these improvement also should be considered as protection scope of the present invention.

Claims (5)

1. a ZrO ₂-BN stupalith submerged nozzle, is characterized in that the material composition comprising following mass percent: zirconium white 70%-95%, boron nitride 5%-35%, antioxidant 0%-5% and bonding agent 1%-5%.

2. ZrO according to claim 1 ₂-BN stupalith submerged nozzle, is characterized in that: described ZrO ₂granularity be 1000 order ~ 1500 orders.

3. ZrO according to claim 1 ₂-BN stupalith submerged nozzle, is characterized in that: described antioxidant is ZrBr ₂.

4. ZrO described in more than one any one claims ₂the preparation method of-BN stupalith submerged nozzle, is characterized in that comprising the following steps:

1) raw material is put into ball mill, carry out ball milling granulation batch mixing;

2) raw material that ball milling is good is put into mold cold isostatic pressing, forming pressure is 80-160MPa;

3) nitridation sintered in nitriding furnace, heat-up rate is 1-2 DEG C/min, at 0 DEG C ~ 900 DEG C, sinter 1-2 hour, at 900 DEG C ~ 1200 DEG C, sinter 2-3 hour, insulation 5-7 hour.

5. ZrO according to claim 4 ₂the preparation method of-BN stupalith submerged nozzle, is characterized in that: described ball-milling technology Ball-milling Time is positive and negative each 1-2 hour.