阅读说明：本技术 一种提高AlV55合金成品质量的方法 (Method for improving quality of AlV55 alloy finished product ) 是由 陈海军 尹丹凤 余彬 叶明峰 于 2020-06-10 设计创作，主要内容包括：本发明提供一种提高AlV55合金成品质量的方法,该方法包括以下步骤：步骤1：将五氧化二钒和铝粒原料按照一定配比混合均匀；步骤2：将混合好的物料倒入到反应器中,引燃镁带触发反应,进行铝热还原冶炼；步骤3：向反应器的熔体内通入惰性气体进行熔池搅拌；步骤4：对反应器进行水冷；步骤5：向反应器的熔体上方通入惰性气体进行吹扫；步骤6：冷却后,经喷砂破碎处理得到AlV55合金成品。采用本发明的方法制备AlV55合金,可以提高其成品质量,使得成品中钒含量可控制在59％～59.6％,合金成品率可提高到70％以上。(The invention provides a method for improving the quality of an AlV55 alloy finished product, which comprises the following steps: step 1: mixing vanadium pentoxide and aluminum particle raw materials uniformly according to a certain proportion; step 2: pouring the mixed materials into a reactor, igniting a magnesium strip to trigger reaction, and carrying out aluminothermic reduction smelting; and step 3: introducing inert gas into the melt of the reactor to stir a molten pool; and 4, step 4: water cooling the reactor; and 5: introducing inert gas to the upper part of the melt of the reactor for purging; step 6: and after cooling, performing sand blasting and crushing treatment to obtain an AlV55 alloy finished product. The method for preparing the AlV55 alloy can improve the quality of finished products, control the vanadium content in the finished products to be 59-59.6% and improve the alloy yield to be more than 70%.)

1. A method for improving the quality of an AlV55 alloy finished product is characterized by comprising the following steps:

step 1: mixing vanadium pentoxide and aluminum particle raw materials uniformly according to a certain proportion;

step 2: pouring the mixed materials into a reactor, igniting a magnesium strip to trigger reaction, and carrying out aluminothermic reduction smelting;

and step 3: introducing inert gas into the melt of the reactor to stir a molten pool;

and 4, step 4: water cooling the reactor;

and 5: introducing inert gas to the upper part of the melt of the reactor for purging;

step 6: and after cooling, performing sand blasting and crushing treatment to obtain an AlV55 alloy finished product.

2. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein in step 1, the weight ratio of vanadium pentoxide to aluminum particles is 1.12: 1-1.9: 1.

3. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein the particle size of vanadium pentoxide is less than or equal to 120 meshes, and the particle size of metallic Al is less than or equal to 80 meshes.

4. The method for improving the quality of the finished AlV55 alloy according to claim 1, wherein in step 3, inert gas is blown into the melt in the reactor through a lance to stir the molten pool.

5. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein in the step 3, inert gas is introduced for molten pool stirring 1-2 min after smelting is finished, and the stirring time is controlled within 20-40 s.

6. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein the inert gas introduced in step 3 is high-pressure gas, and the pressure of the inert gas is controlled to be between 2atm and 3 atm.

7. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein in the step 4, water cooling is started 3-5 min after smelting is finished, and the water cooling lasts for 5-8 hours.

8. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein the water cooling is performed through cooling water pipes spirally arranged around the periphery of the reactor, and the diameter ratio of the cooling water pipes to the reactor is 1: 20-1: 10, the flow rate of the cooling water is 0.5 to 1 m/s.

9. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein in the step 5, after smelting is finished, inert gas is introduced into the upper part of the molten pool of the reactor for purging, and the inert gas introduction time is 5-8 hours.

10. The method for improving the quality of the AlV55 alloy finished product according to claim 1, wherein in the step 5, the flow rate of the inert gas is kept between 1 and 5m³/h。

Technical Field

The invention relates to the field of metallurgy, in particular to a method for improving the quality of an AlV55 alloy finished product.

Background

The vanadium-aluminum alloy is used as an important additive of titanium alloy, is commonly used for improving the performance of the titanium alloy, has more advantages in the aspects of strength, toughness, formability, corrosion resistance, high temperature resistance and the like, and is an important material for manufacturing seaplanes, gliders, automobile engine systems, automobile chassis parts, golf clubs and medical devices.

With the rapid development of the economy of China and the continuous improvement of the consumption level of people, the national defense strength and the space navigation strength of China are obviously enhanced, and the titanium alloy applied to the fields of civil industry and aerospace has a great growth tendency. China mainly adopts AlV55 alloy to prepare Ti-6Al-4V alloy, so the market demand is very large, but the quality (especially the yield) of the AlV55 alloy finished product prepared by a one-step method is generally not high at present, although the unqualified product can be taken as a coolant in a melting way, the loss of the total vanadium amount is not large, but the production cost is always high.

Based on this, the prior art still remains to be improved.

Disclosure of Invention

In order to solve the technical problems, the embodiment of the invention provides a method for improving the quality of an AlV55 alloy finished product, and the method can effectively solve the problems of low quality and high cost of an AlV55 alloy finished product prepared by a one-step method.

According to the invention, the method for improving the quality of the AlV55 alloy finished product comprises the following steps:

step 1: mixing vanadium pentoxide and aluminum particle raw materials uniformly according to a certain proportion;

step 2: pouring the mixed materials into a reactor, igniting a magnesium strip to trigger reaction, and carrying out aluminothermic reduction smelting;

and step 3: introducing inert gas into the melt of the reactor to stir a molten pool;

and 4, step 4: water cooling the reactor;

and 5: introducing inert gas to the upper part of the melt of the reactor for purging;

step 6: and after cooling, performing sand blasting and crushing treatment to obtain an AlV55 alloy finished product.

According to an embodiment of the invention, in the step 1, the weight ratio of the vanadium pentoxide to the aluminum particles is 1.12: 1-1.9: 1.

According to one embodiment of the invention, the vanadium pentoxide has a particle size of 120 mesh or less and the metallic Al has a particle size of 80 mesh or less.

According to one embodiment of the invention, in step 3, inert gas is introduced into the melt in the reactor through a lance, the outside of which is coated with a refractory material, to stir the molten bath.

According to an embodiment of the invention, in the step 3, inert gas is introduced for stirring the molten pool 1-2 min after smelting, and the stirring time is controlled within 20-40 s.

According to an embodiment of the invention, in the step 3, the introduced inert gas is a high-pressure gas, and the pressure of the inert gas is controlled to be between 2atm and 3 atm.

According to an embodiment of the invention, in the step 4, water cooling is started 3-5 min after smelting is finished, and the water cooling lasts for 5-8 hours.

According to one embodiment of the invention, the periphery of the reactor can be spirally provided with cooling water pipes for water cooling, and the diameter ratio of the cooling water pipes to the reactor is 1: 20-1: 10, the flow rate of the cooling water is 0.5 to 1 m/s.

According to an embodiment of the invention, in the step 5, after smelting is finished, inert gas is introduced into the upper part of the molten pool of the reactor for purging, wherein the inert gas introduction time is 5-8 hours.

According to one embodiment of the invention, in the step 5, the flow rate of the inert gas is kept between 1 and 5m³/h。

By adopting the technical scheme, the invention at least has the following beneficial effects:

on the basis of one-step aluminothermic reduction, the method adopts high-purity raw materials to reduce the intake of impurity elements, adopts inert gas to stir a molten pool to control alloy segregation, adopts water cooling to control alloy phase change, and adopts inert gas purging to reduce alloy oxidation and nitridation, thereby improving the quality of AlV55 alloy finished products, and particularly improving the yield of AlV55 alloy to more than 70%. In addition, the method has the advantages of simple process, low equipment requirement, low cost and the like, can prepare the AlV55 alloy with the vanadium content controlled between 59 and 59.6 percent in high yield, and has wide market application prospect.

Drawings

Fig. 1 shows a process flow diagram of the method for improving the quality of the AlV55 alloy finished product according to the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments of the present invention are described in further detail with reference to the accompanying drawings.

The invention provides a method for improving the quality of an AlV55 alloy finished product, which comprises the following steps as shown in figure 1:

step 1: vanadium pentoxide (V)₂O₅) Mixing with aluminum (Al) particles in certain proportion;

step 2: pouring the mixed materials into a reactor, igniting a magnesium strip to trigger reaction, and carrying out aluminothermic reduction smelting;

and step 3: after smelting is finished, introducing inert gas into the melt of the reactor to stir a molten pool;

and 4, step 4: after smelting is finished, cooling the reactor by water;

and 5: after smelting is finished, introducing inert gas to the upper part of the melt of the reactor for purging;

step 6: and after cooling, performing sand blasting and crushing treatment to obtain an AlV55 alloy finished product.

In the step 1, vanadium pentoxide with the purity of not less than 99%, Si of not more than 0.15% and Fe of not more than 0.07% and aluminum particles with the purity of not less than 99% are adopted, and the adoption of high-purity raw materials is favorable for controlling the intake of impurity elements of the alloy, so that the quality of the AlV55 alloy meets the standard requirement. In the step 1, the weight ratio of vanadium pentoxide to aluminum particles is 1.12: 1-1.9: 1, and excessive aluminum particles are adopted, so that a vanadium-aluminum alloy can be formed by fusing the aluminum particles and metal vanadium in a reduction reaction process. In the step 1, preferably, the granularity of vanadium pentoxide is less than or equal to 160 meshes, and the granularity of metal Al is less than or equal to 120 meshes; more preferably, the particle size of the vanadium pentoxide is less than or equal to 120 meshes, and the particle size of the metal Al is less than or equal to 80 meshes, so that the uniform mixing of the raw materials, the full contact of the materials and the full reaction are ensured.

In the step 1, a certain amount of coolant can be added to reduce the unit furnace charge heat of the thermite reaction, so as to avoid serious splashing caused by over violent reaction, which is helpful for improving the safety. Preferably, AlV55 rejects can be used as coolant, which on the one hand contributes to cost reduction and on the other hand avoids the introduction of impurities. However, the present invention is not limited thereto, and other conventional coolants in the art, such as lime or fluorite, etc., may be used.

Wherein, in step 1, vanadium pentoxide and aluminium grain are packed into the material jar after weighing according to certain ratio misce bene, and this kind of mode compounding in-process material is lossless basically, can the accurate control material addition to because the material can make the material mix more evenly between the material of compounding in-process collision each other.

In the step 2, the mixed materials are poured into a reactor, and after the ignition magnesium tape triggers reaction, the mixed materials react in the reactor as follows: 3V₂O₅+10Al＝6V+5Al₂O₃. In one embodiment, after the mixed material is poured into the reactor and laid flat, a magnesium strip may be inserted into the material, and the reaction triggered by ignition of the magnesium strip. Although in the above examples the reaction is initiated by igniting the magnesium strip, the invention is not so limited and the reaction may be initiated by other means conventional in the art, for example, by electrically striking a titanium wire.

In step 3, after smelting, introducing inert gas into the melt of the reactor through a spray gun to stir the molten pool so as to promote the mass transfer and heat transfer processes of the molten pool and homogenize the components and temperature of the alloy liquid, thereby controlling alloy segregation. A lance may be inserted into the melt (i.e., the alloy liquid) from the top, side, or bottom of the reaction chamber to introduce inert gas. The lance inserted into the melt is externally coated with a refractory material to improve its service life. The spray gun is inserted into the position 1/3-1/2 of the liquid level height in the melt, in other words, the distance between the air outlet of the spray gun and the liquid level is 1/3-1/2 of the whole liquid level height, and the position is favorable for effective stirring and prevents over-stirring. The lance can spray the melt horizontally, vertically or obliquely. Specifically, the lance may be inserted vertically into the melt from the top and bottom so that the gas emitted by the lance is in a vertical jet, may be inserted horizontally into the melt from the side so that the gas emitted by the lance is in a horizontal jet, and may be inserted obliquely into the melt so that the gas emitted by the lance is in an oblique jet. In embodiments of the present application, a plurality of lances for bath stirring may be provided to simultaneously inject the melt horizontally and/or vertically and/or obliquely.

In the step 3, inert gas is introduced for stirring the molten pool 1-2 min after the smelting is finished, and the time of 1-2 min after the smelting is selected because the alloy liquid has good fluidity and can achieve a better stirring effect. The inert gas used here is high-pressure gas, the pressure should be controlled between 2-3 atm, too large or too small is not suitable, too large pressure easily causes the alloy liquid and the slag to be stirred together again, is not beneficial to alloy separation, and too small pressure can only play a local stirring effect. The stirring time of stirring the molten pool by using the inert gas is controlled to be 20-40 s, the stirring time is not too long or too short, the stirring time is too long, the fluidity of the alloy liquid is poor after the alloy liquid is cooled, the gas cannot be blown into the molten pool, the gas waste is caused, the time is too short, and the stirring effect is poor. The inert gas can be argon, helium, neon and the like.

In the step 4, water cooling is carried out on the reactor 3-5 min after smelting is finished so as to avoid the alloy phase from generating brittle phase and ensure complete separation of slag and gold. Specifically, the periphery of reactor can encircle to be equipped with condenser tube in the spiral, and the water inlet is located the downside, and it links to each other with the cooling water switch, and the delivery port is located the upside, and it links to each other with cooling water discharge pipe, and when consequently carrying out the water-cooling as required, through opening the cooling water switch, during water enters into condenser tube from the water inlet of downside, encircles the periphery of reactor, finally flows from the delivery port that is located the upside to play the purpose of cooling down the reactor. In order to carry out effective water cooling, the ratio of the diameter of the cooling water pipe to the diameter of the reactor is 1: 20-1: 10. for example, the reactor diameter is usually about 1m, and the diameter of the cooling water pipe may be set to 5 to 10 cm. The flow rate of the cooling water can be 0.5-1 m/s, so that the reactor can be effectively cooled. The water cooling operation can last for 5-8 hours, the temperature of the reactor is basically cooled to 80-100 ℃ after 5-8 hours, the phase can not change at this moment, only natural cooling is needed, the need of continuous water cooling is avoided, and the cost is unnecessarily increased when the reactor is continuously operated.

Wherein, in step 5, after smelting is finished, inert gas is blown into the upper part of the melt of the reactor through the spray gun for purging, which helps to prevent air from entering the liquid alloy to cause oxidation and nitridation of the alloy. The inert gas can be argon, helium, neon and the like. In the reaction process, a large amount of smoke generated in the reaction can prevent air from entering the liquid alloy, so that inert gas does not need to be introduced in the reaction process, but once the reaction is finished, a large amount of smoke is not generated any more, the air can be close to the liquid alloy to cause pollution, and the inert gas needs to be introduced in time after smelting is finished. The gas outlet of the spray gun can be arranged 5-10 cm away from the melt liquid level so as to effectively purge the melt. In addition, in order to further improve the purging effect, rotary purging may be performed.

In the step 5, inert gas is introduced for 5-8 hours to ensure that the alloy is not oxidized and nitrided due to air pollution. After smelting, the generated liquid alloy starts to be slowly cooled immediately, after the liquid alloy is cooled for 5-8 hours, the alloy on the outer side is basically solidified, oxidation and nitridation risks are basically avoided, the inert gas can be stopped from being introduced, the cost is reduced, and meanwhile waste is avoided. If the cooling time is insufficient and the inert gas feed is stopped prematurely, the risk of oxidation and nitridation of the alloy is greater.

Wherein, in the step 5, the flow rate of the inert gas is kept between 1 and 5m³H to ensure that the alloy is not contaminated by air causing oxidation and nitridation. The flow rate of the inert gas is in an optimal range, and the inert gas is not too small or too large, wherein the too small inert gas does not play a role in preventing the oxidation and the nitridation of the alloy, and the too large inert gas causes unnecessary waste and increases the cost.

It should be noted here that whether smelting is finished or not is judged according to the existence of splashing, the aluminothermic reaction is generally violent, the phenomenon of splashing exists, the reaction time is usually several minutes, and the reaction ending time is judged according to the fact that splashing does not occur any more on site. In addition, the inert gas introduced in step 3 and step 5 may be the same or different.

Although the execution order of step 3, step 4 and step 5 is described above, it should be understood that the execution order of step 3, step 4 and step 5 is not limited thereto, and they may be executed simultaneously or in an order different from that described above.

In step 6, after smelting, cooling for 24 hours, taking out the alloy cake from the reactor, removing corundum slag on the alloy cake, and if the alloy cake has a little slag, putting the alloy cake into a sand blasting machine to blast the alloy cake completely so as to minimize the loss of the alloy. The sand blasting can adopt iron sand and/or aluminum sand. And crushing the alloy cake after sand blasting to obtain an AlV55 alloy packaging finished product. The vanadium content of the AlV55 alloy is controlled to be 59-59.6%, when the crystallized phase of the alloy is more in a solid solution structure, the brittle phase is relatively less, and the alloy can generate less fine powder when being crushed.

Specific examples of the present invention are given below.