阅读说明：本技术 一种中间合金及其制备方法 (Intermediate alloy and preparation method thereof ) 是由 王晓蓉 贾明 陈道华 马步洋 于 2020-07-22 设计创作，主要内容包括：本发明涉及一种中间合金及其制备方法,属于合金技术领域。所述的合金各组分的成分范围为：Mg:4-6％,C:<0.07％Max；Si:<0.2％Max；Co:<0.08％Max；Fe:<0.1％max；Ni:余量本发明还公开了NiMg5中间合金材料的制备方法。本发明公开的NiMg5中间合金产品,熔点1250-1350℃,MiMg5合金加入高温合金中可以降低高温合金中的氧含量。可以用用在航空发动机用高纯高温合金,燃气轮机涡轮用高温合金等。添加NiMg5中间合金可以提高高温合金的各项性能指标。本发明适用的熔炼方法采用两部中频感应熔炼方法,第一步先熔炼成NiMg20合金,第二步,利用NiMg20合金和镍原料,熔炼成NiMg5合金。该方法熔炼的NiMg5合金,Mg含量控制均匀,偏析小,镁烧损少,回收率高,氧氮含量低。(The invention relates to an intermediate alloy and a preparation method thereof, belonging to the technical field of alloys. The alloy comprises the following components in percentage by weight: 4 to 6 percent of Mg, and C is <0.07 percent of Max; si < 0.2% Max; co < 0.08% Max; fe < 0.1% max; the invention also discloses a preparation method of the NiMg5 intermediate alloy material. The NiMg5 intermediate alloy product disclosed by the invention has the melting point of 1250-. Can be used for high-purity high-temperature alloy for aeroengines, high-temperature alloy for gas turbine turbines and the like. The addition of the NiMg5 intermediate alloy can improve various performance indexes of the high-temperature alloy. The invention adopts a two-part medium frequency induction smelting method, wherein the first step is to smelt NiMg20 alloy, and the second step is to smelt NiMg5 alloy by using NiMg20 alloy and nickel raw materials. The NiMg5 alloy smelted by the method has the advantages of uniform Mg content control, small segregation, less magnesium burning loss, high recovery rate and low oxygen and nitrogen content.)

1. The intermediate alloy comprises 4-6% of Mg and less than 0.07% of C by mass percent; si < 0.2%; co is less than 0.08 percent; fe < 0.1%; o: < 0.01%, N < 0.015% and Ni in balance.

2. The method for preparing the master alloy of claim 1, comprising the steps of:

firstly, smelting NiMg20 alloy by adopting a nickel plate and a magnesium ingot, wherein the smelting power is 100-120 kilowatts, and the smelting time is 30-40 minutes to obtain NiMg20 alloy;

secondly, carrying out surface finishing treatment on the NiMg20 alloy, and crushing the NiMg20 alloy into alloy blocks with the diameter of less than 100mm for later use;

and thirdly, smelting the NiMg20 alloy and the nickel plate in a medium-frequency induction furnace to obtain the NiMg5 alloy.

And fourthly, cooling to room temperature after the alloy smelting is finished, and processing to the specified granularity.

3. The method for producing the master alloy according to claim 2, wherein: and the fourth step, the NiMg5 alloy is finished, and the shearing granularity is 5-50 mm.

4. The method for producing the master alloy according to claim 2, wherein: the content of Mg in the NiMg20 alloy in the first step is 18-22%.

5. The method for producing the master alloy according to claim 2, wherein: in the first step, Ni, Mg ═ (3.9-4.2) 1; and the smelting and cooling processes are protected by argon.

6. The method for producing the master alloy according to claim 2, wherein: in the third step, NiMg 20: 3, the melting power is 100-.

7. The method for producing the master alloy according to claim 2, wherein: the crucible used for smelting is a corundum-mullite crucible.

8. The method for producing the master alloy according to claim 2, wherein: the thickness of the alloy ingot is 20-50 mm.

Technical Field

The invention relates to an intermediate alloy and a preparation method thereof, belonging to the technical field of alloys.

Background

The nickel-magnesium alloy is an intermediate alloy (binary alloy) obtained by high-temperature smelting of metal nickel and metal magnesium, and the magnesium content is 15-50%. For nickel-magnesium alloy, because the melting point of nickel is 1452 ℃, the melting point of magnesium is 650 ℃, and metal magnesium also has the characteristics of high steam pressure, no induction and the like, the actual production difficulty is high, fire, smoke and even explosion are easily caused during smelting, the magnesium yield is extremely low, vacuum smelting is adopted in production, and the composition segregation is large. The product can be produced by a medium-frequency high-temperature furnace generally, and the current product has NiMg15 but has larger smoke dust. The traditional NiMg15-20 alloy has low use efficiency and much volatilization in the process of adding the high-temperature alloy.

Disclosure of Invention

The invention aims to provide an intermediate alloy and a preparation method thereof aiming at the defects in the prior art, and the use efficiency of the NiMg alloy is improved.

The invention solves the technical problem by the following technical scheme: the intermediate alloy comprises 4-6% of Mg and less than 0.07% of C by mass percent; si < 0.2%; co is less than 0.08 percent; fe < 0.1%; the balance being Ni. In order to improve the use efficiency of the NiMg alloy and reduce the volatilization of the NiMg alloy, the invention designs the NiMg5 intermediate alloy to replace the prior NiMg15-20 intermediate alloy.

Because the content of Mg in the NiMg5 alloy is lower, the uniformity of the components is not easy to control, the smelting effect is not good by adopting the traditional one-step method, the recovery rate is low, and the content of magnesium can not be uniformly controlled, however, the oxygen content in the high-temperature alloy can be reduced by adding the MiMg5 alloy into the high-temperature alloy, therefore, the invention further provides the preparation method of the NiMg5 alloy, which comprises the following steps:

firstly, smelting NiMg20 alloy by adopting a nickel plate and a magnesium ingot, wherein the smelting power is 100-120 kilowatts, and the smelting time is 30-40 minutes to obtain NiMg20 alloy;

secondly, carrying out surface finishing treatment on the NiMg20 alloy, and crushing the NiMg20 alloy into alloy blocks with the diameter of less than 100mm for later use;

and thirdly, smelting the NiMg20 alloy and the nickel plate in a medium-frequency induction furnace to obtain the NiMg5 alloy.

The method also comprises a fourth step of finishing the NiMg5 alloy with a shearing granularity of 5-50 mm.

The content of Mg in the NiMg20 alloy in the first step is 18-22%.

In the first step, Ni and Mg are 4:1, argon is adopted for protection in the smelting and cooling processes, the reaction with air is reduced as far as possible, and the NiMg5 alloy is low in oxygen and nitrogen content which can be less than 150 ppm. .

In the third step, NiMg 20: 3 (1-2), the melting power is 100-120 kilowatts, and the melting time is 30-50 minutes.

The crucible used for smelting is a corundum-mullite crucible.

The thickness of the cast alloy ingot is controlled to be 20-50mm, so that the specific gravity segregation is reduced, and the subsequent crushing work is facilitated.

The smelting method adopts a two-part medium frequency induction smelting method, wherein the first step is to smelt the NiMg20 alloy, and the second step is to smelt the NiMg5 alloy by utilizing the NiMg20 alloy and nickel raw materials. The NiMg5 alloy smelted by the method has the advantages of uniform Mg content control, small segregation, less magnesium burning loss, high recovery rate and low oxygen and nitrogen content.

The NiMg5 intermediate alloy has low content of various impurities and high purity, and is suitable for being added and applied in high-quality high-temperature alloys. Compared with one-step smelting, the two-step smelting method can stably control the burning loss of the magnesium of the NiMg5 alloy, the magnesium content in the product is uniform, the deviation of the magnesium content of different sampling points of different heats can be controlled within 0.3%, the difference of the magnesium among different heats can be controlled within 0.3%, and the product stability is good. The beneficial effects are as follows: high purity high temperature alloys for aircraft engines, high temperature alloys for gas turbine turbines, and the like. And various performance indexes of the high-temperature alloy can be improved by adding the NiMg5 intermediate alloy.

Detailed Description