阅读说明：本技术 一种氮化合金重熔加密方法及其系统 (Remelting and encrypting method and system for nitrided alloy ) 是由 吕韬 李秦灿 于洪翔 于 2020-05-21 设计创作，主要内容包括：本发明属于金属熔炼领域,具体涉及一种氮化合金重熔加密方法及其系统。所述氮化合金重熔加密方法,包括：(1)将掺有增强剂的低密度氮化合金放入变频感应炉中,于氮气气氛下进行冶炼；(2)到达冶炼终点后,在氮气气氛下将部分合金液浇铸入锭模；(3)在氮气气氛下将合金锭模运至精整跨并冷却。本发明的氮化合金重熔加密方法,可以有效提高合金的密度和强度,降低含水率,满足下游钢铁工业用户的需求。(The invention belongs to the field of metal smelting, and particularly relates to a remelting and encrypting method and a remelting and encrypting system for a nitrided alloy. The remelting and encrypting method for the nitrided alloy comprises the following steps: (1) placing the low-density nitrided alloy doped with the reinforcing agent into a variable frequency induction furnace, and smelting in a nitrogen atmosphere; (2) after the smelting end point is reached, casting part of alloy liquid into an ingot mold in a nitrogen atmosphere; (3) the alloy ingot mold was transported to the finishing span and cooled under a nitrogen atmosphere. The remelting and encrypting method for the nitrided alloy can effectively improve the density and the strength of the alloy, reduce the water content and meet the requirements of downstream steel industry users.)

1. A remelting and densifying method for a nitride alloy is characterized by comprising the following steps:

(1) placing the low-density nitrided alloy doped with the reinforcing agent into a variable frequency induction furnace, and smelting in a nitrogen atmosphere;

(2) after the smelting end point is reached, casting part of alloy liquid into an ingot mold in a nitrogen atmosphere;

(3) the alloy ingot mold was transported to the finishing span and cooled under a nitrogen atmosphere.

2. The method of remelting and densifying a nitride alloy according to claim 1, wherein the strengthening agent is iron powder.

3. The method of remelting and densifying a nitride alloy according to claim 1, wherein the low density nitride alloy is one of silicon series, manganese series, vanadium series, and chromium series.

4. The method for remelting and densifying nitrided alloy according to claim 3, wherein the low-density nitrided alloy is one of ferrosilicon nitride, ferromanganese nitride, manganese silicon nitride, ferrovanadium nitride, vanadium-nitrogen silicon, and ferrochromium nitride.

5. The method for remelting and densifying a nitride alloy according to claim 1, wherein in the step (2), 85% -90% of the alloy liquid is poured into the ingot mold under a nitrogen atmosphere by hydraulic tilting.

6. The method for remelting and densifying a nitride alloy according to claim 1, wherein the purity of the nitrogen gas is not less than 99.99%.

7. The method for remelting and densifying a nitride alloy according to claim 1, wherein the temperature of the smelting is 1250 to 2100 ℃, and the time period of the smelting is 12 to 30 min-t^-1。

8. The method for remelting and densifying a nitride alloy according to claim 1, wherein the judgment criterion of the smelting end point is that the furnace pressure tends to be stable without significant change after the alloy is completely melted.

9. A nitride alloy remelting encryption system for carrying out the nitride alloy remelting encryption method according to any one of claims 1 to 8, comprising:

the variable frequency induction furnace is used for smelting low-density nitrided alloy;

the ingot mould is used for casting the nitriding alloy molten steel and solidifying the nitriding alloy molten steel into an ingot;

the chute is positioned between the variable frequency induction furnace and the ingot mold and is used for guiding the molten nitrided alloy steel to the ingot mold from the variable frequency induction furnace;

the casting nitrogen pipeline is positioned on one side of the chute and used for blowing nitrogen into the chute;

and the ingot mould nitrogen introducing pipeline is positioned at one side of the ingot mould and is used for blowing nitrogen into the ingot mould.

10. The nitride alloy remelting encryption system of claim 9, further comprising:

a trolley for transporting the ingot mold;

the steel rail and the winch are positioned below the trolley to pull the trolley;

and the dust removal system is positioned at the upper part of the nitriding alloy remelting and encrypting system and is used for removing high-temperature dust-containing smoke.

Technical Field

The invention belongs to the field of metal smelting, and particularly relates to a remelting and encrypting method and a remelting and encrypting system for a nitrided alloy.

Background

Nitrogen plays a major role in solid solution strengthening and age precipitation strengthening in steel and is therefore an important alloying element. After the steel is doped with partial nitrogen, the strength, hardness, wear resistance, corrosion resistance and the like are improved, and the steel is an excellent engineering material, so that the steel is widely applied to the fields of transportation, chemical industry, biological medicine, sports equipment and the like.

The addition of nitriding alloys in steel making is the predominant nitriding method. At present, the production methods of the nitralloy are many, the adopted equipment, the process flow and the parameters are different, the product quality of each manufacturer is different, the problems of low density, low strength, high water content and the like generally exist, and if the nitralloy is directly applied to the steel industry, the absorptivity of molten steel is influenced, so that further treatment is needed.

At present, most manufacturers adopt an electroslag remelting furnace to remelt the nitriding alloy, and utilize resistance heat generated when current passes through slag as a heat source to smelt. However, in this way, the alloy melting speed is slow, the burning loss is large, the power consumption is high, and in addition, an additional slagging agent needs to be introduced, so that the cost is increased.

In recent years, induction heating technology has been receiving attention and favoured by manufacturers due to its characteristics of high heating speed, high production efficiency, energy saving, no pollution and the like.

Disclosure of Invention

The invention aims to provide a remelting and encrypting method and a remelting and encrypting system for a nitride alloy, aiming at the defects of the prior art.

Specifically, the remelting and encrypting method for the nitride alloy comprises the following steps:

(1) placing the low-density nitrided alloy doped with the reinforcing agent into a variable frequency induction furnace, and smelting in a nitrogen atmosphere;

(2) after the smelting end point is reached, casting part of alloy liquid into an ingot mold in a nitrogen atmosphere;

(3) the alloy ingot mold was transported to the finishing span and cooled under a nitrogen atmosphere.

In the remelting and encrypting method for the nitrided alloy, the reinforcing agent is iron powder.

According to the remelting and encrypting method for the nitrided alloy, the low-density nitrided alloy is one of silicon series, manganese series, vanadium series and chromium series.

According to the remelting and encrypting method for the nitrided alloy, the low-density nitrided alloy is one of ferrosilicon nitride, ferromanganese nitride, manganese silicon nitride, ferrovanadium nitride, vanadium-nitrogen alloy and chromium-iron nitride.

In the remelting and encrypting method for the nitrided alloy, in the step (2), a furnace is hydraulically dumped, and 85 to 90 percent of alloy liquid is cast into an ingot mold in a nitrogen atmosphere.

According to the remelting and encrypting method for the nitrided alloy, the purity of the nitrogen is more than or equal to 99.99%.

According to the remelting and encrypting method for the nitrided alloy, the smelting temperature is 1250-2100 ℃, and the smelting time is 12-30 min-t^-1。

According to the remelting and encrypting method for the nitrided alloy, the judgment standard of the smelting end point is that the furnace pressure tends to be stable and has no obvious change after the alloy is completely melted.

In another aspect, the present invention provides a nitride alloy remelting encryption system for implementing the above nitride alloy remelting encryption method, including:

the variable frequency induction furnace is used for smelting low-density nitrided alloy;

the ingot mould is used for casting the nitriding alloy molten steel and solidifying the nitriding alloy molten steel into an ingot;

the chute is positioned between the variable frequency induction furnace and the ingot mold and is used for guiding the molten nitrided alloy steel to the ingot mold from the variable frequency induction furnace;

the casting nitrogen pipeline is positioned on one side of the chute and used for blowing nitrogen into the chute;

and the ingot mould nitrogen introducing pipeline is positioned at one side of the ingot mould and is used for blowing nitrogen into the ingot mould.

The above-mentioned nitriding alloy remelting encryption system also comprises:

a trolley for transporting the ingot mold;

the steel rail and the winch are positioned below the trolley to pull the trolley;

and the dust removal system is positioned at the upper part of the nitriding alloy remelting and encrypting system and is used for removing high-temperature dust-containing smoke.

The technical scheme of the invention has the following beneficial effects:

(1) the remelting and encrypting method for the nitrided alloy can effectively improve the density and the strength of the alloy, reduce the water content and meet the requirements of downstream steel industry users;

(2) the remelting and encrypting system for the nitrided alloy has the characteristics of high heating speed, high production efficiency, energy conservation, no pollution and the like by adopting an induction heating technology.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention.

FIG. 1 is a schematic view of a nitride alloy remelting encryption system according to the present invention.

Description of the symbols: 1 is an induction furnace; 2 is a chute; 3 is an ingot mold; 4 is a trolley; 5 is a steel rail; 6 is a winch; 7 is a dust hood; 8 is a dust removal flue; 9 is a casting nitrogen pipeline; and 10 is a nitrogen pipeline for introducing nitrogen into the ingot mold.

Detailed Description

The present invention will be described in detail with reference to the following embodiments in order to fully understand the objects, features and effects of the invention. The process of the present invention employs conventional methods or apparatus in the art, except as described below. The following noun terms have meanings commonly understood by those skilled in the art unless otherwise specified.

Specifically, the remelting and encrypting method for the nitride alloy comprises the following steps: (1) placing the low-density nitrided alloy doped with the reinforcing agent into a variable frequency induction furnace, and smelting in a nitrogen atmosphere; (2) after the smelting end point is reached, casting part of alloy liquid into an ingot mold in a nitrogen atmosphere; (3) the alloy ingot mold was transported to the finishing span with a trolley under nitrogen atmosphere until cooled.

The remelting and encrypting method for the nitrided alloy can effectively improve the density and the strength of the alloy, reduce the water content and meet the requirements of downstream steel industry users.

In some preferred embodiments, the inventive method for remelting and densifying a nitride alloy comprises:

(1) and (3) placing the low-density nitrided alloy doped with the reinforcing agent into a variable frequency induction furnace, and smelting in a nitrogen atmosphere.

The frequency conversion induction furnace is an electric furnace which heats or melts materials by utilizing the induction electric heating effect of the materials.

The furnace lining of the variable frequency induction furnace is made of graphite, the inner wall of the graphite is used as a main heating body, the iron powder is used as a secondary heating body, and heat energy is transferred to the nitrided alloy through radiation heat transfer and conduction heat transfer modes to carry out heating and melting operation. In the smelting process, the impedance of the furnace charge can change along with the continuous change of the temperature and the density of the furnace charge. The frequency conversion induction furnace is adopted, so that the frequency can be automatically adjusted, and the induction furnace is ensured to work under certain power.

The induction furnace variable frequency power supply system is cooled by closed distilled water, the furnace body is cooled by closed softened water, and components such as a filter capacitor, a compensation capacitor, a furnace body magnet yoke and the like are cooled naturally, so that about 3% -5% of electric energy can be saved.

Wherein the reinforcing agent is iron powder, and the nitrogen content of the nitrided alloy is maintained and slightly increased by doping the iron powder into the nitrided alloy, and the volume of the finished product is reduced, so that the considerable density and strength are obtained.

Preferably, the amount of the reinforcing agent is 0 to 5% by mass of the low-density nitrided alloy. When the mixing amount of the reinforcing agent is more than 5%, the vanadium content of the product is greatly influenced, and the alloy quality is reduced.

Preferably, the nitrogen is introduced into the furnace before the furnace is electrified, and further preferably, the purity of the nitrogen is more than 99.99%, and the flow rate of the nitrogen is 0.2-0.35 m³/(min. t). In the smelting process of the variable frequency induction furnace, nitrogen is introduced into the furnace, so that the oxidation of the nitriding alloy at high temperature can be prevented, the stability of the nitride is improved, and the nitrogen content of the nitriding alloy is improved to a certain extent.

Preferably, theThe smelting temperature is 1250-2100 ℃, and the smelting time is 12-30 min-t^-1。

Wherein the low-density nitrided alloy is one of silicon series, manganese series, vanadium series and chromium series. Preferably, the low-density nitrided alloy is one of ferrosilicon nitride, ferromanganese nitride, manganese silicon nitride, ferrovanadium nitride, vanadium-nitrogen alloy and chromium-iron nitride.

(2) And after the smelting end point is reached, casting part of the alloy liquid into an ingot mold in a nitrogen atmosphere.

Preferably, after the smelting end point is reached, a hydraulic system of the variable frequency induction furnace works, the furnace body is tilted to enable part of alloy liquid to be cast into an ingot mold along a chute, when 10% -15% of the alloy liquid remains in the furnace, the casting is stopped, and the furnace body is turned to the original position.

According to the invention, 10% -15% of alloy liquid is reserved, so that the change of the load in the furnace can be reduced, high electric power can be input in the initial stage of smelting in the next furnace, and the alloy melting time is shortened.

Wherein the judgment standard of the smelting end point is as follows: after the alloy is completely melted, the furnace pressure tends to be stable and has no obvious change.

Preferably, the purity of the nitrogen is more than or equal to 99.9%, and the nitrogen is continuously blown to the place where the alloy liquid flows in the casting area through a casting nitrogen pipeline so as to prevent the alloy liquid from being oxidized.

(3) The alloy ingot mold was transported to the finishing span with a trolley under nitrogen atmosphere until cooled.

Wherein the purity of the nitrogen is more than or equal to 99.99 percent.

And the nitrogen is continuously conveyed to the surface of the nitrided alloy through an ingot mould nitrogen channel arranged on one side of the trolley.

In some preferred embodiments, the method for remelting and densifying a nitride alloy according to the present invention further comprises: and crushing and screening the nitriding alloy ingot, packaging and warehousing for storage.

The nitrided alloy obtained by the method has the characteristics of high density, high strength and low water content.

In another aspect, as shown in fig. 1, the present invention provides a nitride alloy remelting encryption system for implementing the above-mentioned nitride alloy remelting encryption method, including:

the variable frequency induction furnace 1 is used for remelting low-density nitriding alloy;

the ingot mould 3 is used for casting the nitriding alloy molten steel and solidifying into an ingot;

the chute 2 is positioned between the variable frequency induction furnace 1 and the ingot mold 3 and is used for guiding the molten nitrided alloy steel from the variable frequency induction furnace 1 to the ingot mold 3;

a casting nitrogen pipeline 9 which is positioned above the chute 2 and used for blowing nitrogen into the chute 2;

and the ingot mould nitrogen introducing pipeline 10 is positioned at one side of the ingot mould 3 and is used for blowing nitrogen into the ingot mould 3.

In some preferred embodiments, the above-mentioned remelting encryption system for a nitride alloy further comprises:

a trolley 4 for transporting the ingot mould 3;

a rail 5 and a hoist 6 which are provided below the cart 4 to transport the cart 4;

and the dust removal systems (7,8) are positioned at the upper part of the remelting and encrypting system for the nitrided alloy and are used for removing high-temperature dust-containing flue gas.

The dust removal system comprises a dust removal cover 7 and a dust removal flue 8, wherein the dust removal cover 7 is responsible for collecting a large amount of high-temperature dust-containing flue gas generated in the casting process, sending the high-temperature dust-containing flue gas to a rear bag dust removal system along the dust removal flue 8, and discharging the high-temperature dust-containing flue gas after purification.

The remelting and encrypting system for the nitrided alloy has the characteristics of high heating speed, high production efficiency, energy conservation, no pollution and the like by adopting an induction heating technology.