KR101448597B1 - High alloy steel and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a method for producing a high alloy steel and a high alloy steel produced thereby, which comprises melting Fe-Al alloy metal to melt Fe-Al alloy steel, Al alloy block or Fe-C alloy block is manufactured by processing the Fe-Al alloy iron or Fe-C alloy iron to a predetermined size to prepare an Fe-Al alloy block or an Fe-C alloy block and iron A method for producing a high alloy steel by uniformly mixing and charging molten steel into a melting furnace to dissolve the block and iron charged in the melting furnace, and a high alloy steel produced thereby.

Description

TECHNICAL FIELD [0001] The present invention relates to high alloy steels,

The present invention relates to a high alloy steel and a method of manufacturing the same, and more particularly, to a high alloy steel containing aluminum and carbon by dissolving aluminum and carbon together with iron, .

Generally, in the production of alloy steel, the control of the impurities is mainly carried out in the steelmaking process, and the control of the alloy components is generally performed in the steelmaking process. The molten steel that has undergone the steelmaking process is transferred to a continuous casting machine, casted, and then produced in a desired shape through subsequent processing steps such as hot rolling and cold rolling.

At this time, a small amount of alloy element less than 1 wt% (wt%) can be controlled by directly injecting a high purity element into molten steel. However, high specific specialty steels may contain alloying elements ranging from several weight percent to tens of weight percent. In this case, if the steelmaking process or the alloy melting method is used, the element may be segregated in the material or may be volatilized into the atmosphere during the alloying process, which may result in a failure to meet the target composition.

In such a case, not only the quality of the finished steel product can not be guaranteed but also the result of the production or the experiment in which a precise composition design is essential becomes hard to be relied upon.

Therefore, when a large amount of alloying elements greatly different in physical properties from Fe is added, it is preferable to effectively prepare alloy iron in advance and use it for composition control.

Particularly, aluminum has a lower melting point than iron (Fe), and when it is melted at a high temperature due to its low vapor pressure, a large amount of aluminum volatilizes into the atmosphere, resulting in a case that the target composition is less than that of aluminum. It is difficult to make a large amount of carbon.
In this connection, Korean Patent Laid-Open Publication No. 10-1998-037662 (published on Aug. 8, 1998) discloses a method for manufacturing high alloy steel wire for homogenous spheroidization, and disclosed in Korean Patent Publication No. 10-2002-0046707 2002, 21, 2002) discloses a method of playing a high alloy steel for a cryogenic elngy tank, but still fails to solve the above-mentioned problem.

In order to solve the above problems, the present invention provides a high alloy steel containing aluminum and carbon in a large amount by alloying iron and aluminum, which are alloying elements different in physical properties from iron (Fe) .

In one or more embodiments of the present invention, there is provided a method for producing Fe-Al alloyed iron by melting iron (Fe) and aluminum (Al) Melting iron and carbon to produce Fe-C alloy iron; The Fe-Al alloy iron or the Fe-C alloy iron to a predetermined size to produce an Fe-Al alloy block or an Fe-C alloy block; Uniformly mixing the Fe-Al alloy block, the Fe-C alloy block, and iron into a melting furnace; And melting the Fe-Al alloy block, the Fe-C alloy block, and iron charged into the melting furnace, may be provided.

The amount of carbon in the Fe-C alloy iron is 2 to 7 weight percent, and the amount of aluminum in the Fe-Al alloy iron is 30 to 50 weight percent.

The temperature of the final molten iron of the Fe-Al alloy iron is 1250 to 1450 ° C, and the temperature of the final molten iron of the Fe-C alloy iron is 1140 to 1300 ° C.

The Fe-Al alloy block and the Fe-C alloy block are 10 to 20 weight percent of the high alloy steel.

Further, in the embodiment of the present invention, a high alloy steel produced by any one of the above methods may be provided.

The high alloy steel may contain 7 to 15 weight percent of Al and 0.5 to 4.3 weight percent of C.

According to the embodiment of the present invention, the content of aluminum or carbon may be increased by preparing Fe-Al alloy iron or Fe-C alloy iron, and then preparing the block and melting it together with iron.

In addition, by using Fe-C alloy ferrite, segregation of carbon can be reduced.

1 is a flowchart of a process for manufacturing a high alloy steel according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims.

First, FIG. 1 is a flow chart of a process for manufacturing a high alloy steel according to an embodiment of the present invention. In the embodiment of the present invention, in order to manufacture a high alloy steel containing a large amount of aluminum and carbon, (S100).

The Fe-Al alloy iron can be obtained by melting high purity Fe and Al metals together. In this case, the content of aluminum in the examples according to the present invention is limited to 30 to 50 weight percent.

Further, in order to produce a high-alloy steel containing a large amount of carbon, Fe-C alloy iron (S110) must be prepared (S110). For this purpose, high purity Fe and carbon are melted together.

At this time, the content of carbon in Fe-C alloy iron is limited to 2 to 7 weight percent.

The block is manufactured by processing the Fe-Al alloy Fe and the Fe-C alloy iron obtained in the steps S100 and S110 to a predetermined size (S120), and then the block is loaded into the melting furnace (S130). At this time, Fe and the block are uniformly mixed and charged into the melting furnace.

Then, the block and Fe loaded in the melting furnace are dissolved together to produce a high alloy steel (S140).

Hereinafter, embodiments of the present invention will be described in more detail.

First, the manufacturing process of Fe-Al alloyed iron will be described.

7 to 10 weight percent (wt%) of aluminum (Al) is added to low-grade steel and up to 15 weight percent of aluminum is added in the laboratory. Since aluminum has a melting point of about 660 ° C which is much lower than that of iron at 1538 ° C, when aluminum is directly dissolved in iron, aluminum is volatilized at a high temperature, and the content of aluminum in the final composition is reduced as compared with the target composition.

In order to prevent this, in the embodiment of the present invention, for the production of an alloy containing Fe-Al, Fe-Al alloyed iron is firstly prepared and mixed with Fe so that the composition can be controlled.

For this purpose, iron and aluminum with high purity are measured, and then iron is charged into the melting furnace and dissolved first, and then the measured aluminum is additionally charged. The addition of aluminum lowers the temperature of the melting furnace as the melting point of the melt decreases.

The temperature of the final melt of Fe-Al alloyed iron in the examples according to the present invention is controlled to 1250 to 1450 ° C. If the amount of Al is less than 1250 占 폚, if the amount of Al exceeds 50% by weight, the amount of Fe molten metal becomes too small compared to Al, which makes it difficult to form an Fe-Al alloy. However, since the energy consumption such as electricity becomes large, the temperature of the final molten metal of the Fe-Al alloy iron in the embodiment of the present invention is limited to the above range. That is, if the content of Al is 30%, about 1450 ° C is sufficient.

Thereafter, the molten metal is injected into a mold and solidified.

Hereinafter, the production process of Fe-C alloy iron will be described in more detail.

In order to produce a high carbon steel containing more than 1 weight percent of carbon, it is necessary to add additional carbon. In this case, if carbon is directly injected into the molten metal, the carbon is not uniformly distributed in the molten metal due to the difference in specific gravity between the iron and the carbon.

In order to prevent this, in the embodiment of the present invention, it is effective to prepare Fe-C alloy iron in the production of high carbon steel, and to mix iron (Fe) with carbon. For this purpose, high purity Fe and C are measured, and Fe is charged and melted in the melting furnace, and the measured carbon is added and dissolved together. In the embodiment of the present invention, the composition of the Fe-C alloy iron is 2 to 7 weight percent, and the temperature of the final molten iron is lowered as the carbon content is increased. Thereafter, when the carbon is sufficiently dissolved in the molten metal, the molten metal is injected into the mold and solidified.

The Fe-C alloy iron and the Fe-Al alloy iron are then used to form the block. In the embodiment of the present invention, the Fe-Al alloy iron production process and the Fe -Al alloy iron or Fe-C alloy iron is injected into a mold and processed into a block.

At this time, the processed block is processed so as to be 10 to 20 weight percent of the final alloy. This is a limitation on the size of the alloy block rather than the composition of the alloy block. That is, when the size of the alloy block exceeds 20 weight percent, it becomes difficult to finely control the dissolution and composition of the block. On the other hand, if the size of the alloy block is less than 10 weight percent, The weight of the alloy block in the embodiment according to the invention is limited to the above range.

Finally, the process for producing Fe-Al-C alloy steel will be described.

High-purity Fe, the Fe-Al alloyed iron block and the Fe-C alloyed iron block are measured to prepare a high alloyed steel to which a high content of Al and C is added, and the mixture is uniformly mixed and charged into the melting furnace. After the temperature of the molten metal is raised above the melting point of Fe, the molten metal is maintained in the mold for 10 to 30 minutes, and then the molten metal is injected into the mold to produce the final alloyed steel.

At this time, the final alloy steel has an aluminum content of 7 to 15% by weight and a carbon content of 0.5 to 4.3% by weight. As described above, the content of carbon is limited to 4.3 wt% or less because, if it exceeds this, Fe ₃ C is generated and the steel properties are rapidly deteriorated.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (9)

Melting iron (Fe) and aluminum (Al) metals to produce Fe-Al alloyed iron;
Melting iron and carbon to produce Fe-C alloy iron;
The Fe-Al alloy iron or the Fe-C alloy iron to a predetermined size to produce an Fe-Al alloy block or an Fe-C alloy block;
Uniformly mixing the Fe-Al alloy block, the Fe-C alloy block, and iron into a melting furnace; And
And melting the Fe-Al alloy block, the Fe-C alloy block, and iron charged into the melting furnace,
Wherein the prepared high alloy steel comprises 7-15 weight percent of Al and 0.5-4.3 weight percent of C and inevitably contains impurities of iron and the remainder. The method according to claim 1,
Wherein the amount of aluminum of the Fe-Al alloy iron is 30 to 50 weight percent. The method according to claim 1,
Wherein the amount of carbon in the Fe-C alloy iron is 2 to 7 weight percent. 3. The method of claim 2,
Wherein the temperature of the final molten metal of the Fe-Al alloy steel is 1250 to 1450 ° C. The method of claim 3,
Wherein the temperature of the final molten metal of the Fe-C alloy steel is 1140 to 1300 ° C. 6. The method according to any one of claims 1 to 5,
Wherein the Fe-Al alloy block is 10 to 20 weight percent of the high alloy steel. 6. The method according to any one of claims 1 to 5,
Wherein the Fe-C alloy block is 10 to 20 weight percent of the high alloy steel. delete delete

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