KR101815996B1 - Carburizing Apparatus Having Gas Floating Space - Google Patents

Abstract

According to the present invention, a carburizing apparatus having a gas floating space forms a plurality of layers of which at least a portion is formed to be spaced to form a gas floating space in which a target metal member is mounted, and comprises a surface treatment frame formed by a transition metal material. The surface treatment frame comprises a plurality of passing holes through which reaction gas floats into the gas floating space. Therefore, the reaction gas floats along a surface of the target metal member.

Description

[0001] The present invention relates to a carburizing apparatus including a gas flow space,

The present invention relates to a carburizing apparatus for forming a carburizing layer on a target metal member, and more particularly, to a carburizing apparatus including a gas flow space to form a more uniform and high-quality carburizing layer.

Generally, austenite stainless steel exhibits relatively good corrosion resistance. However, it is vulnerable to corrosion of fitting in an aqueous solution containing Cl groups, and is relatively vulnerable to abrasion due to relatively low hardness. Particularly, .

Therefore, in order to solve such a problem, various surface modification methods have conventionally been performed for nitriding and carburizing.

However, in the case of the specimens treated by the conventional carburizing method, the thickness variation according to the region is severely observed, and the quality of the product is greatly deteriorated.

Also, in the conventional case, carbonization (sooting) occurs in the appearance of the carburizing process, and therefore there is a problem that post-treatment must be performed.

Therefore, a method for solving such problems is required.

Disclosure of the Invention The present invention is conceived to solve the above-described problems of the prior art, and an object of the present invention is to provide a carburizing apparatus for forming a uniform carburizing layer and minimizing the generation of carbon aggregates on the surface of a metal object I have.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In order to accomplish the above object, the present invention provides a carburizing apparatus including a gas flow space, wherein a plurality of layers are formed so as to form a gas flow space in which at least some regions are spaced apart from each other, And a surface treatment frame formed of a transition metal material, wherein the surface treatment frame includes a plurality of through holes through which a reaction gas flows into the gas flow space, so that the reaction gas contacts the surface of the object metal member To flow along.

The surface treatment frame may be provided on at least one side of the target metal member which is formed in a mesh shape and forms one layer.

Also, the surface treatment frame may be provided on at least one side of the object metal member, the steel wool being formed of one layer by being clustered with each other.

The surface treatment frame may be provided on at least one side of the target metal member by forming one layer in a form in which the mesh and the steel wool sandwiched with each other are overlapped.

The carburizing apparatus including the gas flow space of the present invention for solving the above-mentioned problems has the following effects.

First, as the transition metal reaction gas (carbonized gas) meets the transition metal (Fe, Cr, Ni etc ..), the decomposition is accelerated due to the autocatalytic reaction, The carburizing ability and the homogenization are increased and the occurrence of sooting is reduced.

Secondly, since the generation of carbon aggregates in the outer surface of the metal member subjected to the carburizing treatment is suppressed, there is an advantage that the post-treatment process can be omitted.

Third, there is an advantage that the mechanical properties of the object metal member can be further improved by the carburizing layer of excellent quality.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 and 2 are views showing a carburizing apparatus according to a first embodiment of the present invention;
3 is a view illustrating a carburizing process performed by the carburizing apparatus according to the first embodiment of the present invention;
FIG. 4 is a view showing a multi-layered structure of the carburization apparatus according to the first embodiment of the present invention; FIG.
5 is a view showing a carburizing apparatus according to a second embodiment of the present invention;
6 is a view showing a carburizing apparatus according to a third embodiment of the present invention;
7 is a photograph showing an actual application of the carburization apparatus according to the first embodiment of the present invention;
FIG. 8 is a photograph showing a metal member subjected to carburization through the carburizing apparatus according to the first embodiment of the present invention; FIG.
9 is a photograph showing an actual application of the carburizing apparatus according to the second embodiment of the present invention;
10 is a photograph showing a state of a metal member subjected to a carburizing treatment through a carburizing apparatus according to a second embodiment of the present invention;
11 is a photograph showing a state in which the carburizing apparatus according to the third embodiment of the present invention is actually applied;
12 is a photograph showing a state of a metal member subjected to a carburizing process through a carburizing apparatus according to a third embodiment of the present invention; And
13 is a diagram illustrating another object to which the present invention is applicable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present embodiment, the same designations and the same reference numerals are used for the same components, and further description thereof will be omitted.

The carburization treatment apparatus including the gas flow space according to the present invention is characterized in that at least some regions are formed so as to be spaced apart from each other so as to form a plurality of layers so as to form a gas flow space in which a target metal member for carrying out carburization processing is placed, And a processing frame.

At this time, various transition metals can be applied as the material of the surface treatment frame, and the surface treatment frame also includes a plurality of through holes through which reaction gas for carburization flows into the gas flow space.

Accordingly, when the reaction gas is supplied into the chamber after the target metal member is accommodated in the gas flow space formed inside the surface treatment frame, the reaction gas is supplied to the inside of the gas flow space through the through hole And then the reaction gas can flow along the surface of the object metal member.

The surface treatment frame may have various embodiments. Hereinafter, the various embodiments of the surface treatment frame and the results of the carburizing treatment will be described.

1 and 2 are views showing a carburizing apparatus according to a first embodiment of the present invention.

In the first embodiment of the present invention shown in FIGS. 1 and 2, the surface treatment frame of the carburization apparatus is formed into a mesh to form one layer. That is, in this embodiment, the empty space formed between the warp yarns 102 and 202 and the warp yarns 104 and 204 forms a through hole.

As shown in FIG. 1, the first layer 100 is formed on the lower part of the mesh as shown in FIG. 1, and the second metal layer 10 is placed on the mesh, .

Accordingly, a gas flow space S is formed between the first layer 100 and the second layer 200 so that the target metal member 10 is located therebetween. As shown in FIG. 3, The gas flowing through the through holes may remain in the gas flow space S and flow along the surface of the object metal member 10. [

Further, the surface treatment frame according to the present embodiment may form two or more layers. That is, as shown in FIG. 4, a plurality of layers 100, 200, 300, and 400 formed of a plurality of meshes are stacked in layers, and a target metal member 10 is placed in a gas flow space S formed between the layers The carburizing process can be performed.

It will be appreciated that a plurality of the target metal members 10 may be accommodated in one gas flow space S at this time.

5 is a view showing a carburizing apparatus according to a second embodiment of the present invention.

In the case of the second embodiment of the present invention shown in FIG. 5, the surface treatment frames of the carburizing apparatus are formed in the form of steel wool 106 and 206 assembled with each other to form one layer. That is, in this embodiment, the hollow space formed between the assembled unit steel wool 106, 206 forms a through hole.

In this case, first, a plurality of steel wools 106 are laid on the bottom to form a first layer 100, then the target metal member 10 is placed, and another steel wool 206 is raised The second layer 200 is formed.

A gas flow space S in which the target metal member 10 is positioned is formed between the first layer 100 and the second layer 200 where the target metal member 10 is located, The gas introduced through the through holes between the steel wools can remain in the gas flow space S and can flow along the surface of the object metal member 10. [

In this embodiment, two or more layers can be formed as in the first embodiment, and a plurality of object metal members 10 can be accommodated in one gas flow space S.

6 is a view showing a carburizing apparatus according to a third embodiment of the present invention.

In the case of the third embodiment of the present invention shown in FIG. 6, the surface treatment frame of the carburization apparatus forms one layer in a form in which the mesh and the steel wools 106 and 206 are overlapped with each other. That is, in the present embodiment, a hollow space formed between the wefts 102 and 202 and the slopes 104 and 204 of the mesh, and a hollow space formed between the clustered unit steel wools 106 and 206 form through holes .

In this case, first, the first layer 100 having the lower structure 100a and the upper structure 100b is formed by sandwiching a plurality of steel wools 106 on the upper part of the mesh, The member 10 is seated and another mesh and steel wool 206 is placed on the upper side to form a second layer 200 having the lower structure 200a and the upper structure 200b.

A gas flow space S in which the target metal member 10 is positioned is formed between the first layer 100 and the second layer 200 where the target metal member 10 is located, The gas introduced through the through hole between the mesh and the steel wool can remain in the gas flow space S and can flow along the surface of the object metal member 10. [

At this time, the through hole formed between the steel wool clusters may be smaller than the area of the through hole formed in the mesh.

In this embodiment, two or more layers can be formed as in the first and second embodiments, and a plurality of target metal members 10 can be accommodated in one gas flow space S have.

It is needless to say that the layers of the first to third embodiments may be used interchangeably.

Hereinafter, a specific carburization process through such a carburization apparatus will be described.

The carburizing method according to the present invention includes the steps of: (a) performing a pretreatment on a metal object; (b) injecting the metal object into the reaction chamber and raising the temperature to a set temperature; (C) a step of injecting a reactive gas to accelerate the carburization, (d) stopping the injection of the reactive gas, and forming the reaction chamber in a vacuum atmosphere to diffuse the vacuum, and (c) And (e) repeating the step (d) at a predetermined time interval.

In this embodiment, the step (e) may further include the step (f) of cooling the object metal member.

Hereinafter, each step will be described in detail.

In addition, the target metal member 10 for applying the carburizing method according to an embodiment of the present invention is a stainless steel ferrule.

The shape of the ferrule is complicated by the hollow 12 as compared with a general object, so that there is a disadvantage in that it is difficult to control the process parameters in addition to forming a non-uniform surface layer during the carburizing process. Therefore, there is a problem that it is difficult to apply a general carburizing method.

In the carburizing method according to this embodiment, the step of performing the pretreatment on the object metal member is performed first.

This step may be performed by filling a predetermined container with an organic solvent, and then subjecting the object metal member to an organic solvent for washing.

This is because the ferrule, which is a metal object, is subjected to grinding and various lubricants and foreign matter remain on the surface. Therefore, in order to carry out an effective carburizing process, washing is carried out using an organic solvent.

At this time, acetone, ethanol and the like may be applied as the organic solvent. In this embodiment, vibration is applied by using an ultrasonic vibrator provided under the container, and the object metal member is cleaned with acetone or ethanol for about 5 minutes.

In this step, a pickling process may be further performed on the object metal member. The pickling step is a step of cleaning after dipping in an acid solution to remove or weaken the natural oxide film formed on the surface of the object metal member. The reason for doing this is to obtain an excellent carburizing effect in a low temperature atmosphere thereafter.

The pickling solution used in the pickling process is a solution of a first solution containing ammonium hydrogen fluoride ((NH ₄ ) (HF ₂ )), nitric acid and water and a second solution containing hydrogen peroxide and water in a ratio of 7: 3 By weight based on the total weight of the composition.

As the pickling solution, a solution mixed at a weight ratio of 10% of sulfuric acid, 4% of sodium chloride and 86% of distilled water can be used.

Alternatively, as the pickling solution, a mixed solution of 6 to 25% of nitric acid, 0.5 to 8% of hydrogen fluoride (HF), and a residual ratio of distilled water according to the ratio of nitric acid and hydrogen fluoride at a volume ratio may be used.

Next, the step (b) of charging the object metal member into the reaction chamber and raising the temperature to the set temperature is performed.

In this step, the object metal member is placed in the reaction chamber to suitably adjust the surface temperature of the object metal member.

In this embodiment, the reaction chamber includes a stage on which a carburizing apparatus including the above-described surface treatment frame is seated, a first gas inlet, and a second gas inlet. However, it goes without saying that various reaction chambers can be applied as an embodiment.

(B-1) forming the reaction chamber in a vacuum atmosphere; and (b-1) heating the reaction chamber to a target temperature to weaken the internal stress of the metal object member (b-3) of injecting a processing gas into the reaction chamber to treat the surface of the object metal member and weaken the bonding force between the natural oxide film and the object metal member may be sequentially performed .

More specifically, an initial vacuum atmosphere is formed in step (b-1), and then the inert gas is selectively injected in step (b-2) to raise the temperature to a target temperature. The target temperature may be a temperature suitable for the target hardness of the target metal member.

For example, when the target hardness of the target metal member is to be maintained at the original state of machining, the target temperature may be set to a temperature lower than the temperature in the carburization step of steps (c) and (d) to be performed subsequently. In the present embodiment, when the target hardness of the object metal member is to be maintained at the original state of machining, the object metal member is treated at 200 to 350 占 폚.

If the target hardness of the target metal member is to be lowered than the original state of machining, the target temperature may be set to be higher than the recrystallization temperature of the material to be performed subsequently. In this embodiment, the target metal member is a ferrule made of stainless steel. Therefore, when the target hardness of the target metal member is to be lower than the original state of machining, the target metal member is treated at 800 to 1100 占 폚 according to the target hardness.

The reason for doing this is to weaken the internal stress of the object metal member. Thus, this process may be performed selectively with the pickling process, or both processes may be performed.

Thereafter, in the step (b-3), the process gas is injected into the reaction chamber, and the object metal member can be treated for a time suitable for the material hardness of the object metal member. At this time, in this embodiment, the process gas can change the composition of the process gas according to the target temperature of the step (b-2).

For example, in the step (b-2), the process gas may be a hydrogen gas, or a mixed gas of hydrogen and hydrocarbons (C ₂ H ₂ , CH _4, etc.), or an inert gas such as nitrogen may be used. Alternatively, it is also possible to form a vacuum atmosphere without injecting a process gas.

As described above, in the step (b), the surface temperature of the object metal member is raised to weaken the internal stress of the object metal member, and the bonding force between the natural oxide film and the object metal member is weakened through the process gas So that the carburizing process can be performed more effectively.

(C) forming the reaction chamber in a vacuum atmosphere and injecting a reaction gas; (d) stopping the injection of the reaction gas and forming the reaction chamber in a vacuum atmosphere to diffuse the vacuum; (E) is repeatedly performed. This step is a step for forming a carburized layer on the surface of the object metal member 10.

Specifically, in the step (c), the reaction gas may be injected while maintaining a pressure of 2 to 10 mbar in an atmosphere of 400 ° C to 500 ° C. At this time, the reaction gas is a mixed gas of 20 to 70% of hydrogen gas and 30 to 80% of acetylene gas.

In the step (d), the reaction chamber is maintained at a pressure of 0 to 2 mbar to diffuse the vacuum state. However, the injection of the reaction gas may be completely stopped in the step (d), but the supply of the hydrogen gas in the reaction gas may be maintained.

Alternatively, the supply of the hydrocarbon with the hydrogen gas may be maintained, or a method of forming a vacuum atmosphere without the reaction gas may be used.

In the step (e), the steps (c) and (d) are repeatedly performed for about 5 to 30 hours, and then a carburized layer is formed on the surface of the metal object.

In this embodiment, the repeating pattern of step (c) and step (d) may be performed at predetermined time intervals.

More specifically, the step (e) may gradually reduce the total process time of the step (c) and may further increase the total process time of the step (d).

In this case, the carburizing effect can be better, and the time interval of each step can be set according to the characteristics of the metal member and the process environment.

In the case of this embodiment, the method of gradually shortening the total process time of step (c) and the method of gradually increasing the total process time of step (d) are simultaneously applied. Alternatively, Of course it is.

On the other hand, after this step, the step (e) of cooling the object metal member may be further performed. In the step (e), the object metal member may be cooled naturally, but a separate cooling device or a method of rapid cooling using a low-temperature fluid may be applied.

Hereinafter, a practical application of the carburizing apparatus according to the present invention and a result of carburizing treatment will be described.

FIG. 7 is a photograph showing a practical application of the carburizing apparatus according to the first embodiment of the present invention. FIG. 8 is a view showing a state in which the carburizing treatment apparatus according to the first embodiment of the present invention It is a photograph showing the appearance.

Referring to FIG. 7, it can be confirmed that the mesh-type surface treatment frame of the first embodiment is applied as described above.

As a result of performing the carburizing treatment through this, it can be confirmed that almost no appearance of the carbon aggregate appears, as shown in FIG. 8, and it is also confirmed that the carburized layer shows a very uniform deviation .

FIG. 9 is a photograph showing a practical application of the carburizing apparatus according to the second embodiment of the present invention. FIG. 10 is a view showing a state in which the carburizing treatment apparatus according to the second embodiment of the present invention It is a photograph showing the appearance.

Referring to FIG. 9, it can be actually confirmed that the steel-wool-shaped surface treatment frame of the second embodiment is applied as described above.

As a result of performing the carburizing treatment through this, it can be confirmed that almost no appearance of carbon aggregates is seen as shown in FIG. 10, and it is also confirmed that the carburized layer is formed with a very uniform .

FIG. 11 is a photograph showing a practical application of the carburizing apparatus according to the third embodiment of the present invention. FIG. 12 is a view showing a state in which the carburizing treatment apparatus according to the third embodiment of the present invention It is a photograph showing the appearance.

Referring to FIG. 11, it can be confirmed that the surface treatment frame of the combination of the mesh and the steel wool of the third embodiment is applied as described above.

As shown in FIG. 12, the result of carrying out the carburizing treatment through the above is that the carbon aggregate of the outer appearance is not generated at all and is silver-colored, It can be confirmed that they are uniformly formed.

As described above, the present invention is characterized in that it can change according to the shape of the object metal member, the gas flow behavior of the heat treatment equipment, and does not have a prescribed shape.

Further, the present invention can more uniformly distribute the process gas on the surface of the target metal member and further activate the process gas through the transition metal such as mesh or steel wool to uniformly treat the metal member having a complicated shape or small size .

On the other hand, in the case of the above-described embodiment, the stainless steel ferrule is applied as the object metal member, but the object metal member is not limited to this and various types can be used.

For example, a plate heat exchanger may be applied as a target metal as shown in Fig. The plate-type heat exchanger is required to exhibit excellent abrasion resistance and corrosion resistance at the same time, and is thus suitable as an object of the present invention.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. It is obvious to them. Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

10: object metal member 100: first layer
102, 202: slope 104, 204: weft
106, 206: steel wool 200: second layer

Claims (4)

And a surface treatment frame formed of a transition metal material to form a plurality of layers so as to form a gas flow space in which at least some regions are spaced apart from each other and in which an object metal member is seated,
Wherein the surface treatment frame includes a plurality of through holes through which reaction gas flows into the gas flow space so that the reaction gas flows along the surface of the object metal member,
Wherein the surface treatment frame is provided on at least one side of the object metal member, the steel wool being formed of one layer by being clustered with each other. delete delete The method according to claim 1,
Wherein the surface treatment frame is provided on at least one side of the object metal member by forming one layer of the mesh and the steel wool sandwiched together.

Images