KR100906191B1 - The Hearth Roller type continuous carburizing heat treatment furnace - Google Patents

Abstract

The present invention relates to a hearth roller type continuous carburizing heat treatment furnace for industrial use, wherein the preheating chamber 10 for preheating the treated material 100 to be heat treated and carburizing and diffusing the preheated processed material 100. Hardening of the heat treatment chamber 20 consisting of two zones communicating with the carburizing chamber 21 and the diffusion chamber 22, and the treated material 100 carburized in the heat treatment chamber 20. A quenching chamber 1 for processing and a quenching chamber 2 for protecting the atmosphere inside the furnace from outside air are constructed, and these are respectively formed as entrance doors 11, first, second, Comprised of the third partition door (15, 25, 35) and the exit door 41 composed of four chambers (Chamber),

The Hearth roller 60 for the transfer of the processing material 100 is configured to be individually driven in the forward and reverse directions by an independent drive motor 65 for each processing position. According to the control, the loss time due to the cycle change is reduced, and unlike the conventional pusher method, there is no need to load the empty tray, and the atmosphere, cycle time, and temperature of each four chambers can be controlled separately. In addition, it is a novel and useful invention that minimizes the disturbance of the atmosphere gas to make the carburized state of the treatment even and the phase of the tissue uniform.

Preheating chamber, heat treatment chamber, carburizing chamber, diffusion chamber, quenching chamber 1, quenching chamber 2, hearth roller, drive motor, processed material

Description

Hearth Roller type continuous carburizing heat treatment furnace}

1 is a view illustrating a configuration state of a conventional Haw roller continuous carburization heat treatment furnace.

2 is an exemplary configuration state of the present invention.

Figure 3 is an illustration of the configuration state that is the main part of the present invention.

4 is an exemplary embodiment of the present invention.

<Explanation of symbols for each major part of drawing>

10: Preheating room. 11: entrance door. 14: gas burner.

15: First partition. 16: Circulation fan.

20: heat treatment chamber. 21: Carburizing chamber. 22: diffusion chamber.

24: Electric Heater. 25: The second partition.

26: Circulation fan.

30: 1 hardening room. 34: Electric heater. 35: Third partition.

36: Circulation fan.

40: 2 hardening rooms. 41: Exit door. 44: Electric heater.

46: Circulation fan.

50: Hardening tank. 51: cylinder. 56: stirrer.

60: Haas roller. 65: drive motor.

70: O₂ sensor. 80: treatment material loading device. 90: processing material taking out device.

100: processed material. 101: tray.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hearth roller type continuous carburizing furnace for industrial use, comprising: a preheating chamber for preheating the treated material, a heat treating chamber for carburizing and diffusing the preheated processed material, and a carburizing treatment in the heat treatment chamber. It consists of one quenching chamber for hardening water and two quenching chambers to protect the atmosphere inside the furnace from the outside air, and each of the preheating chamber, heat treatment chamber, one quenching chamber, and two quenching rollers It is configured to individually drive in the forward and reverse directions by each independent driving motor for each water position, and it is configured to control the moving speed of the processed products according to the heat treatment specifications, and the atmosphere, cycle time, temperature, etc. Each of these can be controlled separately, minimizing the disturbance of the atmosphere gas, so that the carburized state of the treatment is even and the phase of the tissue is uniform so that a better product can be obtained. The purpose is to.

A major contribution to the development of human civilization is the discovery of metals and the use of them as various tools.

Therefore, all human beings have developed and developed technologies to handle metals, the most important of which is the heat treatment process that deals with the properties of metals. In performing such a heat treatment method, the treated material to be heat-treated is heated to obtain a desired property so that the structure of the metal is recrystallized. At this time, various components are penetrated into the metal structure to obtain the desired structure. It consists of a process of hardening, quenching, or annealing so that a tissue is formed appropriately for use.

In order to obtain a higher quality treatment in this heat treatment process, the heat treatment chamber that infiltrates other components such as carbon gas into the metal structure and the temperature of the martensite transformation (free diffusion transformation) and the quenching agent in the cooling process of the heat treatment treatment There is an Osttempering transformation (diffusion transformation) that takes a long time to complete the transformation.

In addition, the isothermal annealing technique is also used for heat treatment of treated materials. Instead of being cooled slowly in the furnace to ensure proper workability of the steel, it is quenched at a constant temperature (from the A1 transformation point to the nose part of the S curve) and then It is a technology to maintain temperature for a certain time. This isothermal transformation technique is used in that a uniform quality can be obtained than a continuous cooling method of only quenching to a certain temperature.

In particular, in the case of ostempering, the quality is stable, and there is a characteristic that it is possible to make an unusual tissue that is difficult to obtain in continuous cooling called bainite. This bainite is a kind of fine pearlite, which does not cause lattice distortion such as martensite transformation, so that its hardness is comparable with that of martensite, and its use is increasing. This bainite is divided into upper bainite obtained by transformation above 350 ° C and lower bainite obtained below.

The upper bainite is used for parts that require elasticity due to its excellent spring property (clips, spring washers, snap rings, etc.), while the lower bainite has high hardness while maintaining the spring property. Often used for parts.

In all heat treatment, it is very important to maintain the state as a means for heating the treatment to a constant temperature to form a complete recrystallization structure.

Therefore, due to the high temperature inside the heat treatment furnace, the roller inside the heat transfer furnace is configured to be transported and processed, so that the processed material can be advanced or positioned in the furnace according to the heat treatment state of the processed material without being deformed at high temperatures. Play a very important role. In other words, the rollers constituting the heat treatment furnace were divided into a preheating chamber, a heat treatment chamber, a quenching chamber, and a quenching chamber, and the rollers installed therein were simultaneously rotated by a single motor. By passing through all the processes, it was not able to adapt to the change of the size of the processed material and the atmosphere inside the furnace, which caused the failure.

It is developed here and consists of three chambers (Chamber-preheating chamber, heat treatment chamber, crack chamber), and each chamber is divided into two doors, and there are three groups of independent hearth rollers. In this case, the rollers of the preheating chamber and the crack chamber rotate forward and backward, and the rollers of the heat treatment chamber are configured to maintain a stationary state or to rotate only forwardly, and the lower roller is placed in a superheat resistant steel with a small amount of tungsten and cobalt. ), And titanium (Titanium) is added, and the side wall of the furnace body is composed of a brick layer (fireproof), silica layer (insulation material), compression molding layer of titanium oxide and inorganic fiber (Fiber) from the inside of the furnace There was a Japanese Patent Application No. 2002-348639, but this also caused the deformation of the rollers due to high temperature due to the inconsistent waiting time and forward movement time to meet the individual conditions of each thread. However, since the entire roller always moves forward at a constant speed regardless of the size of the tray containing the processed materials, there are many problems in controlling the time to stay inside the heat treatment of the processed materials. In many cases, failure to obtain a processed material of the desired quality due to prolonged loss time at the time of cycle change is impossible.

The present invention has been made in view of the above problems, and relates to a low-roller continuous carburizing heat treatment furnace for industrial use in constructing a low-roller continuous carburizing heat treatment furnace for industrial use. A preheating chamber for preheating the treated material, a heat treatment chamber for carburizing and diffusing the preheated product, a quenching chamber for hardening the carburized material in the heat treatment chamber, and a quenching for atmosphere protection 2 It configures the thread and drives the Hearth rollers of the preheating chamber, the heat treatment chamber, the quenching chamber and the quenching chamber to be individually driven in the forward and reverse directions by the independent motor for each position of the treatment. It is configured to control according to the conditions, and the atmosphere, cycle time, temperature, etc. of each of the four chambers are controlled separately, thereby preventing the disturbance of atmospheric gas. By minimizing the carburizing condition of the treatment and the uniform phase of the tissue to obtain a product of higher quality.

Looking at the technical configuration of the present invention described above are as follows.

2 and 3, in the present invention, a preheating chamber 10 for preheating the treated material 100 to be heat treated, a heat treatment chamber 20 for carburizing and diffusing the preheated processed material 100, These four chambers comprise one quenching chamber 30 for hardening and hardening the treated material 100 carburized in the heat treatment chamber 20 and two quenching chambers 40 for protecting the furnace atmosphere from outside air. Are divided into first, second, and third partition doors (15, 25, 35), respectively, and the atmosphere, cycle time, temperature, etc. of each chamber can be separately controlled. Hearth roller 60 for transfer is configured to be individually driven in the forward and reverse directions by the independent drive motor 65 for each position of each treatment, so that the traveling speed of each treatment is adjusted to the heat treatment specification of the treatment 100. The carburizing state of the treatment product 100 is minimized by the configuration of the control unit and the disturbance of the atmosphere gas. Carrying phase was so uniformly made of tissue.

Here, the preheating chamber 10 has an enclosed space with an entrance door 11 for blocking the charging entrance for charging the processing material 100 from the outside and a first partition door 15 partitioned from the heat treatment chamber 20. The refractory insulation material inside the furnace is formed of bricks, and the lower roller 60 for conveying the processed material 100 is configured to be preheated, but the lower roller 60 is all driven motors independently of each other. By 65, it is comprised so that forward and reverse rotation may be performed separately. And inside the upper side, the circulation fan 16 which makes the furnace temperature and furnace gas atmosphere uniform, and the atmosphere gas discharge port for discharging the furnace atmosphere gas are comprised.

Next, a heat treatment chamber in which the preheated treatment 100 is heated to the carburizing temperature and the gas of a component that changes the properties of the metal is introduced into the room to penetrate other components into the surface layer of the treatment 100. 20 is composed of a carburizing chamber 21 and a diffusion chamber 22 comprising two zones and a first partition door 15 partitioned from the preheating chamber 10 and a carburizing chamber 21 from the side. The diffusion chamber 22 is configured to communicate with each other to form a closed space of the second partition door 25 partitioned from the quenching chamber 1. And therein constitutes a heat transfer heater 24 for heating the internal temperature and at the bottom constitute a hearth roller 60 for transporting the treatment 100, the hearth roller 60 is for each treatment position It is configured to rotate forward and reverse individually by an independent drive motor (65). In addition, the upper part of the inside of the heat treatment chamber 20 has a partial pressure of O 2 to minimize the amount of retained austenite and to minimize the amount of retained austenite and the circulation fan 26 forcing convection of the atmosphere gas for uniform distribution of the atmosphere gas and the atmosphere gas. As a measuring equipment using the principle of electromotive force by the carburizing chamber 21, the O₂ sensor 70 for measuring the atmospheric energy in the furnace by measuring the difference in electromotive force of O₂ in the reference air and the atmosphere gas supplied into the furnace is measured. And are formed in the diffusion chamber 22, respectively.

The quenching one chamber 30 for transforming the properties of the processed material 100 heat-treated in the heat treatment chamber 20 is installed between the heat treatment chamber 20 and the quenching two chamber 40, the heat treatment chamber 20 The section is divided into a second partition door 25, and the hardened two chambers 40 and a third partition door 35 form a separate chamber. Here, the quenching chamber 1 constitutes a heat transfer heater 34 for maintaining a temperature-lowering state, and a lower roller 60 for transporting the processed material 100 at the bottom thereof, but the lower roller 60 is All are configured to be forward and reverse individually by independent drive motors 65, respectively. In addition, the inner side of the quenching chamber 30 has a partial pressure of O₂ in order to minimize the amount of residual austenite and improve the carburizing depth and the circulation fan 36 for forced convection of the internal gas so that the heat and atmosphere inside the quenching chamber 30 are spread evenly. As a measuring device using the principle of electromotive force, an O₂ sensor 70 is installed to measure and regulate the atmosphere in the furnace by measuring the difference in electromotive force of O₂ between the reference air and the atmosphere gas supplied into the furnace.

The quenched two chamber 40, which is divided into the quenched one chamber 30 and the third partition door 35 and forms a space sealed by the exit door 41, has a heat-treated processed material 100 at a transformation temperature. To configure the heat transfer heater 44 for maintaining the temperature in the state of 830 ~ 860 ℃, at the bottom of the lower roller 60 for transporting the treated water 100, but the lower roller 60 is all Each is configured to rotate forward and reverse individually by an independent drive motor (65). In addition, the inside of the quenching chamber 2 constitutes a circulation fan 46 for forcing convection so that the heat and the atmosphere gas inside the quenching chamber 2 are evenly spread.

Here, the hearth roller is filled with fire-resistant insulation on both shafts inside the tube centrifugally cast into a heat-resistant casting steel to which a trace amount of tungsten is added, and a shaft is attached to both ends thereof to support the bearing from the outside of the furnace geared motor. It is driven by the inverter and the position control by the photosensor.

In addition, the entrance door 11 and the exit door 41 are constructed with a silica board and a brick inside, and configured to operate along a guide angle by an external driving device. The third partition doors 15, 25 and 35 are constructed of heat-resistant casting steel and constituted by connecting links and the like.

In addition, the entrance door 11 and the exit door 41 are provided with a curtain burner (Curtain burner) in the lower portion to block the outside air to protect the atmosphere in the furnace when opening and closing.

In the present invention configured as described above, as shown in FIG. 4, a preheating chamber is provided in front of the preheating chamber 10 to be heat treated by installing an existing processing material loading device 80 to match the entrance door 11. (10) a quenching tank 50 for quenching the processing material and a stirrer 56 for vortexing the cooling medium of the quenching tank 50 at the rear of the quenching two chamber 40, and processing A cylinder 51 for immersing the water 100 in the squeeze tank 50 is provided, and a processing material extracting device 90 is installed at the rear thereof so as to draw out the processing material 100 after the heat treatment is completed.

Referring to the embodiment of the heat treatment facility 100 by performing the present invention installed as described above to complete the heat treatment simply described, first to open the entrance door 11 of the preheating chamber 10 to be heat treated (100) ) Is filled into the tray 101 into the preheating chamber 10 by using the treatment material loading device 80 and heated to 890 ~ 910 ℃. At this time, the hearth roller 60 of the preheating chamber 10 has the tray 101 containing the processing material 100 positioned inside the preheating chamber 10 while being reversed and driven separately by the independent driving motor 65. The circulation fan 16 installed on the upper side is driven to spread the internal temperature evenly. As described above, the processed material 100 heated to 890 to 910 ° C. in the preheating chamber 10 is heat treated by driving the Haas roller 60 which is individually driven by the independent driving motors while the first partition door 15 is opened. The carburizing chamber 21 of the chamber 20 enters.

The treated material 100 entering the carburizing chamber 21 of the heat treatment chamber 20 is heated to 910 to 920 ° C. by the heating of the heat transfer heater 24, and at this time, the carburizing gas is purged so that carburizing is performed on the processed material 100. For each position of the treatment in the heat treatment chamber 20, the lower roller 60 which is separately driven by the independent driving motor 65 is driven in the forward and reverse directions while completely carburizing. ) Is placed in the carburizing chamber 21, and a circulation fan 26 installed above the carburizing chamber 21 is driven to promote diffusion of the carburizing gas purged in the carburizing chamber 21. As described above, when carburizing is completed in the carburizing chamber 21, the processed material 100 moves to the diffusion chamber 22 by the driving of the individually driven hearth roller 60, and continuous carburizing is performed by the diffused atmospheric gas. As a result, a plurality of trays 101 containing the processed material 100 are sequentially loaded in the inner space of the heat treatment chamber 20, and new physical properties such as carburization are added to the processed material 100.

The processed material 100 in which the heat treatment is completed in the above-described state is individually performed one by one in order by the lower roller 60 separately driven by the independent drive motor 65 while the second partition door 25 is opened. The quenching chamber 1 is discharged into the quenching chamber 30, in which the quenching chamber 2 has the effect of suppressing the disturbance of the inside of the heat treatment chamber 20 as much as possible to achieve more stable carburization.

When the second partition door 25 is closed in the above state and the heat treatment chamber 20 and the quenching chamber 1 are blocked, the treated material 100 discharged to the quenching chamber 1 has a temperature of 830 to 860 ° C. The third partition door 35 is opened while being formed in a new structure by moving apart, and is moved to the hardening chamber 2 by the lower roller 60 which is separately driven by the independent drive motor 65. At this time, the circulation fan 36 of the quenching chamber 1 is driven to promote diffusion of the atmosphere of the quenching chamber 1.

The O2 sensor 70 installed therein while the processed material 100 passes through the heat treatment chamber 20 and the quenching chamber 1 30 has a partial pressure of O2 in order to minimize the amount of retained austenite and improve the carburizing depth. As a measuring equipment using the principle of electromotive force, the atmosphere in the furnace is measured and controlled by measuring the difference in electromotive force between O 2 in the reference air and the atmosphere gas supplied into the furnace.

The processed material 100 entered into the quenching chamber 1 by the above method is to maintain a transformation temperature of 830 to 860 ° C. in the quenching chamber 1 to form a new structure. 30) The internal hearth roller 60 also rotates forward and reverse individually by independent driving motors 65, so that the processed material 100 remains effectively inside the hardened chamber 1 to form a stable structure. Will be.

In the above state, when the temperature lowering operation for completing the new structure of the processed material 100 is completed, the temporary stay in the hardening 2 chamber 40 is opened for a while and the exit door 41 is opened. 100) is quenched to about 200 ℃ in the sintering tank 50 configured to shower or immerse with oil or salt. At this time, in the style of immersing in the sintering tank 50, the cylinder 51 is operated to immerse the processed material 100 discharged from the heat treatment chamber 20 in the inside of the sintering tank 50, and at this time, the sintering tank The stirrer 56 of 50 is operated to vortex the cooling medium so that the cooling medium cools the processed material 100 at an even temperature.

In this way, if the processed material 100 quenched in the squeezing tank 50 is pulled out to the processing material taking-out device 90, the heat treatment operation is completed.

As described above, the present invention comprises a quenching chamber between two quenching chambers in order to harden the carburized material in the heat treatment chamber in the Haas roller continuous carburizing heat treatment furnace. , Hrush roller of quenching 1 chamber and quenching 2 chamber are individually driven in the forward and reverse direction by independent driving motor for each processing position, and the progress speed of each chamber is adjusted according to the heat treatment specifications. Unlike the conventional pusher method, there is no need to load empty trays, and the atmosphere, cycle, and temperature of each of four chambers can be controlled separately, and the disturbance of atmospheric gas is minimized. Therefore, the carburized state of the treatment is uniform and the phase of the tissue is uniform, which is a novel and useful invention to obtain a higher quality product.

Claims (7)

delete delete delete delete delete delete In constructing the hearth roller continuous carburizing furnace, The refractory insulation material inside the furnace uses a brick and constitutes a lower roller 60 for conveying the processed material 100. The upper part of the furnace has a circulation fan 16 which uniforms the furnace temperature and the atmosphere inside the furnace. Pre-heating chamber 10 for preheating the heat-treated material 100 constituting the atmosphere gas outlet 17 for discharging the atmosphere gas, and two zones communicating with the carburizing chamber 21 and the diffusion chamber 22 ( zone), the heat transfer heater 24 for heating the internal temperature, the lower roller 60 for conveying the processing material 100, and the forced convection of the atmospheric gas in order to make the furnace temperature and the atmosphere inside the furnace uniform. O₂ to measure the atmosphere in the furnace by measuring the electromotive force difference of O₂ in the atmospheric gas supplied on the principle of electromotive force by partial pressure of O₂ in order to minimize the amount of retained austenite and control the carburizing depth. Preheated process consisting of sensor 70 It is installed between the heat treatment chamber 20 and the heat treatment chamber 20 and the quenched two chamber 40 to carburize and diffuse the water 100, and the heat treatment chamber 20 is partitioned into a second partition door 25. The quenching 2 chamber 40 is divided into a third partition door 35 to form an independent chamber, a heat transfer heater 34 for maintaining a temperature-fall state, and a lower roller 60 for transferring the processing material 100. ), A circulation fan 36 for forced convection of the furnace atmosphere in order to uniformize the furnace temperature and the atmosphere in the furnace, and an electromotive force based on the partial pressure of O₂ in order to minimize the amount of retained austenite and increase the carburizing depth. A quenching chamber for hardening the carburized material 100 in the heat treatment chamber 20 in which the O₂ sensor 70 is installed to measure the electromotive force difference of O₂ in the atmosphere gas. ), And two quenching chambers (40) to protect the furnace atmosphere from the outside air. Each of them is constructed with a silica board and a brick inside, and configured to operate along the guide angle by an external driving device, and a curtain burner is installed at the bottom to block outside air. The first, second and third partition doors (15), (25) and (35), which are constructed of an entrance door (11) and heat-resistant casting steel, which are configured to be connected to each other, form a connecting link, and a silica board and a brick therein. 4 chambers by dividing into an exit door 41 configured to block external air by installing a curtain burner at the lower part and constructing it to operate along the guide angle by an external driving device. The heat-resistant casting steel containing the trace amount of tungsten is filled with a refractory insulating material inside the tube which is centrifugally cast, and the shafts are attached to both ends thereof to support the bearings from the outside of the furnace and geared motors. motor and inverter, and the Hearth roller 60, which is configured to be controlled by the photosensor, is individually driven in the forward and reverse directions by an independent drive motor 65 for each processing position. Haas roller continuous carburizing heat treatment furnace.

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