JP2017040420A - Hot isotropic pressurization device and press method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dew condensation.SOLUTION: A pressure container 2 is heated by a heater. An object W to be treated is stored in the pressure container 2 heated by the heater 4. The pressure container 2 storing the object W to be treated is filled with compressed air, the compressed air is heated by the heater 4, and thereby the object W to be treated is pressed under high temperature and high pressure. After the object W to be treated is pressed, the compressed air is discharged from the pressure container 2. The object W to be treated subjected to pressing is cooled under inactive gas.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot isostatic pressing apparatus for pressing an object to be processed under high temperature and pressure and a pressing method thereof.

  A hot isostatic press is a recrystallization temperature of an object to be processed such as a sintered product (ceramics, etc.) or a cast product under a pressure medium gas set to a high pressure of several tens to several hundreds of MPa. The press treatment is performed at the above high temperature. Residual pores in the workpiece can be eliminated by a pressing method using a hot isostatic pressing device, so this pressing method improves mechanical properties, reduces variation in properties, improves yield, etc. Today, it is widely used industrially.

  In such a hot isostatic pressurizing apparatus, air is used as a pressure medium gas instead of an inert gas in order to reduce processing costs. However, when air is used, condensation occurs when the furnace temperature falls below the dew point during pressure reduction after the press treatment, and there is a problem that the dew condensation water adversely affects the workpiece, the pressure vessel, and the heater.

  Therefore, Patent Document 1 describes that moisture in the air is removed by a dehumidifier.

International Publication No. 2007/017086 Pamphlet

  However, the dehumidifier cannot completely remove moisture in the air. Therefore, a method of energizing the heater when the air is discharged is performed, but even this method cannot completely prevent condensation.

  An object of the present invention is to provide a hot isostatic pressing device capable of preventing condensation and a pressing method thereof.

  The present invention is a pressing method of a hot isostatic pressurizing apparatus that press-treats an object contained in a pressure vessel under high temperature and high pressure, and a heating step of heating the inside of the pressure vessel with a heater; An accommodating step of accommodating the object to be processed in the pressure vessel heated by the heater, filling the pressure container accommodating the object to be processed with compressed air, and heating the compressed air with the heater. A processing step of pressing the object to be processed under high temperature and high pressure, a discharging step of discharging the compressed air from the pressure vessel after pressing the object to be processed, and the pressing object to be processed. And a cooling step of cooling under an inert gas.

  The present invention also relates to a hot isostatic pressurizing device for press-processing a workpiece contained in a pressure vessel under high temperature and high pressure, a heater for heating the pressure vessel, and the pressure vessel Air supply means for supplying compressed air to the air, an air discharge passage for discharging the compressed air from the pressure vessel, and gas supply means for supplying an inert gas around the object to be processed, The object to be processed is housed in the pressure vessel heated by the heater, the compressed air is filled in the pressure vessel, and the compressed air is heated by the heater, whereby the object to be processed is subjected to high temperature and high pressure. After the press treatment, the compressed air is discharged from the pressure vessel, and the object to be treated is cooled under the inert gas.

  According to the present invention, before performing the press treatment of the object to be processed, the inside of the pressure vessel is heated to a high temperature state by heating with a heater, compared to the inside of the pressure vessel at a high temperature state only during the press treatment, It is possible to prevent air containing moisture around the pressure vessel from being mixed into the pressure vessel when the workpiece is accommodated. In addition, after the press treatment, the compressed air is discharged in a high temperature state, so that the furnace temperature can be kept below the dew point. Furthermore, cooling can be performed in a dry atmosphere by cooling the to-be-processed object processed under an inert gas. Thereby, dew condensation can be prevented.

It is explanatory drawing of a hot isostatic pressurization apparatus. It is a figure which shows a press process routine.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Configuration of hot isostatic pressurizer)
The hot isostatic pressing apparatus 1 according to the present embodiment presses an object to be processed accommodated in a pressure vessel under high temperature and pressure. As shown in FIG. 1, which is an explanatory diagram, the hot isostatic pressurizing device 1 is arranged in a pressure vessel 2 arranged in a HIP station, a preheating furnace 11 arranged in a preheating station, and a cooling station. And a cooling furnace 21.

(Configuration of HIP station)
The pressure vessel 2 is cylindrical and can accommodate the workpiece W. The upper and lower sides of the pressure vessel 2 are opened, and the upper opening is closed by the upper lid 6. The upper lid 6 is provided with a gas introduction hole 6 a for introducing high-pressure gas into the pressure vessel 2. In the present embodiment, the high-pressure gas is compressed air that has been pressurized to about 10 to 200 MPa.

  An air flow path 30 is connected to the gas introduction hole 6a. The air flow path 30 is provided with an air supply device (air supply means) 31 that supplies compressed air into the pressure vessel 2. The air supply device 31 includes a low-pressure compressor 32, an intermediate container 33, a high-pressure compressor 34, and a dehumidifier 35 in this order from the upstream side to the downstream side.

  A discharge flow path 36 is branched from the air flow path 30. The air flow path 30 and the discharge flow path 36 constitute an air discharge flow path for discharging compressed air from the pressure vessel 2. A blocking valve 37 is provided on the upstream side of the branch portion of the air passage 30 with the discharge passage 36 and on the downstream side of the high-pressure compressor 34. In addition, a blocking valve 38 is provided in the discharge flow path 36.

  The low pressure compressor 32 compresses the atmosphere. The intermediate container 33 stores the air compressed by the low pressure compressor 32. The high-pressure compressor 34 compresses the air stored in the intermediate container 33 into compressed air. The dehumidifier 35 removes moisture in the compressed air. The compressed air produced in this way is supplied into the pressure vessel 2 through the gas introduction hole 6a. At this time, the blocking valve 37 is opened and the blocking valve 38 is closed. Further, the compressed air in the pressure vessel 2 passes through the air flow path 30 and is discharged from the discharge flow path 36 to the outside. At this time, the blocking valve 37 is closed and the blocking valve 38 is opened.

  The lower opening of the pressure vessel 2 can be closed with the lower lid 7. An object to be processed W is placed on the lower lid 7 via a product table 9. The workpiece W is put in and out of the pressure vessel 2 while being placed on the lower lid 7. The lower lid 7 is moved between the preheating station and the HIP station, and between the HIP station and the cooling station, and is moved in and out of each station by a conveyance carriage (not shown).

  A heat insulating layer 3 is disposed in the pressure vessel 2. Inside the heat insulating layer 3 is a processing chamber 8 in which the workpiece W is disposed.

  A heater 4 for heating the inside of the pressure vessel 2 is provided inside the heat insulating layer 3. The heater 4 is composed of a plurality (three in the illustrated example) of heater elements 4a, 4b, and 4c arranged side by side in the vertical direction.

  In such a configuration, when the heater 4 is energized, the inside of the pressure vessel 2 is heated. The heater 4 is energized before the workpiece W is accommodated in the pressure vessel 2. Therefore, when the workpiece W is not accommodated in the pressure vessel 2, the atmosphere in the pressure vessel 2 is heated, and as a result, the pressure vessel 2 is brought into a high temperature state. At this time, the lower opening of the pressure vessel 2 is open.

  And after accommodating the to-be-processed object W in the pressure vessel 2 heated with the heater 4, if compressed air is filled in the pressure vessel 2, compressed air will be heated by the heater 4. FIG. The workpiece W in the processing chamber 8 is pressed under high temperature and pressure by the heated compressed air. After the pressing process, the compressed air is discharged from the pressure vessel 2.

  As described above, the inside of the pressure vessel 2 is heated to a high temperature by the heater 4 before the workpiece W is pressed, so that the pressure vessel 2 is brought to a high temperature only during the press processing. In comparison, it is possible to prevent air containing moisture around the pressure vessel from being mixed into the pressure vessel when the workpiece is accommodated. Further, by discharging the compressed air in a high temperature state after the press treatment, it is possible to prevent the furnace temperature from falling below the dew point, so that condensation can be prevented.

(Configuration of preheating station)
The preheating furnace 11 has a cylindrical shape and is open at the bottom, and can accommodate the workpiece W. The lower opening of the preheating furnace 11 can be closed with the lower lid 7 on which the workpiece W is placed. The workpiece W is put into and out of the preheating furnace 11 while being placed on the lower lid 7.

  A heater 12 that heats the inside of the preheating furnace 11 is provided inside the preheating furnace 11. The heater 12 is composed of a plurality of (three in the illustrated example) heater elements 12a, 12b, and 12c arranged in the vertical direction, similarly to the heater 4 arranged in the pressure vessel 2.

  In such a configuration, when the workpiece W is accommodated in the preheating furnace 11 and then the heater 12 is energized, the workpiece W is heated. In the preheating furnace 11, the workpiece W is heated to, for example, 600 to 1000 ° C.

(Cooling station configuration)
Similarly to the preheating furnace 11, the cooling furnace 21 is also cylindrical and has an opening at the bottom, and can accommodate the workpiece W. The lower opening of the cooling furnace 21 can be closed with the lower lid 7 on which the workpiece W is placed. The workpiece W is put into and out of the cooling furnace 21 while being placed on the lower lid 7.

  A gas introduction hole 21 a for introducing an inert gas into the cooling furnace 21 is provided on the upper wall of the cooling furnace 21. A gas flow path 22 is connected to the gas introduction hole 21a. A nitrogen gas container (gas supply means) 23 for storing nitrogen gas is provided at the end of the gas flow path 22. The nitrogen gas container 23 supplies nitrogen gas into the cooling furnace 21 in which the workpiece W is accommodated. Thereby, nitrogen gas is supplied around the workpiece W. The inert gas supplied into the cooling furnace 21 is not limited to nitrogen gas, and may be a rare gas such as helium, neon, or argon.

  In such a configuration, after the press-treated workpiece W is accommodated in the cooling furnace 21, when nitrogen gas is supplied into the cooling furnace 21, the workpiece W is cooled under the nitrogen gas.

  In this way, by cooling the pressed workpiece W under nitrogen gas, cooling can be performed in a dry atmosphere, so that condensation can be prevented.

  Further, by cooling the workpiece W in the cooling furnace 21 different from the pressure vessel 2, the inside of the pressure vessel 2 can be always kept at a high temperature. Therefore, since the process of raising or lowering the temperature in the pressure vessel 2 can be omitted, batch processing can be performed one after another in a fast cycle, and productivity can be improved.

(Press processing routine)
Next, the press method of the hot isostatic pressing apparatus 1 will be described with reference to the press processing routine shown in FIG. 2 which is a flowchart.

  When the press processing routine is started, the inside of the pressure vessel 2 is heated by the heater 4 (step S1). Next, the workpiece W is carried into the preheating furnace 11 (step S2). And the to-be-processed object W is pre-heated by heating the to-be-processed object W with the heater 12 (step S3).

  Then, it is determined whether or not preheating is completed (step S4). If it is determined in step S4 that preheating has not been completed (S4: NO), step S4 is repeated. On the other hand, if it is determined in step S4 that preheating has been completed (S4: YES), the workpiece W is unloaded from the preheating furnace 11 (step S5).

  Next, the workpiece W is carried into the pressure vessel 2 having a high temperature inside (step S6). And compressed air is supplied in the pressure vessel 2 (step S7). The compressed air in the pressure vessel 2 is heated by the heater 4, and the workpiece W in the processing chamber 8 is pressed under high temperature and pressure by the compressed air.

  Then, it is determined whether or not the press process has been completed (step S8). If it is determined in step S8 that the press process has not been completed (S8: NO), step S8 is repeated. On the other hand, if it is determined in step S8 that the press process has been completed (S8: YES), the compressed air is discharged from the pressure vessel 2 (step S9). And the to-be-processed object W is carried out from the inside of the pressure vessel 2 (step S10).

  As described above, the inside of the pressure vessel 2 is heated to a high temperature by the heater 4 before the workpiece W is pressed, so that the pressure vessel 2 is brought to a high temperature only during the press processing. In comparison, it is possible to prevent air containing moisture around the pressure vessel from being mixed into the pressure vessel when the workpiece is accommodated. Further, by discharging the compressed air in a high temperature state after the press treatment, it is possible to prevent the furnace temperature from falling below the dew point, so that condensation can be prevented.

  Next, the workpiece W is carried into the cooling furnace 21 (step S11). Then, nitrogen gas is supplied into the cooling furnace 21 (step S12). The workpiece W in the cooling furnace 21 is cooled under nitrogen gas.

  And it is determined whether cooling was completed (step S13). If it is determined in step S13 that the cooling has not been completed (S13: NO), step S13 is repeated. On the other hand, if it is determined in step S13 that the cooling is completed (S13: YES), the workpiece W is carried out from the cooling furnace 21 (step S14).

  In this way, by cooling the pressed workpiece W under nitrogen gas, cooling can be performed in a dry atmosphere, so that condensation can be prevented.

  Further, by cooling the workpiece W in the cooling furnace 21 different from the pressure vessel 2, the inside of the pressure vessel 2 can be always kept at a high temperature. Therefore, since the process of raising or lowering the temperature in the pressure vessel 2 can be omitted, batch processing can be performed one after another in a fast cycle, and productivity can be improved.

  Thereafter, it is determined whether or not the next batch process is performed (step S15). If it is determined in step S15 that the next batch process is to be performed (S15: YES), the process returns to step S2 and the next workpiece W is carried into the preheating furnace 11. On the other hand, if it is determined in step S15 that the next batch process is not performed (S15: NO), this routine is terminated.

  In this routine, the pre-heating of the workpieces W for the next batch process is started after cooling the workpieces W in one batch process, but the batch processing is performed as follows. You can speed up the cycle. That is, when the workpiece W in one batch process is being pressed in the pressure vessel 2, the workpiece W in the next batch process is preheated in the preheating furnace 11. Further, when the workpiece W in one batch process is being cooled by the cooling furnace 21, the press treatment of the workpiece W in the next batch process is performed in the pressure vessel 2.

(effect)
As described above, according to the hot isostatic pressing apparatus 1 and the pressing method thereof according to the present embodiment, the inside of the pressure vessel 2 is heated by the heater 4 before the workpiece W is pressed. By keeping the high temperature state, air containing moisture around the pressure vessel is mixed into the pressure vessel when the workpiece is accommodated, compared with the case where the pressure vessel 2 is in a high temperature state only during the press process. Can be prevented. In addition, after the press treatment, the compressed air is discharged in a high temperature state, so that the furnace temperature can be kept below the dew point. Furthermore, by cooling the workpiece W subjected to the press treatment under nitrogen gas, the cooling can be performed in a dry atmosphere. Thereby, dew condensation can be prevented.

  Further, by cooling the workpiece W in the cooling furnace 21 different from the pressure vessel 2, the inside of the pressure vessel 2 can be always kept at a high temperature. Therefore, since the process of raising or lowering the temperature in the pressure vessel 2 can be omitted, batch processing can be performed one after another in a fast cycle, and productivity can be improved.

  The embodiment of the present invention has been described above, but only specific examples are illustrated, and the present invention is not particularly limited, and the specific configuration and the like can be appropriately changed in design. Further, the actions and effects described in the embodiments of the invention only list the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to what was done.

DESCRIPTION OF SYMBOLS 1 Hot isostatic-pressure pressurization apparatus 2 Pressure vessel 3 Heat insulation layer 4 Heater 4a, 4b, 4c Heater element 6 Upper cover 6a Gas introduction hole 7 Lower cover 8 Treatment chamber 9 Product stand 11 Preheating furnace 12 Heater 12a, 12b, 12c Heater Element 21 Cooling furnace 21a Gas introduction hole 22 Gas flow path 23 Nitrogen gas container (gas supply means)
30 air flow path 31 air supply device (air supply means)
32 Low-pressure compressor 33 Intermediate container 34 High-pressure compressor 35 Dehumidifier 36 Discharge flow path 37, 38 Shut-off valve W Workpiece

Claims (4)

A method for pressing a hot isostatic pressurizing apparatus that press-treats an object to be processed contained in a pressure vessel under high temperature and pressure,
A heating step of heating the inside of the pressure vessel with a heater;
An accommodating step of accommodating the object to be processed in the pressure vessel heated by the heater;
A processing step of pressing the processing object under high temperature and high pressure by filling the pressure vessel containing the processing object with compressed air and heating the compressed air with the heater;
A discharge step of discharging the compressed air from the pressure vessel after pressing the object to be processed;
A cooling step of cooling the workpiece to be processed under an inert gas;
A method for pressing a hot isostatic pressing device characterized by comprising:   The cooling process is performed by storing the processing object in a cooling furnace capable of storing the processing object and supplying the inert gas into the cooling furnace. A method for pressing a hot isostatic press. A hot isostatic pressurizing device that presses an object to be processed contained in a pressure vessel under high temperature and pressure,
A heater for heating the inside of the pressure vessel;
Air supply means for supplying compressed air into the pressure vessel;
An air discharge passage for discharging the compressed air from the pressure vessel;
Gas supply means for supplying an inert gas around the object to be processed;
Have
The object to be processed is housed in the pressure vessel heated by the heater, the compressed air is filled in the pressure vessel, and the compressed air is heated by the heater, whereby the object to be processed is subjected to high temperature and high pressure. A hot isostatic pressurizing apparatus, wherein after the press treatment is performed, the compressed air is discharged from the pressure vessel and the workpiece is cooled under the inert gas. A cooling furnace capable of accommodating the object to be processed;
The hot isostatic pressurization device according to claim 3, wherein the gas supply means supplies the inert gas into the cooling furnace containing the workpiece.

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