JP2005342857A - Repairing method by pressure brazing and gas turbine parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repairing method by pressure brazing reducing defects in a repairing part and unnecessitating a welding process for hermetical sealing at the time of heating and pressurizing HIP. <P>SOLUTION: In this method, a repair is performed by filling a repairing material made of a brazing material in the repairing part of a surface defect, etc. of a metal part. In the method, a repairing material melting and solidifying process for melting and solidifying at least a part of the repairing material in the repairing part and a repairing material compressing, melting and solidifying process for melting and solidifying at least a part of the repairing material in compressed gas. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure brazing repair method that reduces the occurrence of defects in repair parts and does not require a welding process for vacuum hermetic sealing during HIP heating and pressurization.

  Parts that are operated under harsh conditions such as gas turbine parts are cracked as the operation time elapses. If it is replaced with a new part, there is no problem, but heat-resistant parts such as gas turbines are generally expensive and require a long time to manufacture, so that the cracked part is repaired and reused. In order to bring the repaired part closer to the characteristics of the base material, repair is performed by mixing a powder equivalent to the base material and a low melting point powder for hardening them.

  As a technique for improving the repair method using such mixed powder, pressurize and fill only the base material equivalent powder into the cracked part, and pour the low melting point powder from the surface part to make the repaired part closer to the characteristics of the base material. Has been proposed (Patent Document 1). The purpose of pressure filling in this technique is to fully pack the powder into the crack when the powder is first filled into the crack at room temperature.

In addition, a technique has also been proposed in which an auxiliary plate having the same quality as that of the base material is brazed to the repaired portion and further subjected to HIP treatment after laser welding (Patent Document 2). In this technique, the welded auxiliary plate functions as a vacuum hermetic seal during HIP processing, and pressurizes the repaired portion.
JP 2001-115857 A JP 09-168927 A

  In the technique described in Patent Document 1 described above, pressure is applied when filling the crack into the crack, but when the molten low melting point repair material is subsequently introduced between the powder, gravity and capillary Only the phenomenon is used. Since the gap between the powders filled in the cracks varies, only the gravity and the capillary phenomenon cause a portion where the melt is difficult to flow in, and defects are likely to occur.

  Further, in the technique described in Patent Document 2, since the HIP process is performed, the repaired part is pressurized at a high temperature, and defects are less likely to remain inside the repaired part. However, after the auxiliary plate having the same quality as that of the base material is brazed to the repaired portion, further laser welding is performed, so that the number of repair steps increases accordingly. When repair parts are provided in a plurality of parts of one part, each of the repair parts is laser-welded, which further increases the number of processes such as changing parts. Moreover, since laser welding is performed including the brazed portion, defects are likely to remain. Also, this method is difficult to apply to materials that are difficult to weld.

  The present invention has been made in view of such circumstances, and is a pressure brazing repair method that reduces the occurrence of defects in repair parts and does not require a welding process for vacuum hermetic sealing during HIP heating and pressurization. The purpose is to provide.

  In order to achieve the above object, in the invention according to claim 1, in a brazing repair method for repairing a repair part such as a surface defect of a metal part by filling a repair material made of a brazing material, A pressure brazing process comprising: a repair material melting and solidifying step for melting and solidifying at least a part of the repair material; and a repair material compressing and melting solidification step for melting and solidifying at least a part of the repair material in a compressed gas. Provide supplementary repair methods.

  In the invention according to claim 2, in the brazing repair method for repairing a repair part such as a surface defect of a metal part by filling a repair material made of a brazing material, at least a part of the repair material is melted in the repair part. There is provided a pressure brazing repair method comprising: a repairing material melting and solidifying step to be performed; and a repairing material cooling and solidifying step of cooling and solidifying after at least part of the repairing material is melted in a compressed gas atmosphere. To do.

  In the invention which concerns on Claim 3, while fixing low melting point repair material to the narrow part of the said repair part, the repair material of higher melting point than this is arrange | positioned to surface layer part, The pressure brazing repair method of Claim 1 or 2 I will provide a.

  In the invention which concerns on Claim 4, the pressurization material of Claim 1 or 2 which arrange | positions a low melting point repair material to at least one part of the upper layer part of the high melting point repair material arrange | positioned at the surface layer part of the said metal components from this Provide brazing repair methods.

  According to a fifth aspect of the present invention, there is provided the pressure brazing repair method according to the first or second aspect, wherein a repair material having better oxidation resistance than the inside is disposed at least on the surface layer of the metal part.

  According to a sixth aspect of the present invention, there is provided the pressure brazing repair method according to the first or second aspect, wherein a repair material that does not contain aluminum is disposed in at least a part of the metal part that contacts the base material.

  In the invention which concerns on Claim 7, the pressure brazing repair method of Claim 1 which has the airtight test process of the melt-solidified part after the said repair material melt-solidification process is provided.

  According to an eighth aspect of the present invention, there is provided the pressure brazing repair method according to the seventh aspect, wherein a part of the portion melted and solidified in the repair material melting and solidifying step is evacuated and subjected to an airtight inspection.

  In the invention which concerns on Claim 9, the brazing repair method of Claim 7 which pressurizes a part of part melted and solidified at the said repair material melt-solidification process, and carries out an airtight inspection is provided.

  In the invention which concerns on Claim 10, the gas turbine component repaired using the pressure brazing repair method of Claims 1-9 is provided.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the defect generation | occurrence | production of a repair part, the pressure brazing repair method which does not require the welding process for the vacuum airtight sealing at the time of HIP heating pressurization can be provided.

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

[First Embodiment (FIGS. 1, 2, and 3)]
FIG. 1 is an explanatory view (longitudinal sectional view of a repair portion) of a brazing repair method according to a first embodiment of the present invention. 2 and 3 are flowcharts showing the flow of the brazing repair method according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, in this embodiment, the repair portion of the Ni-based alloy base material 1 is shaped with a grinder or the like (S 101), and the groove 2 is provided. The oxide 3 may remain inside the groove 2. However, the vicinity of the surface of the groove 2 is removed by shaving the oxide during shaping with a grinder or the like.

  The mixed repair material 4 is placed in the groove (S102). The mixed repair material is a mixture of a powder of the same material as the base material and a powder in which boron (B) and silicon (Si) are added to this powder to reduce the melting temperature, and is made into a paste using an organic substance. It is a thing.

  This mixed repair material is placed in a vacuum furnace (not shown) (S103) and heated (S104). The heating temperature is set to a temperature at which the powder whose melting temperature is lowered is melted and the powder of the same material as the substrate is not melted.

  After the mixed repair material is brazed to the base material repair portion in this way, it is once solidified (S105). This is then inserted into a HIP furnace (S106) and heated and pressurized (S107). The HIP heating temperature is set to a temperature at which a powder having a melting temperature similar to the heating temperature in the previous vacuum furnace is melted and a powder of the same material as the substrate is not melted. The pressurization is about 1000 atm which can be easily obtained with a normal HIP furnace.

  After holding for about 30 minutes to several hours under such conditions, the repair material is melted and solidified by cooling to room temperature (S108) and taken out from the HIP furnace. The unevenness of the repaired portion is finished with a grinder or the like to finish the repair (S109).

  As shown in FIG. 3 as (S201) to (S209), after the repair material is placed, it is inserted into the HIP furnace instead of the vacuum furnace, and only the heating is performed to melt a part of the mixed repair material, and then into the HIP furnace. Argon gas may be introduced to perform the heating and pressurizing step. At this time, if sufficient pressurizing force cannot be obtained, the temperature is once lowered, but reheating and pressurizing is performed as it is without taking out the repaired product from the furnace. The subsequent steps are the same as those shown in FIG.

  According to the present embodiment, at first, at least a part of the mixed repair material is melted or melted and solidified so that the mixed repair material itself performs a vacuum hermetic sealing function that can withstand heating and pressurization of HIP. become.

  Further, the once repaired and solidified mixed repair material can easily flow and maintain a vacuum airtightness in subsequent HIP heating and pressurization as compared with canning such as a plate material. For this reason, even if vacuum sealing such as canning is not performed separately, internal defects such as voids remaining in the repaired portion can be crushed and removed with isotropic pressure of HIP, and the mechanical properties of the repaired portion are improved. improves. Further, in the method in which the vacuum furnace and the HIP furnace are not used together, the cooling and furnace replacement time can be omitted.

[Second Embodiment (FIG. 4)]
FIG. 4 is an explanatory view (longitudinal sectional view of a repair portion) of a brazing repair method according to a second embodiment of the present invention. This embodiment is an application example for a crack having a relatively small opening in the base material 1, and the surface layer of the crack is shaped with a grinder to remove the oxide and provide the groove 2.

  Since the opening of the crack is small, the oxide 3 remains inside the groove. A paste-like brazing material 5 having a melting point lowered by adding several percent of boron (B) and silicon (Si) to components of the same quality as the base material is injected into the crack having a small opening. Further, the mixed repair material 4 is disposed on the surface layer portion of the groove.

  In this state, similar to the first embodiment, the mixed repair material is melted and solidified in vacuum. At this time, the opening of the crack in the groove is small, and the oxide remains in the inside, so that the brazing material does not fully adapt inside the groove. However, since the oxide on the groove surface layer portion is removed by a grinder, the brazing material 5 and the mixed repair material 4 are sufficiently wetted by the base material and are well vacuum-sealed. When heated and pressurized in the HIP furnace in this state, the HIP pressure is transmitted from the mixed repair material 4 once melted and solidified to the inside of the groove 2.

  For this reason, the molten brazing material that was poorly adapted to the base material side in the groove closely adheres to the base material. At this stage, the brazing material is only in close contact with the base material and is not metallicly bonded. However, while maintaining this close contact state, boron (B) in the brazing material diffuses to the base material side, lowers the melting temperature of the base material, and partially melts the surface layer portion of the base material. As the surface layer of the base material melts, the oxide remaining on the base material surface is separated.

  In addition, the molten brazing material also enters from the discontinuous portion of the oxide, and the oxide is separated to partially melt the substrate inside. Due to such a phenomenon, a metallic bonding state between the brazing material and the base material can be obtained even inside the crack. Boron (B) of the brazing material inside the crack diffuses into the substrate and homogenizes. Further, since the mixed repair material is arranged on the groove surface layer portion, the material is close to the base material.

  According to this embodiment, the oxide inside the narrow crack can be removed and repaired without a prior oxide removal step.

[Third Embodiment (FIG. 5)]
FIGS. 5A and 5B are explanatory views (longitudinal sectional views of the repair portion) of the brazing repair method according to the third embodiment of the present invention. In the present embodiment, as shown in the drawing, in addition to the second embodiment, a brazing material 5 is disposed in an upper layer of the mixed repair material 4. In this way, similar heating is performed. Since the brazing material is disposed in the upper layer portion, the groove surface is sufficiently sealed.

  In addition, although sealing is possible only by the mixed repair material 4, since fluidity | liquidity is inferior compared with a brazing material, the part which metal coupling | bonding with a base material becomes inadequate may generate | occur | produce. In such a case, even if the HIP process is performed in the next step, the argon gas in the HIP furnace penetrates into the inside of the groove from the insufficiently bonded portion, and the brazing material 5 and the mixed repair material 4 are removed. It becomes impossible to make it adhere in the groove.

  According to the present embodiment, since the brazing material having good fluidity is disposed in the upper layer, such insufficient bonding can be prevented, and the occurrence of defects in the in-groove repair portion can be surely prevented.

[Fourth Embodiment (FIG. 6)]
FIG. 6 is an explanatory view (longitudinal sectional view of the repaired portion) of the brazing repair method according to the fourth embodiment of the present invention. In the present embodiment, the mixed repair material 4 is disposed in the groove 2 of the base material 1, and the oxidation-resistant repair material 6 that is superior in oxidation resistance characteristics at a higher temperature than the mixed repair material 4 is disposed on the surface layer portion. In this state, heating and heating / pressing are performed in the same manner as in the first embodiment.

  According to the present embodiment, after repair, the surface of the repaired portion has excellent oxidation resistance characteristics, and the oxidation resistance characteristics at high temperatures of the repair parts are improved.

[Fifth Embodiment (FIG. 7)]
FIG. 7 is an explanatory view (longitudinal sectional view of a repair portion) of a brazing repair method according to a fifth embodiment of the present invention.

  In the present embodiment, an aluminum-less repair material 7 that does not contain an aluminum component is disposed on the surface portion of the groove 2 provided in the repair portion of the base material 1. This aluminum-less repair material contains several percent of boron (B) and silicon (Si), and acts as a brazing material.

  Further, the mixed repair material 4 is filled so as to fill the groove. This mixed repair material 4 is a mixture of a powder of the same material as the base material and a powder obtained by adding several percent of boron (B) and silicon (Si) to lower the melting temperature, and using organic matter. It is a paste.

  When such a repaired product is heated in a vacuum furnace in the same manner as in the first embodiment, the low melting temperature powder in the aluminum-less repair material 7 and the mixed repair material 4 is melted to fill the groove and the surface thereof. . Next, when the pressure melting is performed in the HIP furnace, the low melting temperature portion is melted as in the previous vacuum furnace. Since it is isotropically pressurized with high-pressure argon gas, even if a minute gap exists in the repaired portion, it is crushed.

  Cooling as it is, a good repair with almost no void defects can be obtained. The purpose of using the aluminum-less repair material is to prevent a reaction between gas components such as oxygen and nitrogen generated from the base material and the furnace wall and aluminum in the repair material. When such a reaction occurs, alumina, aluminum nitride, or the like is generated in the repaired portion, and the mechanical properties of the repaired portion are deteriorated. When there is a concern about gas generation from the base material, the repair material to be installed on the surface portion in the groove may be made aluminum-free. In addition, when there is a concern about gas generation from the furnace wall or the like, the powder of the mixed repair material 4 in FIG.

  According to the present embodiment, even if gas is generated from the base material or the furnace wall, it is possible to prevent the generation of alumina or aluminum nitride in the repair portion, and it is possible to prevent deterioration of the mechanical properties of the repair portion. .

[Sixth Embodiment (FIGS. 8, 9, and 10)]
FIG. 8 is an explanatory view of the diffusion brazing repair method of the present embodiment (a longitudinal sectional view of the repair portion), and FIG. 9 is a flowchart showing the flow of the brazing repair method of the present embodiment.

  In this embodiment, it is a thing about the case where the crack which generate | occur | produced in the base material 1 is a repair part which penetrated plate | board thickness and penetrated from the surface to the back surface. Also in this embodiment, as shown as steps (S301 to S311) in FIG. 9, it is substantially the same as the above embodiment, but in the case of this embodiment, the inside of the repairing groove penetrating is described in the above embodiment. In the same manner as described above, it is filled with the repair material 8 after temporary melting. If there is a defect penetrating from the front surface to the back surface of the repair material 8 after the temporary melting, the HIP argon gas penetrates into the defect during the heating and pressurization by the next HIP (S308, S309), and repair is performed. A portion where appropriate pressure is not applied to the portion is generated.

  In order to prevent this, in this embodiment, after the temporary melting in the vacuum furnace, the vacuum inspection container 9 is installed on one side, and the inside is evacuated.

  If it is recognized that there is a clear leak when the vacuum is pulled, a low-melting repair material is applied to the surface of the repair material 8 after the temporary melting, and the melting process is performed again in a vacuum furnace, and a vacuum inspection is performed. A leak check is performed using the container 9 (S306). In addition, if no leak is clearly observed at the first evacuation stage, helium (He) gas is allowed to flow out to the side opposite to the side where the vacuum cuvette 9 is installed, and this helium is removed from the vacuum cuvette 9 side. Detect. If helium is detected, there is a fine leak, so re-premelting is performed in the same manner as described above.

  In addition, as shown in FIG. 10, even if a pressurized inspection container 10 is installed, a gas pressure is applied to the repaired portion, and the presence or absence of a penetration defect in the repaired portion is inspected due to a decrease in the gas pressure after holding for a certain period of time. Good.

  According to this embodiment, since the penetration defect of the repaired portion can be detected at the stage where the repaired portion is temporarily melted and this can be filled by remelting processing, the penetration defect remains after the final HIP repair. Can be prevented. For this reason, the fall of the mechanical strength of a repair part can be prevented.

Explanatory drawing which shows 1st Embodiment of this invention. The flowchart which shows the flow of 1st Embodiment of this invention. The flowchart which shows the flow of 1st Embodiment of this invention. Explanatory drawing which shows 2nd Embodiment of this invention. (A), (b) is explanatory drawing which shows 3rd Embodiment of this invention. Explanatory drawing which shows 4th Embodiment of this invention. Explanatory drawing which shows 5th Embodiment of this invention. Explanatory drawing which shows 6th Embodiment of this invention. The flowchart which shows the flow of 6th Embodiment of this invention. Explanatory drawing which shows 6th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Groove 3 Oxide 4 Mixed repair material 5 Brazing material 6 Oxidation-resistant repair material 7 Aluminum-less repair material 8 Repair material 9 after temporary melting Vacuum inspection container 10 Pressure inspection container

Claims (10)

In a brazing repair method in which a repairing part made of a brazing material is filled in a repairing part such as a surface defect of a metal part and repaired, a repairing material melting and solidifying step in which at least a part of the repairing material is melted and solidified in the repairing part; A pressure brazing repair method comprising: a repair material compression melting solidification step in which at least a part of the repair material is melted and solidified in a compressed gas. In a brazing repair method in which a repair material such as a surface defect of a metal part is filled with a repair material made of a brazing material and repaired, a repair material melting and solidifying step of melting at least a part of the repair material in the repair portion; A pressure brazing repair method comprising: a repair material cooling and solidifying step of cooling and solidifying after forming a compressed gas atmosphere while at least a part of the repair material is melted. The pressure brazing repair method according to claim 1 or 2, wherein a low melting point repair material is disposed in a narrow portion of the repair portion, and a repair material having a higher melting point is disposed in a surface layer portion. The pressure brazing repair method according to claim 1 or 2, wherein a repair material having a lower melting point is disposed on at least a part of a further upper layer portion of the high melting point repair material disposed on a surface layer portion of the metal part. The pressure brazing repair method according to claim 1 or 2, wherein a repair material having better oxidation resistance than the inside is disposed on at least a surface layer portion of the metal part. The pressure brazing repair method according to claim 1 or 2, wherein a repair material that does not contain aluminum is disposed on at least a part of the metal part that contacts the base material. The pressure brazing repair method according to claim 1, further comprising an airtightness inspection step for a melt-solidified portion after the repair material melt-solidification step. The pressure brazing repair method according to claim 7, wherein a part of the portion melted and solidified in the repair material melting and solidifying step is subjected to an airtight inspection by applying a vacuum. The brazing repair method according to claim 7, wherein a part of the portion melted and solidified in the repair material melting and solidifying step is pressurized to perform an airtight inspection. A gas turbine component repaired using the pressure brazing repair method according to claim 1.

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